Catherine on fri 24 nov 06
Hi, all,=0D
=0D
My wonderful Christmas gift is a compressor and appropriate accessories.=0D
I culled the archives. It seems the most likely purchases would be: =0D
=0D
DeVilbis HVLP gravity feed spray gun=0D
PorterCable HVLP gravity gun=0D
Campbell-Hausfield automotive type guns=0D
Binks=0D
Critter sprayer with detachable one quart bottles=0D
=0D
Notes ?????:=0D
18-20 lbs of pressure=0D
In-line pressure-regulator so that you can use a lower pressure=0D
Spray heads of varying sizes=0D
=0D
At this point I am lost. I'd like to be able to do quick changes of gla=
zes
=0D
Rarely if ever would I do much fine brush type work, at least for now.=0D
I am not strong enough to handle 5# containers, but I'd like not to run o=
ut
of glaze in minutes. Are there sprayers that can work off a container se=
t
on an adjacent shelf?=0D
=0D
I'd appreciate information that says, "Go to Harbor Freight and buy
Compressor xxx and sprayers xyx." =0D
=0D
I do need to keep the compressor under $100 and the sprayers around $10 e=
ach
if possible. I don't do any production work so the equipment won't get l=
ots
of use. I do mostly large pieces.=0D
=0D
Thanks to all and an early wish for happy holidays.=0D
=0D
Catherine in Yuma, AZ hitting the 80s today.
Vince Pitelka on sat 25 nov 06
Katherine wrote:
"I do need to keep the compressor under $100 and the sprayers around $10
each
if possible. I don't do any production work so the equipment won't get lots
of use. I do mostly large pieces."
Katherine -
You leave us little room in your request above. I am afraid you are in for
a disappointment if you try to purchase a serviceable air compressor and
spray gun for those prices. There is always the chance that you might luck
out on good used equipment, but you can never count on that.
The only way you can end up with a practical spraying outfit for the price
you quote is by purchasing a self-contained turbine-driven HVLP system.
Campbell Hausfeld makes a variety of very reasonably-priced systems, and you
can find one for $100 at http://www.gleempaint.com/ch-hvlp-hv1120.html. Of
course, then you don't have the air compressor to use for other
applications. The turbine on a self-contained HVLP system is low pressure,
and isn't good for much else except perhaps inflating plastic toys.
If you want to get a real air compressor, the units for home/shop/studio use
fit into three primary categories - 1) direct-drive "maintenance-free," 2)
direct drive with oil-filled crankcase, and 3) belt-driven with cast iron
compressor barrel or compressor sleeve and oil-filled crankcase. The first
category is completely worthless. The parts wear out quickly. If you go
online and look for factory-reconditioned compressors you will see that they
are almost all of the direct-drive "maintenance-free" variety. The second
category is better, but still doesn't have nearly the useful life of the
third category. An appropriate Campbell Hausfeld belt-driven compressor
with cast-iron compressor barrel or sleeve will last you for the rest of
your life, but it will also cost you a minimum of $350. When you buy tools
and equipment, you get just what you pay for. As a matter of personal
conviction, I believe it is always worthwhile to buy quality tools, and
quality air compressors that will last a lifetime are expensive, and
anything less-expensive will cause problems over time. Quality tools and
equipment are a joy to use every time.
Regarding spray guns, sometimes it is best to keep it simple. The Paasche
Model "L" spray gun is a high-pressure gun, but it is designed specifically
for glaze-type applications. It is an external-mix gun, where air exiting
a nozzle passes over a pickup tube and creates a vacuum, sucking glaze up
from the attached reservoir. That eliminates the chance of internal parts
getting clogged with glaze. The aluminum one-quart reservoir is big enough
to spray quite a few pots, and you can purchase extra reservoirs. The
Paasche Type "L" as sold by a number of ceramic suppliers comes with the #4
nozzle set that is appropriate for glazes and slips. You can find the
Paasche type "L" at http://www.clay-king.com/paasche.htm for $75.
If you want to get into HVLP conversion guns (the ones that have a small
pressure regulator attached to the gun air inlet port) you can get those
from Harbor Freight for less than $40, but you need to contact Harbor
Freight customer service to purchase a 2.0, 2.1, or 2.2 mm spray-orifice set
in order to handle glazes.
If you really want a cheap compressor right now, and don't mind replacing it
in five, you can go to
http://www.aircompressorsdirect.com/catalog/product_info.php?cPath=1_190_77&products_id=356
(be sure to paste the whole link into your browser if it doesn't open by
clicking on it) and get a direct-drive Campbell Hausfeld for $225. That's
100 bucks off retail for an inferior compressor.
Within the price range you mention, you can purchase a cheap Harbor Freight
turbine-driven HVLP system including turbine and gun. A number of Clayart
members have posted good results with these guns. I am no fan of Harbor
Freight's own brand electric or pneumatic tools - they are pretty poorly
made, but apparently they have figured out a way to make the turbine and gun
so inexpensively that they can sell the set for less then 100 bucks.
