glue for wooden mast

charliespan

charliespan

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Dad is currently repairing the hollow wooden mast on his
dutch botter. The four longitudinal sections forming the mast
are beginning to separate . Can the forum suggest a good strong
adhesive for re-joining the sections ? Ease of application and strength
would be preferred over "traditionality" of materials.

I've searched the forum re: glue , but nothing exactly answers
what we are trying to do.

Thanks

SC
 
I assume he's going to separate them completely and not try to poke glue down the cracks. The polyurethane type of adhesive - Balcotan is one brand name- has all the performance needed and is so easy to use - no mixing just squeeze from tube. I did similar decades ago and main problem was cramping it up ; getting enough and also getting them tight before it went off.
 
to "cramp" it up, use big jubilee clips. just the job, or a couple or three smaller ones, screwed together. They are cheap enough in galvanised,
 
I suspect that the original adhesive may have been epoxy. As epoxy is affected by UV, unless over coated with a varnish containing a UV screen the same may happen again. I would suggest using a resorcinol such as Cascophen (not below 50 degrees C!) or polyurethane.Preparation is every thing, you will have to remove all traces of the old glue and degrease thoroughly.
 
What part of the epoxy is subject to UV degadation? That part the suncan get at. That means the actual glue line only. It does degrade the whole joint, just that part exposed.
My mast extension is epoxy glued, 14 years so far and no sign of degradation, as are most wooden masts these days.
 
You can buy incredibly heavy duty cable ties quite cheaply that would be suitable for crampng up a hollow mast, pull the tie as tight as it will go and then knock some wooden wedges under the tie to make it tighter.
You can reuse them as well.
I got mine from Tools UK at a show but I see that they sell them on EBAY.
ToolsUK Ebay
 
Epoxy will not hold the humidity in the wood will cause the joint to fail.PPU glue will hold but i wouldent recomend it.
Masts have been glued for many years and masts glued with aerodux and cascomite have stayed intact for years, the mast on my old EAsloop is now over 45 years old and still fine,at least the new owner still has the same mast up,where as a scaff glued with PPU failed (not sure how old the repair was)
 
I cant help there.Epoxy isent good for wood.Just try and see

Ive used PPU which dose work but again id rather use a glue thats known and seen to work well for a long period in real conditions

Use epoxy if you prefer just remember to tell a future owner.
 
You are completely wrong!

Epoxy is used world wide for wooden boat manufacture, I can only assume, you are getting mistaken with another type of glue.
Cedar strip boats are built with epoxy, for a start!

Read some of the old posts on here, search for them, you will see.
 
I wont argue with you about to epoxy or not as ive never much used it for wood.

When i saw the west system for example and the strip/stitch & epoxy glue wooden boat construction they said that they could get the moisture leavel to that needed,but for existing wooden boats wouldent recomend the use of epoxy,becouse of high moisture levals while the glue sets.

So epoxy can be used with sucess on wooden marine construction.Ill only say that i personaly would stay with cascopheine or aerodux,I do fully agree with what you say and boats built and glued with epoxy do do very well.

I did once route out and spline a Dragon for someone and he insisted i used epoxy.The work was awful as i got my hands epoxied as well, when the job was done it became a plastic Dragon eater,very stiff.The splins are still ok and i did that in 1988 but thats only 20 years ago how much longer the glue will hold i cant say.

So far then epoxy has held together for almost half as long as a mast glued with aerodux! If you wait another 20 years i can post again to tell you how if the splines are still holding??
 
Yes, epoxy will hold fine if the timber is not too damp and is the best for bridging gaps caused by innacuracy, warping and insufficient cramping. Polyurethane is an option but I would not use a fast glue on a job which will take time to do. Late assembly of Pu glue joints is bad news.
 
Many wooden spars used to be glued with Casein glue but it was not very water resistant.
The best Glue for spars is still Aerolite 306 which is a two part urea formaldehyde similar to cascamite but better, it was developed in ww2 for aircraft construction particularly the Mosquito fighter bomber.
I beleive you can still get it and it is fully UV resistant, you will need loads of clamps when regluing a mast and have a dry run first to get all the clamps set nearly to length, you will find the glue goes of rather fast whatever you use!
 
I agree with epoxy. Use microfibres as the thickening agent, make sure the mix proportions are absolutely accurate and that you avoid exothermic reactions by thorough mixing and not leaving the mix in the pot (ie spread it on the job quickly or even empty the mix into a shallow container). Before you start, do a dry run, so all your clamps are set up and ready to hand.
PU glues do not have a long enough open time to allow for a large complex glueing operation. As for Cascamite (or its modern day equivalent) I feel that it is much too brittle for a mast. Personally I wouldn't use it - ALL the cascamite jobs I've ever seen have suffered from failure at the glue line. Aerolite 306 is a glue that I would consider using, as I know it has been use for composite spars, but it has poorer gap filling properties than epoxy, and that might be important if you're re-glueing a mast using the original parts.
Most varnishes are fairly UV resistant, and paint obviously is, and anyway, UV is not an issue as it doesn't penetrate timber to my knowledge.
 
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