Remove caulk from between mahogany strips

My second boat (or third depending on whether or not it’s my wife counting) Is a mahogany runabout. I’m restoring the deck and have used a heat gun to strip the varnish. But now I’m needing to get the caulking out from between the strips. So... yeah. Suggestions?

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SloopJonB

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I confess to peeking past my ignore list and see that Moon has added his usual high value contribution.

Doesn't even know that white caulk was the norm on those runabouts.

I mean you can see at a glance that those are splined seams - it's obvious isn't it? :rolleyes:

There are special tools for reefing seams. The best one I found was a hooked carving chisel the same width as the seam. Worked well for short sections of repair but would be tedious for a full deck.

Some people rig up a base plate for a router with pins that follow the reefed seam - probably would work well with straight seams like yours but didn't on the curves of a sprung deck.

 
From the pics it looks fine.  If there is no separation of the caulk and wood, then sand everything out and refinish.  If not Fien sells various size reefing hooks for multi tools, probably off brands out there as well.  It's pretty easy to mess up the wood though. Teak deck systems has white seam caulk, it's the only thing I would use if you have to replace.  I have had the best luck cleaning seams with a razor knife.  Go slow and cut 45 deg into seam from each side, remove the bulk. Then cut close to the edge straight down and come back 45 to bottom each side. This will get it to a sandable clean.

 
Okay, so now that I'm going white on the seams, should I go with white Sikaflex or TDS white? Pros/Cons and experiences of those with great victories and/or dark regrets are welcome.

And do I varnish before or after? I'm assuming after, but I've been horribly wrong before.

 
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Use TDS it is designed to do exactly what you are doing, I would not use sika flex for this.  TDS sands really well and adhears to itself really well if you have to make repairs in the future.  I would go bright over the whole thing. Most people shoot the seams and putty proud then sand it all out, it's a little messier but way faster.  Just make sure the wood is all stable when you do it.  You don't want it to sit forever sanded bare then shoot and coat as it will dry way out.

 

Zonker

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And do consider a bond breaker tape to lay on bottom of seam before caulking. Then caulking only sticks to 2 sides of the wood and is less subject to breaking the bond to the sides.

Looked like white polysulphide to me.

 

crankcall

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It will be tedious but its mostly going to be hand work, and careful handwork at that as the old caulk is brittle and then you find the spot where it stuck well and you dont want to pull out any wood, that will stick out like a sore thumb. SLOW and careful i sorry to say. Make a chisel the same width as the caulk with a grinder and start whittling.

 
I would guess they are square cut seams, if so 3m fine line tape works well for a release on the bottom, Fisheries has it.  Another thing to consider is dealing with the seams first.  I would probably stop scraping and sanding till they are all reefed out.  Then sand the seams really well tape the bottom and shoot with caulk, putty knife proud.  After it's kicked sand the whole thing out.  The rubber sands harder than the wood so it acts as a nice guage to eliminate wasting too much wood. You can coat right away so you don't have to worry about it getting super dried out

 
@SASSAFRASS & @Zonker - Thanks for the tips! TDS reefing hook and 2 tubes of white ordered from Fisheries Supply. I’m gonna rewatch Andy from the Boatworks Today YouTube channel and the episode on varnish comparisons. Yay, more sanding!

 
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SloopJonB

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Couple of things - buying some rolls of masking tape and masking beside every seam makes everything much nicer and cleaner but takes a few hours of work. Cheap tape works fine as long as you don't leave it on long (days & days) or out in the sun.

Second - you will need a lot more than 2 tubes of goo unless they are BIG tubes. Those skinny little seam are long and use a lot of goo.

 




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