Sealant

[PabloPicasso]

Which marine sealant IS NOT an adhesive?

For bolting through a grp balsa sandwich deck.

Needs to seal out water, and allow bolts to be potentially removable

 

[geem]

Which marine sealant IS NOT an adhesive?

For bolting through a grp balsa sandwich deck.

Needs to seal out water, and allow bolts to be potentially removable

Geocell Works from Screwfix. £9/ tube.

 

[PabloPicasso]

Geocell Works from Screwfix. £9/ tube.

Which geocel product? There are loads of them

 

[geem]

Which geocel product? There are loads of them

WORKS

 

[Boathook]

I've used a butyl sealant (arbomast) for all my fittings, above and below the waterline. Grey in colour and not UV resistant, but behind a fitting doesn't matter.

 

[Cerebus]

Yes, butyl sealant has a good reputation for doing what you require.

Your project sounds as though the aesthetics are not in consideration (because butyl can be messy).

But it has a good reputation for being a good sealant and rust proofing product.

 

[Concerto]

Butyl rubber is my choice above and below the water. I normally use it in 50 mm wide roll form, rather than in tube form. It can be easily shaped around bolts for extra protection. Any excess can be trimmed away with a sharp knife. It best to repeat this the following day after checking the tension on the nuts. Any butyl rubber that sticks where it should not be can be removed with white spirit. I have bought it in white and black, but I prefer using the black as it is easier to see any excess.