Perhaps someone will post about these systems.
Sorry that this message is not more encouraging, but the maximum prices you
quoted just don't make sense once you really research available air
compressors and spray guns.
Good luck, and please post any further questions.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Catherine on sat 25 nov 06
Vince,=0D
=0D
Yes, you are so correct. My husband and I spent the day browsing online.=
=0D
The first thing we decided was that I'll buy two spray guns with my own
personal cash-stash and he'll buy a decent compressor that can also be us=
ed
for tools and other things. =0D
=0D
If I only were to do one piece a year, still the frustration of equipment
that =0D
ruined that piece wouldn't be worth the savings. Also, I think the =0D
husband-person is excited at having pneumatic tools. =0D
=0D
Don't go there, Folks.......=0D
=0D
I printed out your information but condensed it in this reply.=0D
=0D
Thank you for your expert help. I met you at an NCECA - in San Diego, I
think.=0D
=0D
Anyway, thanks again.=0D
=0D
Catherine=0D
=0D
-------Original Message-------=0D
=0D
From: Vince Pitelka=0D
Date: 11/25/06 22:38:52=0D
To: CLAYART@LSV.CERAMICS.ORG=0D
Subject: Re: Christmas Gift Spray Gun & Compressor=0D
=0D
Katherine wrote:=0D
"I do need to keep the compressor under $100 and the sprayers around $10=0D
each=0D
if possible. I don't do any production work so the equipment won't get l=
ots=0D
of use. I do mostly large pieces."=0D
=0D
Katherine -=0D
=0D
If you want to get a real air compressor, the units for home/shop/studio =
use=0D
fit into three primary categories - 1) direct-drive "maintenance-free," 2=
)=0D
direct drive with oil-filled crankcase, and 3) belt-driven with cast iron=
=0D
compressor barrel or compressor sleeve and oil-filled crankcase. The fir=
st=0D
category is completely worthless. The parts wear out quickly. If you go=
=0D
online and look for factory-reconditioned compressors you will see that t=
hey=0D
are almost all of the direct-drive "maintenance-free" variety. The secon=
d=0D
category is better, but still doesn't have nearly the useful life of the=0D
third category. An appropriate Campbell Hausfeld belt-driven compressor=0D
with cast-iron compressor barrel or sleeve will last you for the rest of=0D
your life, but it will also cost you a minimum of $350. When you buy too=
ls=0D
and equipment, you get just what you pay for. =0D
=0D
Regarding spray guns, sometimes it is best to keep it simple. The Paasch=
e=0D
Model "L" spray gun is a high-pressure gun, but it is designed specifical=
ly=0D
for glaze-type applications. =0D
=0D
Sorry that this message is not more encouraging, but the maximum prices y=
ou=0D
quoted just don't make sense once you really research available air=0D
compressors and spray guns.=0D
=0D
Good luck, and please post any further questions.=0D
- Vince=0D
vpitelka@dtccom.net, wpitelka@tntech.edu=0D
http://iweb.tntech.edu/wpitelka/=0D
http://www.tntech.edu/craftcenter/
Vince Pitelka on sun 26 nov 06
Kathleen in Boston wrote:
"About compressors: could you advise in terms of quieter compressors? I
bought a little compressor some years ago, and it runs continuously at
a great roar. I can't bear to use it - even with hearing protectors on
it's so loud! I'm wondering if there are quieter options, in a
compressor that isn't too gigantic. Do you have any opinions about the
Paasche Model D Air Compressor, which is advertised as "studio queit"
Also, do you have opinions about how best to ventilate when you are
spraying?"
Kathleen -
A good quality belt drive cast iron compressor is often quiter than many of
the smaller maintenance-free compressors. Also, with such a compressor, you
can easily place it in another room or in an outside shed (assuming that it
is not too cold outside) and pipe the compressed air into your studio. Any
quality compressor should have an automatic switch that turns the compressor
on and off to maintain the appropriate temperature range in the tank. The
small continuous-operation compressors like the Paasche one you mention are
for powering an airbrush, and are inadequate for running a spray gun.
Compressors are just noisy. The only way to deal with that is to remove
them from the space where you are working. As mentioned, as long as they
have an automatic pressure switch, that's no problem.
You cannot spray indoors unless you have a proper spraybooth. Some
information about spraybooths has been published in the clay magazines, and
you can probably find it by searching their online index utilities. You can
purchase ready-made spraybooths from a number of the major ceramics
suppliers like Bailey and Laguna, or you can build your own. My January
2003 Clay Times column was about how to build a simple, effective, homemade
spray booth.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Mark Issenberg on sun 26 nov 06
I was reading the paper today and looked at the add for PEPBOYS,, they have
air compressors from $27 up. Ive been using a air compressor from sears that
was rebuilt. I bought it when I was in Miami. I been using it for years. Its
the type that is cheap. All I do is drain the water out of it. Its been great
for spraying ash glazes for years and also great for filling up tires and
sometimes for blowing air. Also used the same compressor for spraying my Alpine
with ITC years ago.
