Ann Brink on tue 9 jan 07
Hello all,
Someone offered to give me some 3/4 inch plywood and I was wondering if =
I could use it for bats. In all the years I've been on Clayart and =
during all the many discussions about throwing surfaces, I can't =
remember anything about plywood. Maybe there's a reason for =
that....anyone have experience with this?
Thanks,
Ann Brink in CA
(mostly about pottery)
Taylor Hendrix on tue 9 jan 07
Almost all of my Hendley bats are made from plywood. I used Thompsons
Waterseal on the top surface and edges. They are still working fine
for me (2 years). If you are going to have simple bats with no cleats
and no pin holes, you will want to coat both sides with waterseal I
would think.
About time for me to do a bit of sanding and reapply my seal, btw.
Taylor, in Rockport TX
On 1/9/07, Ann Brink wrote:
...discussions about throwing surfaces, I can't remember anything
about plywood. Maybe there's a reason for that....anyone have
experience with this?
...
Vince Pitelka on tue 9 jan 07
Ann Brink wrote:
"Someone offered to give me some 3/4 inch plywood and I was wondering if I
could use it for bats. In all the years I've been on Clayart and during all
the many discussions about throwing surfaces, I can't remember anything
about plywood. Maybe there's a reason for that....anyone have experience
with this?"
Ann -
The problem with plywood is that unless it is very well-sealed, water can
enter between the plies and causes it to delaminate. Once that starts,
there's no turnin' back. Plywood can make great bats, as long as you seal
it very thoroughly. I know that another post suggested Thompson's Water
Seal, but if you are going to the trouble to cut your circles and do the
finish work, it's well worth it to take the time to seal them properly.
After you cut your circles, (and drill your bat pin holes if you are
planning on doing that), Put the bat on the wheel and sand the upper edge.
If you want a nice bevel, you can even use a sanding disk on an angle
grinder, with the bat spinning on the wheel. Once you have done all finish
work and have sanded all the edges, brush-coat surfaces with marine spar
varnish, let them dry completely, sand lightly, and paint on another coat.
When it is dry, just sand it very lightly with steel wool. You will end up
with a silky surface, and the bats will last at least ten or fifteen years.
If you don't seal them thorougly, they will delaminate within a few years.
Forgive me for the self-promotion, but in my book there are complete
isntructions on how to make perfect circular bats and drill the bat-pin
holes.
- 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/
WJ Seidl on tue 9 jan 07
Ann:
Plywood will do nicely for a bat, with one caveat.
If the plywood is rated for exterior or marine use, and you throw
sloppy-wet, it will be fine. Interior plywood might delaminate over time if
not allowed to dry thoroughly between uses. That said, I have a half inch
thick plywood bat someone made for me as a joke gift when I first learned
(finally) how to center. (It's an oval, not a circle.) 16 years later, I'm
still using it. Interior grade it is, too.
Free is good. Smile, say thank you, grab it and run!
Best,
Wayne Seidl
in Key West FL, enjoying the winter weather that finally arrived...
68F and breezy!
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ann Brink
Sent: Tuesday, January 09, 2007 12:07 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Plywood bats?
Hello all,
Someone offered to give me some 3/4 inch plywood and I was wondering if I
could use it for bats. In all the years I've been on Clayart and during all
the many discussions about throwing surfaces, I can't remember anything
about plywood. Maybe there's a reason for that....anyone have experience
with this?
Thanks,
Ann Brink in CA
(mostly about pottery)
____________________________________________________________________________
__
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.
Robert Edney on tue 9 jan 07
It depends. It it's standard fir ply it's what's called rotary cut. That means that the top layer of veneer has both hard and soft areas randomly and widely spread -- unlike a piece of normally cut lumber. Why would you care? Because if you throw a gritty clay you'll soon wear down the softer wood and have a somewhat lumpy bat. You can always flip it over, of course -- and the water seal idea is a good one, as cheap ply will eventually delaminate given enough moisture. Masonite or plaster wear evenly -- more or less. If you're just going to saw it up into square bats, go for it. If you're going to all the trouble to make nice round bats, masonite is cheap.
