Can a crack at the foot of a mast be fixed?

C

carl170

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halcyon23.blogspot.co.uk
I have been looking at a boat for sale and it all seems sound apart from a crack at the very base of the mast which is about an inch long going straight up.

Does anyone know if alloy can be repaired easily?

Thanks

Carl
 
I thought the correct solution was to drill a hole at the top of the crack to stop it progressing.
 
carl170 said:
I have been looking at a boat for sale and it all seems sound apart from a crack at the very base of the mast which is about an inch long going straight up.

Does anyone know if alloy can be repaired easily?

Thanks

Carl
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Have to drop the mast to weld it and find a man who will bring his TIG welding gear to you. Or find the end of the crack and drill it to stop it propogating and then make a patch and drill and pop rivet it
 
carl170 said:
I have been looking at a boat for sale and it all seems sound apart from a crack at the very base of the mast which is about an inch long going straight up.

Does anyone know if alloy can be repaired easily?

Thanks

Carl
Click to expand...

We are missing important information here: what is the mast made of? Others seem to have assumed it's made of aluminium alloy. Perhaps it's a wooden spar: that would make welding and riveting fun!
 
I had a few crack appear in the foot of my mast and I got a firm (in Chichester marina, if I remember correctly) to make and weld in place a 5mm thick aluminium collar about 100mm deep right around the base of the mast. They did a brilliant job and the price was very reasonable.
 
Thistle said:
We are missing important information here: what is the mast made of? Others seem to have assumed it's made of aluminium alloy. Perhaps it's a wooden spar: that would make welding and riveting fun!
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Perhaps there's a clue in his post:

"Does anyone know if alloy can be repaired easily?"
 
Best to find out what has caused the crack in the first place. It could be that the mast foot casting, fitting inside the bottom end of the stick, has expanded. This can be caused by water being trapped inside at the bottom of the cavity and leading to 'salt' encrustations. I would first remove such a casting to check and then have the crack welded. The addition of a drain hole just above the foot casting would also prevent similar problems in future.
 
Daydream believer said:
Bronze is an ALLOY so it could be the banding round the base of the wooden mast :nonchalance:
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That's an extremely interesting and intriguing suggestion.

I've only owned two wooden boats and neither had bands of any kind around the mast foot. They both had the usual tenon worked into the foot which engaged with a mortise in the mast step.

I have just had a look in "Yacht Construction" by K.H.C. Jurd, C. Eng. AMRINA, formerly the Technical Manager at Camper & Nicholson Ltd., and he makes no mention of such a band being fitted to the foot of a wooden mast, although he does describe the other bands and fittings one would expect to find on such a mast.

Have you yourself seen a bronze band around the foot of a mast? If so, it must have been on a very finely-constructed yacht.
 
carl170 said:
I have been looking at a boat for sale and it all seems sound apart from a crack at the very base of the mast which is about an inch long going straight up.

Does anyone know if alloy can be repaired easily?

Thanks

Carl
Click to expand...

Hi, from a technical point of view, alloy is not an easy repair. IF you find a coded welder or a company with EXPERIENCE in welding alloys (I’m assuming Aluminium because that is the easiest one) then they can weld a plate on top to reinforce the mast. BUT a 1.5-inch crack has not evolved out of nothing, there must be other stress areas, normally the affected area will be at least 4 to 6 times bigger in area. You will not be able to see the micro stresses but the crack only appears after they formed and is the final result of said stress. A surveyor should be able to inform you of the repair.
I must add that I am not coded for Aluminium, I am TUV coded for Stainless / and some other exotic forms of steel. That job asks for someone that really knows what he is doing. Having found him, that should not be too expensive, it’s a couple of hours and a bit of material at worse.
It’s the welder not the crack … you need someone that really is good at Alu. ( or coded ) best is referrals.
 
I would be inclined to suggest OP buys the boat if he likes the deal and either ignores the crack or pop rivets a piece of alloy around the base and over the crack. As said it probably was caused by corrosion of a alloy plug in the bottom of the mast. This probably can not be removed and would require you cut off the mast to the depth of the plug. The corrosion in itself will not cause a big problem being surface corrosion in the faying surface between the mast and plug.
This part of the mast is only subjected to crushing forces (trying to shorten the mast) from pull of the stays. Rather than fail completely it will slowly crumple causing loss of rig tension and obvious folding out of the metal.
I foolishly mounted turning blocks with cut outs near the base of my mast all in one level near the bottom. With age and corrosion the remaining metal did crumple by a centimetre or so. The fix was to weld on additional sleeve outside. Certainly not catastrophic failure. olewill
 
penberth3 said:
So he should have said "Ally".
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Even if he had, we'd be none the wiser. Only if he'd written it...;)

Whatever it's made from, and whether deck- or keel-stepped, I daresay the OP gets the picture by now. If he plans to have the vessel surveyed, he might ask the surveyor in advance for his view on such an issue which, in turn, might be of interest to any future insurer. Could save money and hassle further down the line. A photo might help with that.
 
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