My $.02
Mark
Inua on sun 26 nov 06
For glazing I use an HVLP turbine setup I got from Harbor Freight for
under $100. The compressor is a turbine type, the hose is like that of a
vacuum cleaner, and the spray gun is the type with the cannister on the
bottom of the gun. This unit is very lightweight and so is very
portable. The compressor has a place in the back where the sprayer is
stored when not in use. The spray gun itself is all plastic with metal
for those parts that experience wear. It performs well enough as a glaze
gun. The spray guns themselves are so cheap (were less than $15 when I
bought mine) that is is worth while to get two or three extra guns so
you can have several different glazes loaded for multiple glazing when
you are in the glazing mode. That way, all you need do is just swap the
guns on the end of the hose, rather than having to clean the gun every
time for the next glaze. Saves lots of time.
I have had my HF spray setup for 5 years now. It has held up well.
Regards.
John Rodgers
Chelsea, AL
Catherine wrote:
> Hi, all,
>
>
>
> My wonderful Christmas gift is a compressor and appropriate accessories.
>
> I culled the archives. It seems the most likely purchases would be:
>
>
>
> DeVilbis HVLP gravity feed spray gun
>
> PorterCable HVLP gravity gun
>
> Campbell-Hausfield automotive type guns
>
> Binks
>
> Critter sprayer with detachable one quart bottles
>
>
>
> Notes ?????:
>
> 18-20 lbs of pressure
>
> In-line pressure-regulator so that you can use a lower pressure
>
> Spray heads of varying sizes
>
>
>
> At this point I am lost. I'd like to be able to do quick changes of glazes
>
>
> Rarely if ever would I do much fine brush type work, at least for now.
>
> I am not strong enough to handle 5# containers, but I'd like not to run out
> of glaze in minutes. Are there sprayers that can work off a container set
> on an adjacent shelf?
>
>
>
> I'd appreciate information that says, "Go to Harbor Freight and buy
> Compressor xxx and sprayers xyx."
>
>
>
> I do need to keep the compressor under $100 and the sprayers around $10 each
> if possible. I don't do any production work so the equipment won't get lots
> of use. I do mostly large pieces.
>
>
>
> Thanks to all and an early wish for happy holidays.
>
>
>
> Catherine in Yuma, AZ hitting the 80s today.
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
>
WJ Seidl on sun 26 nov 06
Catherine:
That sounds like a plan. However...
If hubby is to buy the compressor, be SURE to include a few dollars (yours
or his, whichever) for a filter. The purpose of the filter will be to
remove oil and liquid condensates from the air which then is delivered to
your spray gun(s). No real need to use a filter on air tools, but moisture
can affect those too.
A decent filter will run around $30-50, looks like a glass bowl that can be
emptied through a petcock on the bottom, or by unscrewing the bowl from the
top. Note that I am NOT talking about an air _dryer_, which is more like a
dehumidifier for the air line. Those run around $1500 for a good one.
Harbor Freight carries both, as do Brookstone and a few of the better wood
working catalogs.
Best,
Wayne Seidl
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Catherine
Sent: Sunday, November 26, 2006 1:29 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Christmas Gift Spray Gun & Compressor
Vince,
Yes, you are so correct. My husband and I spent the day browsing online.
The first thing we decided was that I'll buy two spray guns with my own
personal cash-stash and he'll buy a decent compressor that can also be used
for tools and other things.
SNIP
Snail Scott on sun 26 nov 06
At 10:27 AM 11/26/2006 EST, MArk wrote:
>...Ive been using a air compressor from sears that
>was rebuilt. I bought it when I was in Miami. I been using it for years. Its
>the type that is cheap...
Both Mark and Vince have valid points.
In a public studio or educational facility,
it's worthwhile to get the best, because of
intensive daily use and the number of people
affected by any downtime for repair. Futher,
there is often someone whose job it is to
kep tabs on oiling and maintenance.
If there isn't, a maintenance-free unit may
actually last longer, especially in a place
with major staff turnover and uncertain
delegation of upkeep duties.
In a one-person studio where a compressor
may be used a few hours a week or less, an
inexpensive unit may be sufficient and last
for years, freeing up capital for more
pressing expenses.
Every studio must make tradeoff decisions
about how money is spent, and a few hundred
extra $$ for a top-of-the-line, long-lasting
compressor may be an easy choice in an
institutional setting, while kiln shelves
or gas bills or materials may be a better
way to spend that same money in a personal
studio. Replacement of that unit may cost
more in the long run, but deferment of the
expense may be well worth it.
Whatever you get, make sure it will handle
your job. A nail-gun compressor will seldom
handle a regular paint sprayer. The numbers
to watch for are the CFM: cubic feet per
minute (or the metric equivalent), and the
max. pressure at that rate. Intermittent
tools like a nail gun can get away with
small CFM, because it stores up the air
between 'bangs'. Continuous-use tools like
spray guns will need more volume, but less
pressure. Some tools need both. Read the
label on your tools to see; these ratings
are usually in big easy-to-find numbers.