Robert
Megan Mason on tue 9 jan 07
Plywood bats are just fine but are better if you seal them first. I use a
marine spar varnish or similar.3/4" is great but if buying plywood for them a
much thinner plywood works fine especially for the smaller sizes.You could
use 3/4" for those Texan size 4 foot diameter platters and huge sculptures
too,lol.
Meg
Snail Scott on wed 10 jan 07
At 09:07 AM 1/9/2007 -0800, you wrote:
>Someone offered to give me some 3/4 inch plywood and I was wondering if I
could use it for bats...
Normal plywood tends to split if it gets
very wet, but good coating of urethane
will protect it.
3/4" seems like overkill for bats, though,
and since it's so expensive, I'd use it
for something that will really take advantage
of it - where that extra rigidity is needed
and the extra weight is irrelevant - like
sturdy shelving.
Free is free, though, and I admit that one
whole wall of my new studio is sheathed in
3/4" plywood. Total overkill, but it's what
I had, so it got used. One wall is a crazy
quilt of 3/4"and 5/8" scrap plywood; another
is the 1/2" and 3/8" scrap, and the rest
is drywall that cost actual money...how
humiliating to pay retail.
I also use 3/4" ply for the lazy susans
that I build my sculpture on: too thick
to warp, even with a hundred+ pounds of
clay on it. Urethaned well, though.
So, I ain't gonna tell anyone they
shouldn't use their free plywood however
they please.
-Snail
Keith Arbogast on wed 10 jan 07
"....anyone have experience with this?"
Ann,
We have used 'forms ply' as bats for five or six years, maybe more,
with no lamination. It's made for concrete forms, so it has a better
glue that resists water. It is more expensive than regular plywood,
but not as expensive as marine grade or birch plywood. It's not
likely that the plywood you were given is forms-ply, but if it is, it
will work well. Its main drawback is the storage room it takes
because of its thickness.
Best wishes,
Keith Arbogast
Bloomington, IN
Craig Clark on wed 10 jan 07
One more comment on this. Snail speaks truth about the use of the
Urethane to seal (even though I still haven't gotten around to sealing
mine) and the danger of the edges of a plywood bat. I forgot to mention
that I use a router to round out the edges of my plywood as well as MDF
bats.
Hope this helps
Craig Dunn Clark
619 East 11 1/2 St
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
Snail Scott wrote:
> At 09:07 AM 1/9/2007 -0800, you wrote:
>
>> Someone offered to give me some 3/4 inch plywood and I was wondering if I
>>
> could use it for bats...
>
>
> Normal plywood tends to split if it gets
> very wet, but good coating of urethane
> will protect it.
>
> 3/4" seems like overkill for bats, though,
> and since it's so expensive, I'd use it
> for something that will really take advantage
> of it - where that extra rigidity is needed
> and the extra weight is irrelevant - like
> sturdy shelving.
>
> Free is free, though, and I admit that one
> whole wall of my new studio is sheathed in
> 3/4" plywood. Total overkill, but it's what
> I had, so it got used. One wall is a crazy
> quilt of 3/4"and 5/8" scrap plywood; another
> is the 1/2" and 3/8" scrap, and the rest
> is drywall that cost actual money...how
> humiliating to pay retail.
>
> I also use 3/4" ply for the lazy susans
> that I build my sculpture on: too thick
> to warp, even with a hundred+ pounds of
> clay on it. Urethaned well, though.
>
> So, I ain't gonna tell anyone they
> shouldn't use their free plywood however
> they please.
>
> -Snail
>
> ______________________________________________________________________________
> 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.
>
>
Craig Clark on wed 10 jan 07
Ann, I have two old plywood bats that I have had for what seems like a
really long time, perhaps 12 years of so. I had planned on sealing them
but never got around to it. They came from some scrap that I picked up
off a neighbors heavy trash pile if memory serves me correctly. Just cut
out a coupla 22 inch disks. The material is 3/4 inch thick. It has
worked well for my purposes.I store them with the other bats in a
vertical position and try not to soak them with water.
Hope this helps
Craig Dunn Clark
619 East 11 1/2 St
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
Keith Arbogast wrote:
> "....anyone have experience with this?"
