Skin Fitting - Which Sealant?

[Touching Cloth]

I am replacing my log impeller with one of a larger through-hull diameter.

Which brand and type of sticky stuff would you recommend to bed the (Airmar plastic) skin fitting in with?

Thank you.

 

[lustyd]

Sikaflex 591 is the standard stuff (since 291i was discontinued)

 

[vyv_cox]

Being short of stowage on a summer liveaboard boat in Greece I only carry one type of sealant. This was always Sikaflex 291 until Puraflex 40 appeared, apparently the same stuff at half the price. All my underwater and above water fittings are sealed with it.

 

[doug748]

I am replacing my log impeller with one of a larger through-hull diameter.

Which brand and type of sticky stuff would you recommend to bed the (Airmar plastic) skin fitting in with?

Thank you.

Almost anything will do the job even cheap silicone if that's what you have. I would avoid high strength adhesive/sealants unless you are absolutely sure you will not be the one who has to remove it.

 

[PabloPicasso]

No, don't use silicone on a boat.

You have been warned now. Never use silicone on a boat, not ever.

Tek7 works well, and can even be used in the wet. Tek 7 even sets under water. But it is both adhesive and sealant.

 

[doug748]

"....... use conventional methods for sealing. It is advisable to avoid the use of mastic materials - use a form of proprietary silicon sealant."

Nasa Marine

 

[lustyd]

You have been warned now. Never use silicone on a boat, not ever.

What do you bed a winch in which needs regular removal for maintenance?

I use sanitary silicone and am extremely happy with it.

What do you seal your bathroom fittings with?

I use sanitary silicone and an extremely happy with it.

 

[Boathook]

No, don't use silicone on a boat.

You have been warned now. Never use silicone on a boat, not ever.

Tek7 works well, and can even be used in the wet. Tek 7 even sets under water. But it is both adhesive and sealant.

I've used silicone. It was an expensive marine one and it worked very well.

I've also used https://www.screwfix.com/p/fernox-ls-x-leak-sealer-50ml/23614 on board with excellent results.

 

[fredrussell]

The boat builders I worked at had a very strict policy of no silicone anywhere on boats. Obviously older boat’s used it all over the place for sealing fittings so it can’t be that bad.

 

[PabloPicasso]

SIlicone fails, leaks, (think bathrooms), and leaves behind residue nothing else will adhere to very well.

It is a real nuisance when there are many better alternatives that are little different in cost.

Silicone is a bodge. Avoid buying a boat where the owner has used silicone and bodged it.

Buy hey, I'm an amateur boater. What do I know...

 

[Tranona]

SIlicone fails, leaks, (think bathrooms), and leaves behind residue nothing else will adhere to very well.

It is a real nuisance when there are many better alternatives that are little different in cost.

Silicone is a bodge. Avoid buying a boat where the owner has used silicone and bodged it.

Buy hey, I'm an amateur boater. What do I know...

Despite that some makers recommend it and only IT such as NASA noted earlier and Spinlock for their clutches

 

[PabloPicasso]

You have to wonder how much boat maintenance the guys who write these recomendations actually do themselves?

 

[lustyd]

i’ll ask again then, what would you use to seal around the shower and to bed winches that need to be removed for maintenance?

 

[fredrussell]

i’ll ask again then, what would you use to seal around the shower and to bed winches that need to be removed for maintenance?

Arbomast BR or butyl tape?

 

[vyv_cox]

Despite that some makers recommend it and only IT such as NASA noted earlier and Spinlock for their clutches

I suspect that the plastic used by Nasa is pretty poor stuff that is attacked by a variety of solvents. Hence they suggest silicone, which is water based. There is little doubt that the non-setting problems experienced by many sealant users are caused by previous use of silicones, very difficult to remove and a known inhibitor of curing.

 

[potentillaCO32]

I have been using ct1 (black) for underwater sealing/bonding. It seems as good as sika to me and lasts much longer in the tube.

 

[PaulRainbow]

CT1 or OB1 works fine, cheaper than Sikaflex and i would never, ever use Silicone.

 

[Boathook]

I've started to use OB1 for sealing where butyl has failed due to dampness caused by the recent rain. My preferred Sealant is butyl, but the surfaces do need to be dry.

 

[Touching Cloth]

Thank you for your replies.
Based on those, I was going to get some Puraflex 40 but couldn't get any on a Sunday, but can report that Sikaflex 291i is alive and well in Marine Superstore in Port Solent.

 

[lustyd]

Arbomast BR or butyl tape?

You’re going to seal a shower cubicle with Butyl tape?! I certainly wouldn’t use a non setting butyl for bedding winches it’d be squeezed out in no time and leak.