New mast question: Why do the two halves need to be epoxied?

My lower mast was dinged by the previous owner and has served me well for the last 3 years, but this past weekend the mast buckled more while I was getting ready to step it.

So, I'm ordering a new lower mast today in the hopes I can get more action out of the boat before the cold weather hits...

For whatever reason, my old mast was never epoxied together, which worked out well when I got the boat, because my tow vehicle was tall and the mast would have either hit it, or dragged on the ground behind the trailer, so I've been disassembling the halves for trailering.

Now I have a new tow vehicle that's a reasonable height and my dealer wants to epoxy the two pieces of mast together.

What is the reason for epoxying them together? Is there a disadvantage to not doing this? It's somewhat nice to have the flexibility in being able to disassemble it, plus I'd rather not have to pay my dealer to do this.

What do you think?

Not to be too cute, but the reason you epoxy stuff together is so it doesn't come apart. I suspect that if you try to trailer it without the epoxy, you could have one piece end up on the road.

I am curious about the bottom half buckling while raising. Was there a big side breeze, did it buckle fore/aft? It usually takes a LOT of force to buckle a mast.

_________________
R/Thom
SeaRail 19
Triak
BMW C600
Formerly Getaway with Custom Spinnakers
Formerly raced F24 Mk II

Somewhere in these fora, there was a similar question and I seem to recall that the Hobie answer was that it allows a stronger mast unit for the larger sail plans of the Getaways and T2s! (yet the not-much-smaller, but half-the-sail-area, Wave mast doesn't need to be epoxied)

The original concept for the Getaway mast was to follow the Wave system and not glue, but due to the larger loads on the Getaway rig... the CompTip was either pulling down into the aluminum or wallowing out and getting looser. Both are bad, so glueing is now the go.

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

What if the comptip was pinned in place which allows for separation as needed.

Going to wobble still.

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

As I said, the previous owned dinged/dented the mast and I've lived with it for the last 3 years. This past weekend it appeared to buckle even more, so I'm loathe to try to sail with it for a good many reasons...

Follow up question: What kind of epoxy is used to glue the halves together? Is there a procedure for this somewhere?

I always used automotive bondo. Slathered on the tip and inside the mast. Press together and then support on saw horses aligned / square until hard.

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

I would use G/Flex epoxy from West System. They offer a thickened adhesive product.

http://www.westsystem.com/ss/g-flex-epoxy/

Thanks, everyone.

Epoxy on order, mast supposedly on truck from California. Hopefully I can get it put together in time for another 1 or 2 days on the water before it gets too cold up these ways...

My 18 had a slight wobble between the comp-tip and aluminum mast extrusion two months ago, and after a great day sailing in heavy air, developed more wobble. It went from barely discernible to worrisome, so I drilled out the rivets, used a heat gun to loosen up the joint, and pulled the pieces apart... they were still pretty well joined, which says a lot for the design -- close mechanical fit even after the rivets were pulled and the adhesive yielded. I found what looks/feels like silicone in the joint, so I'll be cleaning/sanding this away to prepare the surfaces for reunion.

I've read here that Bondo is a good adhesive for this task, but I may look into what West Systems recommends. Reassembly looks otherwise pretty straightforward, but I do have a couple questions:
- what should I align -- there's slight wobble at the hounds. side-to-side tilt seems obvious to avoid, but is it better to line up the front or back of the mast/tip (or does it really not matter, since it is going to flex)?
- the comp tip foam 'absorbed' the spent rivets and casings. is it worth cutting that away, or can I just leave them entombed in there?
- any need for silicone on the rivets as they go it, or should I dab with epoxy/bondo?
- should I reach in and 'goop' 3M 5200 on the top of the inside plug below the hounds?
- is the 2-part foam truly necessary between the comp tip bottom and the top of the inside foam plug?

I'll be using 3M 5200 Marine sealant elsewhere on the mast to make sure it is watertight. Any specific suggestions on where to look other than 'for bubbles' in underwater testing?

Randii

From another post, Matt said "Installation instructions: http://static.hobiecat.com/digital_asse ... 00CTIP.pdf"
Looks like the 2-part foam is optional.