Then look for a unit that matches those
ratings, in whatever type of compressor
best suits your needs.
-Snail
Catherine on sun 26 nov 06
To all who have helped me with these decisions......=0D
=0D
I ordered two Critter Nozzles and two maintenance kits. =0D
Requires 3/4 HP compressor, 2 to 3 CFM @ 10 to 90 PSI.=0D
=0D
To run them, we plan on purchasing 4Gallon, 115 PSI Pancake Compressor =0D
which is on sale now marked down from $150 to $90.=0D
=0D
It has a 1 3/4 HP rated motor.=0D
Air delivery is: 5.2 SCFM @ 40 PSI =0D
4.2 SCFM @ 90 PSI=0D
=0D
If anyone sees problems here, please let me know as =0D
the compressor is due in the store tomorrow, Monday=0D
=0D
Thank you, thank you, thank you, All. I was really out of my element =0D
making these decisions.=0D
=0D
Catherine in rapidly cooling Yuma where it may only hit 70=BA tomorrow.=0D
=0D
=0D
-------Original Message-------Snip..........=0D
=0D
From: Snail Scott=0D
Date: 11/26/06 18:07:36=0D
To: CLAYART@LSV.CERAMICS.ORG=0D
Subject: Re: Christmas Gift Spray Gun & Compressor=0D
=0D
In a one-person studio where a compressor=0D
may be used a few hours a week or less, an=0D
inexpensive unit may be sufficient and last=0D
for years, freeing up capital for more=0D
pressing expenses.=0D
=0D
Whatever you get, make sure it will handle=0D
your job. A nail-gun compressor will seldom=0D
handle a regular paint sprayer. The numbers=0D
to watch for are the CFM: cubic feet per=0D
minute (or the metric equivalent), and the=0D
max. pressure at that rate. Intermittent=0D
tools like a nail gun can get away with=0D
small CFM, because it stores up the air=0D
between 'bangs'. Continuous-use tools like=0D
spray guns will need more volume, but less=0D
pressure. Some tools need both. Read the=0D
label on your tools to see; these ratings=0D
are usually in big easy-to-find numbers.=0D
Then look for a unit that matches those=0D
ratings, in whatever type of compressor=0D
best suits your needs.=0D
-Snail
Vince Pitelka on sun 26 nov 06
Snail wrote:
> If there isn't, a maintenance-free unit may
> actually last longer, especially in a place
> with major staff turnover and uncertain
> delegation of upkeep duties.
Snail -
I don't think that's true. "Maintenance-free" does not mean that such a
compressor will last longer with no maintenance than a belt-drive oil-sump
compressor. In the sales literature for a "maintenance-free" unit they will
say that you don't have to do any maintenance, but it really means that you
cannot do anything to maintain it and increase it's performance and useable
life. I would wager that a belt-drive oil-sump compressor with absolutely
no maintenance done to it other than bleeding the tank (which you must do
with all types of compressors) will always outlast a maintenance-free
compressor. The way they get "maintenance-free" with a compressor is to use
an oil-less compressor pump with teflon piston rings, and an aluminum
compressor cylinder that will dissipate heat quickly, which is necessary due
to the higher compressor speed. The compressor and motor are directly
connected, so the compressor runs at motor speed. That way, they can
produce the rated CFM output with a much smaller compressor. With
belt-drive compressors there is always a step-down in speed between the
motor and the compressor. They have to use a larger compressor to get the
rated CFM output, and the compressor runs slower and cooler.
I am serious when I say that a well-maintained belt-drive oil-sump
compressor with a cast iron compressor cylinder or sleeve will last you the
rest of your life. It is my opinion that it simply does not make any sense
at all to buy any other kind of compressor unless you are using it on
construction jobs and need the lightweight portable model. In that case
there is a compelling reason to buy the unit that delivers the highest
performance with the least weight, even if it wears out after five or ten
years.
Five or ten years is a very short life for a good compressor. With proper
maintenance, a good compressor will last indefinitely. Regardless of how
rarely you have to use a compressor, it pays to get one that will never have
to be replaced. To do otherwise will be more expensive in the long run.
That said, as Snail points out, each studio artist must decide where the
available funds are best spent. If you must purchase an inferior compressor
for a lower price, keep an eye on local auctions and eBay. At some point
you might find a belt-drive oil-sump cast iron compressor for a very low
price. Then you can re-sell the inferior compressor to someone and give
them a good deal, and still come out ahead overall.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Vince Pitelka on mon 27 nov 06
Wow, sometimes I find that I have written something completely different
from what I was thinking.
I wrote "Any quality compressor should have an automatic switch that turns
the compressor on and off to maintain the appropriate temperature range in
the tank."
Heck, I don't know what I was thinking. That should have read "Any quality
compressor should have an automatic pressure switch that turns the
compressor on and off to maintain the appropriate pressure range in the
tank."
