To Sand or not to Sand?

N

nite fisherman

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I am in the process of replacing the transom in my Starcraft FM160. I already have my new transom cut out, holes drilled and first coat of epoxy #635 from US Composites went on today. Can someone tell me if I need to sand before I apply the second coat of epoxy? If so, what grit would be best? Thanks for all the help. I would not be as far along as I am now if not for the help of this forum. I really appreciate all the help.
Thanks
 
jigngrub

jigngrub

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Re: To Sand or not to Sand?

Sanding will be the best bet, I like to use 120 grit to sand epoxy. 150 grit tends to clog too easy.

Wipe the dust off with a damp cloth and let the piece dry before applying another coat.

If you'll put the transom wood out in the sun after applying the epoxy it'll set and cure much faster... the hotter it is the better.
 
ondarvr

ondarvr

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Re: To Sand or not to Sand?

It's even better to not let it cure, just harden slightly, then give it another coat. Less work and a better bond.
 
Bob_VT

Bob_VT

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Re: To Sand or not to Sand?

ondarvr said:
It's even better to not let it cure, just harden slightly, then give it another coat. Less work and a better bond.
Click to expand...

Agree, and this will enhance the "chemical bond" between the layers too. The reason I jumped in was because the chemical bond question was recently asked and this is a good example.

For future info, you can lay up epoxy and fiberglass cloth thicker (as compared to polyester resin and fiberglass) during each application session.
 
N

nite fisherman

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Re: To Sand or not to Sand?

Thanks for the replies. I think it is almost too dry to go with the second coat now. Think I will just wait and finish it tomorrow. I applied the first coat today about 3 and it is just past 8:30 now. I will definitely remember about the second coat next time for sure.
 
jigngrub

jigngrub

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Re: To Sand or not to Sand?

ondarvr said:
It's even better to not let it cure, just harden slightly, then give it another coat. Less work and a better bond.
Click to expand...

Yeah, I tried that once and got a gobbed up mess that pulled a lot of bristles out of my brush and stuck them to my plywood. Ended up letting it cure, then sanding that junk off.
 
ondarvr

ondarvr

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Re: To Sand or not to Sand?

jigngrub said:
Yeah, I tried that once and got a gobbed up mess that pulled a lot of bristles out of my brush and stuck them to my plywood. Ended up letting it cure, then sanding that junk off.
Click to expand...

Your timing must have been off, this is the normal and preferred method.
 
Yacht Dr.

Yacht Dr.

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Re: To Sand or not to Sand?

80 grit is what I use for epoxy to epoxy.

I agree with the above about chemical bonding .. I just coat and recoat after recoat until im done coating ( no sanding between coats ). If you need something faster try a roller instead of a brush. ( dont try this in the hot sun .. patience is key )

YD.
 
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