Hobie Cat Forums

SO.... I have taken on a project to restore a 1987 Hobie 18. ( I know... run!! right?) This boat has crush zones from the rear rollers, and no reinforcement of the front crossbar areas..... Some cracking is evident, and one of the hulls leaks at the rear crush zone, and at the daggerboard trunk. (Reading up on the procedures to repair by searching on the forum.)

Before I get started I thought I would ask for some help..

Specifically...

1. Epoxy or laminating resin? Carbon fiber or fiberglass cloth?

( I was thinking of using carbon fiber cloth to reinforce the crossbar areas.....I have a source at reasonable cost for this)...Pros and cons?

2. What is it that we add to the Gel-Coat to thin it for spraying that also hardened it?

I think it was styrene, but the last boat I redid was like 20 years ago.....So I need help there...

3. I have a crossbar reinforcement kit on the way, and will install that after the glass work is complete on the front crossbar.....

Pictures on the way! Hoping to get this project done in 3 weeks......

Sound like fun??

Thanks for any help....!

Yes styrene is what you need to thin it.

I am about to reinforce my 18's fwd crossbar anchor plate. I just had mmiller take a look at this photo and he gave it an OK.

Make sure you sand down the glue beads to a nice curve and remove the anchor plate and bolts.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277

Good picture.

The idea is that you want to reinforce the bond strength between the hull and deck, so it's critical that you create a nice smooth fillet at the hull/deck joint. So you will have to sand/grind down the excess (red) glue and possibly fill in any voids so there is a nice smooth transition in that area. Then lay in your glass or carbon.

You should use polyester or vinylester resin, not epoxy. The hulls are made using polyester. Be sure to scuff the area real well and wipe with acetone before laminating.

sm

Will also try and make cradles to replace or augment the rollers on the trailer. I am having a difficult time finding 10" PVC pipe. Home Depot doesn't sell it and the wholesale plumbing supply stores require a tax ID number to start an account.

Where did/do you guys get your 10" PVC pipe from?

My zip is 85202 if you know of someplace local to me......

Thanks!

Search craigslist. Ringo and I were able to get a 10" pvc pipe for free in Orlando to make our H16 cradles.

I did a quick search in your zip code and quite a few craigslist ads came up. Try searchtempest.com

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-Zach
Hobie 16 for sale
West Lafayette, IN (school)
Melbourne, FL (summer)

I just spent 2 freaking hours sanding down the red bead of glue and I am only half way done with one.

I removed the deck port for a larger hole but rougher edge. I made a sanding block 6 inch by 3/4 inch by 1.5 inch. One corner is rounded and its covered with 60 grit paper. I also have a small electric sander with 80 grit. And the boat is upside down.

Anyone got tips for quicker removal, Im taking an ice tea break.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277

Dremel tool with a flexible extension.

sm

Please tell me this is enough.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277

I found my 12" pipe for my cradles at a local contractors yard. If you look for a General Engineering contractor that does underground he will more than likely have scrap. The guy I came across begged me to take as much as I wanted.

If you need pics on assembly and construction of saddles let me know. Mine are pretty similar to others posted on this site.

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H18 '86 "Knotty Passion"
H18 '85 Signature Series
H20 '96 "20/20 Vision
Fleet 259 Central Coast California

Here are some more pics I just did this. I missed one tiny spot as you can see, anyone think if its a big deal if brush resin onto the spots I missed later.

I applied 4 layers of 3m glass matte with resin thickened by a little 404 just so it would run a little bit less.

I searched the net for these pics and could not find them so here they are.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277

Thickening w/404 is not necessary - and it causes two problems:

1) You used way too much resin. Resin isn't what's strong - it's the glass. The optimum strength of laminates results from the lowest practical resin content. Optimum in this case is somewhere around 35 - 50% resin by weight (that's only because you're not using something like vacuum-bagging, which would allow you to get it even lower.)
2) The glass doesn't wet out as well - evidenced by your missed spots. When you use straight resin, you can tell when the glass is fully wetted out because it turns clear. You can't tell that with the white glop you sloshed on. The additional viscosity also prevents the resin from penetrating in between the bundles of glass fibers. Think of pudding going through a screen as opposed to syrup.

Nevertheless, what you did won't hurt - but it's heavier and not as strong as it could be. Besides, it's too late now.

Thank you very much for your tips. Right now I am taking a break from sanding the other sides glue bead.

Also note I did not thicken it that much and after I was done I just gooped as much extra resin on there, cause I did not know what to do with it. I brushed it in good. I missed the spots cause Im working on my back blind and at quote," It was at a funny angle."

Anyway, I will incorporate all your advice into the other side which I should have done in 2-3 hours. A rasp takes that glue bead down real fast.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277

Sometimes it's easier to wet out the glass first on a sheet of plastic or cardboard before applying it in the hull, this way you can see that the glass is fully wet out first. Then brush a light coat of resin inside the hull where you want to put the patch and put the patch in. Move the patch where you want and then work out any excess resin with your brush.

sm

You were 1000% right srm. I just finished the other side, and it went much smoother and came out clear like you said. It also ran much better. I only used 4oz of resin and I only used 4 oz on the other side too but the 404 made it seem like more. I laid 5 layers of matte and I think it came out great.

Thanks for the help. It feels good to know my redline has the anchor plate reinforcement even though one side is better than the other.

Also how much torque when reinstalling the anchor plate bolts? Im guessing not much due to the fact its a flat head.

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ALLEY CAT 1984 RED LINE HOBIE 18 MAGNUM
Sail # 10505 or 277

re the screw torques, I think the spec is "Gutentight". When I tightened mine down, I used the slot only to hold the screw in place and used a ratchet on the inside to apply the torque. There was a small difference (1-2mm) in contour between the bracket and hull, so used the screws to pull it in tight and then gave it an extra ~1/8 turn. I didn't go much beyond that as I bedded the brackets in 5200 and expect that to hold things in place as well. In retrospect I probably shouldn't have used something as aggressive as the 5200, but what is past is past. Hope I never have to take them off!

I appreciate your photo documentation of this as its in my future within the next few weeks. I had only done a half-job last year of applying the reinforcement brackets but not adding the additional glass on the inside.

Question: Do you think this is something that can be accomplished with the boat right-side up? I suppose you probably need the benefit of gravity when applying the glass/resin. The thought of having to either completely disassemble the boat or finding a way to safely invert it while assembled has given me pause. Time to call my buddies I guess!

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Jeff R
'88 H18 "Jolly Mon"
Sail Michigan's Great Lakes in 2013
cramsailing.com