Sorry for any confusion -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Snail Scott on mon 27 nov 06
At 02:05 AM 11/27/2006 -0000, you wrote:
>About compressors: could you advise in terms of quieter compressors? I
>bought a little compressor some years ago, and it runs continuously at
>a great roar. I can't bear to use it...
You could build a lean-to shed for the
compressor outdoors, and pipe the air
into the studio, keeping a wall between
you and the noise. Another option
is to use a portable tank. Keep the
actual compressor outside your working
space (or run it while you aren't
working) and use it to fill a tank
that you carry into the studio. You can
even carry it to the gas station and
fill it from the tire air pump there,
if your needs are small and occasional.
Portable tanks are fairly inexpensive,
as they are really just cans with
connectors and a handle, but you will
want to get a regulator for it.
If it must live in your studio, you can
build a box for it, cushioned with many
inches of insulation (foam or batting).
Have a hole or a hinged hatch to reach
in to the controls. It will need to have
some air intake, of course, but it won't
need much of a hole for that; air is
flexible stuff. (You will need to make sure
it doesn't run too hot, since yours is a
continumous-duty unit.) The box won't make
it silent, but the thicker the insulation,
the quieter it will get. Since you've got
a small compressor, building a quiet box
may be a good option.
A compressor with a large tank will
be just as loud as any other, but will
run in cycles instead of continuously,
allowing you to flee or cover your ears
for that interval, then work after the
tank has filled. The larger the tank,
the longer it can go between cycles.
Genuinely quiet compressors are usually
expensive ones, or very small, and none
are super-quiet. Probably better to work
with what you've got.
-Snail
knoelle2 on mon 27 nov 06
About compressors: could you advise in terms of quieter compressors? I
bought a little compressor some years ago, and it runs continuously at
a great roar. I can't bear to use it - even with hearing protectors on
it's so loud! I'm wondering if there are quieter options, in a
compressor that isn't too gigantic. Do you have any opinions about the
Paasche Model D Air Compressor, which is advertised as "studio queit"
Also, do you have opinions about how best to ventilate when you are
spraying?
Thanks so much for any advice you can offer(I'm setting up a clay
studio again, after having taken about 11 years off.)
Kathleen in Boston---
In clayart@yahoogroups.com, Snail Scott wrote:
>
> At 10:27 AM 11/26/2006 EST, MArk wrote:
> >...Ive been using a air compressor from sears that
> >was rebuilt. I bought it when I was in Miami. I been using it for
years. Its
> >the type that is cheap...
>
>
> Both Mark and Vince have valid points.
>
> In a public studio or educational facility,
> it's worthwhile to get the best, because of
> intensive daily use and the number of people
> affected by any downtime for repair. Futher,
> there is often someone whose job it is to
> kep tabs on oiling and maintenance.
>
> If there isn't, a maintenance-free unit may
> actually last longer, especially in a place
> with major staff turnover and uncertain
> delegation of upkeep duties.
>
> In a one-person studio where a compressor
> may be used a few hours a week or less, an
> inexpensive unit may be sufficient and last
> for years, freeing up capital for more
> pressing expenses.
>
> Every studio must make tradeoff decisions
> about how money is spent, and a few hundred
> extra $$ for a top-of-the-line, long-lasting
> compressor may be an easy choice in an
> institutional setting, while kiln shelves
> or gas bills or materials may be a better
> way to spend that same money in a personal
> studio. Replacement of that unit may cost
> more in the long run, but deferment of the
> expense may be well worth it.
>
> Whatever you get, make sure it will handle
> your job. A nail-gun compressor will seldom
> handle a regular paint sprayer. The numbers
> to watch for are the CFM: cubic feet per
> minute (or the metric equivalent), and the
> max. pressure at that rate. Intermittent
> tools like a nail gun can get away with
> small CFM, because it stores up the air
> between 'bangs'. Continuous-use tools like
> spray guns will need more volume, but less
> pressure. Some tools need both. Read the
> label on your tools to see; these ratings
> are usually in big easy-to-find numbers.
> Then look for a unit that matches those
> ratings, in whatever type of compressor
> best suits your needs.
> -Snail
>
>
___________________________________________________________________________=
___
> Send postings to clayart@...
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@...
>
Vicki Wicker on tue 28 nov 06
Catherine, I have the Critter. I like it. I like being able to store
glazes in the jars. You can use pints, quarts, or even those small jelly
jars if you have a real small quantity. I just use the sprayer to put a
clear coat over slip, I don't do a lot of intricate glazing, so just need
something that gives me a good quick, even coat.
As for compressor noise, the hubby fixed it up outside and the hose comes
in through the wall, so I don't have to hear it. Saves me the space, too.
I am using his work compressor. He's in nursing school now and only does
carpenter work part time, so no problem sharing.
I bought a booth on ebay. There's a guy selling them on there regularly.
Hobby type, but I wrote and asked if he could make me one a bit larger and
with a bigger blower. He did and it was real reasonable. It's been about a
year now but I think it cost me about 350. Way cheaper than the ones in
the clay catalogs. I think if you type in spray booth you'll see it.