>
> Ann,
> We have used 'forms ply' as bats for five or six years, maybe more,
> with no lamination. It's made for concrete forms, so it has a better
> glue that resists water. It is more expensive than regular plywood,
> but not as expensive as marine grade or birch plywood. It's not
> likely that the plywood you were given is forms-ply, but if it is, it
> will work well. Its main drawback is the storage room it takes
> because of its thickness.
> Best wishes,
> Keith Arbogast
> Bloomington, IN
>
> ______________________________________________________________________________
>
> 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.
>
Anne Doyle on thu 11 jan 07
I love free plywood for shelves and ware boards! I am sure you can come
up with dozens of ways to use that for pottery:) Cool! A gift of a
thousand uses!
Anne
Paul Borian on wed 15 aug 07
I have all kinds of bats that I use and the best are the hardy backer =
board ones, at least for certain pots, but they tend to dry the pots =
that it can sometimes cause problems. So I need to cut some 12" bats out =
of regular old =BE" plywood to use for certain forms that don't need to =
dry as fast. I don't think I have ever cut bats from plywood - I have =
used just about everything else - and was wondering is there any =
particular type of plywood to look for that would work best? My main =
concern is that the plywood I see at the home improvement stores looks =
so cheap - always warped and with all kinds of flaws and it makes me =
wonder if this stuff will hold up at all without warping. If I put some =
kind of sealant over it than that would defeat the purpose of having a =
bat that absorbs some water off the base to help even out the drying.
Does anyone have some tips on how to make the best wood bats? If this =
kind of wood is just going to fall apart and warp I may just end up =
cutting more backer board bats.
Thanks,
Paul
Marcia Selsor on wed 15 aug 07
Birch plywood is good.
Also for a nice round cut, make a jig with wood strips and clamps on
a bandsaw table with a nail in the center of your future bat so it
turns into a circle along the blade. Sand the edges when you finish
cutting.
Marcia Selsor
http://marciaselsor.com
snip
> Does anyone have some tips on how to make the best wood bats? If
> this kind of wood is just going to fall apart and warp I may just
> end up cutting more backer board bats.
>
> Thanks,
>
> Paul
>
> _
Gordon Ward on wed 15 aug 07
Hi Paul,
Although a sheet of plywood may look warped over an 8' length, when
cut into smaller pieces, it is usually flat enough. Use an exterior
grade plywood, as the glues in this type will resist moisture. The
best type would be marine grade, but it is prohibitively expensive.
I have used MDO plywood, which, I believe was developed for sign
makers. It has a very smooth surface on one or both sides. I have
some 14" dia. x 1/2" thick ones which have held up well for many
years. The only thing is that it is less absorbent than regular
plywood due to the special smooth surface. Plywood made for floor
underlayment is usually pretty nice quality with lots of plys.
Sometimes it's tongue and groove, but that won't matter. If you are
only going to make 12" bats, regular exterior A/C plywood should be
fine too. 5/8" would probably be thick enough.
If you live in an area that produces wood products, there may be
"bargain stores" where you can get odd pieces and rems. I have
gotten loads of material from one in Eugene, but haven't found
anything like it in the S.F. Bay area.
Gordon
On Aug 15, 2007, at 10:24 AM, Paul Borian wrote:
> Does anyone have some tips on how to make the best wood bats?
Taylor Hendrix on wed 15 aug 07
Hey Paul,
If I were to make more plywood bats I would take Vince P's suggestion
that you seal the plywood with marine varnish. You can pay the money
for high grade plywood (several grades and types exist) or you can
just avoid the pitted areas and sand the top part smooth before
covering with the spar varnish.
Have you priced marine plywood? Some of my few Hendley bats are doing
the wave already as I only put on a water seal for protection. They
are not marine grade and only 1/4 inch (free scrap, btw).
Sealed hardibats may be great too.
Tropical depression is a-commin'! Hang on.
Taylor, in Rockport TX
On 8/15/07, Paul Borian wrote:
..
> Does anyone have some tips on how to make the best wood bats? If this kind of wood is just going to fall apart and warp I may just end up cutting more backer board bats.
