Hey you resin boys...

Chris Binnett · Post by **Chris Binnett** » Tue Jul 10, 2007 9:55 pm

I'm casting a tire with some intricate tread...I have a seal a meal canister set that would allow me to de-gas some resin (vacuum chamber). Since a pressure pot is out of the question, is degassing enough?

Powder mold
pour degassed resin
wait
perfect piece...

or am I dreamin'

Phd dream-on

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Wed Jul 11, 2007 12:23 am

It will help.
As long as you have a good seal, a shop vac can generate enough vacuum to get a bit of a boil.

Paulbo · Post by **Paulbo** » Wed Jul 11, 2007 12:52 pm

I've found that vibrating the mold can help drive out some gas bubbles. I used a reciprocating sander.

I really like the seal a meal idea, though - got one of those guys with the separate canister-on-a-hose arrangements. Thanks for the idea.

SgtFang · Post by **SgtFang** » Wed Jul 11, 2007 1:36 pm

If your resin has a working time of 5 min or so, powdering your mold should be plenty.

Just be careful not to trap any new air when putting your mold together and you should be fine!

-Sarge

thunderbearr · Post by **thunderbearr** » Wed Jul 11, 2007 4:53 pm

It occurs to me you might be able to place the mold in the cannister, pour your resin and then de-gas. Sort of a reverse-pressure pot.

Might work.

Post by **TER-OR** » Wed Jul 11, 2007 9:23 pm

If you're going to vacuum mold, make sure you degas your rubber. You don't want bubbles in the mold which also expand under vacuum.

Post this in the construction forum. In fact, I'll move it there.

schweinhund227 · Post by **schweinhund227** » Wed Jul 11, 2007 11:15 pm

We all dream of Vacuum pumps and pressure pots and all..

I was pricing Vacuum pumps and they were all very expensive for the range we need to get at .. Neg 11 mercury... something.. and I was hitting 400+ USD too steep for my Blood till I watch the ALUMILITE BOYS DVD

they Had an industrial Vacuum chamber for them selfs but they also carry an attachment for a normal compressor...

the size of a cigarette pack... it plugs in your compressor which makes it turn.. and the output is actually a vacuum pump.. you plug the other end on vacuum chamber... which I found NEAT and will try to get .. through Alumilite.com.... for sure..

so all you really need is a Compressor... and a pressure pot .. which is an expensive endeavor for budgeted Hobbyist but WELL WORTH IT.. in the End if you cast a lot for yourself or others.... as a Hobby !

if you don't degas.. and pressure cast.. you parts risk of getting out with little tinny pebbles... which can be sanded down... but otherwise... a pain in the neck... Tapping on the bottom or vibrating the RTV Works great... Mixing slowly and not having too much Catalyst.. help the RTV Cure slowly and not forming too much gas which is a part of the curing process... !

powdering is one option as well but I use Mold release spray... works for me....

Best of luck with your Casting project...... let us know how you made out !

OUT !

DLMatthys · Post by **DLMatthys** » Fri Jul 13, 2007 12:37 pm

schweinhund227 wrote:We all dream of Vacuum pumps and pressure pots and all..

The reality is that after I plunked $700 down on a 3cfm vac pump, bell jar, 2 paint pots, air compressor and pnuematic accessories I made that money back in a month.

Umi_Ryuzuki · Post by **Umi_Ryuzuki** » Fri Jul 13, 2007 1:54 pm

I traded the $200 I put down on the construction of kerosene jet turbine for the vacuum pump I use.

Chris Binnett · Post by **Chris Binnett** » Mon Jul 16, 2007 1:17 am

Well the Seal-a-meal couldn't pull enough Hg...no magic "foam up" for me

However the project plugs along, my mold worked out well, and the slow set epoxy I had layin' around is watery enough to make nice clean castings. I have 6 wheels done, but need "a few" more

PhD The wheels on the bus...

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Hey you resin boys...

Hey you resin boys...

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