Mike,

We all live and learn. The big trick is to survive the errors.

Half a millimeter is nothing to worry about. Unless the hull is vacuum
processed (highly unlikely unless it is a high buck or a one design), it
was sprayed into the mold with a chop gun. The hull thickness variation
is probably already three or more mm.

You never did indicate how large and area you were rebuilding. Now you
mention vertical elements. Thwartships (accross the boat) parts are
either frames or bulkheads - Stringers are fore-aft structures.

Were these frames original and you are replacing them?
Or were they your own addition to shore up the damaged area?

Either case....Sail the boat.

If they are original structure that you replaced. Then they are the
real structure of the boat and the glass that you just patched is only
there to keep the water out.

If they are something you added, then the hull is probably a whole lot
stronger than it came out of the box - even with 1/2 mm of laminate
missing locally.

In this case, I think it makes little difference, but if you said more
about the boat (manufacturer, version) and the actual area and possible
cause of damage. It might make a concise answer more possible.

You can use the gelcoat over a wet coat of vinylester resin. Polyester
doesn't actually stick to much, but the base of vinylester will do as
good a job of anything at making it work.

You can post pictures at:
http://www.web-a-photo.com/
http://community.webshots.com/
Both have free and suscription packages, look them over.

If I missed anything - try again. I'm here a lot.

Fair Wind and Smooth Sea
Matt Colie
Lifelong Waterman, Licensed Mariner and Pathological Sailor


Bonasa wrote:
Bryan and Matt,

Thank you both very much for taking the time to help this newbie. I already
had to grind out and redo one of the patches cuz I wasn't happy with the
layup, I'd rather not do it again.

I've complicated things (I know, by now you're slapping your forehead, don't
blame ya) by glassing in vertical stringers across the patch so I need to
look and see if I can avoid the stringers.

I think first I'm going to try the easier way and grind down from the
outside. I only need to come down about a 1/2mm at the center of the patch,
the sides recessed. If I'm not satisfied with the integrity of the repair,
then I'll suck it up, break out the grinder, and do it again.

If anyone else has any input I'd love to hear it, I'm a student here. Well,
at least I'm learning alot...

By the way if anyone knows of a free web site I'll post pictures of the
damage and repairs, maybe it will benefit others.

Thanks again,
Mike



Now I'm not sure what to do. My first impulse is to sand (scuff) the
fiberglass down past the hull and lay on gelcoat, then sand the gelcoat
flush with the hull. Would this work or am I just ruining the patch job?
I'd rather not use paint so any suggestions that would allow me to use
gelcoat (I've already got it) would be appreciated. Thank you in advance
for any help!

Mike