Two of my plastic pylon nuts have split. I went to the local Hobie dealer, to buy some new nuts. The young kid working there couldn't find any in stock. He did some cross-checking in the Hobie catalog, then said they are no longer using the all plastic nut. He then gave me some stainless nuts, with a locking nylon inset. I refused these for now. I'm suspecious of the "kid's" advise.
Are the all plastic nuts no longer available ??? I'd prefer the forgiving nature of the all nylon nut.

The nylon nuts were originally used so that you couldn't overtighten them and break the castings.

Hobie has long since abandoned them and gone to the type of nut you describe (nylock).

Just don't overtighten them. <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

I guess you just figured out why the Nylon nut idea was abandoned - they all split when they age.
You do not have to get them from the Hobie dealer - I got mine in SS quality from the local hardware store.

Patrick

Just don't over tighten and you'll be fine. Use anti-seize too!!!

At $1.90 each for the SS Hobie nut, I could buy a handful of the plastic nuts and let them split as they wish. And it would be impossible to overtighten them.

If you use solid nuts, how much play should you allow for thermal expansion and contraction? Would using a stainless split-lock washer that is not completely tightened be the better way? (Maybe I should just buy a 1/2"-13 tap and make my own nuts.)

IIRC there is not much space for extra washers (bolt should not be long enough). Also, if you use a split lock washer you should use a regular washer to keep the split lock washer from gigging in casting. I do not think there is space for both.
Do not worry about thermal expansion - the length of the bolt and the temperature difference that this thing encounters is not worthwhile worrying about.
Tighten the SS nut to a point you would have tighten the nylon nut and you are good.
Check the holes - in the casting and in the pylon. In my case the ones in the rear pylons and the matching castings turned oval. I decided to file them round to the next bolt size to reduce movement. I also used this opportunity to shim the pylons / castings.

I had to replace the plastic nuts on my H-16. It seems the squirrels in my yard liked the taste of them. I bought S/S nuts with the nylon insert but the existing bolts were too short. I could thread the nuts on but they wouldn't get to the nylon so I turned the nuts around and put them on backwards. It seems to have worked alright.

Howard

Unless there's a thread and a half extending out of the nut you're over stressing the threads in the nut. Spend a couple bucks and do the job right.

Mike,

There are several threads that engage the nut but the bolts do not extend through them. There is no stress on the nuts otherwise they never would have been able to use plastic in the first place. I made sure not to tighten them so I wouldn't stress the castings.

Howard

You can always buy "short" Nylocks for that very reason. For a total of $16 you will not have to buy new nuts again... not a bad investment, especially for the peace of mind knowing they will not split at an inopportune moment.