h18 – major delaminated fix project

I have an h18 that as severely delaminated hulls. Both hulls, on the outside are completely delaminated from stem to stern. The insides are still strong.
I’m very familiar and experienced with “conventionalâ€

Good luck on what sounds like an ambitious repair. I’ve done small delam’s but this sounds enormous. I do hate to see any Hobie’s destroyed and parted-out, especially 18’s since they are out of production. I look forward to hearing and seeing your progress. Post Pic’s.

Consider, if you can, to draw a vacuum from one end of the delam and both draw and push the epoxy into the void. Drawing a vacuum may help to avoid trapped air pockets.

Good luck.

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John Latimer
'79 Hobie18 - Magnum
Sail#4854

Thanks for the reply. I suppose i'm looking for moral support
Yes, I have considered coming up with some way to create vaccuum to suck the epox in as well as using pressure of some sort to push epox in. I have a vaccumn box that is used from an air compressor to evac auto a/c units and was wondering if I could make that work. Not sure how i might pressurize to put the epoxy in. Need something that would despence at least 12 ounces or more at a time. I was thinking of a caulk gun with a bunch of empty caulk cartridges. I do know one thing, I do NOT want to drill hole every 2-3 inches along entire length of hull.
Here are the epoxy applications i've been thinking of.
1. CHANNELING METHOD: With hulls removed from frame and turned upside down on saw horses,
drill holes just above the solid glass area of the keel and just below the deck(in reference to keels being right side up) maybe 3 inches apart for maybe a foot, starting at one end of the hull. Use a wire or cable made of spring type steel so it can flex but not bend, and run it through the hole to the top of the hull close to the deck. These would be channels, 3 inches used to run the epox into.
2. SURGICAL METHOD: Cut slit, maybe 1 or 2 feet long just above the solid glass area of the keel. Use small spacers to hold the slit open like an evelope. Use thin piece of spring type steel to fully seperate foam from outside layer of glass. Poor epoxy down into this area and then remove the spacers.

I'm leaning towards method 1.

I'll be ordering a 2 gallon penatrating epoxy kit from local distributer in next few days. WIth shipping, should cost around $100. I wonder how far that will get me.

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John Lillie
83 h16
79 h18
~Have you hugged your hulls today?~

Just so you can really torture yourself later on down the road, you may want to weigh the hulls before and after the repair.

sm

Good idea! Will do.....and yes, I obviously like torturing myself.

Hmmm....I wonder if cured epoxy wieghs same as uncured.

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John Lillie
83 h16
79 h18
~Have you hugged your hulls today?~

Epoxy weighs the same, whether cured or not - about 12 lbs / gallon.

a gallon = 0.13368 cu. ft. or 231 cu. in.

Therefore, 1 gallon, spread 1/8" thick = 12.83 sq. ft.

An educated guess of the area of one side of an 18 hull is about 36 sq. ft.

I think you're going to need more epoxy . . .

It may be hard as a rock when you're done, but it's going to weigh like one, too. It'll be like having another person on the boat.

The foam core layer is more like 1/4 to 3/8 thick, right?

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John Lillie
83 h16
79 h18
~Have you hugged your hulls today?~

That's right. However, when the boat delams, the foam doesn't go away. By injecting resin, you are just re-adhering the glass skins to the foam, plus filling any voids. That's why a vacuum system (or some other method of compressing the laminate) is so important.

By using 1/8", I was making a guess as to the general thickness of the resin. It'll probably be thicker (and heavier).

Right. I just wanted to see where you were getting the 1/8" from.
I'm guessing you used an average of 2' from keel to deck and the entire length of the hull to get the 18 (18' * 2' = 36 sq. ft)
I measured and marked the soft areas of the outside on one of the hulls. The 1st 9' feet or so averages about 1.5' (from keel to deck). The rear portion averages about .8 (from keel to deck) and about 7'.
so, 1.5' * 9' = 13.5 sq. ft.
.8' * 7' = 5.6 sq. ft.
Total 19.1 sq. ft.
It will be interesting to see how much epoxy it actually does consume.
I'm definitly going to weigh the hulls before and after.
You've got me wondering if I should go to the trouble of setting up a vaccuum. If the vaccuum exists while injecting the epoxy, the glass layers would pull against foam, possibly not allowing epoxy to get between foam glass. What if I injected epoxy first let saturate as long as possible, then apply vaccuum to squeeze out access?
MBounds, thank you for your input.
~john

Note that the vaccum system I mentioned (for laminate compression) is different from what you suggested above (for drawing the resin through).