I agree with Vince on buying good stuff. I went through 3 "cheap" used
kilns before I finally bit the bullet and ordered a new one,cone 10, from
a supplier. I think it's not a bad idea, though, to go with the bargain
priced stuff until you're sure of the direction you want to go. You might
decide you'd just a soon dip your stuff as spray. I've bought a few pieces
of equipment that I regretted later.
Vince Pitelka on tue 28 nov 06
Snail -
I hope you won't think I am picking you, because I am not. You are one of
the most knowledgable and generous of Clayart contributors. But I know
compressors and compressed air. Before I was a potter, I was a professional
mechanic for quite a few years, and among the things I maintained and
repaired were air compressors. A portable air tank is not appropriate for
anything but inflating tires and for perhaps very brief, limited
air-brushing. Any sort of reasonable-sized spray gun would empty a portable
air tank in a matter of seconds.
And regarding building an insulated enclosure for your compressor, the
reason that air compressors have fins on the compressor cylinder is because
they generate a great deal of heat. That's what happens when you compress
air - a byproduct is heat, and the heat must be dissipated. All air
compressors need a lot of air flowing around the cylinder to prevent
overheating.
The outside lean-to shed is the ideal solution, with the air piped into the
studio. That need not be pipe plumbing - it could be accomplished with just
a long air hose.
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Snail Scott on wed 29 nov 06
At 08:05 PM 11/28/2006 -0600, Vince P wrote:
>...A portable air tank is not appropriate for
>anything but inflating tires and for perhaps very brief, limited
>air-brushing. Any sort of reasonable-sized spray gun would empty a portable
>air tank in a matter of seconds.
I mentioned portable tanks mainly to be
complete; perhaps I shouldn't have. Still,
for a small gun and only occasional use,
they could be useful, especially for someone
who can't possibly own a compressor of any
sort but still needs occasional air.
>...All air
>compressors need a lot of air flowing around the cylinder to prevent
>overheating...
I think that I mentioned the need to avoid
overheating, but a box can be made to work.
If built high enough, (above head level) the
top can be left open and still cut the
racket considerably. It could also be fitted
with a fan, or put against an operable window,
or both.
>The outside lean-to shed is the ideal solution, with the air piped into the
>studio. That need not be pipe plumbing - it could be accomplished with just
>a long air hose.
This is actually my own setup, more or less.
Avoid those cheap Harbor-Freight-type plastic
air hoses, though. They have a very short
lifespan which is likely to be worse outdoors.
The extra 10-20 bucks for a good quality hose
is well worth it, even for a cheapskate like
me.
-Snail
Catherine on wed 29 nov 06
We intended making a spray booth outdoors that consisted of =0D
a table with a shower curtain suspended on three sides. Not cool. =0D
=0D
Thank you, Vince. I found my January 2003 Clay Times magazine.=0D
My husband is building your folding spray booth. We'll set it atop a=0D
heavy duty folding table so that we can reclaim the glazing sector of=0D
the patio for other use when necessary.=0D
=0D
Catherine in Yuma, AZ where it is cold today!=0D
=0D
-------Original Message-------snip...............=0D
=0D
From: Vince Pitelka=0D
Date: 11/27/06 11:24:01=0D
You can=0D
purchase ready-made spraybooths from a number of the major ceramics=0D
suppliers like Bailey and Laguna, or you can build your own. My January=0D
2003 Clay Times column was about how to build a simple, effective, homema=
de=0D
spray booth.=0D
Good luck -=0D
- Vince=0D
=0D
Vince Pitelka=0D
Appalachian Center for Craft, Tennessee Technological University=0D
Smithville TN 37166, 615/597-6801 x111=0D
vpitelka@dtccom.net, wpitelka@tntech.edu=0D
http://iweb.tntech.edu/wpitelka/=0D
http://www.tntech.edu/craftcenter/
Fred Parker on wed 29 nov 06
I'd like to add a little more to what Vince said abt air compressors:
If you install a compressor remotely (lean-to, etc.) do NOT succumb to the
temptation to use PVC piping for the distribution network. Although it is
a miniscule change, reciprocating compressors change pipeline pressure
with every piston stroke in addition to changes with constant
depressurization/repressurization from normal use. Over time, PVC will
fatigue and fail. "Failure" means it bursts. Compressors typically run
at pressures between 125 psi for single stage pumps, up to 175 psi for two-
stage units. A bursting PVC pipe at either of these pressures can send
shards through the studio at lethal speeds.
The least expensive safe solution is, as Vince mentioned, an air hose.
Unfortunately, because they are flexible they expand and contract with
changing pressures, causing a net pressure loss at the business end of the
hose. For long runs the pressure drop can be significant if the tool you
are using needs high pressure. The most expensive safe solution, and the
one recommended by many manufacturers of serious air compressors is either
black iron pipe or copper tubing. I forget whether it is type "L" or the
other type copper, but either iron or copper will not have the pressure
loss problem a rubber hose has.
