Trimming Teak Deck Caulking

dje67

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The teak decks on my Beneteau are around 13 years old. They are the "glued down" type with a sort-of rubber caulking between the strips. Over the years, the teak has worn down a couple of mm, and left the caulking standing slightly proud of the wood. I'm worried that moving around the deck will cause some of the caulking seams to get pulled out.

I'm looking to trim the level of the caulking back so that it is level with the surface of the teak. Anyone done this?

What tools are available?

It feels like I need a really sharp blade that can be drawn along the seam at an angle so that it is slicing the top off the caulking. I thought about using a chisel, but am worried that even a sharp chisel might rip the caulking out. Also, if the angle is not perfect, the cut will be too shallow, or will gouge the teak. I do not want to lose any wood in the process.

Whatever tool is used needs to get in close to the coachroof and toe-rail, so needs to be small and compact. It will also need to be able to be re-sharpened.

Thoughts, please?
 
If it is proud by a couple of mm. it is possible it is coming loose. Normal wear will leave it just slightly higher than the teak, unless you scrub the deck an awful lot, or it is in a non trafficed area, (teak is actually very soft) If it is secure you might be better to leave it as is, unless you always go barefoot it should wear down with boot traffic over the deck. It will give you good grip in the meantime.
I have tried trimming off after putting in Sikaflex deck caulking and found a new Stanley knife blade would cut that, I kept the masking tape in place either side until it was trimmed to avoid nicking the surface of the teak and to avoid going too low but it is a mornings work to do a few feet. The blade will need to be almost flat, a bit of broken hacksaw blade secured across the back half of the blade with duck tape or similar will give enough angle and give you something to grip. You can try lubricating the blade with a bowl of soapy water.
I am not recommending you to do it though.
 
I did it about 8 years ago on my deck, using a small craft knife (the type which takes scalpel blades). I can truthfully say it was a tedious and seemingly never-ending job! Frequent replacements of the scalpel blade helped. After trimming off the excess caulking I lightly sanded the deck. The result didn't look bad.

teakdeck2002.jpg
 
If you do decide to trim the caulk try a sharp Stanley blade,as suggested,held in a Stanley plastic handled window scraper - draw sideways when held at 90 deg to the seam.
 
Stanley knife blade, then palm sander. Tedious job. Grind off the end tips of the blade if you can otherwise you will occasionally dig into teak. Replace blade as soon as it stops cutting like butter.
 
If you do decide to trim the caulk try a sharp Stanley blade,as suggested,held in a Stanley plastic handled window scraper - draw sideways when held at 90 deg to the seam.

It's usually the case that the teak isn't worn as much immediately next to the caulking, so you have to be very careful not to let the blade bite into the teak. As a result, the blade has to be almost horizontal. Whilst Stanley window scrapers are excellent tools, the angle of the blade is too great for trimming caulking.
 
I used a blade out of a small block plane. It lay flat on the deck and as it was only sharpened on one side (unlike a stanley knife blade which has a double bevel) it cut true and could not dig in to the deck
 
I haven't had to do mine yet but was advised last year that I should try a very well-sharpened woodcarving chisel, which is what I intend to use when I have to. The chap who advised me also said that it is a mistake to leave the caulking proud since walking on it detaches it from the adjacent wood and allows water to get in.
 
If you do decide to trim the caulk try a sharp Stanley blade,as suggested,held in a Stanley plastic handled window scraper - draw sideways when held at 90 deg to the seam.

Here's a tip if using a window scraper.
I learnt this wheeze from two guys who peroiiodically remove posters from windows, etc.,

Take a plastic scraper and grind down the underside of the handle to suit.
The effect of this is that the blade angle is reduced.

Grind down until the blade is 1/4 to 1/2 mmm off the surface.

Check the clearance as you grind by using a piece of plate glass.

Use the new contraption by sliding along at an angle.

If the distance between the two seams is too narrow you can grind off the outside edges of the blade to clear the seams on either side, so you can reduce one seam at a time.
 
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It depends on the type of caulking. If it's Sikaflex (or another polyurethane based caulking) you can actually sand it down to be level with the teak. If it's Silicone (like Hallberg uses) then you are in for a treat. I tried a few options myself as described above on our previous boat but in the end I had to remove all the old silicone, clean the seams VERY well to be able to re-caulk with Sikaflex. A horrible job, but if done carefully very rewarding as well. The point is that silicone and polyurethane do not adhere to each other, not even a little bit.
 
Another method is to take a hacksaw blade and draw it across an oilstone, removing the edges of the teeth that protude either side until the whole blade sides are smooth. This makes a very efficient cutting tool, not only for trimming caulking but also for trimming down teak buttons.
 
I haven't had to do mine yet but was advised last year that I should try a very well-sharpened woodcarving chisel, which is what I intend to use when I have to. The chap who advised me also said that it is a mistake to leave the caulking proud since walking on it detaches it from the adjacent wood and allows water to get in.
Good advice, it's what I use. But I do ensure the chisel blade is very, very sharp and it has to be a broad one to spread the pressure on the wood either side of the seam to minimise digging in. Held with the bevel down and adopting the right pressure and angle, it does the best job in my opinion - and I think I've tried most things. But it does need some practice to get perfect.

As aluijten posts, there is quite a difference in silicon or polyurethane based caulking and, as stated, the former can be difficult by not cutting smoothly - ending up as a wave-like surface that needs sanding.
 
In areas that are easy to get to has anyone tried a hand held electric planer with new blades or a new router cutter to take off extra caulking? I can imagine you would have to travel at a very slow speed??
Or how about a Fein Multimaster - experimenting with different blades I reckon this should certainly be possible.
Fein also do special 3,4 and 5mm cutters that will go to the bottom of the plank to remove the caulking altogether, having a depth stop fitted to the side of the multimaster.

If caulking is 30+ yrs old what type will it be?
 
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