Caulking deck seam adjacent to cabin sides

[MikeBz]

I need to recaulk the seam between the cabin side and the adjacent teak plank (GRP boat, teak decks Sika’ed on top). Any tips for making a neat job of where the caulk will meet the GRP? I’m thinking of masking the GRP but inevitably get some caulk over lapping the masking tape, and then be tempted to try and smooth that down resulting in an area of about 3 square miles being smeared with caulk and the seam looking like a mess.



Obviously I need to do a better job of removing traces of old caulk first - difficult to do without scratching the gelcoat.

 

[Neeves]

I need to recaulk the seam between the cabin side and the adjacent teak plank (GRP boat, teak decks Sika’ed on top). Any tips for making a neat job of where the caulk will meet the GRP? I’m thinking of masking the GRP but inevitably get some caulk over lapping the masking tape, and then be tempted to try and smooth that down resulting in an area of about 3 square miles being smeared with caulk and the seam looking like a mess.

View attachment 178559

Obviously I need to do a better job of removing traces of old caulk first - difficult to do without scratching the gelcoat.

To remove old caulk.

Make your self some scrapers/chisels from old acrylic. You just need a sharp edge so cut the acrylic back to 45 degrees on one edge and then sharpen with a fine grinding wheel. Ideally the other end, away from the chisel edge you have made then becomes the handle. The sharp edge will remove the caulk but is sufficiently soft not to damage the gelcoat. You will need a number of chisels and they lose their edge quite quickly - so some means to sharpen them is good. Old acrylic - rummage through a marina skip or one used by sign writers.

The rest you know, patience, care and masking tape. Don't be tempted to use turps to clean up - the turps wicks under the Sika and the joint is then compromised. Sika suggest water and liquid detergent - it works. Work in small sections.

Jonathan

 

[Tranona]

Mask with light hold tape on both GRP and teak, fill. smooth out then remove tape immediately. Have a box or bucket handy to drop tape in. If windy put a brick in the box to stop it blowing away just as you drop the sticky tape in! Retire quickly and open a beer.

 

[Neeves]

I'm a skin flint, of Scots education and upbringing, and always use cheap - as cheap as we can find - masking tape. I have spent so much time making sure we buy the cheapest I did not know you could source 'light hold tape'. We learn something new every day. A problem with cheap tape is that if it gets wet, rain or dew, when you remove the tape most of the adhesive stays on the gelcoat - and is a devil to remove. Tranona's advice is good, if you leave the tape too long you can remove some of the caulking with the tape (as its only set off on the surface not in the bulk of your application - so has cured to the tape but not where you want it - that curing comes later. I'm not sure I would sacrifice a good bucket - but whatever you use, its interior will become a mess - a bucket liner? - might be a good idea. You will apply the tape as a really long length and the box/bucket idea makes the idea of a black Sika coated tape more manageable.

Its not difficult having an extra pair of clean hands can be useful.

Jonathan

 

[Ostara24]

I have switchedfrom SIKA products to CT-1 construction sealant, it is easier to work with, and less messy.

I also switched to DOWSIL 895 for window/ports sealing, it is what is used on all glazing in modern skyscrapers. Very impressive results.

I come from the construction sector and find they keep up with modern materials better than the marine industry.

 

[MikeBz]

Thanks to both, very useful advice.

 

[Neeves]

I have switchedfrom SIKA products to CT-1 construction sealant, it is easier to work with, and less messy.

I also switched to DOWSIL 895 for window/ports sealing, it is what is used on all glazing in modern skyscrapers. Very impressive results.

I come from the construction sector and find they keep up with modern materials better than the marine industry.

DOW 895 used on the glazing on the Petronas twin towers in KL

I'm not sure if it is recommended for caulking

Jonathan

 

[Rappey]

I've used tds ,teak deck caulking. It is expensive but its so nice to use, ever so easy to squeeze out of the tube and does not require a primer.
Don't forget your non stick strip in the bottom of the Grove to be caulked.
The art of doing it without getting covered in it or getting it everywhere is to apply it neatly in the first place resulting in not having to remove so much excess sealant.

 

[MikeBz]

I will be using TDS.

 

[Ian_Edwards]

I did this job last winter, around the joint between the teak deck and the cabin side and between the teak deck and the bulwark. 46ft boat so, I guess over 160ft in total. It took me 10days, working about 5 to 6 hours per day. My knees wouldn't stand much longer.
I used a Fein multool with a caulking removal blade, well worth the money. The caulking comes out as a continuous strip.
I bought some teak caulking, but didn’t use it. If I remember correctly the teak has to be less than 12% water content. The chances of getting that in an unheated shed, in the middle of a Scottish winter are remote. I used OB1 and that seems to have worked well, it will set under water. I'm not sure how well it'll stand up to UV, time will tell.
I also bought a cheap battert powered caulking gun, money well spent, compared to squeezing the handle on a manual caulking gun.
I used good quality green masking tape, and a marked a pencil line just above the teak deck, using a very thing bit of plywood to get a consistent line, then placed the edge of the masking tape on the pencil line. I got a more consistent edge that way. I also masked the edge off the teak.
I second removing the masking tape as soon as you can. It's messy but get a better line.

 

[AntarcticPilot]

No help to the OP, but the phrase "The devil to pay" is a contraction of "The devil to pay and no tar hot". The devil was the deck seam adjacent to the bulwarks, and was notoriously difficult to pay (i.e. to caulk with tar or pitch). So the phrase was used to indicate a difficult task with inadequate materials at hand.

The seam the OP wishes to deal with looks like a modern equivalent of the devil!

 

[salar]

I have done exactly that with masking tape and Sikaflex. Previous advice is good. The results are as perfect as I need, and it's easy to get a smooth finish because the masking tape takes care of the edge.