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Building a Steam Dewaxer


#1

I’m looking for a simple method of building a steam dewaxer for my
shop that will not cause harm to the investment. The challenge
being size, I’m in a apartment using a bedroom for my studio. Most
models currently on the market are larger than I have room for.
Thanks in advance!

Terri Collier

Terri’s Place
Dallas, TX
@Terri_Collier


#2
I'm looking for a simple method of building a steam dewaxer for my
shop that will not cause harm to the investment.  The challenge
being size, I'm in a apartment using a bedroom for my studio.  Most
models currently on the market are larger than I have room for.

I built a steam dewaxer from a hotplate, a spaghetti pot and a piece
of a bakery cooling rack. The spaghetti pot is a two-piece thing,
with an outside pot and an inside perforated pan that fits tightly
inside, and of course, a lid. I cut and bent the circular cake
cooling rack to fit inside the perforated pan, in order to raise
flasks up off the bottom by an inch or so.

I put just enough water in the bottom pan to come almost to the
bottom of the perforated inner pan, set the flasks opening side down
on the cooling rack, and cover it with the lid. Then I turn on the
hotplate and let it boil for 60 to 90 minutes, depending on the size
of the flasks and the amount of wax in them. When they come out,
there’s hardly any wax left to be burned out. I’ve accidentally left
flasks in there for over 2 hours, and the investment is not harmed
in any way. The wax drips out into the water, and when it cools, it
can be peeled out and removed in one large flat piece. The only thing
you need to be concerned about is not letting it boil dry–that might
be ugly.

The whole thing cost me about $12 for the hotplate and the cooling
rack. I already had an old spaghetti pot that wasn’t being used, I
got the hotplate new for $10 and the cooling rack for a couple
dollars at a thrift store.

Here’s a link to a site that sells a spaghetti pot like the one I
have (not affiliated, just found one with the right photo). You can
sometimes find them cheaper at local department stores, and you might
even get lucky and find one in a thrift store.
http://www.kitchenhomegadgets.com/granwarpaspo.html

–Kathy Johnson
Feathered Gems Jewelry
http://www.featheredgems.com


#3

I am also interested in any thoughts on this. My shop is now in a
building that I share with others. Large casts will produce enough
odour that I am concerned and now that winter is around the corner,
just opening a window is not practical.

From what I understand a steam dewaxer is an enclosed container that
has a rack to hold the flasks above the water in the bottom of it.
The water is brought to a boil and the temperature within the
container must I assume, rise to around the boiling point of water at
212F. The flasks inside would rise to that temp and the wax would
melt out since injection waxes we use melt at about 150 - 170 F. The
wax appears to after melting just drop into the water and after
cooling can be removed. I understand that the flask can then go to a
oven preheated to 300F and the regular burnout followed. OK?..so
could we not use a large pot on the stove with a lid and a rack to
hold the flasks above the water and do the same thing?? Am I missing
something here? (I use a tray in my oven to catch wax tat is melted
out during the 300F cycle and remove it before increasing the temp to
700F, have I really gained anything by steam dewaxing?) So far so good
I think. But carving waxes melt at 220 - 230F. Does that mean that
mean that they cannot be steam dewaxed? How about using a pressure
cooker? I would look forward to your thoughts and experiences. Thank
you. Franklin


#4

Terri

You will find a domestic pressure cooker will do an excellent job
and quick too. Place two pieces of 2" x 2" x 6 inch-ish long pieces
of timber on the bottom - inside and fill with water just below the
timber, place your inverted flask on the timber after the water has
began to boil - refit the lid and give it another 20 minutes or so.
Remember to wear gloves when you remove the flask - it will be hot.

Regards
Alan Lewis
UK


#5

Hi Terri,

    I'm looking for a simple method of building a steam dewaxer
for my shop that will not cause harm to the investment. 

Depending on the size of the flasks, have you considered using
regular pressure cooker & the kitchen stove?

Leave the pressure guage off so no excessive pressure builds up in
the cooker. Use a small amount of water, 1 or 2". Put a grate of
some kind on the bottom to keep the flask out of the water. A little
experimentation may be needed to determine the amount of water needed
& the time needed to melt the wax out.

Dave


#6

Terri, You can use an old thrift store pressure cooker, make a
rack that will keep the flasks above the level of the two or three
inches of water you need in the bottom, do not use a valve to seal
the pressure, just let the steam escape. When it is hissing strong
for 15-20 minutes that should be enough for the wax to have melted
out. I use a large pressure canner to dewax 4 to 6 3’ by 7 'flasks and
it works great. Wait about an hour after you have invested to
dewax, and after you do it, you can put the flask right in the kiln
and turn it to 700 degrees and start burn out, or you can wait till
the next day, as I have my kiln go on at 7am, hours before I get to
work. Richard in Denver


#7

Save your money. Go out and buy a cheap spaghetti pot with a
removable colander. Put enough water in to come below the bottom of
the colander, put your flask in (remove the base first) cover with
lid and turn on. Check after about fifteen minutes. Larry
Paul…Larry Paul Casting Co. Inc 740 Sansom St 740 Sansom St
Philadelphia, PA , 19106 215-928-1644


#8

Go to a used restaurant supply and pick up a hotdog steamer they
work great and are not typically as large as commercial steam
dewaxers.

James


#9
   But carving waxes melt at 220 - 230F. Does that mean that mean
that they cannot be steam dewaxed? How about using a pressure
cooker? 

