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Pops, bust mast

Created by Ben1973 Ben1973  > 9 months ago, 7 Jul 2019
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Ben1973
Ben1973

1008 posts

7 Jul 2019 3:56am
so the top section of my mast split today, from the join and goes up about 2cm. What's the best option, cut the split bit off? There seems to be some reinforcement around the bottom cm so I would lose that Or wrap some glass around it and leave it the same length.

what I've done as a quick fix to keep sailing was a found a piece of pvc pipe about 2cm long and exactly right diameter and used it as a sleeve. Thinking this might work permanently as it was such I tight fit I may not be able to get it off.
JakeNN
JakeNN

372 posts

7 Jul 2019 4:22am
Just but a new mast. They're not that expensive and it's the safest option.
Relic
Relic

TAS

837 posts

7 Jul 2019 6:29am
After some trial and error I've found the strongest repair method is not glass. It doesn't provide strength against the bending force on the join. The PVC will shatter if placed under force.
Wrapping 5mm carbon fibre strand around the stress cracks tightly works the best. About 1m of strand per cm of fracture will do it. Plus it's cheap at 50c a metre. Having an assistant to hold and rotate the mast as you feed, roll on the strand and wet it out with epoxy resin makes it much easier.
However make an assessment of how bad the damage is first. If it has split all the way through and is more than stress cracks I wouldn't use the mast in any situation where you could be at risk if it fails. Keep it as a spare and grab a new top half. Peace of mind and safety is worth a couple hundred bucks!
olskool
olskool

QLD

2459 posts

7 Jul 2019 6:58am
Ive done a similar repair to a 550 100%C mast. It had damage to both upper n lower sections of ferrule. Basically, superglue cracked area of sleeve together. Use hoseclamps to secure once ferrule is put together. Leave it to set. Remove hoseclamps.
Then use carbon weave around the sleeved section. Make sure wraps go further past the cracked area. Use a few wraps to build it up. Finish with a wrap of glass for abrasion resistance n strength.
For the inner spigot section if cracked. I used a section of carbon mast the correct diameter. Epoxy that inside the spigot. Fair around the cracked spigot area with epoxy, sand to fit upper/sleeve. Go sail once cured. Happy days.
Ben1973
Ben1973

1008 posts

7 Jul 2019 7:12am



So this is what it looks like at the moment, sanded the pvc down to get rid of shape edges. It completely covers the crack.
musorianin
musorianin

QLD

597 posts

7 Jul 2019 9:16am
It's not worth the risk. But if you do repair it, make sure to drill out a small hole at the very top of the crack to stop it running further
Ben1973
Ben1973

1008 posts

7 Jul 2019 7:17am



Ignore the shiny bit, I had mixed some resin up to glue the pipe on but it was such a tight fit I didn't need it so just wiped some around the mast where I had scratched it up a bit. It's gonna take at least a week to get a new mast so it only has to last maybe 4 or 5 sails
Ben1973
Ben1973

1008 posts

7 Jul 2019 7:21am
My other thought was just to epoxy the top and bottom sections together, I don't need to take the mast apart, would that be the strongest option?
olskool
olskool

QLD

2459 posts

7 Jul 2019 10:00am
If youre just looking for a temporary fix. Slide pvc collar off. Clean out crack. Superglue it. Slide pvc back down snugly. Wipe excess superglue from inside of mast. Put mast together until superglue cures. Then use. Place a mark on mast where crack was. Rotate that side to front of mast sleeve. Itll be under tension loads there. Compression loads is what broke it. Wrapping in carbon n glass about 1-2mm thick up to the Apex logo will fix it nicely.
Mark _australia
Mark _australia

WA

23526 posts

7 Jul 2019 12:13pm
definitely superglue and hose clamp first so the crack is closed up and the mast is sized right. Leaving it a bit big there is loading it more.
Then sleeve it for sure. But Ben, I know you repaired a board so why not do the mast properly? sleeving with a bit of weak plastic may or may not work but for such a small crack we do know wrapping with carbon works as many people have done it

Oh yeah and after laminating - wrap it tight as you can with electrical tape to get rid of resin, too much is actually weaker.
decrepit
decrepit

