Rubbing strake/wood bending advice

I did a similar job on Avocet some years ago. I used teak "L" section and found that it bent fairly easily to the curve of the hull when cold. The OP doesn't say whether the 2"part is vertical, but I assume it is? Avocet's was about 1.25" (horizontal) and 1.5" vertical. I used a 6:1 scarph and if I was doing it again, I'd make it 8:1. Also, when glueing the scarph, I soaked the ends of the teak in acetone for about 10 minutes to get as much ofthe wood's natural oil away from the joint as possible. I then used epoxy as the glue.
 
Thanks for all the advice guys. I went over to the boat and the strake could actually end up very slightly narrower and shallower as the original is. This would mean that the need to steam could be avoided.

One thing I didn't ask was about the type of mastic/ bedding/sealant to use?

What is the best method? I noticed that my previous boats appeared to have a non-setting putty type bedding.

You're all a great help - thanks again. :)
 
Avocet said:
I used a 6:1 scarph and if I was doing it again, I'd make it 8:1. Also, when glueing the scarph, I soaked the ends of the teak in acetone for about 10 minutes to get as much ofthe wood's natural oil away from the joint as possible. I then used epoxy as the glue.
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This is good advice. Did you screw as well as glue? Also, I have been advised to consider a stepped joint as opposed to a scarf.

Any opinions?
 
No I didn't because, being L shped in cross section, there wasn't really enough "meat" to gat a screw to bite properly. That said, the rubbing strake is mechanically fastened to the side of the hull with several dozen 6mm screws and nuts on the inside of the scuppers (yeah, it looks great (NOT!) but I was stuck with that arrangement from the previous owner. In effect, the hull-to-deck joint is such that at the top of the gunwhales, there's a vertical upstand about 3" high all round the edge of the deck, so the fasteners pass through the wood, the side of the hull, and the side of the deck moulding. What I DID do, was to plan the positions of the scarph joints so that at least one of the fasteners would pass through the thickest part of each joint before passing through the hull-deck joint. Unfortunately, some utter scumbag must have had a "berthing incident" and I came out to the boat one day to find several dep gouges in my new rubbing strake and one of the scarph joints had "popped" open at the tip. That resulted in me having to re-glue it AND put a second fastener through it nearer the tip - hence my inclination to do an 8:1 joint next time, so that (a) I'd have a bigger glue area and (b) the "thin end of the wedge" (so to speak!) would be sufficiently thin to have very little stiffness compared to the glue. Had I thought about it at the time, I probably should have gone for the stepped joint!

I didn't use any sealant / mastic / bedding compound, by the way. I figured that as teak is pretty rot-proof stuff anyway, I'd prefer the water to be able to get under it and run back out than to try and prevent it getting under in the first place and risk it getting trapped under there. It also makes the strake very easy to remove for varnishing every few years. On the other hand, it could also be argued that if I HAD bedded it to the hull, the impact might not have popped the joint!
 
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Avocet said:
I'd prefer the water to be able to get under it and run back out than to try and prevent it getting under in the first place and risk it getting trapped under there.
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My thinking is similar although I will run a bead of brown Sikkaflex around the joint on the top of the strake to prevent water entering from above but will leave the underneath to breath.

Incidentally, I got a great deal on Iroko from my local yard here in County Down. They have charged my £97 for 68' of 2"x1" planed all round. In 2x16' lengths and 3x12' lengths.

This is beat the highest price of £190 from another local supplier. It pays to shop around.
 
Earlier this year I had to bend 100 x 22mm mahogany for the hull and 50 x 40mm oak for the strakes. I tried it cold but was terrified I was going to strip the ribs. I made a long box out of 3/4 ply and used a wallpaper stripper. Steamed the timber for about an hour and clamped the wood to a bench having placed a piece of wood under where I wanted the bend to be. Worked a treat. I'm of the opinion that if you're replacing a single piece of wood (into a 'blind' gap) you are far better bending it off the boat. Less stress for a start.
I enjoyed my steamy session, then, don't we all....
Hope this helps, Stu
 
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I just thought I would report back in and let everyone know that I single handedly removed, made new and fitted a new iroko rubbing strake.

Definitely a win!

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My first sight of a "boatbuilder/repairer" was at Bingham's pond in Glasgow of all places, and the equipment used was a piece of cast iron roanpipe blocked at the lower end, bonfire underneath, water and wood inside.
Fleet of clinker boats well kept, in spite of what we did to them.
That's the way to do it.
 
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