On Mon, 28 Feb 2005 17:56:32 -0600, "Reynaud" wrote:


wrote in message
roups.com...
I am repairing a fibreglass hull that has quite a few hairline cracks
and deep gouges over the hull. I sanded the hull using 180 grit wet &
dry and cleaned out the gouges using a small grinder. The hull has been
left to thoroughly dry for a few weeks after a good cleaning, and then
wiped over with acetone. I have applied some epoxy resin over a small

All acetones are not created equal. Many sold to the consumer have numerous
impurities that cause problems. I use a solvent wash (Interlux 202 ) with good
results. Other manufacturers have similar products. I pay the extra money
because of problems with what is sold by the mass market stores.

Also 180 grit is a little fine for a pure epoxy coat. I would use 120 grit. 180
to 220 grits are for finish primers and color coats. Check the manufacturers
recommendations for the particular product that you are using.

Hairline crack filling is not straight epoxy's strong point, it is usually much
to viscous for that. Epoxy primers are what you use for hairline cracks, then
use an appropriate filler for the dings and imperfections that primer can't
cover.

If there are numerous problems then start with a high build primer.

Note: Any proper surface prep most often involves multiple coats of primer and
filler with sanding in between until the surface is ready for the finish primer
and color coats.

JJ


ares to test, the idea was for the resin to weep into the hairline
cracks and gouges to seal them before applying any required filler. I
used a roller to apply the resin to the hull and it looked good for a
couple of minutes, then it all went wrong. The resin formed hundreds of
little globules/islands and no amount of brushing or using a roller
would give me a smooth even coat.
What has happened???

Regards Bruce


##** Hello Bruce, I've done an fair amount of Epoxy repair and the problem
you describe sounds like gassing which happens when some type chemical
evaporates through the epoxy layer. Also any kind of silicone contaminate
will cause similar problems. I usually wipe down any surface with white
vinegar and then wash with soap and water before applying resin.Hope this
may help.

Rey


James Johnson
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