Need to know if PVA is flexible enough and can it take the flexing?
I have heard of Airalite??? can u still get it, would it be better?
Cheers all
Pete
Glueing up an OK Mast (Wooden)
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Brian E. Evans
- Posts: 127
- Joined: Sat Oct 02, 2004 6:31 am
- Location: USA
- Contact:
A couple of quick Questions. Are you doing a repair or is the mast completely apart?
Aerolite would be fine if the mast is apart and both sides of the wood are clean. With this glue a hardener is placed on one side of the wood and the glue on the other, it does not start to cure until the two parts are brought together.
PVA glues will soften if immersed in water which is ok if you do not intend to capsize your OK.
To me a better glue is the one part polyurethane type such as Gorilla Grip or similar,When cured this glue is water resistant and is a gap filling glue. Ed and a few of the other Unterlords may swear by epoxy and that is fine too.
B.E.
Aerolite would be fine if the mast is apart and both sides of the wood are clean. With this glue a hardener is placed on one side of the wood and the glue on the other, it does not start to cure until the two parts are brought together.
PVA glues will soften if immersed in water which is ok if you do not intend to capsize your OK.
To me a better glue is the one part polyurethane type such as Gorilla Grip or similar,When cured this glue is water resistant and is a gap filling glue. Ed and a few of the other Unterlords may swear by epoxy and that is fine too.
B.E.
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Stephen Hill
- Posts: 33
- Joined: Mon Jan 31, 2005 1:46 pm
Yup as Brian says....I swear by Epoxy for this kind of join in this kind of application
Aerolite would certainly work....as would a resorcynaol glue.
I wouldn't use PVA though....even a waterproof pva.
Although masts bend, I doubt that it is enough to break the glue joint. Having said that I have never fixed an una rigged mast.
Your other possibility is a foaming polyurethane as Brian suggests. Balcotan is what I have used. I don't particularly like balcotan in very structural joints under much stress....but in this case there is plenty of joint area, so it should be ok. It is however a very messy glue and sticking two sides of a mast together can be a very messy job, which I think would persuade me to use epoxy which is a little harder, but a little cleaner to use.
mmmmmm....actually the more I think about it the less I would like to use Balcotan. The problem with fixing a mast is getting enough clamps on it to secure (but not remove all glue from joint) and keep the mast straight. As balcotan foams, it can push a joint appart unless it is really well clamped.....so you would need lots of clamps. the other thing that would worry me is that the glue will expand into the mast track from the internal joint and that could be a complete nightmare to remove.
I think that whatever glue you use, you really need to get all the mast apart and really clean all joints of any old glue.
cheers
eib
Aerolite would certainly work....as would a resorcynaol glue.
I wouldn't use PVA though....even a waterproof pva.
Although masts bend, I doubt that it is enough to break the glue joint. Having said that I have never fixed an una rigged mast.
Your other possibility is a foaming polyurethane as Brian suggests. Balcotan is what I have used. I don't particularly like balcotan in very structural joints under much stress....but in this case there is plenty of joint area, so it should be ok. It is however a very messy glue and sticking two sides of a mast together can be a very messy job, which I think would persuade me to use epoxy which is a little harder, but a little cleaner to use.
mmmmmm....actually the more I think about it the less I would like to use Balcotan. The problem with fixing a mast is getting enough clamps on it to secure (but not remove all glue from joint) and keep the mast straight. As balcotan foams, it can push a joint appart unless it is really well clamped.....so you would need lots of clamps. the other thing that would worry me is that the glue will expand into the mast track from the internal joint and that could be a complete nightmare to remove.
I think that whatever glue you use, you really need to get all the mast apart and really clean all joints of any old glue.
cheers
eib
Ed Bremner
CVRDA
Jollyboat J3
Firefly F2942
IC GBR314 ex S51 - 1970 Slurp
MR 638 - Please come and take it away
Phelps Scull
Bathurst Whiff - looking for someone to love it
CVRDA
Jollyboat J3
Firefly F2942
IC GBR314 ex S51 - 1970 Slurp
MR 638 - Please come and take it away
Phelps Scull
Bathurst Whiff - looking for someone to love it
If using polyurethane foaming glue (balcotan is one that comes recommended by many) you will need to clamp it every few inches (probebly twice as often as epoxy), as the foaming will push the joint apart otherwise. I would use epoxy for the job, and wouldn't touch PVA with a barge pole.
Another glue I used to use alot but don't any more (just got out of the habit when I ceased doing much cold moulding) was Cascophen, a resorcinol formaldihyde glue, which is easier to use than epoxy, and doesn't foam like balcotan. I expect Robbins timber still sell it, and it would be strong enough for the job.
Another glue I used to use alot but don't any more (just got out of the habit when I ceased doing much cold moulding) was Cascophen, a resorcinol formaldihyde glue, which is easier to use than epoxy, and doesn't foam like balcotan. I expect Robbins timber still sell it, and it would be strong enough for the job.
Rupert
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Alan Price
- Posts: 115
- Joined: Sat Sep 18, 2004 9:37 pm
If the joint on a mast is split but not all the way what is the best way about getting the joint open enough to get a fresh lot of epoxy in. I may have to do some work on the mast of 111. Someone has put bolts (I think they look like guttering bolts!) right through in two places and also there are a couple of copper rivets which makes me think that it may have come apart in the past. As the bolts are steel (why on earth do people do this?) I would like to get them out and hopefully peg the holes but perhaps it won't be possible. However if I can get epoxy in there I should think that anything is possible. Jim - you advise SP106 - what aditive do you use bearing in mind that I would like to varnish the mast after repair so would like to keep it clean.
Caveat - I've never glued a mast back together
(though there's one in the garage roof that needs it). My biggest mast job has been a new balsa fairing on my Bethwaite wooden wing mast.
If its split but not all the way you have to think very carefully about how good the rest of the glue is actually likely to be... I'd tend to use something like a palette knife to ease the two sides apart. Smart money is if you do so the crack will propogate, thus showing the rest of the glue is NBG anymore either. In that case it would probably make sense to bite the bullet, dismantle completely and then you can really clean up the surfaces. No point in gluing epoxy to old glue which will just come off again. Don't forget to organise some sort of jig so that you can be sure the mast is setting dead straight.
Fillers. depends on the raw wood colour. 106 is lightly brown anyway, so just thickened with some microfibres for strength may be ok. If the wood is darker then mixing in a greater or lesser amount of microballoons would darken it a bit, but they are natively sort of mahogany colour so don't overdo it. Make up some test mixes and play! Also you want the mix to be fibre-rich for strength.
(though there's one in the garage roof that needs it). My biggest mast job has been a new balsa fairing on my Bethwaite wooden wing mast.
If its split but not all the way you have to think very carefully about how good the rest of the glue is actually likely to be... I'd tend to use something like a palette knife to ease the two sides apart. Smart money is if you do so the crack will propogate, thus showing the rest of the glue is NBG anymore either. In that case it would probably make sense to bite the bullet, dismantle completely and then you can really clean up the surfaces. No point in gluing epoxy to old glue which will just come off again. Don't forget to organise some sort of jig so that you can be sure the mast is setting dead straight.
Fillers. depends on the raw wood colour. 106 is lightly brown anyway, so just thickened with some microfibres for strength may be ok. If the wood is darker then mixing in a greater or lesser amount of microballoons would darken it a bit, but they are natively sort of mahogany colour so don't overdo it. Make up some test mixes and play! Also you want the mix to be fibre-rich for strength.