hobie 16 hulls

I have recently acquired a 79' hobie 16. The hulls visibly are very chalked and oxidized, but the top sides or decks are wavey like there is some delamination. instead of being blistered there are depressions. I was wondering if I could beef up these areas via injection and raise or lower these areas reshaping them to original profiles. Has anyone experienced this and what was done.

Yes. Here's the solution:



Seriously, so delammed that it's wavy? You're just asking for big peices of hull to break off.

Unfortunately I think Matt is right. It you look elsewhere on this site like the "Repairs" forum you can see pics of how the Hobie 16 is made. The hulls and decks are a Resin/glass - foam - resine/glass sandwich which can be SEVERELY weakened by delaminations. If you have waves, it may be that both the outer skin and inner skins have delaminated from the foam core. I suggest you find a local expert to examine your boat and help you decide whether it can be repaired or not.

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Alan
'86 H16, Sail #89057

I don't think the condition is all that bad. I have felt of these and I really believe that even if the interior and exterior layers are seperated I can pull them back together filling voids thus strengthening these. I really wanted to know if anyone has seen this.

Check out the repair articles in the last three issues of the HCA newsletter. There is another thread here that I added a link to that has some neat repair videos. Maybe your description sounded worse that the problem is. But something to think about is where it is located. If the problem is just forward of the front pylon, a high stress area, you could end up with a hull that breaks in two.

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Alan
'86 H16, Sail #89057

If you can see a wave that's bad. Most efforts at repair at that point are bleak, at best. I know you want to think you can save it, but I would save time and move on. I would either a) only sail on a small lake that I could swim to shore or b) part out the boat and sell it on ebay while saying goodbye to the hulls. I wouldn't even waste my time to try to fix it. Sorry, but the truth hurts. There are too many old hobies out there with good hulls. Remember, it's not the water pressure on the hull, but the main sheet tension that will cause the failure as your hull will collapse at the weakest point.

I was under the impression that they didn't move to the foam sandwich until around 83/84. They used to make them with no foam layered between the fiberglass, just a thick layer of fiberglass with foam glued onto the inside of the hull. I worked for Hobie for a brief period in 1969-1970 and that's how they were made then.

I have a 79 H16 and it has some waves on the sides of the hull from being stood on while righting, but they are rock solid, no softness at all and they have been no problem.

Is the delamination issue a problem at all for the older type hulls?

Are you sure about the foam sandwich not being employed until 83/84? I was under the impression that the only significant change in hull design was a weight decrease in 84'. I thought the sandwich is what gave the hull strength without the weight of solid glass.

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James
86' Redline Hobie 16
Sail # 76909

I think you are right James. A single layer glass hull that would be strong enough would be really heavy, and a single layer backed by foam wouldn't be much stronger. Maybe the Matts can answer this.

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Alan
'86 H16, Sail #89057

Well as I have said maybe I stated incorrectly, but these hulls are very solid except for the top and I believe that this is possibly from being stepped on and being 30 years old. I think that with some work I can have these in solid form again. I guess I really should have included some photos.

They're all fiberglass foam sandwiches. However they don't taste as good as roast beef and swiss.

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1984 H16 - #80541

The tops are what usually go bad (delaminate) but I've seen a whole boat that was soft (the guy had it tied down to the trailer so hard, the hulls bulged at the rollers )

The problem with the decks delaminating is that they are under shear stress, especially just forward of the front pylons. This is the weakest aspect of a fiberglass/foam sandwich - the forces actually try to separate the laminate from the foam.

The sideways force of the bridles will literally pull the bow off the boat.


That happened to a friend of mine about 20 years ago - on a boat that was only about 10 years old at the time.

The beer can in the wound is a nice touch.

Well, 1969 was a long time ago and I only worked there 2-3 weeks, but I remember pretty much about how they made them. I believe they were the 14s at that time but I remember some new bigger ones they were starting to make - 16s I assume.

1. The molds were sprayed on the inside with gel coat.

2. Multiple layers of glass were laid on the inside of the molds and the resin poured and worked in. I believe the pylons were added at that point also.

3. Once the resin had cured, foam was glued to the inside and pressed in place with vacuum bags.

4. The edge of the foam was sure-formed (my job) so that it was not in the way when the deck and and hull were glued together. The foam was on the inside, not sandwiched.

5. Then the deck and hull were extracted from the mold and were glued together and the edges trimmed. Sometimes, a deck or hull was cracked and ruined when extracting from the mold.

6. Then blemished in the get coat were fixed.

I actually saw a guy light his hands on fire my first day there. I had just walked in to start working. The guy had just washed his hands in acetone and was wearing a long sleeved shirt soaked in resin. He lit a cigarette and his hands went up in big flames until someone tore his shirt off his back. I'll never forget it!