Renewing Stikaflex join in teak?

[Tim Good]

Ok so I'm lucky in that only my cockpit has teak. The sikaflex is coming away though although the teak is still in good condition. Has anyone got some useful advice on renewing this or is it just a case of prying out the old, masking off the links and squirting in new?

 

[knuterikt]

Ok so I'm lucky in that only my cockpit has teak. The sikaflex is coming away though although the teak is still in good condition. Has anyone got some useful advice on renewing this or is it just a case of prying out the old, masking off the links and squirting in new?

You want clean teak surface for the new deck caulking to attach to, there are special sanding tools for this or you can improvise..
To prevent the deck caulking to attach to the bottom, so you should use a release tape (this give more flex in the seam)
Most producers of deck caulking advise that you use a primer on the teak before filling the seam with the deck caulk.

Mask the teak
Apply the caulk
Even out the caulk
Remove masking tape immediately.

 

[Tranona]

Ok so I'm lucky in that only my cockpit has teak. The sikaflex is coming away though although the teak is still in good condition. Has anyone got some useful advice on renewing this or is it just a case of prying out the old, masking off the links and squirting in new?

You need to look carefully at the construction before deciding exactly how to do it. It may well be just teak veneer on a ply substrate and the caulking may only be 2-3mm deep. So just digging the old out and cleaning the seam with acetone may be enough. If, however they are solid teak strips glued to the GRP then the seam could be 6mm deep, or it could be stepped. You still need to get all the old out, but with full depth seams this can be hard work. As suggested might be a good idea to prime the edges before caulking, particularly on full depth seams.

 

[gjgm]

Ok so I'm lucky in that only my cockpit has teak. The sikaflex is coming away though although the teak is still in good condition. Has anyone got some useful advice on renewing this or is it just a case of prying out the old, masking off the links and squirting in new?

It isnt too hard to do small areas. First make sure you get the right sikaflex product.. its £20-25 a tube...! It is very messy and this stuff seems to get everywhere and sticks like ''''.
For a small areas, you can run down the edges with a stanley knife, but be very careful that you try to keep the blade vertical and don't wander off into the teak, or you will end up with wobbly caulk strips.
You can then prise it out with a suitably wide screwdriver. Clean it up so there is no grease etc. Top job is to put tape in the bottom of the groove.
Now you can either mask off each side of the strip (preferable IMHO) or just cover the whole place in caulking. Assuming the rather time consuming masking off, then squirt the caulk in, and make sure you have filled the groove properly. I would then take the excess off with a spatula and leave to bake
Use about 80 grit sandpaper when dry.
To be honest, buy a tube and have a go with a single strip. You should be able to make a pretty ok job. It won't be as perfectly straight as new, but as long as you didn't mess up the teak, it should be ok. You can then decide if you want to do the whole thing yourself. But note, when you remove the wet masking tape, any wind will blow this all over the boat, and you, and give you a bigger headache trying to get the stuff off everywhere!

 

[pmagowan]

There are two main schools of thought on applying the sikaflex, to mask or not. The other preparations are the same for either and primer is highly advised. Sika do good instruction sheets IIRC. Then you either mask up and squidge in or dont mask and simply overfill each channel without any squidging. In the former you remove the tape while wet to give a neat edge and then sand to get it perfect. In the later you wait until dry and they cut off the extra with a sharp blade or chisel and sand as required. Some people think the taping takes too long and since you often get sikaflex everywhere anyway (as you remove the tape) that it is a waste of time. It can also potentially pull the Sika away from the seam at the very top.

 

[Tim Good]

I think I may try both ways side by side and make a decision for the rest.

 

[pmagowan]

Also, to get a good bead it is worthwhile profiling the application nozzle. Some people cut a v into it and then squish it slightly so that it fits in the seam. Others make a more complex profile with a V and a little strip that extends to keep the nozzle the exact right distance off the bottom of the seam (essentially a V with one side longer than the other. You need to make sure the sika gets to the base of the seam without trapping air otherwise you can find whole strips of it coming up with the masking tape.

 

[pvb]

Do use Sikaflex primer - it's ridiculously expensive but works. When applying the caulking, push the nozzle away rather than pulling it towards you. Have a large weighted cardboard box handy to drop the masking tape into. Meths is useful for cleaning your hands, etc. It's a good idea to add some masking tape to the middle of the teak strips where you've put new caulking, to alert you not to tread on it (don't ask!).