has it been recently professionally tested??? most professional equipment used in industry be it pressurised or under vacuum has to go under regular testing during its life (as well as destructive testing of new designs by the manufacturer) to ensure it remains suitable to maintain that pressure.

You should really take it to be tested to make sure you arent going to destroy your workshop.

Its a fallacy that items under vacuum always implode safely if they fail. You can still easily get fataly dangerous shrapnel in some cases.

Hi Fred,

Fascinating stuff! - You're right that smaller vessels are available and if you can fit what you need to make into them then it can be more within reach (although maybe not so many people are as technically minded as yourself). When I think autoclave I tend to think of larger vessels (we have a 4m x 2m x 2m vessel, it weighs 7 tonnes!) but you're quite right that much smaller vessels are more widely available in the form of pressure pots or scientific autoclaves (often used for sterilizing).

We did have another customer who had built his own autoclave but I won't post any details of that in case I get sued.... It was not so legitimate as yours!

Still, anyone reading this article should keep in mind that the fastest growing area of prepreg is out-of-autoclave and I defy anyone to be able to tell the difference (we certainly couldn't).

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Matt, like someone else mentioned above, when I click the link to download the guide I just get forwarded to the forum home page, there is no download which starts?

arren

Hi Warren
I would never use the chamber at full pressure maybe 70 psi or so. The 120psi rating gives it a good margin. I have put a new seal in it.
By the way it, is a pressure vessel not a vacuum vessel therefore it could not implode, it could only explode. I have heard of many people using these tanks for prepreg and plastic casting where you don't want any air bubbles showing in the clear castings.
I am not encouraging anyone to build one, but only showing what is possible for the right person.
Fred

   

Hi Matt
I have heard that and I am very eager to try prepreg in and out of the autoclave. Is it possible to ship your special prepreg to Canada?
Fred

Hi Fred, 

Thanks for putting this together - it what I've been looking for for a while.

If you do put togther a sampler / starter kit, would it be possible to halve the min quanitites to 0.5 x 1.25m (or equivalent area) of the surface and backing ply materials.  With a small oven and a lack of suitable moulds I think getting through even the min quanties would be a struggle for me (and take up less freezer space).

Brilliant guide, especially now there are photos, keep up the good work!

Andy

Matt and the Easycomposites staff,

  Great write-up on the prepreg! very detailed as usual, and straight to the point. I only wish It didn't cost so much for your items to be shipped to the states! regardless of that, I'll look forward to trying my hand at prepreg in the near future. Thanks for the knowledge!

 Fred,

I'm genuinly jealous of the pressure vessel setup you built!  I'd had a similar vision in my head, but you beat me to it. well done sir.

David

Hi David,

You're welcome!

Shipping prepreg to the 'States should be pretty cheap actually, it's not 'dangerous goods' and so there is no surcharge of any kind. I expect a starter pack could be with 'next-day' for around £20-30 delivery.

--Matt

Matt Statham
Easy Composites / Carbon Mods - Technical Sales

Matt,

  I'd read in the previous posts that it wasn't considered "dangerous goods"... didn't even register with me!  looks like I've got to go find an old freezer and pressure vessel now... thanks again for everything guys!

David