Josh Berkus on thu 23 aug 07
William,
> Josh, there really isn't much to a kiln vent. =A0I explain how to make yo=
ur
> own here:
> http://www.handspiral.com/kiln_vent.htm
Ah, I read Mark's article early on and saw that it required $200 worth of=20
parts and metalworking tools, so I gave up on the idea of making my own. A=
re=20
you really able to use an off-the-shelf junction box for a diffuser? Can y=
ou=20
give us some information on the number of holes, etc. you ended up with? =
=20
And how you attached it to the kiln?
=2D-=20
The Fuzzy Chef
San Francisco
William Melstrom on thu 23 aug 07
Josh, there really isn't much to a kiln vent. I explain how to make your
own here:
http://www.handspiral.com/kiln_vent.htm
The only real added work is going to Home Depot and Grainger or Johnstone
Supply and buying the parts, and making the holes in the "diffuser box."
Everything else, such as making holes in the kiln, assembling the duct work,
and making a hole in your wall, you will still have to do even with an
expensive kiln vent kit.
William Melstrom
Moderator, Crystalline Glaze Forum
http://board3.cgiworld.paran.com/list.cgi?id=Crystal
I'm buying a negative pressure venting system for my high-fire electric.
I've
done some online research, including list list archives, enough to know that
small passive venting systems (like the Vent-a-Kiln) don't work.
The Fuzzy Chef
San Francisco
Josh Berkus on thu 23 aug 07
All,
I'm buying a negative pressure venting system for my high-fire electric. I've
done some online research, including list list archives, enough to know that
small passive venting systems (like the Vent-a-Kiln) don't work.
However, even among the negative systems there are at least 4 options:
http://bigceramicstore.com/Supplies/kilns/kiln-ventilation.htm
The Cress system is $600 for a 3rd-party kiln. But all of the rest (Skutt,
Orton, L&L) are between $300 and $400; all require drilling holes. I don't
really see a way to distinguish between them. Advice?
--
The Fuzzy Chef
San Francisco
Dave Finkelnburg on thu 23 aug 07
Josh,
Good for you for doing your homework!
You don't mention the Bailey vent, which can be
seen at:
http://www.baileypottery.com/kilns/fumeventsys.htm
As long as the vent keeps your kiln under negative
pressure, and mixes the vented air with room air to
cool the vented air, then the system will work. You
need to ask the vendor about service, support,
warranty, fan and motor life, materials of
construction of the bits and pieces, especially the
duct. In my experience kiln fumes are HIGHLY
corrosive and eat through cheap dryer duct very
rapidly...but, it's relatively easy to replace. The
Bailey system I have works very well and uses that
sort of ducting.
Good firing,
Dave Finkelnburg
From: Josh Berkus
I'm buying a negative pressure venting system for my
high-fire electric. I've
done some online research, including list list
archives,
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Alex Solla on thu 23 aug 07
Josh-
My take on the whole vent system is: GET THE BAILEY vent system.
Throw away their flexible ducting and rig some ridgid vent pipe.
Yes it will take an extra half hour to put it all together, but you wont
make 150 firings on the flexible ducting. It will completely ROT out.
Plan on a complete duct replacement (with ridgid) every 2-3 years if you
fire
100 times a year. VERY easy to set up. One small hole in the side of your
kiln.
The Bailey system is awesome.
josh asked:
The Cress system is $600 for a 3rd-party kiln. But all of the rest (Skutt,
Orton, L&L) are between $300 and $400; all require drilling holes. I don't
really see a way to distinguish between them. Advice?
--
The Fuzzy Chef
San Francisco
______
William Melstrom on fri 24 aug 07
Here are some options for attaching the diffuser box to the bottom of =
the
kiln:
http://www.handspiral.com/images/Forum/DiffuserBox.jpg
You don't want to actually screw or bolt the box to your kiln -- you =
need to
allow for expansion and contraction.
Try putting a 1" diameter hole in all four sides of the box. You can =
always
drill more holes later, or plug one or more holes if need be.
It would really help if you could find someone's installed commercial =
system
to see how the "diffuser box" functions and how to drill the inlet holes =
in
your kiln.
The best cheap diffuser box is an un-painted, galvanized "indoor" =
junction
box. You will discard the lid.
William
-----Original Message-----
From: Josh Berkus [mailto:fuzzy@agliodbs.com]=20
Sent: Friday, August 24, 2007 12:36 AM
To: William Melstrom
Cc: Clayart
Subject: Re: Choice of venting systems?
William,
> Josh, there really isn't much to a kiln vent. =A0I explain how to make =
your
> own here:
> http://www.handspiral.com/kiln_vent.htm
Ah, I read Mark's article early on and saw that it required $200 worth =
of=20
parts and metalworking tools, so I gave up on the idea of making my own.
Are=20
you really able to use an off-the-shelf junction box for a diffuser? =
Can
you=20
give us some information on the number of holes, etc. you ended up with? =
=20
And how you attached it to the kiln?
--=20
The Fuzzy Chef
San Francisco
William & Susan Schran User on fri 24 aug 07
On 8/24/07 1:54 AM, "William Melstrom" wrote:
> You don't want to actually screw or bolt the box to your kiln -- you need to
> allow for expansion and contraction.
> Try putting a 1" diameter hole in all four sides of the box. You can always
> drill more holes later, or plug one or more holes if need be.
> It would really help if you could find someone's installed commercial system
> to see how the "diffuser box" functions and how to drill the inlet holes in
> your kiln.
I have the Bailey vent that I have connected 2 kilns using a tee in the duct
work. The Bailey, L&L and others are squirrel cage motors. After getting the
Bailey, I thought, hmmm, I coulda done that myself.
