Sealants - Polysulphide

[G12]

Morning guys,

I've always used single pack polysulphide sealants for deck fittings but they seem to be hard to get hold of these days. The main brand I used to like was Boat Life's "Life Calk" (it's American) but there seem to be no UK distributors for it any more. I used a building brand after that, same stuff but a bit cheaper but even that supply has dried up. Single pack Polysulphide obviously does a good job at sealing fittings as you'd expect (often used on aircraft for panel sealing), remains flexible after many years etc but more importantly the whole tube doesn't go hard just because you used a tiny bit of it which means it's great to keep onboard for when you just need a tiny amount. It's far cheaper in the long run despite the initial cost being a bit steeper and less wasteful.
Has anyone got any recommendations for something decent that doesn't go off in the tube?

 

[andyc352]

I use Arbokol 1000 polysulphide. Available online from Dortech direct. £6.11 for a tube. Hope that helps.

Andy

 

[G12]

Hi Andy, Thanks! I'll order some from them. I had a really good look about this morning for a replacement (I've run out of white) and it seems most places don't stock polysulphide stating that the technology has moved on (probably because it has some nasties in it). That Arbokol is about half the price of the other brand I was using too.

 

[peteK]

Butyl strip is another sealant that doesnt go hard.

 

[michael_w]

Sikaflex 291i keeps well in the freezer.

 

[nickbailhache]

CT1 made in Belfast will set under water and is food safe. Excellent all rounder

 

[G12]

I've seen much CT1 used by a very well known superyacht yard instead of the more expensive sika. As you say, it's a pretty decent all rounder but I'm 99% sure it goes off in the tube once opened.

Good tip on the Sikaflex in the freezer - I guess that'll be because the freezer is 0% humidity or thereabouts.

I've seen a video of a guy using butyl strip to bed a cleat onto a deck. Apparently it's a great product if you do it carefully. I might scrounge a bit for the spares box just incase.

 

[rogerthebodger]

I now try to buy my sikaflex in foil sausages which can be sealed up again after opening.

I always keep my sikaflex in a sealed plastic bag in the fridge and find it can last years.

I also buy out of date sikaflex at a knock down price and store it unopened in the fridge.

 

[JumbleDuck]

Boatlife "Life-Calk" and other products wree unobtainable for a while, until a company in Kilmarnock started improting them about ten years ago. That supply seems to have dried up, but it's available though Amazon. A bit pricey. I used to use it a lot - it's great stuff if you ignore the smell!

 

[andyc352]

Polysulphide and butyl have the advantage that things can be easily taken apart as unlike CT1 and Sika, they’re not adhesives. This, of course, may not always be an advantage. I was told years ago by a boatyard that sikaflex 291 should mainly be confined to use below the waterline. I try to follow that advice when possible.

 

[Keith 66]

I can assure you that Arbokol 1000 polysulphide sticks most things together extremely well, I took some fittings off recently that had been on 20 years & they were a sod to remove! We used to bond decks on with the two part version, that stuff is mega sticky!

 

[JumbleDuck]

A pedant notes:

The official spelling in the UK has been polysulfide (cf sulfur, sulfate, sulfuric) for over twenty years now.

 

[G12]

Sulfide - Wikipedia
"Sulfide (British English also sulphide)[2] is an inorganic anion of sulfur with the chemical formula S2"
Sulphide | Meaning of Sulphide by Lexico

Sulfur - Wikipedia
"Sulfur (in British English, sulphur) is a chemical element with the symbol S"

Polysulphide Sealants - ARBO

EVO-STIK One Part Polysulphide

 

[JumbleDuck]

Sulfide - Wikipedia
"Sulfide (British English also sulphide)[2] is an inorganic anion of sulfur with the chemical formula S2"
Sulphide | Meaning of Sulphide by Lexico

Sulfur - Wikipedia
"Sulfur (in British English, sulphur) is a chemical element with the symbol S"

Polysulphide Sealants - ARBO

EVO-STIK One Part Polysulphide

"Sulphur" was an odd British invention of the 19th century. The Royal Society of Chemistry changed back to "sulfur" in 1992 and that's the spelling used in school science since 1996.

 

[Quandary]

The UK went metric while I was a student, mid sixties? 60 years later I still have to keep answering 'what is that in feet?'
So I reckon we should be able to keep the traditional spelling of sulphides to at leat 2050 without annoying anyone.

(other than academics of course?)

 

[JumbleDuck]

The UK went metric while I was a student, mid sixties? 60 years later I still have to keep answering 'what is that in feet?'
So I reckon we should be able to keep the traditional spelling of sulphides to at leat 2050 without annoying anyone.

(other than academics of course?)

Bored academics with nothing better to do than nitpick, you mean? Yes, that's me.

 

[V1701]

I've seen much CT1 used by a very well known superyacht yard instead of the more expensive sika. As you say, it's a pretty decent all rounder but I'm 99% sure it goes off in the tube once opened.

No CT1 doesn't go off in the tube, it's really good in that respect - you just get a little plug right at the end that pulls out easily and off you go again. I've used it loads but the clear isn't as good...

 

[Saltram31]

I used black CT1 to replace the old polysulphide on the teak in my cockpit. It doesn't shrink when it goes off and is easy to clean up.

 

[MOBY2]

+ 1 for CT1 although I hear there is an OB1 now no honestly there is, from Screwfix I think, there was a thread a while back may be worth a read...

 

[MOBY2]

Thinking about it ... would that make me "OB1 KMOBY sorry couldn`t resist ...