difference in these ahesives?

[Catalina36]

In 20 years I've used probably hundreds of tubes of this one from Evode in so many jobs and under various different names. When I first came across it, it was "Superior to Silicone" and it was, at a time when there was less choice - available then in both brown and white. Later it became Nail and Seal for many years , white only which is a shame, and in the past two or three years it's now Seriously Strong Stuff.

EVO-STIK Seriously Strong Stuff Ultimate Adhesive

https://diy.evo-stik.co.uk/sites/di.../seriously-strong-stuff-ultimate-adhesive.pdf

For 22 years it's been holding an underwater patch to a rubber pond liner and for the past 13 the plywood box holding my bow thruster battery in the focsle has been held together and to the boat with nothing else at all. The frame for the Webasto water heater is also held to the hull with it alone. I don't think I can recall anything it can't stick and its grab makes it handy for fabricating without support, though it can't be used around fuel etc as white spirit kills it even when set - which is good for cleaning up..

The downside it that with the new name the bvggers have increased the price from about £6 a tube to over £9. I just try to use/waste less of it.

 

[RJJ]

It came up in this thread a few months ago. Screwfix OB1 sealant / adhesive

There were posts about the "similarity" with CT1 and that it was actually an improved formulation. Also a threat of legal action plus mention in advertising that the OB1 formulation had been in use for over 15 years and made by a private company. I could not find details of the manufacturer and it almost seemed to be a big secret. It appeared reasonable to assume that some sort of legally binding agreement had been signed regarding direct competition or comparison with CT1 by name (could be wrong).

My memory of the MSDS data is that OB1 was essentially the same as CT1 apart from an additional component. I can't remember what it was but did write that I thought it likely to enhance cross-linking to either speed up setting time or strength of the material, probably both (by promoting formation of urethane links).

I pretty much assumed that if CT1 was suitable then OB1 would work as well, probably slightly better. I was going to buy some for my boat but Covid-19 knocked that idea on the head and I suspect others had the same problem.

I have just used OB1 around the top of the keel and it seemed to go on well. After drying was sandable, paintable and flexible. Now it's in the water and hopefully will look acceptable next winter.

There is also discussion whether you can use OB1 (or CT,1) for teak. I spoke to a couple of folks who said yea, and others who said it didn't adhere to the sides of the strips. Hard to tell if the surfaces were properly prepared; if not then it would seem nothing would work. I am going to try it on the small area of helmsman's seat and see how it goes.

 

[vyv_cox]

I have used OB1 at home to plug cracks in pebbledash. Most impressed, it has worked well.