Surface prep. Epoxy over painted surface.

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txjm
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Surface prep. Epoxy over painted surface.

Post by txjm »

I am modifying my GF16. I am cutting splicing in new plywood. The hull is meranti, the epoxy is marinepoxy and i believe the paint is petit ezpoxy. I am attempting to sand off the paint and as much of the fairing compound and primer as possible. I am having to leave splotches of paint and fairing compound so I am not getting into the glass. Is this acceptable? I am using 40g and I am scuffing it very well. Boy the paint is tough.
I am also cleaning up an area of the bottom that has 3 coats of epoxy/graphite mix. Do I need to go all the way to wood or is it ok to grind through a few layers and bond to that?
Chip

fallguy1000
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Re: Surface prep. Epoxy over painted surface.

Post by fallguy1000 »

You want to the epoxy layer for further on bonding work.

I made the mistake of bonding a lite use cleat over paint and it broke off when I bumped it.
My boat build is here -------->

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OneWayTraffic
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Re: Surface prep. Epoxy over painted surface.

Post by OneWayTraffic »

Agreed. Right to the epoxy. That means through any fairing compound as well for max strength. I find that a strip disc on a grinder is great for this. Take off more than you need, you will need to paint the whole thing after anyway.

narfi
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Re: Surface prep. Epoxy over painted surface.

Post by narfi »

Here is how I just did it,
I ground off enough paint on the beam but should have taken a bit more off the case, you can see the edges of the tape overlap the paint some..... So should have sanded back a bit more.
20210830_175026.jpg
20210904_165223.jpg

Jeff
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Re: Surface prep. Epoxy over painted surface.

Post by Jeff »

Nice work Narfi!! I love the term "hanger rash"!!! Jeff

txjm
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Re: Surface prep. Epoxy over painted surface.

Post by txjm »

Thanks. A little more grinding.

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