Wendy Kelsey on sun 17 sep 06
I need to make an inexpensive vacuum chamber - can someone
tell me how to do this?
It is to be used for getting rid of the air bubbles in
Synair S1-12 silicone mold stuff.
Thanks all!
Wendy Kelsey, Operations Manager
www.martiniceramics.com
Martini Ceramics
Custom Tile, Gifts and Ceramic Art
1272 Paradise Cove
Ferndale, WA 98248-9469
Telephone: 360-392-8607
Fax: 832-550-4856
pdp1@EARTHLINK.NET on sun 17 sep 06
Hi Wendy,
Well, a Vacuum Chamber of course must not only be
Air tight, but it must be strong enough, and
designed with the idea in mind, for it to resist
more or less 15 pounds per squre inch pressure of
the ambient Atmosphere, against it's outside,
whenever a Vacuum is being maintained in it's
inside.
If it were me, I would look for some ready made
form, which will fit-the-bill, and which also
would permite easy and ample opening for putting
the things into it, for processing.
The old forms of Pressure Cookers, when large
enough, would probably work perfectly, and already
posess a 1/8th inch Pipe Thread hole, where their
Pressure Gauge stem screwed in...so you could
remove that, put a 'Tee', and have a Vacuum Gauge
and Vacuum line, going to the lid...and be quite
elegant with it.
Phil
el v
----- Original Message -----
From: "Wendy Kelsey"
> I need to make an inexpensive vacuum chamber -
can someone
> tell me how to do this?
>
> It is to be used for getting rid of the air
bubbles in
> Synair S1-12 silicone mold stuff.
>
> Thanks all!
>
> Wendy Kelsey, Operations Manager
Don Goodrich on sun 17 sep 06
Hi Wendy,
"Inexpensive vacuum chamber" is in the same category as
"honest politician" or "safe sex", in that it's almost an oxymoron.
The instant way to have a vacuum chamber is to plug the hose
inlet of a shop-vac and turn it on. Unfortunately, the vacuum
produced this way doesn't amount to much ( not what you'd need
for de-airing silicone), and is very unkind to the machine's
motor. For serious vacuum you need heavier equipment.
It would help to know the size of the containers holding the
mold stuff you wish to de-bubble. If they're relatively narrow,
you can get by with an assembly of PVC tubing. Use thicker-walled
PVC, especially if you need a larger diameter. Just get a length
of tubing, of a diameter that will hold your container.
Then a cap for one end and a removable plug (a cleanout
fitting should do) for the other end, where you'll be loading
and unloading the chamber. You'll need to have a hole and
appropriate fitting to attach your vacuum pump. You could use a
"T" fitting to hold the removable plug, and reducers in the leg
of the T to connect to your vacuum source.
If you need to evacuate a larger container, such as a gallon
or 5-gallon pail, the problem becomes more challenging. It's
possible to make a vacuum chamber from a household water tank,
but you'd need to be able to cut an opening in it and then
fabricate a well-sealed door. Unless you can do it or have capable
volunteer help, this won't be very cheap. If there are any
industrial equipment resellers in the area, you may find
something suitable. Dispensers for glue, ink, or grease are made
to be sealed and pressurized, and could be adapted pretty easily
for vacuum.
You'll need a vacuum pump. They turn up on eBay regularly, and
it's worth checking there. Some air compressors will draw a vacuum
if you connect to the air inlet side, but it's not always easy to
find one that allows this. People who maintain air conditioning
and refrigeration often have vacuum pumps, and you may be able to
borrow one. Of course if you already have access to a de-airing
pugmill, it's just a matter of connecting to your chamber.
Vacuum hoses should be thick-walled or wire-reinforced so they
don't collapse. Plastic fittings are okay since they won't need
to handle more force than that of city water. Use hose clamps to
minimize leaks.
That's all I can think of at the moment, and more than I'd
expected to say. Guess I'm nostalgic for the big vacuum chamber
I used to play with at the factory .
Good luck,
Don Goodrich
goodrichdn@aol.com
http://dongoodrichpottery.com/
normana on sun 17 sep 06
Something else to consider, when getting rid the bubbles in silicon. I
feel it's important to be able to see what's going on with the silicon
as it is going to boil before it releases the bubbles. I used a piece
of 1 inch thick Lexan plastic, which I attached to the vacuum chamber,
which I fabricated, with silicon sealant .
Something else to think about, the silicon is very viscous stuff and
when putting it into the mold it is very easy to reintroduce air
bubbles. I would consider brushing the silicon on being careful not to
entrapped air bubbles. I'm not familiar with the this silicon you are
using, and it's been years since I used any silicon mold materials. But
if it's a similar this type of silicon. It should come in a brush-on form.
When I used to use silicon to make molds I put the whole mold into the
vacuum chamber. It's very important to get a very strong vacuum,
depending on your altitude. I think it has to be over 20 pounds per
square inch, that's what I think I got at 7000 feet. It's really
amazing to watch that moment when the air leaves the silicon very
intense boiling, one would never realize that their was so much air in
the silicon.
