Some thoughts.
my much loved Severn Enigma Boom snapped last weekend where the oversized straight section on the arm joins the narrow diameter section. No crash, just mid jibe. The break is very clean. Has anyone managed to successfully repair a boom arm. I was thinking an internal sleeve and carbon wrap on the outside??
Is this wise??
^^ Yeah its possible, wait for AUS808 to chime in he's done TONS professionally and I've got two of his that are still going strong.
When you look at how much material is in a boom (not much!!) its clear that a sleeve and wrap would be more than strong enough. You can custom your own sleeve by making a bit of foam just undersized, 3-4 layers of carbon/ epoxy around it and tape firmly with plastic masking tape.
Then glue that in with a good epoxy like JB Weld. Its almost useable at that point.....pretty damn strong ......and the wrap is then just helping a bit.
But as I said wait for AUS808 he's the expert
How old is it? I found Severne warranty to be bloody tops.
As an aside,I think many manufacturers have gone too skinny on carbon wave booms, I can see the flex in them when I load downward in the harness. Put aGoPro out on the clew and you see a massive difference.
Increase the dia around 2mm seems just as comfy and way stronger- I can't bend the 27-28mm ones when sailing but the skinny ones do seem to. And can't see 2mm difference in my forearm pump or lack thereof.
Select to expand quotegregcacace said..Some thoughts.
my much loved Severn Enigma Boom snapped last weekend where the oversized straight section on the arm joins the narrow diameter section. No crash, just mid jibe. The break is very clean. Has anyone managed to successfully repair a boom arm. I was thinking an internal sleeve and carbon wrap on the outside??
Is this wise??
Yep, no problem. Have done exactly that.
As Mark says there's not much material in many of them so your joint is usually way better than original.
FYI ....Maui boom od 27.0 , id 22.5 (2.25mm wall)
Kinda hijack . On boom diameter . Thinner is better to hang on to . But not all is lost , v grip,is the answer . My 32 mm V gripped is easier to hang onto than my 28 round .
I would Araldyte a thick 5 mm aluminium tube core 300 mm long with tapered ends . That repair would hold up half a Land Cruiser at 200gm. Re grip and away you go . It will never break in that area again. Find someone with a lathe. I'd make it for $ 40 plus postage. It's a love job 
Well this sounds a little promising!!
Severne can't be faulted with backup service but this boom has had a good life since getting it in 2014ish. I wouldn't dream asking about a claim.
If you go for the insert, "play with carbon" has all sizes of carbon tubes, with differing wall thicknesses. They supply carbon tubes for drones etc. Pulltruded would be the go. I can't see why it wouldn't work.. I'd take the tail off for the insertion, then put it all back together for the application of the "wrap". That way the holes will line up properly.
^^^ +1
Ally is going to be a bit heavy and risk galvanic corrosion if it touches the carbon
Done one which is still going strong, don't use Ally, use carbon tube and a good epoxy
I would have thought alloy needs air and water to corrode therefore glueing it in solid would have been fine. Unlike a alloy boom end grinding with salt water and sand in and out of a carbon boom . Alloy would be easy to make , trying to find strong enough carbon tube at the correct diameter especially where the boom broke at the two different diameters .???
Id also go hee for tiggy if you could notice the weight. Alloys not that heavy.
And a light wrap over the top.
Just trying co come up with the easiest , cheapest solution that would be strong as an Ox. I'm sure the well used boom would fail elsewhere before the repair does.
I repaied a maui boom yeas ago that cracked at the head, veed it out wrapped more carbon arround then wrapped in insualtion tape to hold it all down while it dried just load it up with carbon and you cant go wrong. it turned out really well and i used it for years after with no issues.
it would be simular to a broken SUP paddle .if you can find a paddle insert the right size to fit in glass that in ,,people cut paddles to size .
if not make one .I used a piece of circular cardboard to get the right size ,just taped a piece together .,i carbon glasses the outside of the cardboard ,let dry ,then sanded it
glassed it in ,as well as carbon glassed the outside joint .done .4 years ago ,still going .
dont use alloy insert.
^^^ haha yours is fine mate but if the ally touched the carbon when inserting it will corrode, hard tobe 100% sure there is glue all around
Plus it means fabricating which you can do but everyone else can't so will just buy a bit of carbon tube for $20 or make a tube
Imax .at least you didnt use a broom stick ..yours wouldn't break ,just corrode maybe in time .
just keep it out of salt water .
