roy leyva
Member
If interested in constructing an Inexpensive Vac. for your PR, consider this set-up I've made (half-hour) for myself and several fellow resin castors, (total less $75), read on:
Materials:
Using your existing "Standard" Air Compressor (found in most/every shop)--
1. Purchase a Harbor "Fright" Automotive r134 AC Vac. Pump ($13-$14).
2. Brass Air connectors-3 male and 3 female (1/4" or 3/8") and 1 coupler.- +- $10 @HF
3. One self-coiling (yellow/orange c.) air hose (HF:<$10)-a Space saver
4. One standard tube silica sealant (Lowe's:$4)
5. Couple-1/2" holed silicon gaskets ($2)
6. Key Item--One 4qt to 8 qt Al. kitchen Pressure Cooker (Penny's-$30)
Note to fellow skeptics-Please read on...
Now, do not Fret!! You are not building a "Widow Maker" that will blow your head off as in the "lid incident in previous Threads" reg. Pressure pots. This is a vacuum!, that once connected to the compressor will not let you take the lid off, even if you wanted to (due to the vacuum built within) ie-Nothing to "Explode!".
Set-up:
(Make sure the Press. Cooker has one of those rubber 1/2 inch plugs that are meant as safety relief for the "normal" cooking process/design)--
a. Remove lid's rubber "plug" and replace w/ one of brass male coupler, use 2 gaskets and the 3/8" fe. connection under lid and screw on tight. The hole may need slight filing/hogging out. Add some caulking to connections above and under lid. Remove large (10"-12") rubber lid seal and put a medium bead along inside curved edge, replace gasket, and twist lid back onto pan. Allow to cure over-night. This will now give you a Vacuum tight connection that will Prevent air from leaking INTO the pot and ruining the vac./ negative pressure during actual useage.
b. Screw on the two brass female air connectors to both ends of self-coiling hose. Make sure you use white plumbers tape to all threads and test for good seal (I use bubbles & test under air pressure from the compressor).
c. Connect brass male ends to both ends of AC pump, if not already installed. Mine came with one already in place. Again, test for leakage! of any connection. Air In vs. Vac. sides are marked!
d. Next day, when lid is curred with s. sealant, hook-up in series, male-to-female, and you're in Business!!
Usage: You can add an optional On-Off valve in series/in line, if you wish to control entry of air (allows you to shut off compressor once Vacuum is achieved). I place my just mixed PC mold (single or stacked) into pot, seal lid shut, hook-up compressed air Supply at left of AC pump, and let run for 5-10 minutes, depending on power of compressor (I use 40-50 PSI).
e. After a short +10 min. wait, remove compressor hose coupler, allow to balance to atmosphere, remove-unlatch pot lid, and reach in for a frothy casting (if you had any bubbles). I usually do, because...
[I am casting make-up/mica colored resin in a shallow tupperware that has a chunk of highly contoured maple burl cap, so..voila,.. bubbles removed and ready to let cure for a day or two.]
Summary: Sounds a little difficult, but in actuality, you can put it all together with the help of a couple of wrenches, a little time, plumbing tape (and $75
). Thanks for your reading interest on this verbose topic/thread.
Materials:
Using your existing "Standard" Air Compressor (found in most/every shop)--
1. Purchase a Harbor "Fright" Automotive r134 AC Vac. Pump ($13-$14).
2. Brass Air connectors-3 male and 3 female (1/4" or 3/8") and 1 coupler.- +- $10 @HF
3. One self-coiling (yellow/orange c.) air hose (HF:<$10)-a Space saver
4. One standard tube silica sealant (Lowe's:$4)
5. Couple-1/2" holed silicon gaskets ($2)
6. Key Item--One 4qt to 8 qt Al. kitchen Pressure Cooker (Penny's-$30)
Note to fellow skeptics-Please read on...
Now, do not Fret!! You are not building a "Widow Maker" that will blow your head off as in the "lid incident in previous Threads" reg. Pressure pots. This is a vacuum!, that once connected to the compressor will not let you take the lid off, even if you wanted to (due to the vacuum built within) ie-Nothing to "Explode!".
Set-up:
(Make sure the Press. Cooker has one of those rubber 1/2 inch plugs that are meant as safety relief for the "normal" cooking process/design)--
a. Remove lid's rubber "plug" and replace w/ one of brass male coupler, use 2 gaskets and the 3/8" fe. connection under lid and screw on tight. The hole may need slight filing/hogging out. Add some caulking to connections above and under lid. Remove large (10"-12") rubber lid seal and put a medium bead along inside curved edge, replace gasket, and twist lid back onto pan. Allow to cure over-night. This will now give you a Vacuum tight connection that will Prevent air from leaking INTO the pot and ruining the vac./ negative pressure during actual useage.
b. Screw on the two brass female air connectors to both ends of self-coiling hose. Make sure you use white plumbers tape to all threads and test for good seal (I use bubbles & test under air pressure from the compressor).
c. Connect brass male ends to both ends of AC pump, if not already installed. Mine came with one already in place. Again, test for leakage! of any connection. Air In vs. Vac. sides are marked!
d. Next day, when lid is curred with s. sealant, hook-up in series, male-to-female, and you're in Business!!
Usage: You can add an optional On-Off valve in series/in line, if you wish to control entry of air (allows you to shut off compressor once Vacuum is achieved). I place my just mixed PC mold (single or stacked) into pot, seal lid shut, hook-up compressed air Supply at left of AC pump, and let run for 5-10 minutes, depending on power of compressor (I use 40-50 PSI).
e. After a short +10 min. wait, remove compressor hose coupler, allow to balance to atmosphere, remove-unlatch pot lid, and reach in for a frothy casting (if you had any bubbles). I usually do, because...
[I am casting make-up/mica colored resin in a shallow tupperware that has a chunk of highly contoured maple burl cap, so..voila,.. bubbles removed and ready to let cure for a day or two.]
Summary: Sounds a little difficult, but in actuality, you can put it all together with the help of a couple of wrenches, a little time, plumbing tape (and $75
). Thanks for your reading interest on this verbose topic/thread.
