A sleeve on a cut mast

[RupertW]

We and some trouble at the end of this season with our mast being damaged (we think) by another boat catching it's rigging in ours at some speed when we were parked and away from the boat.

Our insurers have played their part in agreeing to fund most of the remedial work and getting better prices for some parts.

The actual damage is that the mast has been squashed in by one lower crosstree and that indentation has a smallish vertical crack at one edge.

New mast was the ideal option as the idea of a sleeve around the weak bit was not something I'd want to rely on or find easy to sell the boat on with, I think.

So all going fine, about to put the order in and the mast makers says, "You do understand that the mast will need to be cut in two to be delivered but we make and supply a sleeve to make it as robust as an uncut mast".

Options - go with it?
- keep the existing mast and get a sleeve made around the weak bit?
- go to a much more expensive but local mast maker (unknown reputation) who wont have to cut their mast, and negotiate with the insurer about me paying the extra
- or.....am I worrying about nothing?

 

[MoodySabre]

I've noticed several boats in the marina have masts with a join. Must be fairly normal and as long as the mast supplier warrants the mast against failure and the insurance company are happy then I wouldn't worry.

 

[dt4134]

I understand masts come in 40' sections anyway so they can fit into containers. If your mast is over 40' it will likely need a join.

Sleeving is a pretty common technique, so I imagine it is well understood and should be pretty safe when done by the right people.

 

[Rigger Mortice]

I'ld rather take the advice from a reputable manufacturer than risk a botch up from a local, but unknown, supplier.

 

[Zen Zero]

The same thing happened to us! 4 boats and a piece of pontoon went for an impromptu trip downriver in a flood. The result could have been a lot worse. We were lucky to get away with a squashed mast at crosstree level.

The solution, that has worked so far (2 years), was to rivet on two "cheek" plates, cut from a larger scrap mast that the riggers had lying around (am I going to get screamed at here?). Our mast already had a join in it (and it's only 10,5m long), with an internal sleeve held in place with rivets, I have no idea why.

What worries me about yours is the crack! Cracks are bad news! Cracks are stress concentrators and will tend to grow unobserved and fail with dangerous results when you are least expecting it. Get rid of the crack! Remove the length of profile with the crack in it. You can "cut and shut" the mast which will then be 10cm or so shorter, and add a bit at the foot to make up for it.

 

[lw395]

I'm sure it will be fine, but I would still be getting quotes from other suppliers, to see if a single section is possible.
A lot of masts not only have joins, but also reinforcement of the lower section to take the thrust of the spinnaker pole.

I suppose that transport of a single whole mast is expensive now that I believe a lot of ali masts are made in Poland.

Also who joins it back together? Is that a fool proof process or is some poor bloke going to be struggling with it in the marina carpark, resulting in a misaligned rig and a track that catches every time?

 

[30boat]

I was told by Z Spars when I bought my mast that these days most masts are supplied in two or more parts because of the cost of shipping.They call it an egineered joint and it is very strong.I assembled the two halves myself and it was a simple matter of screwing (with loctite)loads of little screws in.There's no possibility of misalignment because everything is predrilled and tapped.

 

[Fantasie 19]

I've noticed several boats in the marina have masts with a join. Must be fairly normal and as long as the mast supplier warrants the mast against failure and the insurance company are happy then I wouldn't worry.

+1 ...these guys know their stuff and have been doing it far longer than we have....

 

[merlin3688]

Most most companies use joins. Z Spars have longer sections however even they use joins when the masts are longer then they have. If they do a join it is assembled in the factory and then taken apart for transport, fairly easy to push back together and fasten.

 

[jwilson]

We and some trouble at the end of this season with our mast being damaged (we think) by another boat catching it's rigging in ours at some speed when we were parked and away from the boat.

Our insurers have played their part in agreeing to fund most of the remedial work and getting better prices for some parts.

The actual damage is that the mast has been squashed in by one lower crosstree and that indentation has a smallish vertical crack at one edge.

