HighStateToke
Member
Sand.
Thank you sir!
Thank you sir!
There is a technique used in Vacuum Casting (for lost-wax casting, for making jewelry) where they use a vacuum pump to pull a vacuum on a much larger chamber.
Right when the hot molten metal is poured into the mold, a switch is thrown, and the volume around the mold gets exposed to the bigger vacuum. It sucks the hot metal into the mold, which is slightly porous.
I wonder if you can use something similar to help with the extraction process. But it would be a pulsed process, not continuous.
I suggest Auction BDI as a possible source for surplus vacuum pumps. They are a big surplus re-seller in Silicon Valley. They sell almost everything.
http://www.auctionbdi.com/
I got my one vacuum pump from a surplus electronics place in San Diego.
While I realize Best Value Vac only provides the 3/4” lid (I mistakingly thought they were uniformly 1”)
.. As long as you don't drop that lid, crack it, chip..or fracture in any way....
The integrity of the lid should hold up...
@GW.. Have you had a chance to inspect these chambers first hand? I will never doubt your advice, as it is of more value than a precious metal in our context...
But I've had the chance to use one, and I must say, they are well-made...
Deflection is not visible to the naked eye..
I have two friends running the 3 gal and one running their 5 gal about once a week, and they are both pleased with the results.
Perhaps the proverbial...
” better safe than sorry ” should apply in this application.
Particularly if you plan on using the chamber a lot.
I will contact the friend with the Best Value 5 gal, he works in the industry and uses his maybe up to 3 times a week, I'll even visit him and inspect and inquire about the integrity of the lid.
I will report back on this thread after the evaluation.
Trying to find a better (but still economical) vacuum chamber because all the ones on ebay and amazon have only 1/2" to 3/4" lids which Greywolf advises against.They also all have rivets in the handles which either don't allow full vac due to leaks,or hold vac poorly because of leaks.I think the rivet leak issue can be solved with a little JB weld,but unsure of how long the lids will last before deflecting and breaking.He also says they come with crap gauges,but I could replace the gauge with a quality analog gauge if need be.
Anyone using one of the vac chambers I posted above?
I wanted to get a steel/aluminum one so I can just set it on my griddle/hot plate for heat vac purging.
But I suppose I could go with one of those belart food saver/dessicators...but how would I add heat?
Interested to hear from those using a ProVac or Best Value Vac vacuum chamber.
2 Gallon Aluminum Vacuum Chamber & 3 CFM 50 micron Single Stage Vacuum Pump Kit from best value vacs for $250
3 gallon ProVac vacuum chamber
My question is what can I do to stop my chamber from going past 29.5hg? I really don't want to play with the valve for an hour back an forth trying to keep it in range.
The ball valve.
I don't see what's so hard about it...turn the vacuum pump on,once your chamber reaches a vacuum of -29.5" HG just shut the ball valve the pump is connected to and turn off the pump.
What is it you're trying to make (shatter,wax)?
I have read to do an initial vacuum of -15"HG and then devac,etc.
But I'll let GW and the others answer.
Yes all of this u just said i allready know man, that dosnt answer the question about moister??Well your cac chamber should have two ball valves on it.One is connected by tubing to the vacuum pump and the other not connected to anything (but maybe a coffee filter over it).
Close the ball valve that isn't connected to it.Open the ball valve that is connected to the pump via tubing.Pull your vac down to -29.5" HG,then close the ball valve that's connected to the pump via tubing and turn off your pump.
When you go to devac,DON'T open the ball valve that's connected to the pump,the reason being that there is a vacuum pulled in the vac chamber and if you ope that ball valve you could end up pulling the pumps oil into the chamber...so instead,open the ball valve that isn't connected to the pump to devac the chamber.
When you're ready to pull another vac,shut the unconnected ball valve,open the ball valve that's connected to the pumps tubing.