Waterproofing screws

[Posse]

How do you ensure that water does not seep in at screws or bolts going through the deck? A little Sikaflex? Or rubber washers? Or may just some suber lube grease or similar?

 

[pcatterall]

I thought always to countersink and seal over the top ( wood plug or sealant) but I have seen a lot of screws with rubber 'cup' type washers which seem to work well. I'm trying to source them!!

 

[oldsaltoz]

Cored or composite and solid glass should be drilled out oversize then filled with Micro fibres or finely chopped glass, after curing, drill the new hole so the thread will still bite, and half dip the screw/bolt in epoxy resin.

Good luck.

 

[VicS]

If you are talking about stainless steel fasteners it is imperative that they are well sealed.
If water can seep between them and the deck they will suffer from crevice corrosion.

Sikaflex or whatever sealant you favour for general use on the boat

 

[xtiffer]

For fasteners going into wood then I would suggest Dolfinite
if you can get hold of it.
It is an American putty-like pate that never totally dries
thus movement stops being a problem.
Years ago I did varnish work on Ticonderoga and bits of trim
were fastened by SB screws and Dolfinite. All came out sweetly
and had been doing that job for many years without damage to them.
In the Med summer they were revarnished every 6-8 weeks
so that was a lot of unscrewing and refixing. All the slots were perfect.
Mind you this was perfectionist work.
Cheers,
Chris

 

[Ex-SolentBoy]

For fasteners going into wood then I would suggest Dolfinite
if you can get hold of it.
It is an American putty-like pate that never totally dries
thus movement stops being a problem.
Years ago I did varnish work on Ticonderoga and bits of trim
were fastened by SB screws and Dolfinite. All came out sweetly
and had been doing that job for many years without damage to them.
In the Med summer they were revarnished every 6-8 weeks
so that was a lot of unscrewing and refixing. All the slots were perfect.
Mind you this was perfectionist work.
Cheers,
Chris

Is that the same as Ralli Bondite, which is easy to get in the UK. It is used for hull/deck fixing and stays soft and waterproof forever!

 

[Posse]

Thanks for your suggestions. In this case, it is the steel base on the deck, where the stays are fastened. It is mounted with 4 bolts and nuts on the inside. So, it is steel screws on steel plate, and it will exposed to quite a lot of strain.

Seems to me that sikaflex or similar is the way to go... Or is it a bad idea to use something flexible together with this amount of strain?

 

[xtiffer]

Is that the same as Ralli Bondite, which is easy to get in the UK. It is used for hull/deck fixing and stays soft and waterproof forever!

Sorry but I am in Turkey and left UK in 1987 so I don't know.
I came across it working on US flag yachts.
I suspect it is glaziers putty with added linseed oil.
Cheers,
Chris