New mast was the ideal option as the idea of a sleeve around the weak bit was not something I'd want to rely on or find easy to sell the boat on with, I think.

So all going fine, about to put the order in and the mast makers says, "You do understand that the mast will need to be cut in two to be delivered but we make and supply a sleeve to make it as robust as an uncut mast".

Options - go with it?
- keep the existing mast and get a sleeve made around the weak bit?
- go to a much more expensive but local mast maker (unknown reputation) who wont have to cut their mast, and negotiate with the insurer about me paying the extra
- or.....am I worrying about nothing?

When you buy a brand new boat with a constant-section mast, it is pure chance whether or not it has a sleeved and riveted join in it from new. The alloy mast section gets manufactured in long lengths, and if it is only enough to make (say) 4.3 masts the fifth boat's mast gets a joint, rather than throwing away 0.7 of a mast. So there is nothing inherently wrong with a joint in a mast.

 

[RupertW]

All good advice and much appreciated.

I'm still wondering what the great advantage is with having a new sleeved mast compared to old sleeved mast but from what people are saying, a new one will have a sleeve designed into it. Keeping the old one means i need the sleeve in the visibly damaged place, and who knows what else could have been damaged.

 

[Quandary]

When you buy a brand new boat with a constant-section mast, it is pure chance whether or not it has a sleeved and riveted join in it from new. The alloy mast section gets manufactured in long lengths, and if it is only enough to make (say) 4.3 masts the fifth boat's mast gets a joint, rather than throwing away 0.7 of a mast. So there is nothing inherently wrong with a joint in a mast.

Are you sure about this? Any examples? The only boats I know with internal sleeves from new are older designs like the Sigma 38 where it is a constantly located feature on all of them. Why would a purchaser of a new boat accept a randomly positioned sleeve with consequent affect on mast bend and shape when he could have a good one. Perhaps they could use the left over section for a boat with a shorter mast, motor sailer or similar, would seem more sensible than persuading a minority of customers it was not a problem. More masts are a lot longer than 12m. these days but you see very few new boats with sleeves, another complication is that most masts have sections which include integral conduits and multi directional internal batten car tracks.
In response to the OP I am sure properly done at the spreader roots it would be fine structurally and might not affect the curve too much still allowing the mainsail to be kept flat but perhaps other future customers would be put off by a sleeved repair no matter how well done, and would adjust their offer accordingly.

 

[merlin3688]

All Selden masts over 12mtrs are joined, Z Spars and possibly Sparcraft can supply up to about 18mtrs in one length and had a selling point of "why buy a mast that has a join in it"? The join make no difference to the mast and could make it stronger as the part joined is double thickness. Go and look in the local Marina, a lot of masts are joined. In the good old days at Sailspar when we had oval sections that needed joining we used to rivet and fit a s/s band around the join, hours was spent trying to line up the tracks on both sections!

 

[William_H]

mast repair

I presume that your boat is a GK 24 so about 10 metre mast.
I would prefer a local mast supplier who can provide a mast in one piece to a reputable one who would supply in 2 pieces with a join. This if you (the insurance company) are going to replace the mast.
If you have to pay for the mast yourself I would go for a reinforcing outside sleeve under the spreader bases. This should spread the end load of the spreaders. Cover up the dent and reinforce the crack.
good luck olewill

 

[Quandary]

All Selden masts over 12mtrs are joined, Z Spars and possibly Sparcraft can supply up to about 18mtrs in one length and had a selling point of "why buy a mast that has a join in it"? The join make no difference to the mast and could make it stronger as the part joined is double thickness. Go and look in the local Marina, a lot of masts are joined. In the good old days at Sailspar when we had oval sections that needed joining we used to rivet and fit a s/s band around the join, hours was spent trying to line up the tracks on both sections!

They make a hell of a neat job of it then, mine is 15.75m.(Selden MDS) and I have not been able to find the join and I have been looking at it for five years. I was right to the top of it on Sunday and the grip I had on it with my quivering thighs would surely have revealed the join if it was there, I suspect that the info. you have been given is a decade or so out of date.