Hobie Cat Forums

Hi, I installed new dolphin post and new ball. The ball is rotating on the dolphin post thread instaed of between ball and mast base. Should I glue ball to the dolphin post? What is the best glue to use?

Do I need to use any wax between mast base and ball?

Thank you,
Alexei

Really
I have this problem some of the time I usually get a cotton towel and a vice grip and get it good and snug This seems to work pretty well
Do not strip the threads
I use marine silicone greese on the ball and socket before raising mast
Former Hobie Admiral Gary

I used one of those rubber strap wrenches and it worked great. Definitly lube the b all before raising mast.

Mine has always rotated. It won't screw itself off, just go back and forth with the mast. I always figured there was just more friction between the ball and the mast foot, than the ball and it's treads. Just make sure it's screwed all the way down before stepping the mast.

The problem with that is that the post isn't bottomed out in the ball, leaving a small gap. With enough mast compression, the threads will strip. And you won't know it until you lower the mast. The ball will fly off and the mast will come down a lot faster than you want it to.

This was a real problem with the Tiger's setup to the point where Hobie had to make the ball out of a different plastic that could take the load.

Hobie Matt
Could the problem somehow be air trapped at the top of the bolt
What was the fix that you used on the newer boat
I might try a tiny tiny drilled hole
I have never worn out the ball however i did replace one that had the threads stripped
I do not sleep very well thinking about loose balls
Former Hobie Admiral Gary

I would think lubricating the ball will likely solve your problem.

If you're really worried about it, another possible solution would be to drill a small hole through the ball and striker post and insert a stainless roll pin. This would entirely eliminate the ability of the ball to spin on the post.



sm

I've been watching it and figured I'd epoxy the threads if there was ever any play when I unstepped the mast. I did polish the inside of the mast step, but the ball still rotates back and forth. So far, there is still no play up and down with the ball, so evidently, there is no wear yet on the threads. It's an '88 model. I thought if I added torque, that the extra torque might damage the threads. Is the Tiger ball the same ball with the same threads? How many cases of the problem were presented? It's pretty easy to strip any kind of plastic threads with a tool to add leverage.

That's a good idea. I think I'll do that. I don't think much of putting enough distortion on the plastic threads with extra torque so it doesn't move.

Pretty sure it is, but the Tiger is/was made in Europe, so the plastic may not have been the same spec as the US version. I would think that the 21SE's mast is bigger/heavier/puts more compression on the ball than the Tiger's mast (which has been likened to a telephone pole).

I had it happen to me twice and I personally know two other Tiger owners who had it happen. That's a significant occurrence in a very small sample.

Fortunately, the Tiger mast is very robust, so as long as it doesn't hit anything (or anybody) on the way down, there's usually no damage other than some scratches. Dropping a 21SE's mast on the Comptip would probably break out the head casting from the Comptip (I had it happen on my 17 after the mast came off the ball a couple of times.)

I decided to not bother with the roll pin, but while I was thinking about it, I stuck it on with some 3M DP810. If the ball breaks, I'll just heat the shaft with a propane torch, and the DP810 bubbles right up and gives up its grip. I use it to glue on golf club heads, as do a number of the Tour vans. It has respectably strong bond to plastics {800psi on polycarbonate}as well as metals.

I thought about using DP100, which is my usual go-to for plastics, but went to 3M website to check, and specs for 810 were even a little stronger. I knew how 810 responds to heat, so I went with that.

When I first got the 21SE I was practicing raising and lowering the mast and one time when the mast was almost down on the rear support yoke the ball released beacuse it was stripped and the mast went down. Scary as hell. No one got hurt.

It seems like the only time there is an uplift at the mount ball is when the mast is hooked to the ball and the mast is resting on the rear yoke support. Even after repacing the ball, I now place the mast on a ladder probably 10-15' behind the rear cross bar which makes the mast not have this uplift as I NEVER want this to happen again!!!!