Typhoon Compression Post Base Mounting and Keel Fastening?

[Vcoast]

Has anyone added a Compression Post to their Typhoon, and hard fastened the mounting base to the top of the Keel?

Specifically, what am I drilling into? What dia/length fasteners were used?

A local shop is fabricating the post in stl. stl., and suggested fabricating the base in DELRIN, or UHMV, as these plastics are easy to work with. Initially I thought great, I can probably bed this stuff in glass and be done with it. Wrong, appears these plastics are so slick nothing sticks to them.

Thanks,

[Bob B]

I made the base and upper units out of oak that I worked to fit the area. The oak at the base extends from one side of the area where the porta pottie was to the other and is anchored with some screws to the liner. I just cut a shallow hole for the posts to fit into. Underneath the liner, I supported it with a couple of boards epoxied into place. This carries the load all the way to the keel. It wasn't hard and I'm still putting the final touches on each. I also used stainless steel for the post.

Bob B.
CD Typhoon Weekender Liberty

[Steve Laume]

If you wanted to use a rot proof plastic material for your base and the only concern is that epoxy will not stick to it why not put in a couple of SS pins or a groove. The resin would not have to form a chemical bond as it would be held in place by a mechanical bond.

Even a series of holes in the bottom of your compression post foot would index it sufficiently.

Compression is your ally, Steve.

[Vcoast]

Thanks Steve.

The problem is not fixing the post to the Plastic Base, the problem is fixing the plastic base to the hull.

[Steve Laume]

that is what I was talking about. Make the base with some sort of tooth, thicken up some epoxy and set it in there. It isn't going to go anywhere.

The load is helping you, Steve.

[Markst95]

On my 72 which didn't have any sag I cut a hole in the floor underneath where the head used to be. I then cut a piece of 3" PVC pipe to fit from the keel up to the floor inside the bilge. I put in my SS compression post and filled in the area around the post inside of the PVC with a mix of epoxy, colloidal sillica and chopped cloth. For the top I mounted a large washer and secured everything with a piece of Teak screwed into the ceiling. I cleaned out some core around the hole so the epoxy flowed into the floor which locked everything together nicely. Solid as a rock!

[Vcoast]

I'm starting to smell what the rock is cooking...

While I still don't think over the long haul anything will make a permanent bond to this hi-tech plastic, you make a great point, the base is not going to move much anyways under load.

Taking your point into account I think I will form and glass in a well around this base so it can't go anywhere, and even if it just sits in the well, what does it matter, when adjusted under tension it won't be able to drift. I might even glass a little over the edge just to keep it in place, not that any extra is needed. Thanks!

[Vcoast]

Thanks for the advice. Sounds like your post is now a permanent fixture.

I noticed you have the same gaping cut-outs in your bunks. Your photo confirms this must have been done in the factory to accomododate the head plumbing and overboard through hull. Boy, you think they could have taken more care dressing it up a bit.

I should say I use to have the same cut-outs, I just glassed my back up, I couldn't take looking at it, and since I've replaced practically the entire deck, I dealt with it at the same time.

[Gary H]

I have a stainless steel compression post installed in my Ty by the PO. I have ocassionally wondered where I should go if I were to be caught in a lightning storm. Being in the cabin, up against the metal post which is just barely separated from the mast above it, does not sound like a good idea.
Any thoughts on this - other than staying away from lightning storms?

[Oswego John]

Hi Gary,

I was recntly reading about motoring in a thunder storm. The article mentioned that probably the worst place to be is holding on to a tiller or wheel that is wet with rain.

The thought being conveyed was that the operator would be a direct link between the aluminum mast receptor, the aluminum boom and the metal rudder post which would be immersed in water.

But then again, there aren't many places where a person can hide on a Ty. My own thought on the subject is having a piece of teak on hand so as to keep knocking on wood until your knuckles bleed and the storm passes.

Blue skies and brisk breezes for all,
O J

[Vcoast]

I'm stilling working out the fabrication of my post, but in theory, so far, we'll have a piece of non-conductive plastic DELRIN between the top of the post and the bottom of the Mast Step. That said, if I were to take a direct lightening strike of 50,000 volts, I highly doubt if the newspaper article accompanying my demise would carry a single quote to the effect, "Authorities found his death to be highly unusual given the small piece of plastic he used to fabricate his after market compression post".

[Steve Laume]

I always thought the path of a lightening strike was supposed to be down the shrouds and stays. I have read about the "cone of protection" that is set up around a boat and protects the occupants. Please don't tell me that is not the case.

I encountered a truly scary lightening event two years ago and did not want to be touching the metal wheel. I was mostly steering with the wind vane but had just installed it and had not yet grounded it. I thought about that a great deal for the duration of the storm. I was trying to run away but the damn thing kept following me. Hunkered down under the dodger frame seemed like the safest place to be.

I am not really afraid of lightening but there have been three times in my life when I believe fear was justified.

I wouldn't be pole dancing down below durring a thunder storm but I don't think I would worry too much about that compression post, Steve.

[Duncan]

I always thought the path of a lightening strike was supposed to be down the shrouds and stays. I have read about the "cone of protection" that is set up around a boat and protects the occupants. Please don't tell me that is not the case.

From some research I did a while back, the lightning is much more likely to come down the aluminum mast. It's a better conductor than the stainless steel rigging. If there is no path to ground from the mast, the lightning is likely to arc across to the stays/chainplates.

Another thing I learned from that 'research phase' is that the energies involved are so high that prediction is very difficult. There was a Whitby 42 struck by lightning up here that looked like a bomb had exploded in the cabin - there was a great big hole in the middle of the deck.

[Gary H]

Perhaps a reason to consider a non-conducting compression post?

[Oswego John]

Below is a link to the publication "Lightning And Sailboats. It was written by Dr. Ewen M Thomson, who was a director of studies at the U. of Florida at Tampa.

The publication provides scientific answers to many questions that have been asked by sailors. It also disproves many old wives tales concerning lightning. I found it to be very interesting reading and hope it will be for many of you, too.

O J

http://edis.ifas.ufl.edu/sg071