First infusion and how to heat cure the part....

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#1

Hello all,

I finally did my first infusion yesterday, it was just a test sample and I got 3 layers of 2x2 CF twill mounted on a mirror, I used the mirror because it was an old heated one I had kicking around, I figured the heat would be beneficial to the process.

I waxed the surface a few times and layed out the various layers, bagging material and pipes etc. I pulled 27Hg and let her go, acted a bit too slow on the rapidly emptying resin pot and saw a load of air bubbles enter the part, it didn’t seem to matter however and nearly 24 hrs later it was Christmas morning all over again as I ripped everything off to reveal a near perfect sample :eek:

I was pleasantly surprised to see how well it had gone! The only faults I could find were that some of the epoxy had stuck to the mirror for some reason, it pulled it from the weave leaving some bad patches, I’m thinking this was either down to not waxing enough or the heat element coming from below? It doesn’t get very warm, maybe about 30’c and I waxed (a bit hurriedly) about four times. There were some very minor pin holes scattered here and there, but barely noticeable to the naked eye.
No print through or dry spots though, and look at that shine!

I was thinking of sticking a heated blanket to the underside of a bonnet mould I want to use, what do you think?

#2

Looks good. Glad your first infusion attempt worked OK.
What resin was used? Wait a week before deciding if there’s print through. :wink:

#3

I used Sicomin 8100, it’s very clear with no visible tint when layed out or in the lines, just a slight yellow when in the pot.

This post cure heat is raising some questions though…

The people that sold me it have an in-house expert who has been exceptionally helpful and it seems I have to provide some 40 - 60’c of heat for 12 - 24 hrs after it has cured otherwise I could run into problems later on when the component (a hood for instance) gets hot in the sun or from the engine as it can go into a ‘Glassy transition stage’ (a bit rubbery) so I’m wondering if I need to build some kind of oven…

Your right about the print-through, the sun shone for a while yesterday and I did some hi-tec post-cure (on the dashboard of my workvan!) and I can see it forming now.

#4

well since its epoxy it wont shrink much… after post curing is done, if you re feeling adventurous, you can sand it down very slightly (with either a sanding block or a palm sander)using very small grit sandpaper, and give it a coat of clear (though if you have pinholes they will stick out more)