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Bertram31.com General Bulletin Board
Re: Capt patrick or other knowledge fglass people
Posted By: Capt Patrick McCrary In Response To: Capt patrick or other knowledge fglass people (Capt Jon)
Date: Tuesday, 24 May 2005, at 9:39 p.m.
Capt Jon,
The lifting strakes on all Bertrams are molded in from the mold and integral with the rest of the hull. All one piece...
However, they are bridged over later in the lay up, making them hollow. Any crack will allow them to fill with water, or at the very least be damp in side.
Epoxy will not bond to a damp surface. You'll need to reef out all the cracks and drill a few 3/8" holes down steam of the repair area, and one forward of it. With compressed air, injected into the forward hole, you can blow out any excess water from the strake. You can also inject denatured alcohol into the lead hole, which will combine with any moisture and aid in the drying process.
Grind the repair area down, past the gel coat, to about 1/16" into the fiberglass. The repair should be ground out and feathered at least 3" - 4" beyond the cracks.
After all the above is done, check the entire area with a moisture meter to be sure it's dry. If not, you'll need to let it sit until dry...
At the point that all is dry, wipe, liberally, the area with denatured alcohol. Brush on a thin coat of un-thickened epoxy and allow it to tack up. Fill any voids, reefed out cracks, & holes with epoxy thickened with a high density filler, allow to cure for 24 - 36 hours, sand flush, and add one layer of 6 oz 0/90° fiberglass cloth, making sure that there are no air bubbles.
After that is thoroughly cured, scrub the epoxied area with soap & water to remove any amine blush, & feather in the edged of the cloth.
Do a final fairing of epoxy and high density fill, being sure to fully encase and cover any of the fg cloth. Your repair should be ready for bottom paint...
Best regards,
Patrick
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