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Problems - Carbon Fiber Skinning (Second Layer of resin epoxi)

http://www.talkcomposites.com/Topic36738.aspx

By Dezer - 5/19/2020 11:34:59 AM

I skinned one part and am having problems with the second layer of epoxy resin.

The steps were as follows:

1 - Sanding of the piece with grain 120

2 - Epoxy resin base

3 - After 2h30 I put the carbon fiber and left it overnight

4 - First layer of epoxy resin

5 - After curing, I sanded the first layer to remove imperfections

6 - Second layer of epoxy resin

7 - After curing I went to sand again with grain 120

And then the problem started to appear, the second layer started to peel to the level of being able to remove the entire second layer with a spatula.

Because the night was cold, it took more than a day and a half for me to sand.

Where can I go wrong?
By MarkMK - 5/19/2020 9:27:04 PM

If it was left to cure in fairly cold conditions, this might be the cause of your issue. Epoxy can become very brittle and less likely to bond well in such conditions

If you can, leave it to cure somewhere indoors, if you've been working in a garage or similar.

After the initial coating has cured, it might also be worth applying two or three additional coats after each one has reached a firm tacky stage, to save on having to sand each time. The overall bond between the different coats should be much better too