G’day; A pressure cooker properly used produces superheated steam at
a temperature of 121C which is also 249.8 F They already have a
rack which comes with them to hold items to be cooked. Twenty
minutes in a pressure cooker after steam has appeared from the vent
and the supplied weight put in place will not only melt out even
high temperature waxes but will properly sterilize anything put into
the cooker, to laboratory standards. Even cloth, like towels,
bandages etc, will be completely sterile. You can sterilize these
when placed in an oven bag with the opening loosely fastened. To
sterilize screw top bottles, wash them thoroughly, screw on the cap,
then unscrew by one turn. Screw tightly when still in the cooker but
cool. But under NO CIRCUMSTANCES should you open the cooker until it
has cooled to hand heat. If you buy one second hand make certain it
has with it the proper weight. It won’t work without one. I used
mine for bacteriology.

Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ


#10

My challenge here is that I’m in a wheelchair so, handling large
pots on the stove is rather challenging for me. Too many
opportunities for getting burned (previous experience with canning
and jam making after my accident). I did check the Orchid archives
after posting my question using the beta search (thank you Hanuman,
it works great!) and found previous threads on the subject. The one
that seemed most likely to work best for me is using a roasting
oven/pan. I can place this on my work table and see inside the pot.

I found a Hamilton Beach roasting oven on ebay new for $20.50, I did
a search on roasting pans and on roasting ovens. I’m going to try
this and see what happens. Everyone, thank you for your input and
ideas, they’re great and I’ll keep them handy for anyone asking for
ideas in the future.

Here’s a link to the one I purchased:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item 67056288

This group is so wonderful with sharing ideas, tips, etc. Thanks
again, all of you are great!

Take care.
Terri Collier
Terri’s Place
Dallas, TX
@Terri_Collier


#11
    From what I understand a steam dewaxer is an enclosed
container that has a rack to hold the flasks above the water in the
bottom of it. . . Franklin 

Hello Franklin and others; One thing to note on the issue of steam
de-waxers is this: they aren’t intended to remove carvable waxes
from your investment, they are designed for production work where the
wax being removed is injectable and melts at a much lower melting
temperature. From my they don’t work especially well
with Karvex and Ferris carving waxes. If I’m right about this, then
you’d need to make RTV molds of the carved wax models, shoot them in
injection wax and then you could make use of the steam dewaxer. I’m
open to the experience of others who might disagree with this
opinion.

David L. Huffman
David L. Huffman Studios, Inc.
@David_L_Huffman1


#12

Franklin, I use a two quart sauce pan with a heavy piece of steel
mesh set on the rim, with an upside down stainless steel mixing bowl,
happily of the same diameter, placed over the flasks. I use this on
the hot plate in my studio - beneath my fume hood - let it go for an
hour. It works great. I believe I originally came upon this idea in
Tim McCreight’s Practical Casting.

The pressure cooker idea seems like it might be a good one, too, and
I also have heard good things about hot dog steamers.

What I really want to add to the discussion, however, is what I do
with the flasks after the de-waxing:

I put them into a $50 K-Mart turkey roaster oven for an hour (in a
larger community than ours, one might be found much cheaper in a
second hand store). I began doing this as a pre-lim to going into
the burn-out kiln when I discovered that my kiln was beginning to
rust out from all the humidity the freshly de-waxed flasks produced.
This step is clearly not necessary, but I think a lot cheaper in the
long run.

Les Brown
L.F.Brown Goldwork, Inc.
Kalispell, Montana


#13
    Hello Franklin and others; One thing to note on the issue of
steam de-waxers is this:  they aren't intended to remove carvable
waxes from your investment, they are designed for production work
where the wax being removed is injectable and melts at a much lower
melting temperature 

A lot of the carving waxes melt above 212 degrees Fahrenheit so
steaming obviously won’t work with them. The injection waxes are
fluid in the 140 to 170 degree range so they’ll melt out under steam
temperatures. As David said, the steam dewaxers are meant to melt
out injection waxes for production casting. So if you’re doing small
flasks of carved waxes (Ferris, Matt, etc), you’re going to have to
do the usual burnout or at least put a catch pan under the flasks and
remove the molten carving wax part way through the burnout.

Donna


#14

I have been using a pressure cooker with a vegetable steaming basket
(the type that folds like a flower) on a hot plate. DO let the
investment set up for 2 hours NOT one. keep the water level 1/4 inch
or so below the basket. Heat the water until boiling, put the flasks
upside down on the open basket. Put on the lid with the weight, set
for 15#. Without the pressure, the steam doesn’t get hot enough to
melt carving wax. After the steam starts hissing, run 1/2 hour for
injection wax, 45 minutes for carving wax. (Times for small flasks).
Do not over steam. Set directly in to a 300 degree F preheated oven.
Leave at 300 F for at least one hour to dry, with a normal burnout
otherwise.

This is especially good for stone-in-place work, to remove excess
boric acid from the mold for a smoother surface, plus guaranteeing a
full removal of all the wax.

We have been using this process for over a year, since putting
together several posts to Orchid. Works very well!

Allan Beck
Boise, Idaho


#15

Using John Burgess’ suggestion and his figures, I just checked Rio’s
catalog and blue Matt wax melts at 200 and green at 230. So, it
would seem possible using the pressure cooker. In the past I’ve used a
vegetable steamer with water in the bottom part of course put it on
top of the stove and it worked well enough. If one follows John
Burgess’ suggestion how much water would be needed to evacuate the
wax and still have enough water to catch the wax? If the pressure
cooker drys out, one would have fumes from the burning wax; or have I
misunderstood? K Kelly


#16

we use a gas grill made by holland grills. www.hollandgrills.com they
have a model that sells for about $300 , for what its worth.

Jim Fortescue
President