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PostPosted: Thu Jul 14, 2005 11:01 am 
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Location: Missouri
:?: I have some delamination on the side of my hull on my 1980 H16. I went ahead and bought the west system this year to repair it by injecting with the west system syringes. When I checked the area from the bow to about the front crossbeam most of it made a crunching sound and was soft when I pushed a little on it, also just below the lip where the top attaches. There are a few hairline cracks by the bow, and in a few other areas, delamination seems to be about about 4 feet long on the side of one hull.
I have downloaded the Hobie delamination fix and the beachcats delamination repair. ( The difference I see in the two are the Hobie one says to make one large hole for injecting and several vent holes around the perimiter, while the beachcat method has several injection points and the use of 404 density filler, which the Hobie method does not mention.)
So I probably have a four foot section that has delaminated or is starting to delaminate.
Now for the questions:
1. Is it worth it to try the repair?
2. Is one method better than the other?
3. Can I do the injection with the hull still attached or do I need to detach it from the rest of the boat? The delamination is on the side of the hull.
4. Do I need to turn the hull on its side or can I leave it sitting on the trailer and just let the injected epoxy flow down between the fiberglass and foam when I inject it?
5. Should I use the syringes I have or should I get the caulk type tube?
6. Is the crunchy sound when I push total delamination or something else?
7. Should I use the 404 filler?
8. I have 1 quart of 105 epoxy resin and 7 oz of 206 slow hardner, do you think this is enough?
9. It was nice and dry when I was geting ready to do this project, but rained two days ago, any idea how long after it quits raining to let the hull dry out from humidity?
I have checked a bunch of posts, but they do not answer all my questions.

The boat is not used for racing, occasionally flies a hull- did not get to sail last year- doesn't look that good this year either!
Any help would be appreciated.
John


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PostPosted: Thu Jul 14, 2005 12:04 pm 
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Location: Flagler Beach, Fl
This is what I did, it works very well and you get rock hard hulls. I cut access holes in front of the front pylons. I used 4lb polyurethane marine foam to pour into the hulls from http://www.shopmaninc.com/foam.html. Each hull will take 4 cu ft to fill from the nose to just past the front pylon. It only added 16lbs to each hull and it is truly waterproof. Added a lot of boyancy to the front and the boat is hard to pitchpole. I sail in the ocean and had a recent occasion to put it to the test, 15+wind and 4 to 6' seas. The boat did fine felt real stiff. It has been about 7 months since I put in the foam and I see no sign of deteration and the hulls are still rock hard.

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PostPosted: Thu Jul 14, 2005 8:08 pm 
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Did you just shoot the foam in inside of the hull?, How did that help the delamination between the foam core and fiberglass?
Thanks, John


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PostPosted: Fri Jul 15, 2005 5:08 am 
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The polyurthane is a 2 part foam. You mix the 2 parts and pour into hulls. The boat must be pointed down hill so that the liquid flows all the way to the tips. As the foam expands it put pressure on all sides and top of the hulls forcing the delamination solid. I know it works because 1 of my hulls was soft and now you can stand on the top of that hull and it doesn't budge.

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PostPosted: Mon Jul 18, 2005 9:07 am 
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Location: ventura
that foam idea sounds good but if the fiberglass is delaminating then it's weaker, right? the foam would only support not strenghten, right?. I have no idea really. I just bought a H16 two weeks ago, my first one and the right hull is soft between both pylons and in front of the forward pylon.
is it junk?
should i flip it upside down and send some epoxy in it?
or foam it? foam is easiest.
help


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PostPosted: Mon Jul 18, 2005 10:33 am 
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The only this I can tell you is that you can push against the top of the hulls and feel no delamination at all. 4# polyeurthane foam is extremely hard. I can open the access plate and cannot push my finger into the foam. It's not like the foam you by in the can (Great Stuff). As the foam expands it puts pressure on all sides and top of hulls, everything becomes very solid.

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PostPosted: Fri Jul 29, 2005 7:03 am 
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Location: New Brighton, PA
Using the foam, the fiberglass is still delaminated, the foam it just pushing the sheets together. So yes, it's only support. When it delaminates, you need to get the fiberglass epoxied back together and fill the void for a good strong repair.
I would recommend having the soft spot facing upward, it's easier for the air to escape. I like to drill a lot of 1/8 holes in the top layer and inject the epoxy in. It will work it's way around the cavity and come out some of the other holes. When this sets up you have your repair true fiberglass repair. Then the foam could still be used inside the hulls

Buxton


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 Post subject: Delam FAQ
PostPosted: Mon Aug 01, 2005 3:42 pm 
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Location: Oceanside, California
http://www.hobiecat.com/community/viewtopic.php?t=1156

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PostPosted: Mon Aug 01, 2005 7:09 pm 
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I don't think that adding foam to the forward sections of the hulls will aid in flotation at all. In fact, it will reduce buoyancy... unless the hull is filling quickly with water. Don't add foam as an anti-pitchpolling fix. You could fill the hulls with helium.. That would be better than air! :D


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PostPosted: Tue Aug 02, 2005 5:24 am 
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I went the drilling and epoxy route, I keep my boat on the beach and the first time someone sat their fat butt on the hull the epoxy cracked and I was back in the same situation. The foam I used is rated at 58lbs of positive flotation per cubic foot. Tell Boston Whaler and other boat manufactures that foam reduces flotation. My boat is a 1976 and you can sit, stand or whatever on the hulls and they do not move. It seems one of the benefits I derived was that I could drive the boat harder on the points with less risk of pitchpoling. I know that pontoon boat manufactures are now filling the pontoons with foam for more flotation. Say what you will but the proof is in the pudding.

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PostPosted: Tue Aug 02, 2005 7:42 am 
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Air displaces the mass of the water with almost no associated mass of its own so it provides 62.4 pounds of buoyancy per cubic foot. The reason the foam only provides 58 pounds of buoyancy per cubic foot is that it weighs more than air per unit volume. The advantage of foam (in pontoon boats or boston whalers, for example) is that if the hull is damaged it won't fill with water and sink to the bottom. A boston whaler, before it is injected with foam, floats quite a bit higher than a boston whaler after it is injected with foam. This is a pretty decent website that explains a little about Archimedes principle and why some object float.... http://www.answers.com/topic/buoyancy-1


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PostPosted: Tue Aug 02, 2005 7:57 am 
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This is all fine and dandy, my boat floats, my surfboard floats, my hulls are stiff and my boat is fast. I used to have a WAVE surfboard based on this principle... it didn't float as well as a foam surfboard and was sluggish through the water... so much for the Greeks

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 Post subject: Displacement...
PostPosted: Tue Aug 02, 2005 9:37 am 
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Displacement... is flotation. Increase the displacement of the water while not increasing the weight and you increase floatation. By injecting foam in a hollow hull you add weight. So the boat would ride lower. Only if the hull is expanded by the foam do you increase displacement (This is likely what happens with expanding foam. Bostom Whalers are foam filled so they will float even when broken in pieces. Foam cores also increase stiffness.

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PostPosted: Thu Apr 27, 2006 2:44 pm 
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1 year later,,how is your foam filling working ?


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PostPosted: Fri Apr 28, 2006 4:47 am 
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After a year my hull are still firm, contrary to belief I haven't had a pitchpole and I run only in the ocean. I have had my GPS on the boat and have seen no reduction in speed. Last week we had 3 to 5 seas and a 15 to 17 knot wind, the boat had no problems maintaing a steady 23 knots+ according to the GPS and no worries of pitchpoling plus she blows through the surf.

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