Finally, if you do run iron or copper lines from a remote compressor to
various points in your studio, be sure to isolate the lines from the
compressor via a short length of flexible hose. This will prevent the
compressor's vibration from fatiguing either the lines or the tank where
the lines connect. It's also a good idea to include line drains just
before the regulators at the terminations of the pipeline. COndensate
always forms in air lines. It's not a huge problem for the spray gun to
be spitting water when applying glazes, but if you ever use the air line
to power an air tool or a paint sprayer condensate can really change your
attitude.
Fred Parker
WJ Seidl on thu 30 nov 06
Fred:
I'm sticking my nose in here for a moment.
You are correct for as far as you go, but I would like to clarify what you
said. Using the generic term "pvc pipe" is painting with too broad a brush.
What you speak of is absolutely true for Schedule 40 PVC and CPVC pipe.
Do not use Schedule 40 PVC or CPVC pipe for air lines. The pipe will fail,
because it was not designed to take the constant pressure and flexing.
Schedule 80 pipe (in PVC or CPVC), however, has much higher working
pressure.
Schedule 80 is much heavier and thicker-walled than Schedule 40, and can
usually be found at any decent plumbing shop. But you have to specify that
"Schedule 80" is what you want or you will be sold the lower grade.
Schedule 80 is often used for industrial installations with higher
pressures.
There is a link here that explains it all very clearly:
http://www.harvel.com/tech-specs-pvc-pipe-80.asp
For anyone interested, a 3/4 inch diameter (ID, not OD) of Schedule 80 PVC
pipe has a working pressure of 690 psi, which must then be de-rated for a
rise in temperature which one encounters in the "real world". For a studio
in the south, where temps can reach about 100F, the de-rating multiplier is
0.62, bringing the working pressure of that same 3/4 pipe down to 427 psi.
Strong enough to withstand what a normal air compressor will throw at it,
even at 200 psi. It is all in that chart you'll find on the link.
You have a better chance of having your attached flexible air hose fail than
a properly installed Schedule 80 pipe.
Don't be afraid to use PVC pipe for your air lines, but be sure you're using
the correct PVC pipe --Schedule 80. Leave the Schedule 40 for household
water lines.
Best,
Wayne Seidl
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Fred Parker
Sent: Wednesday, November 29, 2006 3:04 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Christmas Gift Spray Gun & Compressor
I'd like to add a little more to what Vince said abt air compressors:
If you install a compressor remotely (lean-to, etc.) do NOT succumb to the
temptation to use PVC piping for the distribution network. Although it is
a miniscule change, reciprocating compressors change pipeline pressure
with every piston stroke in addition to changes with constant
depressurization/repressurization from normal use. Over time, PVC will
fatigue and fail. "Failure" means it bursts. Compressors typically run
at pressures between 125 psi for single stage pumps, up to 175 psi for two-
stage units. A bursting PVC pipe at either of these pressures can send
shards through the studio at lethal speeds.
The least expensive safe solution is, as Vince mentioned, an air hose.
Unfortunately, because they are flexible they expand and contract with
changing pressures, causing a net pressure loss at the business end of the
hose. For long runs the pressure drop can be significant if the tool you
are using needs high pressure. The most expensive safe solution, and the
one recommended by many manufacturers of serious air compressors is either
black iron pipe or copper tubing. I forget whether it is type "L" or the
other type copper, but either iron or copper will not have the pressure
loss problem a rubber hose has.
Finally, if you do run iron or copper lines from a remote compressor to
various points in your studio, be sure to isolate the lines from the
compressor via a short length of flexible hose. This will prevent the
compressor's vibration from fatiguing either the lines or the tank where
the lines connect. It's also a good idea to include line drains just
before the regulators at the terminations of the pipeline. COndensate
always forms in air lines. It's not a huge problem for the spray gun to
be spitting water when applying glazes, but if you ever use the air line
to power an air tool or a paint sprayer condensate can really change your
attitude.
Fred Parker
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Fred Parker on fri 1 dec 06
Hi Wayne S:
When you wrote that schedule 80 PVC has a much higher working pressure you
are absolutely correct. In fact, to be totally honest, I operated a two-
stage compressor at my home feeding 175 psi into a schedule 40 PVC
distribution system for ten years or so with no ill effects. It was an
intermittent use -- I might go six months with the system shut down, then
another six with it on 24 hours a day -- but the pipe did not burst, in
spite of my constant concern that it might.
But there is more to it.
I am no plastics engineer, but it is my understanding that the
PVC/compressed air problem stems from the fatigue characteristics of the
PVC itself -- not the working pressures it is subjected to. The nature of
the PVC material -- like many metals -- makes failure likely under certain
repetitive-stress conditions. It is my understanding that those
conditions for PVC are less than, for example, certain types of copper,
which makes it much more likely to fail.
