Sikaflex still soft after a year

[wombat88]

Horrible stuff but it has its uses...and it keeps the water out.

(From memory Sika 291)

Last year I filled some cracks in the planks of my '40s wooden clinker dinghy with Sikaflex. I had hoped it would retain some flexibility and move around as the boat 'took up'. Cracks were filled and overpainted. From a 'prevention of water ingress situation' point of view the exercise has been entirely successful. Note, these are cracks in the planks themselves and not the lands. OK so not a 'proper job' but a good way of getting her out on the water.

I've just inverted the boat to attend to various batterings and realise that the Sikaflex is still very soft, it is as if the paint has prevented it from dry out or curing. The paint over is also still tacky, indeed it is a bit of a mess.

So..

Any suggestions as to how to get it to cure?

Does Sikaflex cure by air or moisture?

What can I prime the Sikaflex with that will dry?

Trying to gouge it all out of the cracks would be hard...and since it is doing its job seems the wrong approach.

 

[forelle541]

If there was any old silicone under the Sitka it might not go off and will go snotty, the two don't mix.

 

[Skylark]

I had a similar experience. I had a slight rust stain bleeding out of the trailing edge of the keel to hull joint. Boat still under warranty so done by Dealer. Old Sika removed, joint cleaned with acetone, painted with Primocon, new Sika and Primocon over the top, all in one day in November. Still wet to the touch in April at relaunch. Came off in my hand when I touched it at haul-out the following October.

I'm planning to do it again before this seasons launch but I'll leave plenty of drying time between each stage. Any other tips most welcome.

 

[Slowtack]

Happened to me one time when I painted over it too soon, not enough air contact time I guess
See here........................
https://sikaflexit.wordpress.com/2013/11/26/my-sikaflex-isnt-drying-what-do-i-do/

 

[tillergirl]

"Overpaintability - It is generally not recommended that a finish such as a paint or varnish is applied because solvents or plasticisers can adversely affect the cured Sikaflex®-291i or the drying of the film."

Removal - Uncured Sikaflex®-291i can be removed from tools and equipment with Sika® Remover-208 or another suitable solvent. Once cured, the material can only be removed mechanically.

From their instructions! Personally I would never used 291 on my wooden boat. It's very tough and an adhesive. If I want an adhesive I want an alternative; if I want a mastic I use a polysulphide. But as a quick solution for a crack like you describe it seems like a good solution. But not painted.

 

[wombat88]

Thanks all. The poor boat has the worst of all worlds. Being both cracked and clinker it would benefit from 'taking up'. The problem is that I probably do not sail her for more than a couple of hours at a time and then return her to the dinghy park which is warm, dry and sunny. Hence the use of Sikaflex. I guess, since it doing the job I will just have to put up with a few sticky seams.

 

[Greenheart]

I just used Sika 291 to seal up the kitchen drain, after one of the nastiest unplugging jobs I can remember.

All the parts were clean and dry when I put them together again.

How long can I expect the Sikaflex to take, to seal hard enough for the sink to be usable again?

 

[CJ13]

Probably 12 hours-24 hours max.

 

[Greenheart]

Hope you're right, thanks. :encouragement:

 

[Mr Cassandra]

Use Simpsons

 

[Neil_Y]

For cleaning up uncured sika I've found a product called Scrubs very good. These are like industrial wet wipes.

 

[alteredoutlook]

Sikaflex still soft after a year? Move up North!