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Old 08-08-2005, 03:07 PM
Seadog Seadog is offline
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Fiberglass Hull Liner Question

Hello All! Great forum you have here. I need some help and advise if you please. I am about a year into rebuilding a 1970 Aquasport 222 open fisherman. Have removed the floor, stingers and all the foam and I'm in the process of rebuilding the stringers now. My question is about the original hull liner. The liner was attached to the inside gunnel at the cap, ran down the inside of the hull, and continued along the floor to the other side of the hull. What I'm wondering is the liner was not attached, at all, to the inside hull. It was secured at the top of the side with some adhesive material, and screws to hold the cap and rub rail, but the thing really just free-floated along the hull sides, nothing between the liner and inside hull wall but air. I hope that makes sense. My question is: do I need to replace the hull liner in the same fashion? Free-floating along the inside hull walls? Does this floating liner have some particular function as opposed to bonding the whole liner to the inside hull, or leaving the liner out and going with single skin fiberglass? Any help, insight, ridicule or advise would be great. THANKS!
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Old 08-08-2005, 05:35 PM
Jocko Jocko is offline
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sympathy post

I feel your pain! I'm at a similar point with a sailboat - monkey fur gone, lots of stuff to put back.

The age suggests that the hull itself is probably quite robust? I can't imagine that your replacement 'liner' would need to offer any strength, as the previous one appeared to be cosmetic/functional - not structural per se. I think this brings up the issue that attaching a replacement could cause unanticipated stress points if incorrectly done. That could then lead to cracks and worse case structural problems/failures. Point being that anything you replace shouldn't be carelessly adding structural strength. Sounds counter-intuitive, though.

Good luck.
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Old 08-08-2005, 09:24 PM
Seadog Seadog is offline
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Jocko - I am by no means an expert but I'm not sure if I would classify this old hull as robust. It seemed rather 'thin skinned' to me initially. I've 'beefed up' the hull a bit, with the advise of a local expert. Putting back the liner would really be just a cosmetic thing and a lot less work to finish out the inside rather than filling and fairing out new glass. Now that you have me sufficiently freaked-out about possible failure/problems if not bonded well, I think it will be worth the extra work. Thanks! That's just the input I was lookin for.
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Old 08-08-2005, 11:01 PM
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gonzo gonzo is offline
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The edge of the liner stiffens the hull.
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Old 08-09-2005, 10:36 PM
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PAR PAR is offline
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It's usually easy enough to figure the amount of structural importance in 'glass pieces of that vintage by it's thickness. If the liner is thin (1/8" or less) then it's a bath tub surround attached at the deck cap (where it may be thicker or have structural significance) intended to provide a finished surface to touch. Bonding this to the hull will add little additional strength, though may make it feel more solid. I wouldn't worry about local loading issues in this type of liner, the hull in these era boats are quite heavy (thick) providing the bulk of the strength requirements. Filling (foam) under these areas will add sound proofing, insulation, floatation and some support plus bond it to the hull.
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Old 08-10-2005, 07:34 AM
Seadog Seadog is offline
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'Bath tub surround' is a good analogy. The hull liner is about 1/8" thick, finished off smooth with cloth on the inside that faces the hull wall. The liner was attached at the cap joint with about another 1/8" wide of adhesive material that extended down the hull wall only about 3/4". It seems to me that the only structural support the liner provided was at this joint, like Gonzo said.

The hull itself was only about 1/8" thick, which seemed really thin to me but again, I'm by no means an expert. I've added 1.5 oz mat, 24 oz RW, some more mat and 17 oz DB to the entire inside hull to beef it up, from expect advise I was given. My concern now is that if I don't put back in the original liner, how much of price will the hull pay without the added structural support the liner provided at the cap joint.
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Old 08-10-2005, 03:13 PM
Jocko Jocko is offline
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Wow, my canoe has a layup 1/8" thick. With a hull that thin, and a liner attached as it was, didn't the hull flex considerably? I'm glad that you've thickened the hull. I can't imagine the liner adding significantly to stiffness, as Gonzo suggested, without the liner-hull-rubrail combo become it's own sandwich, but then again I can't think of a hull that thin that isn't paddled. I suspected the hull would have been something like 5x thicker/stiffer than the liner...it must be a function of the stringers/foam/floor you mentioned. It sounds as though you've solved/gained confidence with the structures problems, and now you're looking for "looks". If the liner can still be replaced, looks good, and it doesn't need to create strength, then why wouldn't you replace it in essentially the same way it came out. That sounds completely logical. Building an 'interior' from scratch is a lot of work, and it's only benefits would be adding strength (which you don't seem to need now) or changing the 'feel/look' of the boat. Have you just reached the 'cosmetic' stage of the project? If so - time to celebrate.
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Old 08-14-2005, 07:42 PM
Seadog Seadog is offline
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Jocko - been out of town, thanks for the response. The liner was continuous with the floor originally. The floor core, 1/4" plywood, was rotted, so it's been torn out and cut away from the liner. The floor will be replaced with laminated 1/4" Kledgecell composite. But because the floor has been cut away from the liner, the liner won't be able to be replaced in the same fashion it was originally. Don't think that will be a big deal and the liner will just be a cosmetic thing. It was finished off with gel coat on the inside and that will be easy enough to prep and paint. I won't count on the liner to offer any structural support at all.
I'm just now starting to form the stringers so the inside of the hull is bare right now. No stringers no floor, no nothin'. I am quit a distance from the 'cosmetic stage' but the celebration time is on the way. Probably be another year till shes ready to splash. Maybe longer...
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