What is he proper way to seal/bed hardware

[John Hart]

I am interested in the proper sealant to use, as I refit my 1960 Thompson Seacoaster and mount cleats, engine, etc.

Here are the items I am thinking of, and what I found when I took things apart. I would appreciate anybody copying and pasting any part of the list and giving me your perspective...There were not many places where sealant was used, so perhaps it fosters water trapping and there shouldn't be anything.

-Windshield frame to gasket, gasket to deck
-Engine brackets on transom, four bolts
-Eyebolts through transom
-Speedo tube through transom (above water line)
-Transom and hull snaps, screw-in twist fasteners
-Cleats, guides, screw/snaps for canvas top structure
-Bow light, horn, spotlight, rear post light

Here is what I think was there, or what I am thinking about using now.

Windshield frame to gasket, gasket to deck- Nothing there. I plan to use a thin coat of bedding compound on the frame and stick the gasket to the frame. Then another coat on the bottom of the gasket to seal to the deck.

Engine brackets on transom - There was a thick, white, kind of gummy compound on washers inside transom, and around exit holes between the brackets and transom outside. It was not silicone, but may be polysulfide caulk

Transom eyebolts- Nothing there, I am thinking bedding compound

Transom and hull snaps, twist fasteners - Nothing there, I am thinking bedding compound

Speedo tube through transom... Nothing was there, I probably will grease the tube with bedding compound and force whatever I can into the hole.. It is a really tight fit already, so I probably don't need much.

Cleats, guides, screw/snaps for canvas top structure- Nothing there, I am thinking bedding compound smeared on the bottom of the fittings, and on the threads of the screws.

Bow light, horn, spotlight, rear post light- Nothing there, I am thinking bedding compound
Smeared on the bottom where these meet the decck.

If anyone has any comments I would appreciate it.

Thanks.

[Jack Heinlen]

The short answer, not to be flip, is either.

I'd use a traditional bedding compound for deck hardware, and a poly for places of high vibration such as the motor mount.

Don't use one of the 'glues' like a 5200, use lots of goo and learn how to clean the excess. You want enough to squidge in and fill all the gaps, and overflow a little.

That's all I know.

P.S. I don't know the construction of your boat, but would consider a poly for wood to wood joints such as the windshield frame to deck. My experience with CCs is that that is a weak point if maintainance gets at all lax, and a properly applied poly would be more secure.

Best of luck.

[ 05-29-2004, 12:33 PM: Message edited by: Jack Heinlen ]

[Meerkat]

What you want is a bedding compound like Dolphinite (sp?).

[Joe ( Cold Spring on Hudson )]

I used Plumbers Putty just as good as Dolphinite (sp?).

[N. Scheuer]

I use only 3M 5200.

Being a urethane rubber, it will last almost as long as silicone (which seems to last forever), which makes it superior to any of the sulfide compounds.

It adheres to a wide range of surfaces with more tenacity than silicone, which makes it just plain better.

Moby Nick

[Bob Smalser]

I do one thing worthy of note with plywood....I double drill all my holes just like I would with balsa or ply-cored fiberglass.

Locate and drill the hole...then remove the hardware and drill it oversize....fill hole with thickened epoxy, let cure, and drill it again to the correct size.

A little more trouble, but worth it if you've ever had to repair the inside of a rotten plywood core on the transom of a glass boat. Not to say properly installed hardware will cause delam in a well-maintained wooden boat, but I like to plan for future serious abuse and neglect. Among all the wrecks out there a century from now, mine just might be the one worth saving.