...
om on wed 15 aug 07
On Aug 15, 2007, at 10:24 AM, Paul Borian wrote:
> ... So I need to cut some 12" bats out of regular old =BE" plywood to =20=
> use for certain forms that don't need to dry as fast. I don't think =20=
> I have ever cut bats from plywood - I have used just about =20
> everything else - and was wondering is there any particular type of =20=
> plywood to look for that would work best? My main concern is that =20
> the plywood I see at the home improvement stores looks so cheap - =20
> always warped and with all kinds of flaws and it makes me wonder if =20=
> this stuff will hold up at all without warping. ...
I've personally had good luck just buying the precut plywood rounds. =20=
I've treated them roughly -- left them out in the rain even, and =20
they're still fine after several years. As they are factory cut, =20
they're perfectly round (I don't have a reasonable method of cutting =20
out round discs and I'm not a great wood worker anyway). I don't =20
remember them being terribly expensive, but obviously, if you need =20
hundreds, it would be cheaper to buy plywood and cut them yourself. =20
If you are doing it yourself, you might look at the thick sheets of =20
birch plywood -- it's beautiful but very pricey.
OM
www.anagama-west.com/firing_log=
Bill Merrill on wed 15 aug 07
Paul,
=20
If you use plywood, you might see if you can find marine plywood. It's =
expensive. I use plaster bats that fit into a wheel head (Randall =
wheel) and use 8",12"16" and 20" plaster bats. The plaster bat takes =
moisture from the bottom of the pot and on the small bats I use a =
spatula to remove the pot from the bat. This works well for pitchers =
etc. as the side trimming can be done with the pot already centered. On =
the large bats I us an old time rake tooth from farm machinery and span =
the c shape with piano wire to cut off big platters. Some potters let =
the pots pop off the bat. There's just so many ways to do things. I =
just like using plaster bats. I have an 18" wheel head and have some =
very large (36") bats. A thick piece of plywood is attached to the =
wheel head. You can put a piece of cotton duck canvas on the wood and =
place the clay on the canvas. I pound it into shape, then, use a large =
rib or the heel of my hand to make the bottom of the platter. Then the =
outside wall is pulled up into a wall and lip. It is already released. =
Or you can lift the platter off and place it into a large curved form. =
Don Reitz made some large platters that way many years ago.=20
=20
The standard plaster mix is for every 80 cubic inches of plaster that =
you need use 1 quart of water and add 2 & 3/4 pounds of plaster. This =
will give the density consistency for your plaster. Measure out your =
water and slowly sift the plaster into the water. Let it sit for =
several minutes before stirring. Let it sit until it peaks slightly =
when you drag your finger over the wet plaster, then pour the plaster, =
just don't wait too long.=20
=20
Regards,
=20
Bill
=20
=20
=20
=20
=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Paul Borian
Sent: Wednesday, August 15, 2007 10:25 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: plywood bats?
=20
I have all kinds of bats that I use and the best are the hardy backer =
board ones, at least for certain pots, but they tend to dry the pots =
that it can sometimes cause problems. So I need to cut some 12" bats out =
of regular old =BE" plywood to use for certain forms that don't need to =
dry as fast. I don't think I have ever cut bats from plywood - I have =
used just about everything else - and was wondering is there any =
particular type of plywood to look for that would work best? My main =
concern is that the plywood I see at the home improvement stores looks =
so cheap - always warped and with all kinds of flaws and it makes me =
wonder if this stuff will hold up at all without warping. If I put some =
kind of sealant over it than that would defeat the purpose of having a =
bat that absorbs some water off the base to help even out the drying.
=20
Does anyone have some tips on how to make the best wood bats? If this =
kind of wood is just going to fall apart and warp I may just end up =
cutting more backer board bats.
=20
Thanks,
=20
Paul
=20
_________________________________________________________________________=
_____
Send postings to clayart@lsv.ceramics.org
=20
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
=20
Moderator of the list is Mel Jacobson who may be reached at =
melpots@pclink.com.
Ben Shelton on thu 16 aug 07
We used DOUBLE FACED masonite at a pottery I worked at years ago.
1/4" thick and drilled through for the Brent wheels we used.
