RG asks:

I need to add 3 coats of cloth to re-enforce the hull of my boat. I seem
to
remember that one should NOT wait 24 hours between each application, or
one
would have to sand/grind the surface to wax??? Is that correct, and what
is
the best time to lay the second and third coats?

The area is about 4 x 4 inside of the hull, so I can pretty well time the
applications as I please. All help appreciated. Thanks RichG

"Brian Nystrom" writes:

You have options.

1) You can lay all thee at once, if you feel comfortable doing so. One
shot, all done. You may be less likely to end up with excess resin in
the laminate this way.

2) You can allow the epoxy to reach a "green" cure between layers. This
makes subsequent layers easier to position.

3) You can allow 24 hours and still be able to lay consecutive layers
without sanding (assuming that you use a non-blushing epoxy), as the
epoxy will take longer than that for a full cure and will still
chemically bond between layers. While it varies from one product to
another and with the temperature during curing, some will still
chemically bond within 72 hours.

4) You can wait for a full cure, then sand between coats. This produces
a mechanical bond only. 1, 2 or 3 three if preferable.

All of the above get the job done.

Personally, I purposefully wait at least 48 hours between layers for the
following reasons:

1) Can feather the edges of the glass to have a smooth transition between
layers.

2) Level out any uneven surfaces and any resin blobs that maybe you missed
during lamination.

I don't get hung up about getting a chemical bond. The mechanical bond is
quite good. Epoxy is very forgiving stuff.

I use a lot of 16 grit discs and also be sure to wear a mask.

The laminate is still not fully cured at this stage and the dust can be very
nasty.

HTH

BTW, if all you want to do is get rid of the blush, a ScotchBrite pad and
some water will do the trick.

Good luck.


--
Lew

S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: http://home.earthlink.net/~lewhodgett for Pictures