Best marine glue/adhesive to fix crack in wood

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NickC

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Anyone suggest the best thing to use to fix a longitudinal crack in our wooden rudder blade? This needs to be something quite thin that will soak right into the crack.

Years ago I remember using some very thin Spabond that was almost like water but don't know if that is still available.

Thanks,
Nick
 
I'ld be wary of botching a repair on a rudder unless I was confident that the crack was not the outward sign of something more serious.
If the crack is just superficial then no problem, but if it is more than that then it needs a proper repair.
 
A heat gun will not work on epoxy. All it will do is speed up the cure time. If you send me some more details I will have a look at our (Henkel loctite) product range and let you know the best product.

I will need to know what the substrate is, gap size, length of crack. Having said all that I would agree with the other poster, fir an area of such importance I would be looking at replacing the rudder.
 
Frankly if the inside of the crack is damp you are wasting your time with epoxy in my view. I have some experience of this have followed similar advice to that here in the past. The epoxy will not bond with the damp wood.

Can you tell us some more about where/why the crack is there?
 
Well it is a wooden rudder blade which seems to be splitting from the pivot bolt at the top to perhaps half way down the rudder blade. This is a solid wooden blade of about 5/8" max thickness.

Now my previous experience of wooden boat repairs many years ago using Spabond was that it dried stronger than the surrounding wood, so hopefully that would leave it at least as strong as the original solid wood.

Crack has probably been caused by someone leaving the rudder part-way down and tied off (this is a lifting rudder) while on a mooring. Rudder is now removed from the boat so can be well dried out before glueing.

The crack is not very wide at all hence the need to find a very thin adhesive so as to creep into the crack.

I have read about 3M 5200, is that likely to be suitable or is it not thin enough.
 
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Some epoxy glue such as Devcon plastic metal become very runny when heat from a heat gun is applied. Apply with a spatula and force in as much as you can, heap up more over the top and apply the heat gun. Work fast, the glue runs easily and you can hydraulic the glue into the crack with a spatula. Take away the heat and the glue goes off quickly!
 
If the crack is from the pivot bolt and has any movement as riggerm has asked, then needs more than glue feeding in.Will want a proper job doing on it drying properly gluing and clamping
 
If you can get it dry then I would put epoxy in a syringe and drill a series of suitable diameter holes along the split. Then use the syringe to force the epoxy in. I would apply tape and clamp a piece of wood on the surface to force the epoxy along the crack. From my experience you have to push very hard to get it to flow but it will and when it has reached the limit to where it will flow drill the next hole.Then repeat with slightly thickened epoxy.

I am inclined to look at how the split will be loaded though but might give the above a try and then keep an eye on it.

As for the epoxy I would use either west or SP but what ever is available.

Good luck with it and no short cuts: Think about it being loaded in a gusty F5 when yoou are hanging on to everything!
 
Some good advise there. Epoxy would certainly be a good bet. Just remember the slower the cure the stronger and less brittle the glue line will be. Look for a working life of 60mins and a fixture time of 3-4 hours, That way you are atleast sure to have as stronger joint as possible.
 
Well I had a couple of cracks between each of the two cheeks and the central blade part of the rudder so followed the 'drizzle epoxy into the cracks' route. I was unable to apply any clamping pressure of any significance but had tried to dry out the timber for months. Following year - cracks had reappeared. Last year I took the plunge and removed the cheeks - and two long sharp slivers of hardened epoxy from either side where it had failed to adhere properly because it was impossible to dry the 40 year old wood sufficiently within the crack - and no, the wood was not over saturated and I really did try to dry it. Epoxy is not good in damp applications even if it is only latent dampness. A moisture curing glue is a better option such as Semperoc (one part too but a big bottle for what you have to do). That's what I used in the repair and it has proved itself.

You could, if the crack is wide enough use some white lead putty - yes I know that sounds bizarre but it works on perfectly on seams.

I am by the way assuming that you are happy that the crack is not 'active'. If it were, then a rebuild is the only way forward.
 
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My preference would be to enlarge the split to a uniform width by sawing along it and then glue in a piece of similar wood using polyurethane adhesive.
 
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I would first make sure the timber was very dry, heating it up will help.

I would also open/widen the crack to get better access.

To bond timber I would use wet system resin mixed with Micro-fibres.

Just make sure you wet the whole area with resin only before adding the Micro-fibre mix.

I have used the above in many applications and tested to destruction, in most cases the timber fails before the glued joint.

Good luck and fair winds. :)
 
You could possibly use the wooden blade to make a fibreglass mould. Then if in future after your repair it ever does fall to pieces you'd be able to make a fibreglass replacement :D
 
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