Good luck, Norman Aufrichtig
pdp1@EARTHLINK.NET wrote:
> Hi Wendy,
>
>
> Well, a Vacuum Chamber of course must not only be
> Air tight, but it must be strong enough, and
> designed with the idea in mind, for it to resist
> more or less 15 pounds per squre inch pressure of
> the ambient Atmosphere, against it's outside,
> whenever a Vacuum is being maintained in it's
> inside.
>
> If it were me, I would look for some ready made
> form, which will fit-the-bill, and which also
> would permite easy and ample opening for putting
> the things into it, for processing.
>
>
> The old forms of Pressure Cookers, when large
> enough, would probably work perfectly, and already
> posess a 1/8th inch Pipe Thread hole, where their
> Pressure Gauge stem screwed in...so you could
> remove that, put a 'Tee', and have a Vacuum Gauge
> and Vacuum line, going to the lid...and be quite
> elegant with it.
>
>
> Phil
> el v
>
> ----- Original Message -----
> From: "Wendy Kelsey"
>
>
>
>> I need to make an inexpensive vacuum chamber -
>>
> can someone
>
>> tell me how to do this?
>>
>> It is to be used for getting rid of the air
>>
> bubbles in
>
>> Synair S1-12 silicone mold stuff.
>>
>> Thanks all!
>>
>> Wendy Kelsey, Operations Manager
>>
>
> ______________________________________________________________________________
> 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.
>
>
>
> us
Wendy Kelsey on mon 18 sep 06
Hi Don! I found a vacuum pump at harborfreigt.com for $10
and have ordered that and am getting the other parts
together.
I'll let you know how it goes when it is all assembled! We
are just using 20oz disposable cups so it doesn't have to
be too big!
Thanks for your input!
--- Don Goodrich wrote:
> Hi Wendy,
> "Inexpensive vacuum chamber" is in the same category
> as
> "honest politician" or "safe sex", in that it's almost an
> oxymoron.
>
> The instant way to have a vacuum chamber is to plug
> the hose
> inlet of a shop-vac and turn it on. Unfortunately, the
> vacuum
> produced this way doesn't amount to much ( not what you'd
> need
> for de-airing silicone), and is very unkind to the
> machine's
> motor. For serious vacuum you need heavier equipment.
>
> It would help to know the size of the containers
> holding the
> mold stuff you wish to de-bubble. If they're relatively
> narrow,
> you can get by with an assembly of PVC tubing. Use
> thicker-walled
> PVC, especially if you need a larger diameter. Just get a
> length
> of tubing, of a diameter that will hold your container.
> Then a cap for one end and a removable plug (a cleanout
> fitting should do) for the other end, where you'll be
> loading
> and unloading the chamber. You'll need to have a hole and
> appropriate fitting to attach your vacuum pump. You could
> use a
> "T" fitting to hold the removable plug, and reducers in
> the leg
> of the T to connect to your vacuum source.
>
> If you need to evacuate a larger container, such as a
> gallon
> or 5-gallon pail, the problem becomes more challenging.
> It's
> possible to make a vacuum chamber from a household water
> tank,
> but you'd need to be able to cut an opening in it and
> then
> fabricate a well-sealed door. Unless you can do it or
> have capable
> volunteer help, this won't be very cheap. If there are
> any
> industrial equipment resellers in the area, you may find
> something suitable. Dispensers for glue, ink, or grease
> are made
> to be sealed and pressurized, and could be adapted pretty
> easily
> for vacuum.
>
> You'll need a vacuum pump. They turn up on eBay
> regularly, and
> it's worth checking there. Some air compressors will draw
> a vacuum
> if you connect to the air inlet side, but it's not always
> easy to
> find one that allows this. People who maintain air
> conditioning
> and refrigeration often have vacuum pumps, and you may be
> able to
> borrow one. Of course if you already have access to a
> de-airing
> pugmill, it's just a matter of connecting to your
> chamber.
>
> Vacuum hoses should be thick-walled or wire-reinforced
> so they
> don't collapse. Plastic fittings are okay since they
> won't need
> to handle more force than that of city water. Use hose
> clamps to
> minimize leaks.
>
> That's all I can think of at the moment, and more than
> I'd
> expected to say. Guess I'm nostalgic for the big vacuum
> chamber
> I used to play with at the factory .
>
> Good luck,
> Don Goodrich
>
> goodrichdn@aol.com
> http://dongoodrichpottery.com/
>
>
______________________________________________________________________________
> 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.
>
Wendy Kelsey, Operations Manager
www.martiniceramics.com
Martini Ceramics
Custom Tile, Gifts and Ceramic Art
1272 Paradise Cove
Ferndale, WA 98248-9469
Telephone: 360-392-8607
Fax: 832-550-4856
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