Sealant curing

[pvb]

The location (inside a binnacle) was as dry as anywhere on a boat is. As far as I could see all the damage was done by the sealant in its curing process.

I'm sorry, I thought when you wrote "in a damp situation" you actually meant it was a damp situation.

 

[Vara]

I'm sorry, I thought when you wrote "in a damp situation" you actually meant it was a damp situation.

Written in the sense that nowhere on a boat is truly dry.

To amplify, the box was not in a position where it was directly exposed to rain or sea-water, just the normal high humidity that one would expect in a boats cockpit and was protected by a canvas cover most of the time and the shell of the instrument pod which is it'self sealed, all of the time.

I hope that clarifies things.

So to summarise in a boating environment when damp/water proofing current carrying cable junctions, silicone sealant is not the stuff to use! IMO.

 

[oldgit]

I am a convert from Sikiflex to CT1.

 

[KAL]

Instead of silicone use Sikaflex or CT1 in a marine environment. They are adhesives as well as sealants. Silicone is just about OK in your bathroom but not much else, it does not adhere well to anything.
Most sealants cure from the outside in and it does take some time. CT1 even cures and sticks underwater - great stuff.

Echo the comment about CT1 - it's brilliant - works in the wet, fills, blocks leaks, totally VOC free so smell-free. I just wish the manufacturer would give some clearer instructions about use (curing times, etc).

 

[SAMYL]

I am a convert from Sikiflex to CT1.

And much cheaper too.......

 

[Martin_J]

The other one that was only briefly mentioned just now was ArborMast BR (the butyl based one).. It stays like a putty. It's not an adhesive in any way but stays flexible.. so if you bed hatches in with it, it's probably good for ten years ( service life of 20 years according to the datasheet).. and when you come to replace it will just roll off like blue tac.
www.resapol.com/new/datasheets/data959.pdf

My hatches all bedded in first time with it - and at less than a fiver a tube from Marine Super Store it's worth a try.

 

[LittleShip]

I'm not saying this is a good use of this product ..... but,

I have started to bed woodwork down on Gutter seal from Wicks, it stays soft and 18 months in seems to be working well.

Owning a wooden boat with lots of trim I have to remove some from time to time as water gets behind it. So far the gutter seal has kept eveything dry. It would however be totally useless on deck joints but sealing fittings to the deck and hull seems to be Ok.

Just my observation and it is approx £4.00 a tube.

Tom

 

[ghostlymoron]

the worst thing about silicone is that it will not stick to itself once its gone off,so if it doesnt work the first time you are ------.not only wont it stick to itself nothing else will stick to it,quite worrying on a boat,if you clean the old surfaces perfectly then you may be ok but that is almost imposible to do.that is why i will never use it again.i have checked up on this since my first post ,i did think i was correct but it never hurts to check.if it has worked for you then best of luck in the future but if you are still wondering what to use then i would give silicone a miss.Kieron

It's horses for courses. In a lot of situations like securing deck fittings, what you need is a material that will act like a gasket and it's an advantage if it doesn't stick. You are compressing the sealant between 2 surfaces which makes a seal. In other applications, where the sealant is not compressed, a sealant with adhesive properties is best.