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Hi there,

Can anyone direct me to a cheap vacuum pump as I have had difficulty finding one.

It would be used for resin casting.

UK sites/shops only please unless they're really cheap abroad.

Thanks

Well they arnt cheap for a quality one, you're better off building your own. And its called an Evacuator, when you use a pump to pull the air bubbles out of a resin mix.

 MikeFox wrote:
Well they arnt cheap for a quality one, you're better off building your own. And its called an Evacuator, when you use a pump to pull the air bubbles out of a resin mix.

Hmm I have never read "evacuator" when I did some research, they tend to call them vacuum pump/compressor. Although I did a search and only 3 came up on ebay and 1 on amazon but they're not what I'm after.

Thanks though.

I work in the Fx industry and I promise you thats the name we use for a vacuum chamber. A pressure pot is a vacuum chamber that applies pressure(forcing the air bubbles to become so small you cant see them) and an evacuator is a chamber that pulls pressure(pulls the air out of the mix). All you need to do is use a vacuum and an airtight jar to make one. Look at some fx molding sites and forums for plans to make simple ones. Ours at work is literally just a vacuum motor that pulls air out of a clear acrylic dome.

Whats the pot life on your resin? IF you chill the components before mixing them you can increase the potlife which will help you not to have to rush when using the evacuator.

 MikeFox wrote:
I work in the Fx industry and I promise you thats the name we use for a vacuum chamber. A pressure pot is a vacuum chamber that applies pressure(forcing the air bubbles to become so small you cant see them) and an evacuator is a chamber that pulls pressure(pulls the air out of the mix). All you need to do is use a vacuum and an airtight jar to make one. Look at some fx molding sites and forums for plans to make simple ones. Ours at work is literally just a vacuum motor that pulls air out of a clear acrylic dome.

Whats the pot life on your resin? IF you chill the components before mixing them you can increase the potlife which will help you not to have to rush when using the evacuator.

Does chilling the mix parts increase viscosity? Pot life vs flow into tight spaces is my concern there... And hmmm... I'm not the OP, but I have a vac um down in the basement that isn't really working right for picking stuff up off the floor, but it might just create enough suction for this.

 MikeFox wrote:
I work in the Fx industry and I promise you thats the name we use for a vacuum chamber.

I worked for a jeweller and it was referred to as a vacuum table assuming we're talking about the same thing. Place flask with plaster(investment) on table, cover with dome, suck out the air.

Chilling both parts of the resin will decrease its viscosity making it flow easier and set slower, you are basically slowing down the chemical reaction. Add different industries call it different things, just saying that a vacuum chamber can mean different things. Andif hes looking for guides to build one to make sure hes getting the right information.

 MikeFox wrote:
I work in the Fx industry and I promise you thats the name we use for a vacuum chamber. A pressure pot is a vacuum chamber that applies pressure(forcing the air bubbles to become so small you cant see them) and an evacuator is a chamber that pulls pressure(pulls the air out of the mix). All you need to do is use a vacuum and an airtight jar to make one. Look at some fx molding sites and forums for plans to make simple ones. Ours at work is literally just a vacuum motor that pulls air out of a clear acrylic dome.

Whats the pot life on your resin? IF you chill the components before mixing them you can increase the potlife which will help you not to have to rush when using the evacuator.

I am in the process of making the chamber, however I just need a apparatus to extract the air which seems to be a problem finding one cheap enough (under £80) in England. I did quite a bit of reading but they're mostly US/Aus sites who recommend the various stores but we don't have them here

As for the resin I haven't acquired that yet until I get the chamber and extractor. This will mainly be used to make bases for my armies.

Thanks for the help.

On the subject of resin casting, what resin (as in brand) would be best recommended? And what silicone? Trying to get into resin casting, and yeah, building my degasser as we speak.

For resin, Douglas and Sturgis insta cast off white.

http://www.douglasandsturgess.com/mm5/merchant.mvc?Screen=PROD&Store_Code=DAS&Product_Code=CR-1014&Category_Code=POLYURETHANE-POLYRESINS

IT sets quickly, but not too quickly. mixes 50/50 by volume, and is easy to keep the bubbles out of.

emmagine wrote:
For resin, Douglas and Sturgis insta cast off white.

http://www.douglasandsturgess.com/mm5/merchant.mvc?Screen=PROD&Store_Code=DAS&Product_Code=CR-1014&Category_Code=POLYURETHANE-POLYRESINS

IT sets quickly, but not too quickly. mixes 50/50 by volume, and is easy to keep the bubbles out of.

Do you know what the pot life and demold time are on this stuff, emmagine?



For Silicon, I've used Oomoo 25 from Smooth-On. I have a supply and tool drop coming from Dickblick, where I picked up some Oomoo 30. The main difference between the two is pot life and demold time (the 30 is way longer on both).

For resin, I've used Smoothcast 300 from the same company. But the pot life is only like 3 minutes, so it doesn't have a lot of time to degas before curing. I've been hunting around for another option or store that sells the Smoothcast 305 or 310 - 305 has about a 7 minute pot life. The site that emmagine linked sells the 305, so I may have to order some from them.

it sets in 5-7 minutes. If mixed carefully, I have never had the need to degass.There is an info sheet in the bottom right corner of the page for all their products. This resin is very low viscosity, which is why I like it.

I looked over the info sheet, but I can't find the specs for pot life, demold time, and viscosity. It sounds like it works out to about the same as Smoothcast 305, so that's great. Especially considering the much higher volume you get for the money. This has the specs of the smoothcast: http://www.smooth-on.com/Urethane-Plastic-a/c5_1120_1209/index.html

Back on the subject of a vacuum pump (or whatever you want to call it...), trying to find a good but fairly inexpensive pump myself. I did find this one on ebay:

http://www.ebay.com/itm/3-CFM-Single-Stage-Rotary-Vane-Vacuum-Pump-R410a-R134-HVAC-A-C-Air-Refrigerant-/380633292188?pt=LH_DefaultDomain_0&hash=item589f831d9c

Would this work?

I'd just try an old vacuum from the thrift store