Re teak decking help pls

[Seastoke]

ok so i have taken my teak deck off and brought it home to clean up ,it was screwed down and fixed with silicone,yes i know ,so i have bought 3m 5200fc to glue down and i am going to screw it down until it sets then take out screws and fit plugs ,But the question is does the grp need a primer before i apply the glue ,thanks for the replies ,roy

 

[pvb]

You need to check the 3M instructions, especially if it was previously fixed with silicone.

 

[BabaYaga]

ok so i have taken my teak deck off and brought it home to clean up ,it was screwed down and fixed with silicone,yes i know ,so i have bought 3m 5200fc to glue down and i am going to screw it down until it sets then take out screws and fit plugs ,But the question is does the grp need a primer before i apply the glue ,thanks for the replies ,roy

Out of interest, what is the purpose of taking the screws out?
Regarding primer, don't know about 3M, but several other polyurethan beddings require no primers, just a clean surface.

 

[syneraida]

.... don't know about 3M, but several other polyurethan beddings require no primers, just a clean surface.

Haven't used 3M much but if you go with Sika you can get away without using primer, it just depend if you ever want to remove the teak again, if the answer is no i would use the primer, it'll give you a much better bond to the deck and teak respectively.

 

[blxm]

Would the use of silicone require an aggressive preparation of the surfaces to be mated?
I know that silicon wax is a pain to remove when painting surfaces but does anyone have experience of silicone sealant?

 

[Quandary]

My experience of trying to fix or seal anything that has previously had silicone sealant near it with anything else so far has been disastrous, that is why some boatyards will not let silicone sealants near the place.
I think you will need to be sure all traces of the old bedding are gone but how do you do that?

 

[macd]

My experience of trying to fix or seal anything that has previously had silicone sealant near it with anything else so far has been disastrous, that is why some boatyards will not let silicone sealants near the place.
I think you will need to be sure all traces of the old bedding are gone but how do you do that?

+1
In my experience aggressive mechanical cleaning is the only way that works.
Dow Corning make a solvent for cured silicone, but it seems to be intended and supplied for industrial applications. Most things making similar claims are serpent lubricant.

 

[pvb]

One possibility would be to use a silicone adhesive sealant to stick the teak down and caulk it. Something like Sea Line 100 perhaps.

I'm not too sure why the OP thought it was necessary to take the teak off to clean it up, surely it would have been much easier in situ?

 

[Seastoke]

Out of interest, what is the purpose of taking the screws out?
Regarding primer, don't know about 3M, but several other polyurethan beddings require no primers, just a clean surface.

well it is to put teak plugs in so better finish

 

[Seastoke]

One possibility would be to use a silicone adhesive sealant to stick the teak down and caulk it. Something like Sea Line 100 perhaps.

I'm not too sure why the OP thought it was necessary to take the teak off to clean it up, surely it would have been much easier in situ?

the teak needed to come off as the survey told me about it as it was only held down by the screws and held together with the silkaflex

 

[pvb]

the teak needed to come off as the survey told me about it as it was only held down by the screws and held together with the silkaflex

Your original post said "it was screwed down and fixed with silicone", no mention of sikaflex.

 

[Iliade]

'Assembled with sikaflex then bedded on silicone and screwed down' is how I understood it.

If you managed to peel off 90% of the silicone then you should be able to get a sikaflex adhesive to hold. But, if say one half sticks and the other not, you would be in trouble as any sikaflex that does grip will be a mare to get unstuck to redo the job. I fear you will be better off using a 'nylon pan scrubber-like' disk on a disk grinder to remove the remaining silicone and, undoubtedly, the top surface of the gel coat.
Alternatively, get good quality industrial silicone adhesive* and just screw it back on again. It lasted for some time last time... Also you should not need to remove the screws in order to plug the holes.

* Like Sikaflex's products, there are a wide variety of silicone adhesives and sealants. A lot of the bad name of silicone has been generated because people have just used the first one they came across in Homebase. Screwfix stock a modest range of silicones.

 

[dedwards]

forgive my ignorance, but if the teak is held down with screws then whats wrong with using an adhesive thats not that strong?

 

[BrianH]

ok so i have taken my teak deck off and brought it home to clean up ,it was screwed down and fixed with silicone,yes i know ,so i have bought 3m 5200fc to glue down and i am going to screw it down until it sets then take out screws and fit plugs ,But the question is does the grp need a primer before i apply the glue ,thanks for the replies ,roy

I have a better idea. While the entire teak is removed ... seal the screw holes, grind and clean the surface and paint over with KiwiGrip and be rid of the ticking time-bomb of maintenance and eventual astronomical cost of a teak deck.

I envy you having reached that stage, I plan to start sometime to strip off all my teak planks and paint, just starting is the problem, there's always a higher priority task to do.

 

[rob2]

I'm curious... what thickness is the teak? Is it a proper laid deck?

If the teak is not thick enough to leave the screws in and plug on top, then you might like to consider that 3M mention that the FC (fast cure) is not as strong an adhesive as the ordinary type and it may also be problematical applying it and laying the teak down before it skins over - but I couldn't find any guidance on that. 5200 is an expanding polyurethane adhesive, so it will gap fill any imperfections in the substrate. As it needs moisture to cure, I'd suggest you follow the advice of some woodworkers and spray a mist of water over the teak before laying it just to ensure it does cure!

If the teal is laid with caulking lands, then you will also need a caulking sealant once it is glued down - and some barrier tape to stop it from sticking to the bottom of the groove or it will sheer away from the sides as the wood moves. I believe most caulking materials also require a primer to be applied as teak is notoriously difficult to adhere to.

Of course, I may be wrong - the fact that you "took the teak off" may suggest that these are panels on a backing pad.

Rob.

 

[BabaYaga]

well it is to put teak plugs in so better finish

OK, so the teak was originally screwed down without any plugs covering the heads? Certainly not best practice, you should examine carefully for moisture (assuming a cored deck) while it is off. Then seal the screw holes with marine epoxy or similar.
You don't mention thickness, but if at least 10mm it should be possible to screw down into polyurethan bedding with special flat head screws and then cover with a teak plug. If thinner, only gluing with polyurethan is probably better, which would require some sort of clamping during curing, not necessarily screws.
It's not clear to me if you intend to separate the planks and redo the caulking or if you will put entire panels back with new bedding. If the latter, making neat plugholes where the screw holes were could be challenging. You might want to fill the holes with something to avoid wobble when drilling.