I'm putting my H-18 back together and was wondering....Should I put anything inbetween where the hull and crossbars meet?

Thanks
Todd

What, you mean like a trampoline?

(sorry!)

I've found that the best thing to use is a small amount of silicone grease. Quite a few people use bath sealant or silicone mastic but I don't like it because it's sticky, doesn't compress as well as grease and seems to get everywhere and jams things up when it solidifies. The grease just forms a nice watertight(ish) seal and is easily removed and cleaned off.

How about high density epoxy filler and make the boat stiffer than what it is.

Seat your beams....I used epoxy thickened with milled glass fibers and it made a very hard and perfectly fitting seat for the beam. To keep it pretty, I'll finish it off with some 4200 around the edges after I'm finished sanding the newly sprayed gel coat.

Beam Seating at Team Seacats

Good article, Jake. I am surprised that in the beam seating process, you never checked for hull alignment before letting the slurry cure. In talking to Pete Melvin, he told me that he prepared the slurry for all four pockets, similar to your process, but put both front and rear beams in place, checked that the measurement from port bow to starbord stearn was the same as starboard bow to port stearn. This is when he tightened it all down at all beam bolts, then checked again to make sure nothing moved. He let it cure in a perfectly aligned position.

By doing the process for the front beam at a different time than the rear beam and with all the slurry it took to take up the imperfections of the beam seats, I would be concerned that you might have cured your new beam seats with the alignment less than perfect. Just a thought.

That is why you would use slow curing drying agent. This will give you plenty of time to make sure everything is alinged.

It's buried in the site, but we did check hull alignment. It was very very close with no pressure on it and we measured more of a difference in the length of the hulls than in the crossing measurement. With the 4 degrees or so of cant in the I20 hulls, measuring toe-in (equalizing the measurement from center line of bow to bow and center line of stern to stern) is damn near impossible since nothing is really in a straight line. We checked the cross measurement again after snugging up the beams with the slow cure epoxy and again it was right on...I should have gone into more detail about that.

Shouldn't you be on your way to Spring Fever!?

[quote] Shouldn't you be on your way to Spring Fever!? /quote]

Yes, I should, however, some unexpected expenses to get my car and the motorhome on the road got in the way.

Also, with the A2 on the market, I decided not to take it out, making sure it would be available to whoever buys it when they want to get it. I would love to be bringing down the new F17, however, it just hasn't shown up in time for Spring Fever (bummer). Have fun down there in Georgia! The weather looks like it will be near perfect! And take a close look at that Infusion for me. Bill Gillespie is bringing something (electronic files) from me for you to use when you go over the Infusion with a fine tooth comb.

I am not surprised that you addressed hull alignment in your doing the bedding in of the beams. It is just consistent with the way you do things.

Les,

The diagonal measurement you refer to does not accurately indicate toe out or toe in of the hulls. You can sketch out a couple of examples of hulls radically toed out and toed in and see that the diagonal measurements can be exactly equal from one side of the boat to the other.

A better measurement of toe out/toe in is the distance between the bows compared to the distance betweeen the center of the transoms. On a boat like the Hobie 18 which does not have canted hulls this should set the hulls paralell in the water.

For boats with canted hulls, setting toe out/toe in is more difficult, but not impossible. One technique I recently observed was to establish marks at the center of the bow and transoms at the estimated water line of the boat with crew weight distributed for light air sailing (when toe out/in creates the biggest performance problem). Alignment was then adjusted until the distance between these marks was equal at the front and back of the boat.

As the hulls were canted 7 degrees, had a fair amount of rocker and the carbon beams were being bonded to the hulls, this was not a simple thing (they used an adjustable jig that held everything steady.

The bonding technique in Jake's excellent blog works well, and really tightens up a Hobie 18. This, together with improvements in the steering department such as fitting the one piece gudgeons can transform the feel of the boat.

Chris.

That makes two of us. Work has been really demanding lately (lot of travel) and I couldn't get out for Friday. I am really behind on other stuff at home too - taxes, etc. (not only the I20). I'm not going to make it to Spring Fever either...although I am going to go motor out to the course on Saturday afternoon and take some pictures.