Well, with no other ideas I decided to improvise. I got a can of "Great Stuff" expanding foam, made an extention for the application hose, attached it to a wooden rod, and re-foamed the delaminated area from the hole I had cut for the hull access port. The foam is allegedly waterproof. It was a messy job but it appears to have worked. I cut away the excess foam that oozed out after it had hardened and installed the port. The hull is now rigid and the extra foam is quite light. I'll be taking the boat to the beach in August--if I have any problems with the repair I will post them here when I return.
seems to me that it would be quite frail. Did you re-glass over it?
over time, the foam will break down. it has no sheer strength. do not step on it.
Thanks for the comments! No, I did not glass over the repaired area--(should I have done so?) The foam was injected directly into the delaminated area via a 6 inch round hole I had cut in the hull for an access port. This had exposed an easily accessible cross-section of the delamination. The hull was otherwise intact. I had read somewhere that for areas of delamination over 6 inches in diameter, the damage should be "re-foamed" at a boatyard. Since the damaging incident last summer, the area of delamination had expanded from the original 7-8 inch wide round area (starting about a foot in front of the forward pylon). It now extended from two inches in front of the forward pylon approx. 2.5-3 feet up the hull, narrowing as it went. It was 2-3 inches wider (on both sides) than the 6 inch hole I had cut for the port (that was a foot away from the forward pylon at its closest point).
If I have just managed to stop any further delamination I will be happy--I hope this will prove to be the case. I consider the extra rigidity a bonus.
I am hoping the foam lasts as long as it has where I have used it to seal conduit pipes, windows, etc. in my house--which has been over 10 years now. The foam has remained intact and slightly pliable over the years if not exposed to direct sunlight. I will make every effort to ensure that no-one steps or sits on the repaired area.
If the repair survives the pounding Atlantic surf (at Holden Beach, NC!!) in August, I will be pleased.
I heard that after trimming the foam the cut edge must be sealed as the "skin" that is cut away is what keeps the foam from absorbing water. I would reccomend re-inforcing if possible, a frind and I were sailing a h16 in 15knt winds, both on the wire and snaped a de-laminated hull in two about a foot forward of the frond pylon.
I just got some of that foam and am thinking of injecting it into the tramp casting to try and stiffen them up some. Have you or anyone else had any experince with this?
Thanks
Jody Abrams
H16 58467
this 'spray foam' is not strong enough of stiff enough to use in structural applications. every one knows what happens to a boston whaler after a few years. that is with a good quality two component foam. in a short time this spray foam will soak up water and break down.
Spray foam is good for a lot of things,repairing soft decks and hulls isn't one of them. As a past owener of a "81" hobie 18 I have had to repair delam. in the decks.The best way is to inject resin,vinylester or epoxy.V.E.resin is less efected by moisture than polyester.Epoxy is good and is what I have used when making this repair.Slow cure epoxy 1:1 or1:2 is best. The faster epoxy can generate to much heat as it cures. This causes the epoxy to crack and not bond well with the laminates or foam.You need tape, large syringe,epoxy,drill and bits. First find the ends of the delam.Find a drill bit slighty smaller than the than end of the syringe.Drill a hole through the top of the deck.Make sure the hole is in the soft part of the deck.WARNING do not drill through the bottom lam.Do the same at the other end of the delam.If you can let this air a week.Don't let any water get in.Mix the epoxy fill the syringe(I also drill the end of the syringe to get better flow.don't ruin the syringe) I usually tip the hulls up a little and inject up hill.Keep pumping until it comes out the other hole.If your working on both decks do both, going from one to the other.You can push lighty on the soft area to help get any air out and inject again.To help with clean up put masking tape on the deck before drilling the holes.When cured use a little gel putty or whatever you like to fill the holes. You can use tape striping to hide the holes.If you need to walk on your decks in the future, step near the edges not in the center.This repair has lasted for several years.If it starts to soften again take care of it right away.Boats with portholes.Remove them first. dig the foam out at least a half in. beyond the mounting holes.Fill this with a epoxy putty. Let it kick.Now you can perform the above repair.Redrill the mounting holes,install the ports.I repaired a buddys H-16 a few weeks ago and he is very happy.Another buddy used the foam and regreted it.Foam expands and pushes the outer lam. up and the inner lam. down. This is not a good thing.The most important thing is to deal with it right away....IT WILL GET WORSE!!!!
I am hoping the spray foam will not get wet, as both the outer and inner layers of fiberglass are intact. Also, after I cut the dried foam from the access port hole, I did seal it with "Marine Goop".
If this repair does not hold up at the beach, I will probably try to cut out the inner fiberglass layer and the damaged / re-foamed areas from inside the hull through the access port. If I can do this I will then reinforce the area with an all-glass, multiple layer repair, or add another layer of glass to the outer (gelcoat) layer from below, replace the damaged foam, and put a couple of layers of new glass on that and attach/seal it to the existing inner glass layer. (Unless someone has a better idea?)