91 Bayliner floor HELP

[pattimac]

I am new to the forum and have a 91 capri 21 footer. After pulling up the carpet, I discovered the "very thin" layer of resin they originally applied to the main floor is cracked and the top layer of the plywood in a few areas is peeing away. There are several holes that they used to pour in the foam visible and after peeling away the fiberglass and/or resin from above the holes, the foam is dry in 5 that I have checked. I DO NOT WANT TO PULL UP ALL THE FLOORING, BUT I WANT TO BE SAFE ALSO.

If I drill two 3 inch holes (with a hole saw) in the rear, just in front of the engine cover; one on the outer side of the two main stringers ( on the outside so I don't accidentally hit the gas tank) and above the foam, AND if the foam is dry in each, can I just redo the surface of the floor?

Although the top layer of the wood flooring is bad in some areas, there are no areas where I see soft/rot and I can not push a srewdriver into the wood at all..in any of the areas.

All the fiberglass coating in the engine compartment, beneath the two rear seats and everywhere except the main floor between the engine and front seats looks like brand new. Even in the main floor, 6-8 inches around the "edges" are like new.

 

[Robj]

Re: 91 Bayliner floor HELP

Sorry to tell you the bad news. But the fibreglass is peeling away because the floor is rotten. The only way to fix it is to cut out the rott and replace with new ply. When you are checking the foam for water, are you going right down to the hull? Checking it from the top you may not find the water because it would be lower down.

Have a great day,

Rob.

 

[pattimac]

Re: 91 Bayliner floor HELP

OK...here we go again. I went out and drilled 8 -3 inch holes. 4 on either side of the floor, just outside the main stringers that straddle the gas tank. Everything is dry all the way to the hull and the bottom 1/2 of the plywood in each of the holes is clean/lightcolored plywood as opposed to the upper half or top third that is doscolored from being wet.

I figured you guys are right. Might as well replace the bad plywood and have a little piece of mind. If I get in there and see more damage, then I'll fix that while I'm there. However, are there any specific threads that clearly explain how make sure the seams of the old and new plywood are strong and waterproof? I plan on glassing or treating the underside of the new plywood also, but don't have a clue as to how the seams are done. Basically, I'll be replacing about an 18" x 36" section; where the 36'" section goes from in front of the two rear seats and the 18" section starts about 5" in front of the engine cover and extends forward toward the bow.

A good portion of the 36" section is atop the gas tank area, so there is another layer of 1/2 " ply beneath the top layer based on what I see in the holes I drilled. I may go a little further toward the bow in the center area, just in case?

After my long winded description, how are the seams done since there's only foam below?

Finally, you may be right about why the glass/resin cracked, but in a lot of areas (other than what I'm replacing), it's cracked and the wood beneath is perfect. I do know that Bayliner used fiberglass (meaning cloth AND resin) on the outer 4-6 inches of the entire floor area, but ONLY resin on all the rest, which in effect, is the entire area where anyone would be walking under normal use! The areas on the edge where they did it right is perfect with no hint of cracking or compromise!

I'd buy a new boat since I'm retired now, but the engine (merc 5.0L) is perfect and only has about a total of 100 hours since we bought it new. And, the rest of the boat is in great shape! I hate to get another payment!

One last thing..I promise...for now.....Since it appears that there is another piece of plywood atop the gas tank and below the deck wood, am I going to make my cuts around the bad wood and then not be able to lift it out because it is glued/resined/or whatever to the piece below. I guess it would take someone that knows how bayliners are made...aside from not top-of-the-line!?

Thanks for your help........

 

[Driven1]

Re: 91 Bayliner floor HELP

Welcome to iBoats!

I've no clue how Bayliners are made but it sounds like you're in good shape to just do a patch job on the floor.

Use a square and mark out the area you need to replace keeping the corners as square as possible. Get out your skillsaw and set the blade at a 45 degree angle facing the center of the piece you'll be cutting out and to a depth that will just cut to the bottom of the floor plywood. No deeper. The old ply may be held to the hull by foam, adhesives, or fiberglass (especially if over stringers. You'll just have to do whatever to get it off. You might get lucky and it might just come right out too!

Next cut a patch out of new plywood with the same saw angle and the same outer dimensions of the hole you cut. If done right, when you test fit the new piece, it should sit level with the rest of the floor. If it all looks ok, glue it in place, If it rests on stringers or foam it wouldn't hurt to put some glue on top of the stringers and foam for it to adhere to as well. Use a good polyester based construction glue like PL Premium Construction adhesive. Weigh it down with a couple of cement blocks or whatever you have around that's heavy. Let the glue fully cure and remove the weight.

You mentioned that Bayliner only Resined the original floor for protection. If it were me, I'd rough up the whole thing with 60 grit paper, clean it off real good with acetone, and then put down some glass matt on the whole floor and reglass the whole thing. It will make it stronger and much more resistant to wear. Don't forget to seal up any holes you made during testing! Paint or carpet when the glass is fully cured.

Here's a relatively good video (BTW towards the end of the video they mention using 1708 Biaxial Glass over the patch. Personally, I feel it's overkill.)

Oh, and use a skillsaw. Not a Sawzall.

http://www.youtube.com/watch?v=KqELnDPR0hQ