Hi I am new to this forum and would appreciate any help. I have a 1982 stripper I built with some friends and now would like to get it sea worthy. Over the years of transportation. And storage my canoe started showing air pockets in the outside football and the wood. The inside seems fine but there is a good deflection in the middle when in water. It still floats but I can tell it is pretty delicate as it sits now. Mu question is can I inject resin in the football area with some weight in the boat to give good contact and reattach the wood to the outer fiberglass. I would like to use this boat with my son and evenetually pass it on to him in working order. Tha ks
1982 stripper football separated from the wood
- Thread starter Joe Evans
- Start date
pklonowski
Unrepentant Canoeist
There are folks here with more expertise than me, but... Trying to inject epoxy into the bubble sounds like it'll add a lot of weight, and it won't strengthen the layup. The glass cloth needs to be adhered to the wood core for it to have any real strength. You'd be way better off removing the damaged area and re-glassing.
Todd Bradshaw
Sailmaker
Polyester resin by chance? These days we use epoxy for the glassing process and delamination is pretty rare. Injecting resin, as mentioned, is weak and potentially heavy. Resin only has good strength when it's applied in thin-ish layers and reinforced with a high content of fibers.
In some ways, the deflection of the bottom is a more serious potential problem and it doesn't have much to do with the outer fiberglass. Bottom bounce and deflection will eventually break the core and trash the boat, and what prevents this is the inside fiberglass, not the outside layers. Fiberglass only adds significant strength and stiffness when put in tension (inside layers) and doesn't do much when put in compression (outside layers).
You could remove the glass from just the bad spots and replace it, but that certainly doesn't guarantee that the spots next to those places won't be the next to delaminate. You could also take a heat gun to the boat, remove the glass and re-glass the whole boat. This fixes the problem, but it's a hell of a lot of work. You might find it more rewarding, a lot less hassle and not much more work to start from scratch and build a new hull. If the bottom is flexing, the boat needs either some glassed-in half-ribs or another layer of fiberglass over the inside bottom.
In some ways, the deflection of the bottom is a more serious potential problem and it doesn't have much to do with the outer fiberglass. Bottom bounce and deflection will eventually break the core and trash the boat, and what prevents this is the inside fiberglass, not the outside layers. Fiberglass only adds significant strength and stiffness when put in tension (inside layers) and doesn't do much when put in compression (outside layers).
You could remove the glass from just the bad spots and replace it, but that certainly doesn't guarantee that the spots next to those places won't be the next to delaminate. You could also take a heat gun to the boat, remove the glass and re-glass the whole boat. This fixes the problem, but it's a hell of a lot of work. You might find it more rewarding, a lot less hassle and not much more work to start from scratch and build a new hull. If the bottom is flexing, the boat needs either some glassed-in half-ribs or another layer of fiberglass over the inside bottom.
Thank you for the replies. If I use hAlf ribs is there any advise or articles concering the procedure and resin. It appears that I will remove outer football and replace to get this material to adhear to the wood. Will also I stall two half ribs with glass and resin. Thanks again for your help
pklonowski
Unrepentant Canoeist
Removing the outer shell & re-glassing may fix the deflection issue... just do that, and see if you even need to do any more.
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Todd Bradshaw
Sailmaker
Not at all likely. The outer glass is in compression when the bottom is deflecting - and adding virtually no strength or stiffness to the hull. Until you have added so much that it approaches a stand-alone fiberglass hull, it's not going to contribute any serious stiffness. The easiest way to make half-ribs in a stripper is to get some cedar or balsa and make some decent-sized half-round pieces that span most of the bottom and taper out at both ends near the turn of the bilge. Spread them out every 18"-24". Assuming that the inside glass is in decent shape and you aren't going to remove and replace it, sand it a bit in those areas to get it clean and ready to glue to. Use epoxy resin and glue the ribs to the floor. You can stick a weight on them to bend them into the bottom's curved shape while the resin hardens if needed. Let the epoxy set up. After it's hardened, you want to cover each rib with a couple strips of fiberglass cloth, cut to overlap onto the bottom about 1"-1.5" on either side of the rib. Let that harden. If desired, you can feather out the edges of the fiberglass strips with a sander and/or apply filler coats of resin to match whatever texture you have on the rest of the inner glasswork. A protective coat or three of a good UV filtered marine varnish will protect the epoxy from ultra-violet damage.
When positioning your ribs, don't put any in places where your knees might go if you decide to paddle from a kneeling position, as that would be pretty uncomfortable. You're probably talking about ribs that would be 1" wide or so, and maybe 3/4" tall. Hobby shops sell pre-shaped balsa stock that is made to use as a leading edge on a model airplane wings and nicely curved in cross-section. Cut it to length, taper the ends and it's probably the fastest way possible to get a nice half-rib core.
The glass does the vast majority of the work on these things and the core acts more as a spacer than a structural element. Here's one that Norm and I did many years ago with half-ribs. I tried plastic tubing as the rib cores, as somebody had mentioned that it worked well and we knew that the inside of this boat would be painted, rather than clear-finished. It worked, but I had some trouble keeping the tubing straight. Sawn, shaped and glued-in wooden cores would have been neater.
When positioning your ribs, don't put any in places where your knees might go if you decide to paddle from a kneeling position, as that would be pretty uncomfortable. You're probably talking about ribs that would be 1" wide or so, and maybe 3/4" tall. Hobby shops sell pre-shaped balsa stock that is made to use as a leading edge on a model airplane wings and nicely curved in cross-section. Cut it to length, taper the ends and it's probably the fastest way possible to get a nice half-rib core.
The glass does the vast majority of the work on these things and the core acts more as a spacer than a structural element. Here's one that Norm and I did many years ago with half-ribs. I tried plastic tubing as the rib cores, as somebody had mentioned that it worked well and we knew that the inside of this boat would be painted, rather than clear-finished. It worked, but I had some trouble keeping the tubing straight. Sawn, shaped and glued-in wooden cores would have been neater.
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