The Bailey is attached to the lower wall of the kiln. The attachment is
rigid duct with a flange having 4 holes. Screws go through the holes into
the metal skin of the kiln wall.The flange of the duct is held away from the
kiln wall with washers used as spacers. This allows for a 1/4" air gap
between kiln wall and duct, letting air in to create the negative pressure.
A single 5/16" hole is drilled through the brick.
The L&L collection box has a 1" hole with a flat piece of metal that can be
slid over the hole to allow as much air as needed.
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
William & Susan Schran User on fri 24 aug 07
On 8/24/07 12:25 PM, "Josh Berkus" wrote:
> Last I checked, though, squirrel cage blowers are actually fairly expensive.
> The one on Mark's page is $150. Do you know a better source?
Nope, no sources to report, just reporting on what different manufacturers
are using.
I would think an inline fan might be more prone to being eaten by the fumes
being exhausted by the kiln.
You'd have to decide, is it better to buy less expensive inline fans and
perhaps have to replace them more often, or get a more expensive type fan
and have it last longer?
Here's a squirrel cage fan I found for under $75:
rch&search_type=keyword&QueryString=4c447&submit.x=0&submit.y=0>
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Maurice Weitman on fri 24 aug 07
At 22:36 -0700 on 8/23/07, Josh Berkus wrote:
>William,
>
>> Josh, there really isn't much to a kiln vent. I explain how to make you=
r
>> own here:
>> http://www.handspiral.com/kiln_vent.htm
>
>Ah, I read Mark's article early on and saw that it required $200 worth of
>parts and metalworking tools, so I gave up on the idea of making my own. A=
re
>you really able to use an off-the-shelf junction box for a diffuser? Can y=
ou
>give us some information on the number of holes, etc. you ended up with?
>And how you attached it to the kiln?
Josh,
I can understand how/why you would be concerned and confused by all this.
Here's my take. I, too, didn't want to spend=20
several hundred dollars on a vent. Bailey's vent=20
is a good one, and the new Orton seems fine, too.=20
And yes, you'll need some tools to drill holes,=20
and cut the vent pipe, but it's pretty light=20
stuff.
The key to having a successful vent installation=20
is to have a blower powerful enough to suck lots=20
of air through your (solid, steel) pipe (I used=20
4" to minimize resistance) and fittings. More=20
bends/elbows/distance means more resistance to be=20
overcome by power.
Once you have the blower installed (on your=20
outside wall), plumbed, and powered, all that=20
remains is drilling the hole in the kiln (either=20
on the floor or at the bottom of the side wall=20
opposite the peeps) and mounting your diffuser=20
box. You can start with a small hole, say=20
3/16"... that should be plenty.
It is then that you will tune your air intakes.=20
The more powerful and unencumbered your blower,=20
the more air holes you'll need. The beauty of=20
doing it yourself is that you'll be able to tune=20
it to your own needs, which may change over time.=20
The more air added, the better... that will=20
minimize the inevitable corrosion of the pipe and=20
blower parts. The air exiting my blower is=20
never higher than 85=BA F.
You'll want to have as much added air as possible=20
while maintaining a slight negative pressure in=20
the kiln. You don't want a tornado in the kiln,=20
just enough so that a little air comes in to keep=20
it in oxidation and evacuate the nasties. This=20
can be demonstrated by turning on the vent,=20
closing the lid, opening the top peep and holding=20
a source of smoke near it. Some smoke should be=20
sucked in.
As the kiln heats up, less air will be sucked in,=20
but at that point, less will be needed... most of=20
the nasties will have burned off already.
To regulate the amount of air coming into the=20
box, you can use a piece of scrap steel (part of=20
the junction box) that will swivel over the=20
hole(s) in the box, allowing more or less fresh=20
air in. The balance needed to be achieved is=20
enough suction inside the kiln to vent while=20
adding as much ambient air into the pipes as=20
possible.
Go get 'em!
And I mean that sincerely.
Regards,
Maurice
Josh Berkus on fri 24 aug 07
William,
> I have the Bailey vent that I have connected 2 kilns using a tee in the
> duct work. The Bailey, L&L and others are squirrel cage motors. After
> getting the Bailey, I thought, hmmm, I coulda done that myself.
Last I checked, though, squirrel cage blowers are actually fairly expensive.
The one on Mark's page is $150. Do you know a better source?
> The Bailey is attached to the lower wall of the kiln. The attachment is
> rigid duct with a flange having 4 holes. Screws go through the holes into
> the metal skin of the kiln wall.The flange of the duct is held away from
> the kiln wall with washers used as spacers. This allows for a 1/4" air gap
> between kiln wall and duct, letting air in to create the negative pressure.
> A single 5/16" hole is drilled through the brick.
>
> The L&L collection box has a 1" hole with a flat piece of metal that can be
> slid over the hole to allow as much air as needed.
Yeah, the diffusion box sounds like the easy part. Too bad I don't have
access to my father-in-law's metal shop; just a couple of spot welds would go
a long way.
It occurs to me that electrical junction boxes have pre-punched 1" holes.
Seems like you could do this without any metal cutting at all, if it's
possible to find a deep enough junction box.
--
The Fuzzy Chef
San Francisco
Josh Berkus on sun 26 aug 07
Bill,
> You'd have to decide, is it better to buy less expensive inline fans and
> perhaps have to replace them more often, or get a more expensive type fan
> and have it last longer?
Well, Bailey's currently has their 1-kiln system on sale for $200. I think
I'm going to go with that for now; my time is actually quite scarce and any
time I spend on rigging a ventilation system comes directly away from time I
could spend testing glazes & throwing.
Thanks for advice, though! Maybe my 2nd ventilation system will be home-built.
--
The Fuzzy Chef
San Francisco
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