Hobie 18 Crossbar Reinforcement Patch

Hey all,

I recently purchased a 1984 H18 w/ Magnum wings. Serial numbers indicate that it was constructed in Nov of 1983 and has the black glue and NOT the red. Research on this forum suggests it is still wise to add the fiberglass reinforcement patch at the front crossbar as well as the anchor plates.

I am a little confused on which materials and method to use to make this patch. Matt Miller has recommended a single 12" wide patch that extends 6" into the deck and 6-8" down the sidewall using fiberglass mat followed by a layer of fiberglass cloth. However, many others seem to be using other techniques to make this patch - I have not seen anyone document the use of the single patch with mat & cloth technique. Is the single patch still the Hobie Cat Co recommended method?

I plan to use West System Epoxy Resin 105 w/ 205 hardener. Any suggestions on fiberglass materials and sources for purchase?

Thanks everyone!

Here is how I did it. I used epoxy and several overlapping layers of carbon fiber cloth.

viewtopic.php?f=13&t=49780&p=224528&hilit=hull#p224528

It is a time consuming project and grinding away the excess glue is a pain. It's also easiest if you can disassemble the boat.

Honestly, if your boat is not a red glue boat and does not show any signs of cracking under the hull lips, I would not bother with doing this. I would just install the updated stainless steel anchor plates and be done with it. If the boat lasted 30+ years without the patch and still shows no signs of damage, I think you would be doing a lot of un-needed work (my boat on the other hand had cracks under the hull lips all the way through the hulls...).

sm

Thanks for the quick reply. I have studied your carbon fiber post (among many of your other posts!!) quite extensively and it was one of the reasons I created this thread.

I may indeed follow your advice and simply install the anchor plates, the previous owner included them, so I just need to pick up the hardware. I haven't come across a Hobie instruction sheet or forum post that explains the proper procedure to do that, it seems pretty straight forward, but any tips would be appreciated.

All that being said, I am still curious as to what Hobie recommends as the official patch method. There are a couple of posts with the same 1984 hulls with black glue and what appears to be an insufficient sized patch. Matt Miller recommended the patch be added on those boats.

Love this forum! Thanks again everyone.

To install the updated anchor plates-

1) Remove trampoline and remove the front crossbar bolts (inboard & outboard) and the existing anchor plates. (It may be necessary to loosen the rear crossbar bolts too in order to align the hulls during reassembly.)

2) Apply a bead of silicone on the inside surface of each new anchor plate around each of the four holes. Then place the new plates under the hull flanges one at a time and install the crossbar bolts. Tighten the bolts snug so the plates are held in place securely. Note that it's easiest to install the inboard bolts first and having a second person assist with aligning the crossbar and bolts can help.

3) Use a 1/4" drill to drill the four new holes in each hull side wall using the holes in the anchor plates as a template.

4) Place a small dab of silicone under the head of each bolt and then install each of the four 1/4-20 bolts through the new anchor plate and hull. Install flat washers and nyloc nuts on the inside of hull using the access port and tighten securely.

5) Tighten crossbar bolts to final torque and re-install tramp.

sm

Official? Hmmm,

I have done the patch on at least 5 redline boats and none on "Black Glue" boats. (I have owned over 35 18s). I have used Carbon and fiberglass mat and really don't see any difference. I do worry that the carbon is less flexable than the rest of the boat and could create related stress cracks in boundary areas. I have never seen one fail again after repair in that area under either technique. But, the redline boat will continue to fail in other areas. Rear cross bar areas being the next worse.

Love them all but the white 1983 is a battle axe. Heavy, strong and probably one of the most durable years ever built.

Love the reinforcement plates...

_________________
H18 '85
H18 '89 "Knotty Passion"
H20 '96 "20/20 Vision"
Fleet 259 Central Coast California