I have a 1976 Hunter 30, it has obviously had deck leaks around the hatches and elsewhere, and has substantial core rot. In a lot of the areas I have scraped out the rotten core, and have filled it with Polyester resin mixed with colloidal beads. I am now looking at removing the handrails and resealing the screw holes, and filling the soft spots. It is OK to use Polyester resin, as I cannot get epoxy here, or would it be best to order in epoxy?
Core Rot
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D
Don
preferably epoxy
Two suggestions: First, the polyester will also absorb moisture over time and can cause even more work for you as it will be more difficult to fix the second time. If you want to do it right and be assured of a proper fix, use epoxy. The other suggestion is to grind the glass back sufficiently to do a proper bond with glass mat to spread out the load and fair in the repair. Otherwise, you are only creating a hockey puck fix that isn't properly bonded to the good deck material and which could pull out at the worst time under heavy load.
Two suggestions: First, the polyester will also absorb moisture over time and can cause even more work for you as it will be more difficult to fix the second time. If you want to do it right and be assured of a proper fix, use epoxy. The other suggestion is to grind the glass back sufficiently to do a proper bond with glass mat to spread out the load and fair in the repair. Otherwise, you are only creating a hockey puck fix that isn't properly bonded to the good deck material and which could pull out at the worst time under heavy load.
Check West Systems for Expoxy.
I would suggest that you contact West Systems for epoxy advice. They have all sorts of epoxies that can be poured, injected etc.
I would suggest that you contact West Systems for epoxy advice. They have all sorts of epoxies that can be poured, injected etc.
Starboard Rot
Not sure about the '76 model but the '81 can develop rot in the starboard deck caused by the latch at the anchor locker. It appears that Hunter just drilled a hole thru the fiberglass directly into the balsa core. Over the years water ingress will develop and I found it in the locker and behind the starboard settee. It took me years and a lot of drilling to find the source. Hope this is of some help to any of you
Not sure about the '76 model but the '81 can develop rot in the starboard deck caused by the latch at the anchor locker. It appears that Hunter just drilled a hole thru the fiberglass directly into the balsa core. Over the years water ingress will develop and I found it in the locker and behind the starboard settee. It took me years and a lot of drilling to find the source. Hope this is of some help to any of you
B
Bob
I bought my boat two years ago, and believe me it was a labor of love. The prior owner pulled the port side main chainplate right out of the bulkhead. It seems he had a prior leak at the mast base, and although he repaired that one, didn't look for any collateral damage. I had to cut the bulkhead out (dry rot) midway between the port hull and mast support, and replace it. I used 3/4" plywood, bonded to the hull and existing panel with epoxy and fiberglass mat. I doubled the remaining stays with 3/4" plywood and glassed (and Mat)them in as well. If you boat is like mine, the stanchion bases may need some work as well. One good way it to re-tighten them, and look for water oozing out the screw holes. Several of mine were mushy inside and I used a router to cut them right out, all the way to the interior layer of glass. I built the inside of the new hole up to the required height with plywood (same as before) filled the hole with epoxy, reshaped it to match the originals, then gel coated it, and redrilled the holes. I use SS Fender washers on the underside for added stability. Matching gel coat on a boat that old takes time and effort, but its a good old boat, and worth the time. As far as the screw holes go, for the ones that are not mushy, you can put some duck tape on the underside, mix some epoxy with filler, and push it in with a empty calking cartridge tube, West Marine has them. Good Luck and fair winds!
R
Ross Anderson
Polyester vs Epoxy a different view
Skip the epoxy. There is no reason to go to the expense and the results could be problematic. You see, epoxy has different mechanical properties when cured than the original polyester. This mechanical miss-match could lead to an unpredictable failure under load. Whoa! You epoxy boys say. Yeah I’ve heard this before. Epoxy is great stuff and the manufacturers have done a good job convincing almost everyone that it’s the wonder goo to solve all your problems. Problem is they are wrong. Using the same materials that the original boat was built with, when done correctly, will yield better results than spending a lot of money and mixing mechanical properties. Follow me here. Epoxy has different, some say better, mechanical properties than the polyester resins. I won’t argue one way or the other on that score. I just acknowledge the difference. Lets say that the epoxy has greater strength than the polyester? Is that a good thing? What happens under dynamic load? The polyester breaks before the epoxy, yes? Then what. The boat is just as broken as if it didn’t have epoxy occupying part of the lamination. If the epoxy is actually replacing some of the original polyester layup then the boat is less strong than when it was all polyester. What makes a Monocoque structure strong is the uniformity of its mechanical properties across the whole of the lamination. That uniformity moves loads around inside the lamination sharing the load. If the load sharing is upset by a stronger, harder, more flexible spot in the lamination, it is more likely that the load will be concentrated in the boundary areas where the dissimilar materials come together. Any naval architect will tell you that Load Concentrations are serious issue to be avoided as much as possible. Especially in a boat like structure in a dynamic environment like floating in water. The loads imposed in this environment affect the vessel in its entirety. The sharing of these loads and the management of the transmission of these loads throughout the structure of the vessel are the art and engineering soul of a finely designed fiberglass vessel. No. I diverge from the magic goo advocates on this issue and recommend that when doing restoration work on fiberglass boats, Replace ‘Same with Same’. There is less likelihood of changing the mechanical dynamics of the structure your repairing which could lead to unforeseen consequences. And ‘Same with Same’ means the same layup schedule, the same thickness of the final layup, the same resin to cloth or mat ratio as close as you can get it. After all a fiberglass boat is a system, a carefully designed system that is inadvisable to change.
Skip the epoxy. There is no reason to go to the expense and the results could be problematic. You see, epoxy has different mechanical properties when cured than the original polyester. This mechanical miss-match could lead to an unpredictable failure under load. Whoa! You epoxy boys say. Yeah I’ve heard this before. Epoxy is great stuff and the manufacturers have done a good job convincing almost everyone that it’s the wonder goo to solve all your problems. Problem is they are wrong. Using the same materials that the original boat was built with, when done correctly, will yield better results than spending a lot of money and mixing mechanical properties. Follow me here. Epoxy has different, some say better, mechanical properties than the polyester resins. I won’t argue one way or the other on that score. I just acknowledge the difference. Lets say that the epoxy has greater strength than the polyester? Is that a good thing? What happens under dynamic load? The polyester breaks before the epoxy, yes? Then what. The boat is just as broken as if it didn’t have epoxy occupying part of the lamination. If the epoxy is actually replacing some of the original polyester layup then the boat is less strong than when it was all polyester. What makes a Monocoque structure strong is the uniformity of its mechanical properties across the whole of the lamination. That uniformity moves loads around inside the lamination sharing the load. If the load sharing is upset by a stronger, harder, more flexible spot in the lamination, it is more likely that the load will be concentrated in the boundary areas where the dissimilar materials come together. Any naval architect will tell you that Load Concentrations are serious issue to be avoided as much as possible. Especially in a boat like structure in a dynamic environment like floating in water. The loads imposed in this environment affect the vessel in its entirety. The sharing of these loads and the management of the transmission of these loads throughout the structure of the vessel are the art and engineering soul of a finely designed fiberglass vessel. No. I diverge from the magic goo advocates on this issue and recommend that when doing restoration work on fiberglass boats, Replace ‘Same with Same’. There is less likelihood of changing the mechanical dynamics of the structure your repairing which could lead to unforeseen consequences. And ‘Same with Same’ means the same layup schedule, the same thickness of the final layup, the same resin to cloth or mat ratio as close as you can get it. After all a fiberglass boat is a system, a carefully designed system that is inadvisable to change.
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