Hull Core Material

Status
Not open for further replies.
J

Jerry Conley

Considering buying a Hunter 37 which has some hull damage and have been told that the material Hunter uses for hull coring (end core balsa or somthing else ?) will not absorb water and a fibergalss breach is unimportant. Any truth to this ??????????????? Also have a 'spongy/soft' area on the deck and have heard the same information about the coring material - any thoughts ? And finally, where's the #$%^&%^ holding tank on this boat ???? (bet it's behind the liner !!!!!) Any information would be appreciated (any maybe save me a 'a buck or two') Thanks
 
M

Mike Alge

Hunter 37

Jerry The idea that a breach in the fiberglass is of no consequence is rubbish. I have a 1979 Hunter 37c and I bought it with the knowledge that the cabin sides and top were saturated. Iam now in the process of repairing the damage. The core material so far has been plywood and if balsa is used it must be in the lower hull area, but I am not sure ?? A soft and spongy deck is a dead giveaway for a wet and delaminated core and it will need to be repaired. You would be wise to get an estimate for the repair and use that to reduce your offer. Maybe you can get the seller to go half on the repair. It would be to ypur advantage and his also. On my boat ,the holding tank was located in the v-berth locker. I believe this is an aftermarket instalation. Judging from want I can see ,I think the original location is under the seat in the shower and it appears that to replace it you would have to cut open the shower seat... Mine came with a stainless steel tank that is going to be junked in favor of a polypropilene tank Stainless steel is not a good material for holding tanks because the stuff corrodes in the welds and will begin to leak. For more information on this, contact The Head Mistress and she will set you straight. Hope everything works out for you
 
D

Dave Kelton

no core

I do not believe that Hunter used cored construction on the hull of this boat. Cored construction means that there is an outer layer of fiberglass, an inner layer of fiberglass, and some material between. The material can be balsa wood, cut on end to allow bending, or foam, or a high tech type material. The advantage of this is high strength due to increased thickness, BUT if a hole is poked in the outer fiberglass layer, water WILL get into the balsa, and we all know what wood does when it's wet. It's quite the mess. That is the situation you are seeing on deck. That area will mkost likely have to be cut out, the balsa replaced, and the outer skin re-installed. I think that the hull is layed up fiberglass mat, which can be patched using mat and resin. West epoxy makes a great book that explains how to do this. Good Luck. Dave
 
M

Mike Alge

I have a H. 37c and I can assure you that at least the cabin sides and cabin top have a core and it looks like the side decks are also cored. As for material, I have found nothing but good old A/C fir plywood so far. I see little to suggest that balsa or any other "high tech " material was ever used. The plywood is not even marine grade plywood which did not supprise me as I was told by a professional boat repairman that Iwould find this. If youhave a wet core, plan on repairing it if you live in an area that has freezing tempatures. Drilling holes and filling with epoxy is not a good fix because the epoxy will not displace the water in the core . It will just concentrate the damage more making it even more expencive to repair later. As I said before get a good survayor to check it out and trust his judgement
 
E

Ed Schenck

Glass repair.

Mike is right concerning a 1979 H37C, I also own one, but you may be asking about a Legend? That is quite a different boat. Everything that you read states that older Hunters used end-grain balsa and yet Mike finds that to be false. And some, including the H37C, supposedly did not core the hull, it was laid up heavy and solid. West Systems has an excellent set of books on all types of fiberglass repair as Dave points out. You can find them at BoatUS and West Marine stores. If it is an H37C then the stainless holding tank is indeed under the shower seat. Mine was removed by cutting out the bulkhead at the aft end of the starboard v-berth. Only the section inside the locker, nothing visible above. Reinforced and used for addtional storage, polypro tank now in center v-berth locker. Good luck with the survey.
 
D

Dave Kelton

clarification

Just to jump in once again, if you read the original post from Jerry, he has hull damage PLUS deck damage. Hulls ( normally referred to as the area under the rubrail ), I do believe were not laid up as a core on these boats, but were laid up mat. Decks on the other hand are definitely cored in most places, most particularly flat sections. Plywood is definitely a possible core material. I also would like to add to the idea of drilling and injecting resin. This would be the preferred method for small areas, probably less than 1' in diameter and works best in balsa cores. BUT, the area must be drilled, injected with acetone to clean the core, allowed to dry thoroughly, ( over the winter is great), and injected with resin. Larger areas I would agree are difficult to inject, as voids are most likely created, as well as the fact that resin in itself is fairly brittle without mat mixed in. As a marine surveyor myself, I would agree to get a good one, there are lots of guys that have little if any practical experience with fiberglass work. If they offer a checklist as a survey report, walk away. Good luck, Dave
 
Status
Not open for further replies.