MS Polymer sealant

[stagedamager]

Afternoon all!

I've noticed our local tool shop stocks MS Polymer sealants. What is the difference between these and standard silicones or Polyurethanes?

Does anyone have any experience of using these?

Many thanks

Dan

[blackrose]

I don't know these sealants. I googled "MS Polymer Sealants" and there seem to be quite a few different ones so it would be useful if you could provide more info on which one(s) you have in mind?

 

What job are you trying to do?

 

I always use Marineflex for bedding in skin fittings, cleats, and sticking pieces of marineply or hardwood onto bulkheads so that I can mount things onto the wood rather than into the steel.

 

Heat exchanger, pump, etc, mounted on ply, which is stuck onto bulkhead with marineflex.

 

It's about 6 or 7 quid a tube at chandlers: http://www.marinemastics.com/marine-flex.html

 

It's polyurethane-based and completely different to silicone. It's a structural adhesive and sealant which goes off like rubber - once it's on you won't get it off unless you take a chisel to it. Lightly abrade the area first and wipe off with a cloth dampened with white spirit. Clean up with white spirit too.

Edited November 11, 2012 by blackrose

[stagedamager]

It's to seal a cabin around the gunnel, Marineflex hasn't done the job.

The one which caught my eye is at Toolstation and is called "Stixall".

Dan

[blackrose]

It's to seal a cabin around the gunnel, Marineflex hasn't done the job.

The one which caught my eye is at Toolstation and is called "Stixall".

Dan

 

You mean between a wooden top and steel hull?

 

Assuming the job was done properly and marineflex (or sikaflex) didn't work, then I doubt you'll find another sealant which will.

 

I've used marineflex to seal a (steel to steel) gap of about 13mm and it worked well, so I guess the thermal expansion/contraction differentials of the wood and steel are causing the problem. However sikaflex is what's used to seal decks, etc, by most wooden boatbuilders and marineflex is basically the same stuff, so I don't know what's happened in your case. Are you sure the surfaces were properly prepped and cleaned prior to sealant application?

Edited November 11, 2012 by blackrose

[stagedamager]

Wooden cabin and wooden hull.

[blackrose]

Wooden cabin and wooden hull.

 

I would look into one of the many varieties of Sikaflex then.

 

www.bluemoment.com/downloads/sikaflexmarinehandbook.pdf

Edited November 11, 2012 by blackrose

[George94]

Fixall is another example. I use High Tack, and have had no problems.

 

My link

[Tonka]

Has it failed because it was not applied properley

[stagedamager]

I think we had some cabin shrinkage on the planks which caused it to slit the seal. Ok another question then can anyone recommend a sealant suitable for placing onto damp wood which is hi grab and retains flexibility when set?

Dan

[George94]

I think we had some cabin shrinkage on the planks which caused it to slit the seal. Ok another question then can anyone recommend a sealant suitable for placing onto damp wood which is hi grab and retains flexibility when set?

Dan

 

I just did. Fixall High Tack. It can even be applied under-water.

 

However, there are limits to how much movement even the best product can cope with. And you are advised to use a primer on porous surfaces.

[stagedamager]

Hi George,

I'd realised that after reading the data sheet, but you posted quicker than I could reply! !!

[blackrose]

I think we had some cabin shrinkage on the planks which caused it to slit the seal. Ok another question then can anyone recommend a sealant suitable for placing onto damp wood which is hi grab and retains flexibility when set?

Dan

 

Application onto damp wood is one thing - as long as the surface of the wood is sound and not rotting.

 

Why don't you dry the gap out with a hot air gun?

[stagedamager]

The wood is sound, I think we would try to get some of the dampness out with a hot air gun but just covering all eventualities...just in case!!!