DeTomaso Mailing List: January 98, Message #6
     



From: 	JDeRyke <JDeRyke@aol.com>

Subject: Re:  Re: Carbon Fibre

Date: 	Thu, 1 Jan 1998 17:54:34 +0000



An autoclave is nothing but a vacuum oven, and does two things. First, because

the cure is done @ up to 350psi (usually CO2 or some other cheap dry gas), any

bubbles in the resin are compressed to a much smaller size so you don't get

very big voids. Second, by curing at 150-250 degrees, you have a choice of

lots more curing agents & resins, some of which won't cure at all @ room temp.

You can approximate an autoclave by sealing some kind of poly sheet around the

edge of your piece with a gum like windshield sealant, seal a tube to the poly

and hook a small vacuum pump on. It works better if a sheet of poly is on the

piece,then a piece of cheesecloth, then the outside poly. The cheesecloth

gives channels to the air you're trying to suck out. Then either put the whole

thing in your wife's oven & take her out to supper, or let it room-temp cure

as usual. Aerospace parts are routinely done or repaired this way. J DeRyke