WA

12802 posts

7 Jul 2019 5:06pm
And when it's fixed, don't forget to tape the join before stuffing it up the luff.
Imax1
Imax1

QLD

4926 posts

7 Jul 2019 7:59pm
Select to expand quote
decrepit said
stuffing it up the luff.


Sounds like a porno movie I never owned .
racerX
racerX

463 posts

7 Jul 2019 6:49pm
I have fixed a 490 just like that. I put a small crack in the ferule, because the mast came apart in the sail before I applied downhaul and the two pieces where butted together but not properly inside the ferule, as I applied down haul the force from the downhaul chipped the ferrule as it slipped apart. I repaired it in the same way I repair carbon battens. The crack was such that most of the carbon on the ferrule was completely intact, the idea of the repair was simply to stop the crack propagating.

I used a couple layers of 1K carbon weave (90g) I think about 4 layers, tightly bound with some heat shrink plastic tape. It was 75% carbon 490 still going strong 5 years later. I think I might of done similar to the male end of the ferule but I carbon on the inside, rather than the outside.

But in may case the repair is just to stop further propagation.
decrepit
decrepit

WA

12802 posts

7 Jul 2019 7:39pm
Select to expand quote
Imax1 said..
Sounds like a porno movie I never owned .

Thought you'd like that
Ben1973
Ben1973

1008 posts

7 Jul 2019 11:30pm
The sleeve survived today but it's stressing the luff tube where it's a bigger diameter so I think I'm going to make it a one piece mast and just bond it together with gorilla epoxy.
racerX
racerX

463 posts

8 Jul 2019 8:42pm
Select to expand quote
Ben1973 said..
The sleeve survived today but it's stressing the luff tube where it's a bigger diameter so I think I'm going to make it a one piece mast and just bond it together with gorilla epoxy.


Why not repair it properly, even if you just glue it together what is stopping by the crack from propagating, unless you have some cloth outside the crack to stop the fibres coming apart?
decrepit
decrepit

WA

12802 posts

8 Jul 2019 9:31pm
Select to expand quote
racerX said.. >>>Why not repair it properly, even if you just glue it together what is stopping by the crack from propagating, unless you have some cloth outside the crack to stop the fibres coming apart?

Agreed. I'd worry that just gluing the two together, wouldn't be strong enough under high load. I think a few layers of carbon strand wound tightly round would be a good idea as well. Wouldn't be anywhere as thick as you soft plastic fix
Ben1973
Ben1973

1008 posts

9 Jul 2019 5:34am
Well after an afternoon trying to track down some carbon or glass and epoxy with no luck the guy in the hardware store said use this www.fiberfix.com/products25656156
thought for $10 if was worth a go, got a bit 1m long and 3cm wide soaked in water for 10 seconds, then wrapped the end, 3layers is about the same thickness as the mast and I went up just over 6cm. 15mins later it's as hard as nails. I had about 10cm left which I made into a ring so just one layer with a 1cm overlap at the join to test out how strong it was and I have to say I'm impressed there was no way I could pull it apart or snap it.
5hours of sailing today in 15knot with the 8.6 and no sign of failure, I've give it a few more sails before I trust it but it's looking good
Mastbender
Mastbender

1972 posts

9 Jul 2019 8:02am
So why the split? That's what I'd be asking myself.
A vertical split is usually caused by one of two things, either the ferule was a sloppy fit to begin with, or it wasn't put together all the way before you used it. The same thing can happen with the bottom of the mast where the extension goes into it, either a very sloppy fit or the extension didn't go in far enough.
Being only 2 cm. long, I would have just cut it off (the reinforcement is at least as long as the male end of the ferule), and made sure things still went together nice and snug.
Ben1973
Ben1973

1008 posts

9 Jul 2019 8:23am
I was in a hurry and not thinking straight when I was rigging. User error caused the split.
on the bottom cm of the top section the carbon wrap is a bit different, Wasn't sure if I cut that bit off the end would be strong enough.
could still do that if you think it would work, I would just sand the tape I put on back down to the mast or maybe leave a bit on

its been the first week of hot sunny windy days so trying to minimize time off the water.
mathew
mathew

QLD

2142 posts

9 Jul 2019 10:25am
^^^ Cut the broken bit off, then a half-dozen rubs of sandpaper on the spigot.
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