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Re: Solution to leaking hatch.

PostPosted: Thu Jan 09, 2020 12:36 am
by erbster
That’s sikaflex, Julian. It is a marine grade silicone sealant, but it’s also an excellent adhesive and is highly uv stable. There are similar “unbranded” alternatives but they are not as good. You can buy the solvent but it’s quite expensive. Before the sikaflex has cured, white spirit is an excellent solvent (ie for cleaning up immediately after the job).

Charles Erb CC19 #86 Aurora

Re: Solution to leaking hatch.

PostPosted: Fri Jan 17, 2020 2:42 pm
by Julian Porter
I removed the window yesterday. It is made from toughened glass marked West Cape Toughened. It is not Lexan like the modern boats.
The black sealant came off easily just like a strip of rubber. In fact if you told me it was rubber I would believe you. It had little adhesion to the glass. Some algae was present at the corners between the glass and sealant indicating where the seal had broken. Is this Sikaflex?

To replace the window I need to bed it in a sealant which will bond to mineral glass and fibreglass and allow for plenty of movement. Being glass this panel will not flex like the deck. I asked a boat builder here and he said he would use plain marine silicone and put tape over the top to stop the UV. It’s certainly a lot cheaper than Sikaflex when used together with the primers. He said the adhesion to glass was very good providing it is clean. As I’m not painting anything and don’t need to worry about silicone residue it seems like a reasonable suggestion. It would be a relatively simple job to remove the window and sealant and re-bed it In the future if it breaks down. Thoughts?

Re: Solution to leaking hatch.

PostPosted: Fri Jan 17, 2020 3:17 pm
by erbster
In my experience, Sikaflex sticks to most things like s*** to a blanket. I think something unusual has happened on your boat; my hatch is definitely plastic, not glass. Your suggestion sounds reasonable.

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