This post brings up a very good question: what is the body of evidence that the delam repair with epoxy produces strong or 'strong as new', hulls. This web site should be a great place to get lots of reports of the performance of delaminated and repaired hulls, and to begin to get an idea of the probabilities of success. I STRONGLY ENCOURAGE EVERYONE WHO HAS EXTENSIVE EXPERIENCE SAILING ON REPAIRED HULLS TO PUT A SHORT POSTING ON THEIR EXPERIENCE, especially if problems developed due to the repair. (By the way, my impression is that the repair is very strong, but that is difficult to confirm because this web site has many stories from people who just repaired their boats, but very few from people who have sailed awhile on them). So here is the short version of my own experience (hopefully others will imitate):
I repaired two delaminated hulls with 3' to 4' by ~ 8" soft spot forward of the pylons about a year ago, and have sailed about 12 times with no problems developing. The repaired area is very firm with no 'crunchyness' detected when pressing hard with my hands. The sailing I tested them in was often in light to moderate wind, but once was in wind that was as high 17 mph average with 28mph gusts. The water was always flat.
The longer story (for those who are interested) is: I bought a 78 H16 with the two large soft spots on top and several other small ones which were mostly on the deck but two on the sides. I repaired following the hobie web site closely, except I used FLAG epoxy resin and medium harderner and the two large spots took about 1/2 gal. of resin plus hardener with about a pint of glass fibers mixed. After they were reparied they were extremely firm, stiffer than undamaged parts of the hull or most other H16 top sides I have been able to put my hands on (my guess is that they may be even firmer, perhaps even stronger than new hulls, but can't say for sure). I put another quart of epoxy in the small soft spots (or on the ground from many spills due to difficulty of injection). I have subsequently run the boat into the dock to produce a large delam on the side of the bow that took another pint of epoxy to firm it, and found a slight dimple on the side near the stay anchor that seemed pretty firm but that I pushed on hard enough (with my hand and my elbow braced by my knee for added force) to create a soft spot that I then repaired with about a cup of resin (this was to be sure that there was not a small delam that could have grown large under stress, I don't know if it was really a good idea). The hulls are now firm everywhere, with a few very small spots that are firm but produce some 'cruchyness' when I push on them (I am guessing the foam is deteriorating in these areas) As for the sailing I have done on them I sailed with two adults and two kids and a reefed main in 17mph+ wind on flat water acouple of times, and with two adults in the higher winds mentioned above (also reefed main), and several times in lower wind and/or by my self. I have never pitchpoled or capsized. In all this time I have not detected any evidence that any part of the hull, or certainly not the fore decks, has developed delam due to sailing stresses, so I am pretty happy with my repairs. However, I am obviously conservative in my use, and for example so far have strictly avoided sailing the SF bay due to cold water with chop and high and gusty winds, and certainly do not plan to do that with my kids. But I do sail in the gusty winds on small, warm lakes etc. and would like to be confident enough to sail the bay with another adult. Unfortunately the use I have given the boat may not be a the best stress test, so I look forward to hearing other experiences with repaired hulls (I have also heard mmillers very encouraging story about a bot repaired in the 80s and sailed hard for 20 years, but I have also heard anecdotal info about bow separations....). I also don't know if the delams I created with impacts indicate that the old hulls are substantially weaker and prone to delams than new hulls are. It would be interesting to figure out whether a well maintained (ie; not delamed) hull that is 30 years old is a strong as a new one, as if I lose confidence in my hulls in the future, I will need to decide whether to invest in new ones, or better maintained old ones.
Hope this is helpful to others. No matter what other experiences may show, sailing my 16 has been a blast and well worth the trouble!
Bob
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