Hull Repair - Resin or Epoxy

Hello,
I have to repair a 6 inch vertical hull crack, close to the access hole, on my 82 H18 that I just purchased. The crack is on the outside and the inside fiberglass is blistered at the site of impact. I have been researching, what I can, to find the proper repair method for this. At this point in time, I believe that the best repair method is to 1.) Cut open the blister on the inside, clean the area (grind & acetone wash), glue with polyester resin, compress area with deep throated c-clamp and back up plastic wrap covered boards, layup an additional glass patch on the inside after prepping the surface, let cure. 2.) Grind / feather out the exterior crack, prep surface, layup fiberglass repair, & sand to shape. 3.) Apply Gelcoat, sand to finish & buff. I think that polyester resin is the better repair material, as it is the same as the Original hull material??? Or is it better to use Epoxy such as the West System??
Thank you in advance for any replies.
Keith

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1982 H18

Keith,
Sounds like you've done your homework. First, couple of things....
Never use acetone to prep/wipedown prior to glass layup. All you need to do for a prep is sand.
Never use anything other then penatrating epoxy to fix delamination.
And, standard laminating resin should be fine to repair the outside and inside glass layers.
On the inside, I would layup 1 layer of glass cloth. This would be mostly to stop the injected penatrating epoxy from seaping through the inside glass layer. After layup, lay a piece of plastic over wet glass and then something flexible to conform to shape of hull
Use the C-clamp you mentioned or simply cut a few 1"X1" pieces of wood to wedge between opposite side of hull to keep layup in desired shape. Leave this support in place until job is complete.
To fix the crack on the outside, grind off all gelcoat where the glass will be layed up. This will help in minimizing the hump you'll end up with in relation to the rest of the hull.
I would think 2 layers of glass cloth should be sufficient.
Next, once the layp cures, complete the penatrating epoxy job to ensure a bond between inside and outside layers. Lots have been written about this process elsewhere but one thing. Don't use masking tape to cover holes. This doesn't work and makes a big mess. Use wooden dowl rod instead to plug holes. Let me know if you have any questions on that.
Then,after epoxy cures, sand roughness out of glass layup, and use polyester filler(you might know this as Bondo, but there are better brands) to fill voids/feather and smooth out.
Then gelcoat to a thickness that will allow proper curing (gelcoat requires a proper thickness to cure properly).
Wet sand geloat to feather and blend with surrounding are.
Let me know if you have any questions.
~john

Hello John,
Thank you for the reply. I appreciate the information. The weather is starting to warm up here in Wisconsin and I will be able to work on my hull soon. All of the methods that you have described sound good. I will post my progress here when I do my repairs.
We raised and rigged the mast for the first time yesterday. It looks pretty good. My daughter and I are figuring out ways to stow our stays and trapeze wires so that rigging at the shore will go quicker.

Regards,

Keith

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1982 H18

Keith, Would it be possible for you to take some digital photos of the damage and email them? There's usually more than one way to skin a cat (or make a repair). If you get the HOTLINE magazine there is an article I wrote for the last issue with some photos which may help you plan your upcoming repair. There is another article due to be out soon in the next issue too, which may give more ideas. I'd be glad to offer some ideas, but to give valid tips on making a repair it's best to see what you have to deal with first.
Rick

Hi Rick,
Thank you for the information. I appreciate all of the help. I will be taking some pictures soon, so that I can post them for the forum's reference. I have been busy at work, repairing a lot of broken machinery for customers, and have not had much free time. I have not had a chance to work on the hull as of yet. I am picking up an industrial sewing machine this weekend, so that I can make new covers for my wings and a new tramp in the future and who knows, maybe some sails, when needed. Thank you again, Keith

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1982 H18

I fixed a Hobie 18 near the bow. No "port" cut in. I have pictures and an explaination of the process if your interested. Just send me an E-mail or post your e-mail. Provide some pictures of your problem area.

djanddale "at" charter "dot" net

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1989 Hobie 18 Worlds Boat, Magnum Wings & Spinnaker
1987 Hobie Holder 20 #273

dale.vanlopik"at"att"dot"net

Dude, bad info. I always use acetone to wipe down with between layers as well as thinning resin ,cleaning tools, etc. Also when you are using epoxy you need to clean with water first before sanding.

I have a similar crack that is about 16 inches long and located directly under the front pylon on the inside. the crack flexs under loading, particularly when the stay is tensioned. it is big enough to leak and appears to pose a significant structural problem. should i try to fix the problem from the outside, or am i better off cutting open the top of the hull, and having to install a porthole to fill the gap. while i am hesitant to have to cut into my boat, as there is already a soft spot (large coffee mug sized) in the area, the crack does seem to be big enough and enough of a structural risk that it might be worth putting her under the knife.. opinions/recommendations?

btw, the other hull is showing signs of breakage in the same spot, is there any kind of preventitive maintence i could be doing, or should i just start searching for slightly used hulls.

Loose pylon shoe, rather extensive repair to reattach. Rick Buchanon can help you with the step-by-step

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Sheet In...Max Out
www.fleet297.org
sailflatlands at gmail dot com

will i need to cut the hull open to make the repair?
is it better to cut a round hole and patch it with an access hatch or should i cut an eliptical hole and patch it with the material that i removed plus a bunch of fiberglass?

Hey Speed, If you would send your private email address to [email protected] I have a bunch of photos which might be helpful in making your fix. They show a crack as you've described, and how to reinforce the pylon boot. You will most likely need to install an inspection port (or at least a hole big enough) to do this type of fix. Rick

GenMar Star, dude, I didn't make up that info and I never would have said that without a reference handy.
The information comes from the company I do lots of figerglass business with check out the "Figerglass" area on this page that talks about SURFACE PREPARATION FOR BONDING, COATING OR PAINTING.

This company has a wonderful tech support and I asked them about this during one of many phone calls and they confirmed.
So dude, I think your giving bad info.
~John

http://www.fgci.com/howto/ht001surface_prep.html