We had them in several sizes from 11" to 18"
I wish I had a stack of them for several reasons the main one being space.
you can fit hundreds of these things in one rack. Think of it, at 1/4" you
get 48 bats per foot. One 4'x8' sheet will make 32 bats a little less than
12" square. Drill them to fit your bat pins, put them on the wheel to trim
round.
IF your wheel head is small enough you can use a router with a flush trim
follower bit to trim them to final size after roughing them with a jig saw.
The key thing to note is that the masonite must be DOUBLE SIDED or DOUBLE
FACED or DOUBLE TEMPERED. I have seen it called all these things. IF only
one side is finished the masonite will warp badly.
The only drawback I saw was that they are somewhat flexible. If you make
work that cannot stand any flex these would be a bad idea.
Oh they do absorb some moisture from the work BTW.
Good luck Paul,
Ben
Patty Kaliher on thu 16 aug 07
Must share my plywood bat story.
Out instructor at the art center swears by plywood bats. Personally I am
happy with plastic but he has convinced some of the students that they need
plywood bats. So I figured I could make some money. I went to the lumber
supply and bought Marine Plywood 3/4 inch for $101 for a 4'x 8' sheet. My
husband cut out the 12" circles with a jig saw a job which really did a
number on his back. He sanded the edges and drilled holes for the bat pins
into one side of the bat. We charged $9 for the bats. However, it turns
out that there is Marine Plywood and Marine Plywood. The lumber supplier we
bought from says Marine Plywood is the same as exterior plywood (the same
water proof glue) except the Marine plywood has both sides "A" grade. No
voids. However, a wooden boat builder will tell you that water proof glue
may prevent warping but the species of wood used in the plywood can make a
big difference. The surface of the stuff we bought is probably fir and has
a very open grain. One of the bats did generate splinters. The 30 year old
plywood bats our instructor uses constantly have a very tight grain that may
be mahogany. We have treated some of the bats with Thompson's Water Seal to
prevent splinters but that negates the whole purpose of a bat that draws
water out of the clay. So far because of the splinter problem we have only
sold 6 bats.
Gordon Ward on sat 18 aug 07
Hi Paul,
By now you have had many responses and ideas for making bats, but
since my initial response never got posted I thought I'd try again.
If you are still interested in plywood, I have used 1/2" MDO plywood
(medium density overlay) for my 14 inch bats. MDO is a very flat
plywood made for the sign industry, and as such is designed to resist
rippling and warping. They are slightly absorbent, but not as much
as regular fir plywood. The key is to find material with high
quality exterior glue. 5/8" underlayment plywood is also usually
very good with lots of plys to keep it flat. If you live in an area
where wood products are made, you may be able to find a "bargain
store" that sells rems and odd lots of plywood. I have gotten loads
of material from such a store when I lived in Eugene.
If you have access to a band saw, you can make a jig for perfect
circles.
Cheers,
Gordon
On Aug 15, 2007, at 10:24 AM, Paul Borian wrote:
>
> Does anyone have some tips on how to make the best wood bats? If
> this kind of wood is just going to fall apart and warp I may just
> end up cutting more backer board bats.
>
> Thanks,
>
> Paul
Vince Pitelka on sat 18 aug 07
Paul Borian wrote:
"Does anyone have some tips on how to make the best wood bats? If this kind
of wood is just going to fall apart and warp I may just end up cutting more
backer board bats."
Paul -
About ten years ago we made a large batch of plywood bats. We used 3/4"
exterior plywood that had one good smooth face. We cut the circles, drilled
the bat-pin holes slightly oversize, cut a slight bevel at the opening of
each bat-pin hole, and them put each bat on the wheel, and with the wheel
spinning, used an angle grinder with a flexible sanding disk to grind a
slight bevel on the outside upper edge of the bat. Once that was done, we
gave every surface of the bat a series of coats of marine spar varnish,
sanding between coats. It was LOT of work, and if you value your labor, it
ain't worth it. Those bats are still holding up just fine after ten years
of continual use in an academic facility, but so are our 1/2" Medex
waterproof MDF bats, which require no varnish. If I were considering the
cost of my labor, I would always go for the Medex, even with the cost of
shipping from a supplier. Your local building materials supplier may be
able to order it for you, but even if you have to get it shipped in it will
be worth it.
- 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/
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