Degassing resin in mold?

[bdbrooker]

I guess my mold is a little too complex, I'm getting bubbles on the more detailed areas. I have a vacuum. Ever heard of degassing the resin while it's in the mold to assure a bubbles casting? Is this an option?

Thanks!

[Fleafa]

Many of us do this and don't degas prior to pouring.

[mangozac]

The standard procedure is:
1. Mix resin and pour into mould
2. Vacuum resin while in the mould
3. Apply pressure until resin has cured

You need to ensure that the top of your mould has a reservoir for the resin to expand into during the vacuuming process, otherwise it will overflow, make a mess and won't leave enough resin for the part.

[bdbrooker]

"Applying pressure" in the vacuum? It that just leaving the vacuum on?

[mangozac]

No, if you do that you won't be able to pressurise the system!

I'll update my description to:
1. Mix resin and pour into mould
2. Vacuum resin while in the mould
3. Turn off vacuum pump
4. Apply pressure until resin has cured

Vacuuming the resin in the moulds removes large air pockets. Applying pressure afterwards crushes any small bubbles left.

[bdbrooker]

Sorry if I seem naive, but what's the method to apply pressure?

[mangozac]

Using a compressor and pressure chamber.

Please have a read of the threads here: , specifically .

[bdbrooker]

So I notice your set up is a vacuum and compressor. I have a vac, what would be the most affordable type of compressor and pressure pot? And specific brands you know of and trust?

[mangozac]

We recommend the CA Technologies pots as a high quality solution, but they are not the cheapest. I'm not in the USA so I can't give you any further recommendations.

Any compressor with a tank of at least 20L will do the job.