Hobie 18 loose comptip

Hello Hobie sailors! I'm hoping someone has some insight for me before I start this task.

I bought a 1980 Hobie 18 that was supposedly ready to sail, but after sailing it, then doing a bit of specific research, I found that the comptip was not properly installed. It slides in and out about 1 inch and wiggles significantly. I decided to slide it out as far as possible and apply some marine JB weld and slide it back in to secure it, but it did not hold after a single sail. The JB stuck to the tip, but not the extruded mast and is now in nearly the same condition as before. Until now, I've only sailed and maintained 16s with one piece masts, so im a little out of my depth on this repair.

I have read many forum posts and guides for the proper procedure and have a few questions:
1) Is marine JB Weld suitable for the job? Most people seem to recommend simple auto bondo and it seems to me the JB should be better.
2) Every guide says to remove the tang by drilling out the rivits. Only, I dont have rivits, the tang is held on by bolts sticking through the mast with nuts on the outside. Is this at all normal? And, are the bolts held in place inside the mast somehow? Or are they just loose in there held in place by the outer nuts, needing some way to hold them there while I reassemble everything?

If the bolts are normal and loose, any tips would be greatly appreciated, as my best idea is to use a dab of the JB on each one to hold them, which will add an extra 1-2 days to the repair (Id like to do it all in one go).

Part of me thinks this mas might just need a replacement due to a bad original comptip and tang replacement, please tell me im wrong.

Thanks
Kyrle

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Standard Hobie 18

Bolts are not normal. Only the original Hobie 17 had a thru-bolt at the tang.

Jb Weld might work / I don't use it. The Bondo sets up rock hard and that is what you need. Not a bond really. Just a very still form-fitted sleeve.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

I can’t even envision how one would thru-bolt the tang. As Matt mentioned, only the Hobie 17 had a bolted on tang and it was one single thru bolt. Can you post some pics? Everything on the mast and tang attachment needs to be rock solid or you risk dismasting.

sm

The boat isnt at my house right now. I'll get some pics tomorrow and post them. Thanks for the sleeve comment. I was under the impression it (bondo/jb) was supposed to be like an adhesive. Bondo makes a bit more sense now.

_________________

Standard Hobie 18

Here for s a pic of my tang.

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Standard Hobie 18

Gotta say, that one’s a bit baffling. Not sure how the screws would have been installed from the inside of the comptip.

So if you try to tighten the nuts, the whole screw just turns?

Only thing I can think is maybe the previous owner slotted the holes for the comptip or just ground away channels where the screw heads protrude into the mast. Then they would have been able to install the screws and then slide the comptip in over the screws. That would also explain why you’re able to slide the comptip in and out a few inches.

sm

I haven't actually tried to seriously turn the nuts, other than a finger check to make sure they were secure. They did not spin at all by fingers and the tang has no play or wiggle.

Given that the tang and bolts are secure, and the comptip is not, I suspect that the bolts are not actually going through the comptip. I think the tip may just have slots cut/drilled to accommodate the bolt heads, hence the sliding and wiggling. How far does the comptip go into the mast when properly installed? Any thoughts on drilling a couple extra holes for rivits to better secure the tip? In addition to bondo, and after complete removal and reinstalation of the tip (if removal is necessary and/or worth the risk).

Should I just slide it out as far as I can again or try for complete removal for the bondo step? Im leaning toward complete removal, even with the bolt unknowns, but would like some second opinions.

Kyrle

Edit for sm: I see we are probably on the same page about possible slotting on the tip. I think at this point, I might have to just jump in and wing it, hoping for the best. I'll probably get started saturday, so any tips or thoughts before then are greatly appreciated. I'll also try to document the process, in the unlikely event someone else could benefit.

One last thought, are comptips still made for the 18? How much do they usually go for?

_________________

Standard Hobie 18

The ferrule of the comptip extends inside the mast several inches below the bottom of the tang - all rivets (or in your case bolts) pass into the ferrule so that they secure both the tang and the comptip to the aluminum extrusion.

I think for any epoxy application to be successful, you will need to entirely remove the tip from the mast. Personally, I would use thickened epoxy rather than Bondo. The problem with Bondo is you have to get the hardener ratio right or it will kick off super fast, like a minute or less. No problem if you get the tip installed in time. If it takes longer than you thought, you will be left with a mess. I prefer a pre-thickened epoxy from West called six10. It will take a full day to cure, but plenty of time to get the tip installed right.

Hobie still sells comptips, but they are pricey - will set you back close to $900. You would be better off trying to find a used mast.

sm

9" bury.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Thanks for the info and opinions guys. Ill be diving into this as soon as weather permits. Would it be preferred to document this process in this thread, a new thread, or not at all (to prevent confusion from the unusual setup)?

