Hit bottom today whilst foiling and broke the connection between mast and base on Naish foil. There doesn't appear to be much holding the two bits together apart from a little screw at the rear. Does anybody know anything about these ? Is it bonded with glue ???

predetermined breaking point

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PatK said..
predetermined breaking point

"Sollbruchstelle". Why use 3 words when you can use just one ?

Looks like good engineering to me. Hit with enough force, and something has to give. Better a separation like this than the box moving in the board, or failures like described at www.standupzone.com/forum/index.php?topic=34549.15

Actually, I kind of agree. Sollbruchstelle is a decent engineering idea. The screw, being in back on not in front, is there to help carry the cantilevering loads of the front wing against the board. Hitting something pushes everything aft, bending the screw as the mast comes out, then breaking it.

Just make sure to use a leash with it.

Crash car......expect damage.

So is there glue involved ? Or just sealant ?

If you do not need the Sollbruchstelle anymore glue it together with UHU endfest 300. Best Klebstoff ever

You must foil a lot, the wear and tear looks 2 season's worth, or 120 water days.
Time for new parts.
PS....just tore my 3 year old original Naish apart, easy 150 water days, and MUCH cleaner than yours.

This mast only a few months old. Had the shorter 75cm mast before that with an abracadabra base. That one was held together with three big screws.

Possibly fit between mast and fuze is loose.
Shim with aluminum duct tape for tighter fit.
My 2019 fuze opening is too tight for both my '19 and '20 masts.

Sorry..."18 fuze" is too tight.

Richie - re repair suggestion
I would be gluing it in with West System epoxy or similar, then drill and put a few stainless nut & bolts through (side to side)
You don't want it coming out ever again

use araldite 2015.

Get this:
www.fishpond.com.au/Arts_Crafts/UHU-plus-endfest-300-2-x-15-ml/9999853979760
Heat it as hot as you can get (max. 180 degree C) and after 5 mins it is really strong.
45 mins @ 70 degree C, if you store it in the car in aussi summer
Best glue for metal with some gaps.

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PatK said..
Get this:
www.fishpond.com.au/Arts_Crafts/UHU-plus-endfest-300-2-x-15-ml/9999853979760
Heat it as hot as you can get (max. 180 degree C) and after 5 mins it is really strong.
45 mins @ 70 degree C, if you store it in the car in aussi summer
Best glue for metal with some gaps.

Sounds good.

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LeeD said..
Possibly fit between mast and fuze is loose.
Shim with aluminum duct tape for tighter fit.
My 2019 fuze opening is too tight for both my '19 and '20 masts.

The 2020 Naish masts are bonded, note the lack of screw holes in the mast. They use a much lighter extrusion for the mast.

So what?
We are not talking about new gear here.
We are discussing an ACCIDENT with 2019 gear.
That needs replacement, not superglue.

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LeeD said..
So what?
We are not talking about new gear here.
We are discussing an ACCIDENT with 2019 gear.
That needs replacement, not superglue.

Have a close look at the photo, it's the latest model bonded mast

You are correct....it's labeled like my 2020 65 cm mast, which is sealed with some clear glue like substance.
Still, running aground is grounds for replacement considering the wear and tear at the joint.

Fixed. (with spectra leash just in case)

Okay, that worked for a couple of weeks, then I noticed it was getting a bit loose. Redid the repair using a better epoxy and added a horizontal 5mm screw . I am a bit sceptical about these bonded join foil masts.

I see no issue with gluing, as there are really excellent glues on the market. But: Repairing such a joint with cheap glue, redoing and so on doesn't really make it better. They have a tight fit when they initially glue it. When you destroyed the joint, the parts were bent, so the fit gets sloppier and that is most likely the end of the part. I have no idea how much they charge for an alloy mast, but most companies sell them for a reasonable price. If you want to safe money on the long run: Get yourself a new mast once you destroyed the old one. Do not repair safety-related parts or parts with high loads if you are not a "pro".

Best regards, David