Several Years ago, while I had the engines off my 2005 265 Express for the exhaust kit install, I replaced the aluminum transom cap with one I fabricated out of stainless. During that time I discovered an odd substance growing out from the margin where the hull layup meets the aluminum bar they lay up in the transom. This goopy substance seems to be the result of a chemical reaction where the aluminum and glass resin come into contact. Someone at Grady confirmed this. Now, readying the boat for a repower, I'd like to eliminate this reaction before I glass the transom closed once and for all, hoping that the goopy residue stops pushing its way out of cracks, and hoping to avoid any possible swelling this could cause. Has anyone here dealt with this before, and if so, did you find a solution? I thought I would treat the aluminum with an acid wash and then some sort of coating like zinc chromate, but I am hesitant to risk getting acid into the wood of the transom, particularly immediately prior to sealing this joint once and for all. Thanks for any suggestions.
Another Grady Transom Issue
- Thread starter Uncle Binky
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Hookup1
GreatGrady Captain
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I doubt it's a reaction. Probably excess resin. The aluminum erosion is from water. Do not put acid on it. Wire brush or grinder to clean out.
Sand it out clean, fill with glass cloth and epoxy resin. Re-sand and tidy up or use epoxy fairing compound. Re-install a bang cap with 3M 5200 or 4000.
You can also use West System 610 thickened epoxy in a caulk tube to fill with. Would be a great choice for your project.
That grey filler up top is garbage filler that GW uses and it is brittle. Keep it attached so it doesn't break up. All that junk came out of mine.
What is West System Six10 adhesive?
Six10 Thickened Epoxy Adhesive combines the strength, reliability, and excellent physical properties of a two-part WEST SYSTEM Epoxy with point-and-shoot convenience. The self-metering coaxial cartridge dispenses a gap-filling structural epoxy that bonds tenaciously to wood, metals, fiberglass, and concrete.
Sand it out clean, fill with glass cloth and epoxy resin. Re-sand and tidy up or use epoxy fairing compound. Re-install a bang cap with 3M 5200 or 4000.
You can also use West System 610 thickened epoxy in a caulk tube to fill with. Would be a great choice for your project.
That grey filler up top is garbage filler that GW uses and it is brittle. Keep it attached so it doesn't break up. All that junk came out of mine.
What is West System Six10 adhesive?
Six10 Thickened Epoxy Adhesive combines the strength, reliability, and excellent physical properties of a two-part WEST SYSTEM Epoxy with point-and-shoot convenience. The self-metering coaxial cartridge dispenses a gap-filling structural epoxy that bonds tenaciously to wood, metals, fiberglass, and concrete.
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I agree. Grinding out the corrosion is gonna be the bugger. Laying up a new cap will be the easy part for me.