Once you have the resin in the laminate, you need to squeeze the laminate back together. This will spread out the resin and reduce the overall amount of resin used, since you won't be filling as many voids. I'm not sure how this could be accomlished, though.

You'll need access to the inside of the hull. Perhaps inserting some kind of temporary structure inside the hull to support the area, then weighting the outside with sandbags would work.

I think you will be better off with pressure injection and lots of holes drilled rather than trying to draw the resin through with a vaccum. The hull is easy to refinish.

The hull should be removed from the boat and supported on saw horses with the delam area up so that the resin doesn't leak out. As you inject resin, tape off each hole as resin starts to ooze from it. That will also allow you to track the progress of the resin across the delam area.

Another problem you will have is time.

Once you mix the hardener with the resin, the clock will be ticking. One way to slow down the clock is to reduce the temperature, but that also makes the resin more viscous, which is not what you want.

I suggest you work on a small area (maybe a square foot) at a time.

I wieghed my hulls. They have been removed from the frame/tramp.
They wiegh 115 and 117lbs.
I should be starting the epoxy treatment in few weeks.
~john

Over the weekend I completed the delamination fix on the Port side hull with great results - a rock-hard hull (as MBounds mentioned above).
In summary, I used about 1 gal and 1pint of epoxy in total.
I would guestimate that approximiatly 80% of the hull was delaminated (outside side of hull only. inside side of hull was and is solid).
I drilled a minimum number of injection and vent holes and had some great success with some tools i created/invented.
I also ran into a major setback during the process but was able to overcome it in the end.
I plan to get a personal website going to document my process in detail with pictures.
In the mean time please send any questions anyone might have.
PS I"m really glad I didn't take the circular saw to them as I did with another set up hulls I had in the past.

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

Well, both hull's delaminations have been repaired. I used a total of 2.5 gallons of epoxy (1.25 per hull).
The 2nd hull gave me much more trouble then the 1st. The entire project was definitely a learning experience.
The biggest problem I ran into was the epoxy seeping through the inside glass layer. This ending up being a fairly consistant problem with both hulls. I guess it stands to reason that if the inside glass layer allowed moisture through causing the delamination, it would allow the penatrating epoxy to leak in the opposite direction (to the inside of the hull).
Anyone doing any delamination fix (big or small) should be aware that theres a good probability that a lot of the epoxy is going to leak into the hull unless steps are taken to avoid it. An interestnig fact I'm sure is well known is that the inside glass layer is one thin layer of glass cloth and a very minimal amount of resin was used to laminate it.
When I realized a good deal of epoxy was leaking into the hull I figured what have I got to loose so I cut 4" wide access strip in the bow section deck to gain access to the inside layer. After the first injection attempt cured I mixed up some standard laminating resin and used 4" roller to coat/seal the inside. With the handle extension on the roller i was able to reach fairly deep toward the rear of the hull. Even though I put on a pretty good coat of resin I still ended up having some leakage with the epoxy but not nearly as bad as it would have been. To do it all over again I think I would use something less penatrating, maybe epoxy (to coat the inside).
Another benifit of opening the bow deck was that I was able to create support structure to keep the inside layer of glass from bulging. This is especiall important on the bow end of the hull where there is considerably more hieght in the hull. Actually, I realized that overcoming this problem alone makes opening the hull up a necessity.
But all in all the delamination fix was successful. I ground the gelcoat off around each injection or vent hole to provide some depth for filler and filled with polyester filler. And I have all that leveled out ready for gelcoating. I now have to reglass the bow decks which I should be starting in another week or two.
I'll come back in a few days to share some information on what I used for an epoxy injector (this worked way better then I could have hoped) and some other details.

~john

This is exactly what i am going to have to do. I am in Fort Myers and just bought a '78 18' last weekend. It's apart and in my yard. I would like to talk to you about this and maybe have a look at how you did it. Can you give me a call? 239-410-8171 or [email protected]. I hate to trash these hulls out and they are pretty banged up but was looking for a project when I bought it. Thanks