Select to expand quote
Tardy said..
Imax .at least you didnt use a broom stick ..yours wouldn't break ,just corrode maybe in time . just keep it out of salt water .
It's the two different diameters thing that I'd like to see someone do in laminated cardboard or foam or buying hobby carbon .
By the time a alloy core rusts a new Jesus will be born. Paint the alloy core in resin first and there is no way in hell it will rust out before the third Jesus.
Id comfortably do it on my and my loved ones booms . Rust , corrosion , psht ! , we're talking a heavily used boom getting another couple years , no re writing science.
I understand perfect .
And that's way better than me .
What I try to offer here is a easy strong fix . Thats always my contributions .
That's what this fat cat offers.
Thats why I think Araldyte is a backyarders best friend. Perfect ding repair . Strong and flexy enough on it own , sticks like **** to a blanket and laminated with anything indestructible . 5 minute Araldyte would have to be better than any board fix putty as long as it's dry . You could prepare area with rubbing in sand.
Just one in many methods.
Wrapping the boom in glass , carbon , would be easiest and if bulked up enough would be just fine
Select to expand quoteImax1 said..
It's the two different diameters thing that I'd like to see someone do in laminated cardboard or foam or buying hobby carbon .
Pizza piss.
foam, shape into fat cylinder, then shape half into skinnier cylinder. If any bend is required, cut wedges, bend and tack with glue. Done.
Fair bit easier than lathe job on ally.....
Select to expand quoteImax1 said..Tardy said..
Imax .at least you didnt use a broom stick ..yours wouldn't break ,just corrode maybe in time . just keep it out of salt water .
It's the two different diameters thing that I'd like to see someone do in laminated cardboard or foam or buying hobby carbon .
By the time a alloy core rusts a new Jesus will be born. Paint the alloy core in resin first and there is no way in hell it will rust out before the third Jesus.
Id comfortably do it on my and my loved ones booms . Rust , corrosion , psht ! , we're talking a heavily used boom getting another couple years , no re writing science.
TO true mate ,your back on the water thats all that counts ,
its a mans shed and you can do what ever you want in it 
I'm fond on 5 minute Araldyte .
Select to expand quoteMark _australia said..
^^ Yeah its possible, wait for AUS808 to chime in he's done TONS professionally and I've got two of his that are still going strong.
When you look at how much material is in a boom (not much!!) its clear that a sleeve and wrap would be more than strong enough. You can custom your own sleeve by making a bit of foam just undersized, 3-4 layers of carbon/ epoxy around it and tape firmly with plastic masking tape.
Then glue that in with a good epoxy like JB Weld. Its almost useable at that point.....pretty damn strong ......and the wrap is then just helping a bit.
But as I said wait for AUS808 he's the expert
How old is it? I found Severne warranty to be bloody tops.
As an aside,I think many manufacturers have gone too skinny on carbon wave booms, I can see the flex in them when I load downward in the harness. Put aGoPro out on the clew and you see a massive difference.
Increase the dia around 2mm seems just as comfy and way stronger- I can't bend the 27-28mm ones when sailing but the skinny ones do seem to. And can't see 2mm difference in my forearm pump or lack thereof.
Mark,
I have been waiting for the email telling me you eventually broke my old boom
I actually miss that boom
I'm no expert, just muck around & take on stupid challenges.
To make an odd shaped internal sleeve I use Backer Rod which is a soft foam used between concrete tilt-up panels.
Wrap it in layers of carbon and then wet out the carbon, glad wrap on the outside, squish it down in diameter & fit it into the boom arm where it will end up. It will expand slowly to the exact shape required.
After it dries you can remove the backer rod or leave it in but you have a perfect sleeve ready to be glued in
This works well for booms that are broken near the front on the curve or where they taper, otherwise just use straight tubes.
I have a lot of Carbon Tube laying around if anyone needs some, not sure of the diameters off the top of my head but need to get rid of it.
Sourced from China but super strong when sleeved up in layers of different diameters.
Great thread. How long would you normally make the new internal sleeve? 5cm on each side from the point where the boom cracked?
great thread.
i've got an older carbon boom i snapped after only 6 months of use so it's in as new condition. just ordered a carbon pipe from ebay for $16..
fingers crossed i'll have another boom soon.
