Purchasing a vacuum chamber in the UK

Hi all,

Firstly my apologies if this is in the wrong place or if it's a stupid question, I've done a search of the forum and couldn't yield any results.

Does anyone know of a good supplier of vacuum chambers and pumps in the UK? I've found a few via simple Google searches but I wanted to ask here in case people had recommendations based on experience.

For some background information, I'm doing some silicone moulding and the silicone has to be completely clear of bubbles. I've tried vibrating the molds with various tools and contraptions I've made but it seems nigh on impossible to have it 100% bubble free. My limited research has lead me to the conclusion that a pressure chamber would effectively degas the mix and allow for completely smooth silicone.

If there is another route or option that I've missed then please let me know as I am new to this.

Cheers!

AJ

vaccuum chamber for degassing - Google Search


hope that helps

I've been doing the same sort research my self. It seems, to get the best results, you need both a pressure chamber, and a vacuum chamber. After mixing your resin, you want to put it in the vacuum chamber to remove air that was introduced during the mixing process. Then, after pouring into the mold, you want to place the mold into the pressure chamber while the resin cures. The pressure will shrink any remaining bubbles to a smaller size. This process can also be used when making your silicone molds.

I don't see any reason you cant use the same "chamber" for both pressure (attaching an air compressor) and vacuum (attaching a vacuum pump). but as I said, I'm still researching. I'm anxious to hear what the pros have to say! opcorn

chefhawk said:

hope that helps

Click to expand...

Yep, those are the results I've already found. I just wanted to know if people had personal experience or could recommend a supplier first hand.

jbootes - yep, that's exactly what I've found out. Hope someone who knows their stuff can give us some tips

From my experience a vacuum chamber is more versatile than a pressure pot.

We degass our rubber in it and pour our mould.

Once cured we place the mould back inside the chamber, quickly pour our resin and pull a vacuum. This extracts all the air from the cavities which the resin then fills perfectly.
Mould design is paramount as you have to allow for the amount of resin that initially leaves the mould before returning to fill the void.

The rubber you describe is virtually impossible to use without de-gassing.

The other thing to remember is that if you’re going to cast resin in the future is to buy one with a long pot life of 7+ minutes, otherwise you won’t have enough time to mix, pour and de-gass before it starts to gell.

Rubbers are not a problem as the gell time is usually hours.

If degassing a product always download the data sheet and see what the manufacturer recommends. You can actually remove some of the catalyst from certain rubbers by over vacuuming.

The difference between a vac chamber and a pressure pot is that the vac chamber will have an acrylic lid so you can see what's going on, and which just sits on top of the chamber. The pressure pot has a cast metal lid with heavy clamps to stop it blowing off. The two systems aren't really interchangeable.
You can convert a pressure pot into a vacuum chamber by adding a rubber seal and acrylic lid (drill the lid not the pot) but I wouldn’t recommend trying it the other way round for your personal safety. :cry

Hope this helps.

Have you checked Amazon? I have seen some smaller chambers/dessicators that I am considering buying.

Sent from my Etch-A-Sketch

I forgot to mention earlier that our unit was purchased from;
Island Scientific - High Vacuum Equipment and Vacuum Degassing Systems

Another more economic option is;
10 ltr Degassing / Vacuum Chamber | eBay

Ultimately, the size of the component will determine the size of chamber you require.

This is all fantastic information, thank you so much for taking the time to help.

Will let you know how I get on and hopefully post some results!

Thanks again!

AJ

contact my mate David at ADT creations, he makes the best vacuum chambers with pumps in the uk

sorry meant, ATD.

heres the site

Welcome to ATD Creations | SFX Make-up & Vacuum Degassing Equipment

Is there any more suggestions as to where to buy degassing chambers? Having spent a while looking now it appears that Sweden or at least Google doesn't think anyone in Sweden sells them, so I'll have to broaden my horizons and buy one from the UK and pay the hefty postage fee or make one myself which I'm not too enthusiastic about doing in case I **** it up. Any suggestions would be greatly appreciated.