Dow Corning 795 caulking "keeps on ticking"

[Joe11688]

In 2008 I bought a used Gray Marine Mfg. forward hatch off Rudy to use as parts for the broken hatch on my 86 O'Day 222 and while I was at his store I asked him what kind of caulking is used for plastic hatches and he sold me a large tube of Dow Corning 795. The DC 795 caulking has the same adhesive qualities as polysufide caulking without the adverse effects to plastic hardware. Whereas the ingredients in silicone caulking is kinder to plastics, silicone really doesn't stick all that well. It acts more like a gasket than a true sealant. According to Rudy, most of the boat manufacturers use DC 795 for sealing plastic hatches, deck plates, and sky lights.
This morning I went down the cellar and freed the spout of that same tube of DC 795 that was still in my caulking gun, and much to my surprise, the stuff in the tube squeezed right out as well as the day I bought it. I've noticed that the 3-M caulkings have a long life span as well. Just keep them in a cool place down the cellar and they'll last a long time.
Ahoy!
Joe

 

[bria46]

I use Blue 3M Masking tape around my item; Windows, Ports, Covers, Etc. Then I apply a thick coat of 795 letting it flow out around the installed items. Let stand for 24 hours or until the surface is dry. Use an Exacto knife around the installed item. Then carefully remove the masking tape. The remaining 795 is easily cleaned up with paint thinner.

 

[Joe11688]

I use Blue 3M Masking tape around my item; Windows, Ports, Covers, Etc. Then I apply a thick coat of 795 letting it flow out around the installed items. Let stand for 24 hours or until the surface is dry. Use an Exacto knife around the installed item. Then carefully remove the masking tape. The remaining 795 is easily cleaned up with paint thinner.

There's a girl in Columbus Oh who used a new type of 3-M adhesive caulking tape to secure the two long port lights to her 1987 O'Day 222 and she got some perfect results with it. She didn't even need to screw them to the cabin.
I have to admit that any kind of caulking is messy to work with. I've been using masking tape when I seal hardware to the surfaces of my boat. Don Casey comes out with some nice tips in his books.