I broke my mast in half at the boom. Does anyone have advice on repair?

Any repair there is not going to last. If you do repair it, it's only good for teaching beginners in light winds.

It really can't be repaired at all for high performance applications. Most manufacturers however will sell just the bottom half so that the top can be reused, assuming it's a pretty recently produced mast.

For rigging a no-downhaul tension rig such as a child's rig you can cut out the broken area and bodge up a ferrule from the tip of an old mast, but really it's probably best to just discard. Most sails are pretty sensitive to bend curve and any reasonably durable repair you were to attempt would create a very stiff section.

If it broke right at the boom you might want to consider whether you were overtightening the boom clamp. Some high-leverage booms like Mauisails want to be just tight enough to snap shut and not much tighter, or they'll put a big point-load and crushing force on the mast.

Thanks for all your comments. Very helpful information. I will probably end up not repairing this mast, but if it makes a difference, this mast would only be used for a Kona sail, which is a non-cambered, non-high performance, not a lot of downhaul kind of sail. Does this make a difference in the repairability? Thanks.

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StanSloan said..
Thanks for all your comments. Very helpful information. I will probably end up not repairing this mast, but if it makes a difference, this mast would only be used for a Kona sail, which is a non-cambered, non-high performance, not a lot of downhaul kind of sail. Does this make a difference in the repairability? Thanks.

No not at all. The Kona sails aren't super high tension but they'll still bend the mast quite a bit and it'll fail. About the only sail you could use would be one where the mast is essentially straight even under sail - a kids rig or maybe an old stock Windsurfer sail.

It's important to understand that a windsurf mast is not a flag pole and in windsurfing an engineered tube is created to flex to the shape of the sail's luff panel.
The bending of the tube then provides the spring load and controlled flex that allow the sail to self regulate when a gust hits.
If you break a fibreglass or epoxy or carbon mast then it cannot be repaired, because the structural weave has been compromised.

Thanks. I won't be repairing this one.

You will still be able to reuse the top part with a compatible bottom. You can look for bottom halves alone.

As a side note, to avoid swimming back you can remove the top of the broken half, flip the mast top upside down back inside the sail and slide it down inside the remainder of the broken half. You can pull the top of the sail over if you want. Takes seconds and yes you'll still be able to plane back!

Just bear in mind, the masts you buy these days, have been cut in half and you rejoin them with a spigot.
Not an impossible job to repair a broken mast, but you'd really have to know what you're doing. Safest way is to replace with new.

I've repaired a Severne 550 100C that went bang bcoz spigot wasn't seated correctly when downhauled. Still going strong 3years later. It crushed the inner spigot n split the outer about 100mm.
I found a suitable taper 100C spigot about 200mm. Epoxied into the inner lower piece. Sanded down the damage n rebuilt to correct diameter using carbon n final layer of 2oz glass.
The top was the hardest. Had inner n outer diameters to consider. Covered the lower spigot in mould release then slid the top on. Another collar of mast was slid down the top to compress the outer to correct shape n size. Layed up the carbon above this..After curing I cut the small ring off n continued with carbon. Finally a 2oz glass layer over. Built up inside n sanded to suit rebuilt spigot.
Super super hard to get mast PERFECTLY straight. I ended up with about 5mm run-out over 550 at tip when mast rolled on ground.
Yes it has changed the bend curve very slightly. But nothing to worry a Recreational sailor.
See if I can find a pic somewhere.

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StanSloan said..
I broke my mast in half at the boom. Does anyone have advice on repair?

There is nothing worse than breaking a mast a long way from home. I like to have confidence in the reliability of my gear, particularly my mast and boom.

If you repair and use the mast, there is a risk regarding the reliability of the repair, hence you should also practice your in the water derigging skills and paddling with all your gear rolled and on top of your board.

Your safety and life is worth more than a replacement $300 mast.

The mast I repaired was $1200+ to replace. Well worth the effort. After fixing we put it thru far more side load than ANY sail will produce. Passed with flying colours. No creaks no groans. It can be done successfully.
But the OP sez his broke at boom. Thatd be waaaay to much work to fix. If it was the ferrule I'd say give it a go.

^^ agreed. Repaired many things for people with the caveat that whilst it is good to use it is not permanent and should be a spare etc. then see the same item years later still good.
Not an engineer, just listen to those who know and some common sense.

Last mast ferrule repair I did was glued in at the factory with something like Sikaflex, very hard compared to normal silicone and urethane - and flexible. Got me wondering how many are glued with epoxy or CA, how many with flexibles and if flexible is the way to go. Be interested to hear

Can't find the before pics. But here's the end result.
Spigot was crushed about 75mm length. Just started to rub thru the 2oz glass to get a sweet fit together.

Ferrule

Damage here was about 100mm split. Was able to repair n keep the decals.
Repairing a board is a walk in the park compared to this. Finished Dimensions had to be spot on.
Thanks to Mark Australia for a few tech tips! This guy knows his stuff.

Mark, I guess using a slightly flexible bond might give the join a lil flex (curve) instead of being a rock solid straight join partway along mast curve.

I gots a 10 use 100% NP 520 mast and at the join it now has a slight angle . It's only a little . If I roll it on a flat floor it's about 20 mm high gap at the join . I'm nervous it's going to break and take a sail with it . So I don't use it . It's a shame because it's a zillion dollar mast that I'm scared to use . It's think it's the ferrule on the bottom half .
Anyone want to buy a near new expensive mast for not much ?

Imax1. Err 20mm at the join? She's stuffed. 2.0mm,however should be easily fixable. Just need to determine which bit is the weak link n reinforce it. Easier to do it now before the big bang.
You've already got all the gear to do it.

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Imax1 said..
I gots a 10 use 100% NP 520 mast and at the join it now has a slight angle . It's only a little . If I roll it on a flat floor it's about 20 mm high gap at the join . I'm nervous it's going to break and take a sail with it . So I don't use it . It's a shame because it's a zillion dollar mast that I'm scared to use . It's think it's the ferrule on the bottom half .
Anyone want to buy a near new expensive mast for not much ?

Imax i have a np 520 mast here if you want looks in good condition ,i am heading down to sunny coast early next month i can bring it down if you want

,

^ Quick visit or hangin around a bit mate?

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olskool said..
^ Quick visit or hangin around a bit mate?

in and out the same day,got the wife's fathers birthday at gin gin

Awesome grich62 , your ace