Kyrle

_________________

Standard Hobie 18

You can document here. Would be great to see what you find inside this mast. Very odd.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

The weather agreed it was time to get started, so I did. The news is not good. The good news is that the tip came out easily. Unfortunately, that's also the start of the bad news. I did not have to remove the tang bolts to get the tip off. Those bolts were not supporting the tip at all. In fact, nothing was. Its almost worst case scenario.

The last owner (or who ever installed the tip) basically just cut off large sections of the tip to make it fit around the tang bolts, which are just round top, philips head machine screws. It looks like the cut off peices are still in the mast, but I cannot get them to come out, they are in there good. Since replacing the tip basically means I'll go ahead and replace the whole mast, im going to attempt a repair on this one first considering I have everything I plan to use for the repair left over from other projects. If it doesnt work, I should only lose time.

Here's some pics:



The plan is to thoroughly clean the mating surfaces. Lightly sand with 80 grit to give a better surface for adhesion and use marine jb to fill the gap and glue it together. I wanted to use bondo as recommended almost everywhere, but given the limited surface area, I thought it would be better to use an actual adhesive, and I already have the jb.

After the jb sets, I may use some carefully placed rivits to help hold it. This would mean drilling more holes in the already limited surface area though. Anyone have thoughts on this for either yes/no or best locations and number of rivits? Im an electronic engineer, not structural, so I'd almost be guessing.

More updates to come once the JB sets.

Kyrle

Update: As soon as I finished cleaning it all up, a storm rolled in and dropped buckets on me. Looks like it will be a day or so before I can continue.

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Standard Hobie 18

Bummer.

No amount of JB Weld is going to fix that. Hard to tell exactly what happened from the pictures. Looks like they forced the comptip past the screw heads, potentially cracking the comptip which then broke off. Anyway, I highly doubt glueing the tip in with JB Weld will provide a lasting repair or hold up to any significant load. It would need to be fixed with fiberglass and possibly an internal sleeve.

I’d start searching ebay and craigslist for a used comptip or mast.

Where are you located?

sm

I am located near Greenville, SC. The only broken part is the bow side of the comptip, the rest (V-slots) is actually cut to accommodate the bolts.

I have some fiberglass left over from a minor hull reinforcement. Since I haven't started actually reattaching the tip yet (thank you rain), I may try some force to take out the parts of the tip still stuck in the mast and attempt to build an inner sleeve in the tip and rebuild the broken part on the bow side, but I doubt I'll be able to repair the cut outs without totally redoing how the tang is attached. Im not sure how I'd get it reattached if I totally fixed the the cutouts, as I'd have no way to access the bolts from the inside and I don't have the equipment to replace the bolts with large enough rivits.

So with your comment in mind, im now thinking I should clean the remaining comptip out of the mast, build a thick sleeve inside the comptip lower section (with fiberglass cloth and poly resin, well past the insertion point) then fill the slotted section ( which will have a fiberglass sleeve under the slots) with marine jb, along with coating the comptip and inside of the mast, then reassemble before the jb sets. Possibly adding some rivits for extra support.

It will never be re-repairable again, but at this point, im just looking to get through the season while I find a complete mast replacement (preferrably a full one-piece). I did some checking before I started and the closest I could find was a mast in New Jersey. Im hoping someone will be selling a mast or a complete-ish parts boat in the myrtle beach area, pretty sure there are many cats in that area.

Concerning a one piece mast: The comptip is purely a safety modification right? Well, and North American racing required (again, for safety). I dont plan on officially racing this boat, if there are even official 18 races any more. Being an electronic engineer with experience handeling 100KV+, I have great respect for the dangers of powerlines and don't need the safety precaution of the comptip, if that's its only purpose.

Thoughts?

Kyrle

_________________

Standard Hobie 18

The comptip is primarily a safety feature, that was the original purpose. It is also a little more bendy than the one-piece mast, so the arguement could be made that it also helps flatten the sail to depower in high winds. For Hobie sanctioned racing it is technically required, but Hobie 18 racing has dwindled down so much in recent years that it is unlikely anyone would care unless you’re racing at a championship regatta.

For installing stainless rivets, I recommend the Harbor Freight heavy duty rivet tool. It will handle up to 1/4” diameter stainless rivets (the mast tang uses 3/16” diameter). I’m not a big fan of Harbor Freight in general, but I’ve had this rivet tool for 10+ years, use it pretty often, and it’s still going strong.

https://www.harborfreight.com/heavy-duty-17-1-2-half-inch-hand-riveter-with-collection-bottle-66422.html

sm