Cutting fiberglass ... blind

[LeatherneckPA]

OK, this is what I have discovered. The chainplate on my LS-16 was apparently not sealed very well, if at all. This stainless steel strap goes through the deck and was bolted to a piece of 3/4" plywood. That was then glassed to the inside of the hull. I'm assuming this was done before the deck was glued on because it's not someplace one can easily work or see what one is doing. That's where the working blind comes in. I can either look at where I'm working or get my hand in there, but not both at the same time

Anyway, my port chainplate pulled out of the plywood, which is rotten and useless. What I am thinking about doing is taking a utility knife and scoring/cutting the glass on either side of the plywood to remove it. Then I'll recreate that piece by laminating pieces of 1/4" plywood and bolt the strap to it. Pass it all back up through the deck and probably glue it to the inside of the hull.

Do you guys know if a utility knife will cut through that glass & fabric with any degree of control?

I'm leaning toward epoxying the plywood directly to the hull, since I can't see to do any glass work inside this area. What's your opinion/experience?

ETA: My other option is to use a t-nut on the inside of the plywood, drill through both the plywood and the hull, and drive the bolts through the hull/plywood/t-nut from outside. Not real keen on drilling holes in my hull, as you may imagine.

[Jmckamey]

Is the pic upside down? From my experience a utility knife would be pretty tough to work with unless the glass is thin. A drimmel tool with a cut off wheel might work good. As far as using fastners go, I think some stainless hardware on both sides sealed up up with 3m 5200 would look like it was made that way, and you would never have to worry about it comming a part again.

[sauerleigh]

You might want to invest in a Dremel Multi Max. I could not have done much of my demolition work without it. The tool is easy to control. Harbor Freight sells an asian ripoff of the Fein type multi tool for about $40.00. There are various blades that can be purchased separately.

[clair hofmann]

Do you have room to cut in an access port on deck near the chainplate?
I bought one of the Harbor Freight multi tools and have used it several times. Its a ahndy tool and you should be able to find a blade thatwill cut through the glass. As with any Harbor Freight power tool, spend the extra few bucks for the extended warrenty. I always do that and several times it has paid off.
Clair

[kalamazoogal]

If you have access to an air compressor, I'd suggest getting an air die
grinder. They have a wheel that is about 4-5" across and will cut
through just about anything. To keep the heat build up under control
and the dust down, mist the blade as you cut. Yea, it's messy but the
cut will be clean and you won't have as much dust to contend with.
If you opt not to use the mist option be sure to wear some kind of lung protection as that dust just can't be good.

[LeatherneckPA]

I think it was Chrysler 20%26 who wisely said "They are sailboats not workboats. So sail them." Or words to that effect. Hence, this is what I have all but decided to do. I'm just wondering what the consensus of the more experienced among you is about my chosen tactic.

I am planning to make a press scribed with the curve of the hull at that point. In this I will epoxy-laminate three pieces of 1/4" plywood 6" by about 8" long. That will give about 2" of plywood border around the SS chain plate. Next I'm going to enlarge the holes in the chain plate to 9/64" and use them as a guide to do the same thing to both the plywood and the hull of Cinderella. I will use SS mushroom head bolts with a SS washer on the outside of the hull and SS Ny-Loc nut and washer on the inside of the chainplate to hold it all together. It is my intent to butter the inside of the plywood with epoxy which will affix it to the hull permanently. Since the chain plate will be on the inside of the plywood it will still be able to be removed for some unforeseen reason.

I guess my questions to you would be:

• a) Is drilling through the hull a bad idea?
  b) Epoxy or not to epoxy the plywood to the inside of the hull?

Don't think about this too long, I'm planning to do it this weekend. I really want Cinderella back on the water before Labor Day! But I really want to do this right and make it last. It is my dream to make a present of this boat to my grandson for his 16th birthday, 14 years from now.

[Banshi]

How about a flat plate to help spread the load on the outside. depending on the thickness of the glass in this area they could pull through. Some good caulking is a must of course in either case.

I would epoxy to help distribute the load if for no other reason.

[sauerleigh]

I have not personally seen the chain plate setup in the LS16, but I think if you just replace the rotten plywood and glass it over, you'll be OK. I am guessing that the chain plate passes through the deck and is bolted to the ply. If the ply butts up tight under the deck, the bonded ply and deck will carry the loads. Drilling holes through the hull and sealing them is not that big a deal, but I don't think it is necessary in this case. When gluing up the plywood with epoxy, paint it on, let it absorb a bit and paint it again, and don't over tighten any clamps or fasteners. You don't want to squeeze the epoxy out of the joint.

[Jmckamey]

I think this is a good repair scheme. Wet build up with epoxy or some other structural adhesive for sure and maby some large area washers under the screw heads to address any concerns about pull-thru. Just not too large area for cosmetic reasons. This repair should outlast the boat. Just think, the next time you are heeled over at 30deg. you won't even have to give the shrouds a second thought. Just my 2cents, for what it is worth. Jeff