Sealing with Silicone?

[Ok J]

As I have completed the top of my boat and plan to assemble as much as possible before mating it with the hull, (all fiberglass) I need to know what the differences are in the different types of sealants I should use for deck hardware etc. Are there different grades of silicone? And as I reattach the windshield assembly (aluminum frame) what type of gasket material should I use?

Thanks to all that answer.

-Ok J

[Sander Rave]

Don't use Silicone for your boat, it won't last.

[Ok J]

My boat had silicone around the rub rail (top and bottom) from the factory when it was built 26 years ago and was in good shape when I disassembled it, there must be good materials out there! I work in the autobody industry and we stay away from silicone sealants for contamination reasons, I have been told that there are varying grades of silicone, and there must be if the original stuff on my old boat lasted 26 years. Any help out there?
Cheers...Ok J

[Ok J]

Is the only difference between regular silicone and marine grade the anti mildew additive? UV protection? Hmmm.

[cyclops]

My only chemical caution is that the vinegar smell of it is Acetic acid. Be very selective on which bare metals you put it on.

[PowerTech]

3M 5200 nuff said

[cyclops]

How easy is 3M to remove after a full cure?

[PowerTech]

easy to remove and 5200 do not belong in the same sentance

[cyclops]

Do a search on this site of-- 3M 5200 remove-- keep in mind how large of a area you may have to pull up again.

[PowerTech]

I did do the search.And it sounds like that debond 2000 is some mean stuff I am going to check that out.I use clear black or white regular old silicone like life caluk or any cheap thing I can grab likr GE or whatever on crap that doesent mater and will need removal like gauges and other B.S..But below the water line it is 52 all the way and the crap it the red tube is where it's at.

[Ok J]

After all the work rebuilding the transom, stringers, floor etc. I just don't want to have any issues with sealing, especially thru the transom, this has been alot of work, the boat will never see the salt chuck although this is likely not an issue. If 3m 5200 is the stuff to use...cool, they have alot of great materials.
-Thx...Ok J

[yokebutt]

I prefer sikaflex, it's got a thicker consistency and doesn't sag as much.

Yokebutt.

[FAST FRED]

"I just don't want to have any issues with sealing, especially thru the transom, '

Any penitrations thru the hull or transom should be sealed with an epoxy.

EG cut the hole and paint the raw edges with West , or your favorite brand of 2 part.

Then its your choice of what to bed whatever goes thru the hole to the boat.

3M makes a 101 bedding compound that is removable.

For a properly prepared hull I prefer good pod fashoned Dolphinite, seals great yet it will easily come apart when needed. Good for thru hulls that need to be inspected and other things that require replacement.

5200 is almost forever , think of it as a great GLUE , not for replacable items.

FAST FRED

[Corpus Skipper]

3M 4000 is great stuff, and stays pliable. Mildew resistant and UV stable. I still go 5200 all the way below the waterline. A thin sharp knife will cut the stuff for separating parts.

[Ok J]

Thanks boys, your help is appreciated, the way things are going my boat will float to the next millenium!
Cheers.
Ok J

[marshmat]

amazing the variety of stuff out there....

on my own boat I've got a few different sealants on different things... general-purpose house exterior window/door has held up well. some things have automotive gasket goops that are working great. but this boat is o/b powered and so has no below-water holes...

go with what everyone else said

[Poor Boy]

5200 is indeed forever. Clean your sufaces with acetone and then wipe real clean. I don't like the fast cure stuff except for got-to-have-it-now repairs. Denatured alcohol will do well cleaning before glueing, too, and cleans tools well. WEST is also forever but again be clean when you start, and humidity is very crucial- you want it low if it's a critical area. Have a fan blowing fresh air to you when using WEST.