Butyl putty.

[Rex Fearnehough]

Hi again,
Has anyone had any experience of using a butyl putty as a sealer/bedding compound, for below the water line? It can be applied & cures on wet surfaces. It seems perfect, but where are the problems?
Rex. :rolleyes:

[JormaS]

Corra,

Butyl sealants probably come in many varieties. The ones I have used have a rather limited glueing capacity. They tend to be quite soft, maybe something like Shore A 15 (as a comparison, the 3M company gives Shore A 60 for their glue/sealant 5200). My impression is that they will stay elastic practically forever. The ones I have used are transparent.

All this makes the butyl sealant an ideal bedding compound for moldings etc, because even a delicate molding can later be removed without braking it. It´s rather like silicone without the adverse properties. I also use it as a temporary quick fix to stop leaks on deck. It´s easy to rub off when you want to get rid of it.

In my opinion, all this makes it unsuitable for use below the water line.

I hope this helps.

Jorma

[formerlyknownasprince]

We just used butyl mastic for bedding through-hulls, on the back of the tingles and the backing blocks that sealed off some holes through the hull for fittings that we removed.

Ian

[Rex Fearnehough]

Thanks folks,
I was hanging my head in shame, thinking I had asked something absolutely ridiculous. I have just scraped a boat that has been out of the water for around 8yrs. I intend to prime the wood, tighten up the rivets & fill some cracks so that I can see what other problems that I may have before winter sets in. So the putty may be the thing for this job. I don't want to put any hard stuff in there. I also don't want anything thats going to leave some impossible to clear out goo.
So once again thanks folks,
Rex.

[formerlyknownasprince]

I wouldn't put it anywhere near the seams. Just use it as a bedding compound.

I repaired the below water seams on Grantala using a mix of linseed based putty and anti-fouling primer. Where previous owners had used Sikaflex, the stuff was hanging out of the seams.

Ian