Arbomast BR underwater?

[lesweeks]

Can I use Arbomast BR to seal around thro hull fittings on my wooden hull - e.g. heads inlet and outlet seacocks and plates, log, sounder etc.? The data sheets say nothing about suitability for submerged joints. Maybe Sikaflex is a better option, but I've got lots of Arbomast already!

 

[VicS]

Can I use Arbomast BR to seal around thro hull fittings on my wooden hull - e.g. heads inlet and outlet seacocks and plates, log, sounder etc.? The data sheets say nothing about suitability for submerged joints. Maybe Sikaflex is a better option, but I've got lots of Arbomast already!

It's a non setting sealant.

The usual method of bedding such fittings is to allow the sealant to cure before finally tightening the fastenings so that a definite thickness remains between the joint faces.
That wont be possible with a non setting sealant. You will simply squeeze it all out of the joint.

 

[ianj99]

It's a non setting sealant.

The usual method of bedding such fittings is to allow the sealant to cure before finally tightening the fastenings so that a definite thickness remains between the joint faces.
That wont be possible with a non setting sealant. You will simply squeeze it all out of the joint.

The Arbomast I used certainly does set albeit not as hard as Sikaflex.

Its recommended by my chandlery as a less tough, easier to remove sealant than Sikaflex polyurethane types.
Worked well sealing my windlass to the deck and I did tighten the bolts a touch more a few days after applying it.
Can't see why its not okay for underwater use.

I

 

[VicS]

The Arbomast I used certainly does set albeit not as hard as Sikaflex.

Its recommended by my chandlery as a less tough, easier to remove sealant than Sikaflex polyurethane types.
Worked well sealing my windlass to the deck and I did tighten the bolts a touch more a few days after applying it.
Can't see why its not okay for underwater use.

I

From the data sheet:

Arbomast BR is a One-part Butyl Based Sealant intended for general sealing of many joints in
traditional forms of construction not exposed to sunlight. Arbomast BR exhibits good adhesion to many
common substrates used in construction. It forms a skin, but the bulk of the material remains plastic
beneath the skin​

 

[ianj99]

From the data sheet:

Arbomast BR is a One-part Butyl Based Sealant intended for general sealing of many joints in
traditional forms of construction not exposed to sunlight. Arbomast BR exhibits good adhesion to many
common substrates used in construction. It forms a skin, but the bulk of the material remains plastic
beneath the skin​

Yes you were right - I checked. I must have used another product.

I

 

[Boathook]

I thought that my arbo mast br was suitable for underwater and I seem to remember that it mentioned use in water tanks. Away from home at present so unable to check tubes in the garage.

 

[VicS]

I thought that my arbo mast br was suitable for underwater and I seem to remember that it mentioned use in water tanks. Away from home at present so unable to check tubes in the garage.

Nowhere is there any suggestion that its not suitable for under water. Lack of resistance to UV seems to be the only constraint on its use.

Apart from the above objection it should be OK.

 

[lesweeks]

I'm pleased that everyone seems to have interpreted the data sheet and the info on the mastic tube the same way as I have. If I use it below the waterline and it starts to suffer from UV please call the lifeboat!

Thanks for your views.