It is not the air pressures that cause the problem with PVC -- it is the
constant *changing* of pressures. This is VERY important for potters
considering installing PVC air lines to understand. Even schedule 40 PVC
is rated for pressures MUCH higher than any potter's air compressor can
deliver. It is the going from atmospheric pressure when the system is off
to 125 or 175 psi when it is on, down to 80 while spraying, back up to 125
while repressurizing, back down to etc... that fatigues the PVC.
Schedule 80 PVC is designed for high-pressure "fluids." I remember from
my fluid dynamics class a million years ago that gases are also "fluids,"
but I do not believe the website you referenced uses the word in that
inclusive way. In fact, they make a point of noting that pressure ratings
for schedule 80 pipe shown in a table there "...are for water, non-shock,
@ 73=B0F." (The "non-shock" part is key).
I believe that I *could* install a PVC compressed air distribution system
and use it for years with no problem. I also believe that I could install
one and have it burst the first time I pressurized it.
So I, personally, will never use PVC of any type for compressed air. I
enjoy looking at pottery (and certain other objects) far too much to risk
that in order to save a few bucks on pipe. Also, I appreciate the added
benefit of depth of view two eyes provide over the one-eyed
configuration. That's why I'm not concerned with the possibility that an
air hose might burst. Rubber hoses don't usually send out flying razor-
sharp shards. They just reduce your delivery pressure in use. That's the
trade-off for their much enhanced convenience.
I would conclude that bursting a PVC air line is something that might
never happen in a studio. However, it *could*. Potters should be aware
of the possibility and also the reason why, and then make their own
judgement about using it. Like so much more in life, it's a crapshoot...
Warm regards and Season's Greetings...
Fred Parker
On Thu, 30 Nov 2006 08:53:55 -0500, WJ Seidl wrote:
>Fred:
>I'm sticking my nose in here for a moment.
>You are correct for as far as you go, but I would like to clarify what you
>said. Using the generic term "pvc pipe" is painting with too broad a
brush.
>
>What you speak of is absolutely true for Schedule 40 PVC and CPVC pipe.
>Do not use Schedule 40 PVC or CPVC pipe for air lines. The pipe will
fail,
>because it was not designed to take the constant pressure and flexing.
>
>Schedule 80 pipe (in PVC or CPVC), however, has much higher working
>pressure.
>Schedule 80 is much heavier and thicker-walled than Schedule 40, and can
>usually be found at any decent plumbing shop. But you have to specify
that
>"Schedule 80" is what you want or you will be sold the lower grade.
>Schedule 80 is often used for industrial installations with higher
>pressures.
>
>There is a link here that explains it all very clearly:
>http://www.harvel.com/tech-specs-pvc-pipe-80.asp
>
>For anyone interested, a 3/4 inch diameter (ID, not OD) of Schedule 80 PVC
>pipe has a working pressure of 690 psi, which must then be de-rated for a
>rise in temperature which one encounters in the "real world". For a
studio
>in the south, where temps can reach about 100F, the de-rating multiplier
is
>0.62, bringing the working pressure of that same 3/4 pipe down to 427 psi.
>Strong enough to withstand what a normal air compressor will throw at it,
>even at 200 psi. It is all in that chart you'll find on the link.
>
>You have a better chance of having your attached flexible air hose fail
than
>a properly installed Schedule 80 pipe.
>
>Don't be afraid to use PVC pipe for your air lines, but be sure you're
using
>the correct PVC pipe --Schedule 80. Leave the Schedule 40 for household
>water lines.
>
>Best,
>Wayne Seidl
>
Catherine on sat 2 dec 06
My sprayers arrived. I'm thinking to start out spraying some =0D
colored water against newspapers to get the feel of the thing.=0D
Does it come out in a hard spray, like a torrent, at first 'til you =0D
get the hang of controlling it?=0D
=0D
My husband read Vince Pitelka's spray booth article and is building =0D
that. It's collapsible. I can do all that stuff outside so it can be sto=
red
when =0D
not in use.=0D
=0D
Do you know if the finer detailing Paasche can be used with a compressor =
=0D
running Critters? Is it too powerful? I'm an absolute novice at this.=0D
=0D
Thanks, =0D
=0D
Catherine....... did some bike riding tonight in 49=BA temps. That's nast=
y
cold even for Yuma, AZ.=0D
=0D
=0D
-------Original Message-------snip..........=0D
=0D
From: Vicki Wicker=0D
Date: 11/28/06 21:42:00=0D
Catherine, I have the Critter. I like it. I like being able to store=0D
glazes in the jars. You can use pints, quarts, or even those small jelly=0D
jars if you have a real small quantity. I just use the sprayer to put a=0D
clear coat over slip, I don't do a lot of intricate glazing, so just need=
=0D
something that gives me a good quick, even coat=0D
=0D
Spray booth of the hobby type on EBay, but I wrote and asked if he could
make me one a bit larger and=0D
with a bigger blower. He did and it was real reasonable. It's been about =
a=0D
year now but I think it cost me about 350. Way cheaper than the ones in=0D
the clay catalogs. I think if you type in spray booth you'll see it.
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