to glass or to marine polyurethane

[1955]

can I use marine polyurethane on some good cabinet grade ply for flooring in a 14' Bayliner capri? the floor boards are rotted out just in the middle of floor the outsides are still good. I just want to go over it and not have to put glass and resin down. I would cover all the new wood(ply) with 4-5 coats of marine urethane as well as the edges so no water can get to it. and after put the new carpet back over it. This boat is only going in fresh water (Arizona)

 

[drewmitch44]

Re: to glass or to marine polyurethane

It will be too brittle without the glass.

 

[mthieme]

Re: to glass or to marine polyurethane

Urathane won't last.
Go with glass. You'll have much less maintenance.

 

[109jb]

Re: to glass or to marine polyurethane

It will be too brittle without the glass.

He's talking about polyURETHANE varnish, not polyESTER resin.

I used polyurethane marine varnish on my Aluminum Starcraft floors about 9 years ago. They were then covered with carpet except in the area under the splash well. Has held up pretty well. If I were to do it again, I think I would use bedliner instead of carpet. Using polyester resin and glass would be best, but a waste IMO unless you totally encapsulate the wood.

Edit: For some reason I had it in my head he was doing an aluminum boat. I see it is a glass hull boat. Everything I said above was in regard to an aluminum boat. For a glass boat: You are going to at least have to glass the floor to the hull around the perimeter. Since you have to do that anyway, just go ahead and glass the floor. It would only be a few hundred more dollars and result in a much better job.

 

[ondarvr]

Re: to glass or to marine polyurethane

Before you do anything more, check to just how much rot there is. If you look at other threads with "I found a little rot in the floor" you'll see it's just the tip of the iceberg. Transom, stringers and foam normally need to be replaced.

 

[jonesg]

Re: to glass or to marine polyurethane

Before you do anything more, check to just how much rot there is. If you look at other threads with "I found a little rot in the floor" you'll see it's just the tip of the iceberg. Transom, stringers and foam normally need to be replaced.

yeh, its a bandaid on cancer.

Whats the transom like?

 

[1955]

Re: to glass or to marine polyurethane

The transom is vey good. I went all around and checked the hull all over in and out, no other rot other then 1 -16" cyrcle just in back of the seats and a
4"x9" spot in the front -right in the middle. and this is all about 9" above the bottom skin. All this rot is on wood that was not covered form original build. where they stoped the resin and glass is the only rot spot. so all i want to do is cover it up with 3/8 plywood, but before I do that I will paint all the plywood with the marine polyuethane and screw it down with brass screws then carpet.

 

[109jb]

Re: to glass or to marine polyurethane

Your plan is only a patch and not a fix. The patch you describe may get you a season or 2, but will not stop the rot from progressing and is not going to last. In order to fix the problem you have to get rid of all of the rotted and wet wood. With the 2 spots you describe, I would bet you are seeing the tip of the iceberg. Have you taken plug samples from the floor? If not then that is your first step. If the wood from samples comes back wet, the wood is on its way to being rotted even if it isn't right now. I'm sorry to say this, but it doesn't sound good to me. I did a patch job like you describe on my Sea Ray earlier this year, but with the full expectation that it was only a patch. I only did it to make the boat usable for this season. I will be doing a complete floor/stringer replacement this winter.

 

[1955]

Re: to glass or to marine polyurethane

Thank you for the info. This is a Bayliner 1400 Capri Bowrider with the sequential lift hull.
Like I said the hull is very hard with no soft spots. And from the inside of the boat the very bottom of the hull has no rot. it is just the deck you walk on above the hull that has dry rotted wood. I will cut it all out that I can get to but the rest has white painted fiberglass on it and is still very much in tacked with no soft spots. I guess the real issue is, is the boat worth taking the whole inside out to redo it with so very little tell tail damage to it. Can you tell I 'm looking for the easy way out?
I just thought that the integrity of the hull is good. it is just the inside floor boards that are bad and did not see the urgency to take it all out and replace. But like I said it has been about 30 years sense I worked on boats. All the others never had bad wood on the interior.

 

[fishrdan]

Re: to glass or to marine polyurethane

can I use marine polyurethane on some good cabinet grade ply for flooring in a 14' Bayliner capri?

Marine or exterior grade plywood only, cabinet grade plywood is not made with exterior glue and will begin to de-laminate quickly in a wet environment.

I would fiberglass it (as suggested earlier) instead of using polyurethane since (fir) plywood will check over time. Checking = cracks all over the surface of the plywood = water can get in,,, and the rot begins.

 

[1955]

Re: to glass or to marine polyurethane

your right, was not thinking,
thank you

 

[1955]

Re: to glass or to marine polyurethane

Hello you have all convinced me to do it right,so here I go. I have some pics. not to good will try and get better but as for a plug test how do I do it without going through the hull. I is only ? ? thick and just testing it with a pick nothing is soft so far.The only rot is on top of the floor(seat platform,floor boards). I cut some floor boards out in places and checked the hull.

 

[driz]

Re: to glass or to marine polyurethane

I just landed here and noticed your problem looks familiar to one I had on my 2252 Capri 6 or 7 years ago. What's the bet that your problem was caused by the tarp system used to keep the water out during storage? The guy that owned mine kept it like it was his trophy wife. The problem is that he used one of those snap on tannau covers with the pole and eye with the point sticking up through it. The problem is that water trickles down that pole and in the course of 5 or 6 summers it created a soft spot right where the pole sits dead in the middle of my floor. It didn't take much, just time and dampness as Bayliner uses crap wood for the decks of their boats.
I fixed mine by cutting back to good wood and spanning the whole thing covering the whole thing with 5 coats of enamel paint and then covering the whole thing with a single piece of aluminum. You can get old highway signs at the scrap yard pretty cheap. I just beveled the edges of mine, drilled countersunk holes and covered the entire floor with AL. Something like that might or might not be applicable to your situation. Mine has been fine ever since though I do keep it out of the rain. It just seems that ripping the whole deck up to fix one spot when the rest is otherwise completely sound can mean a lot of unnecessary work. The secret of it all is keeping the cursed rain out and making sure all the drains are free so water doesn't set anywhere on the decks for too long. I wouldn't worry at all about the hull as on these small runabouts it is solid fiberglass. It is the interior decks and worse yet the plywood cored transom that you have to watch out for. It's too bad these boats tend to sink in the back yard rather than the lake.

 

[1955]

Re: to glass or to marine polyurethane

thanks but i still think I will take it all out and redo with 1/2" marine ply and glass. I have nothing but time but a little short on money but so it takes me longer then planed. I will feel a lot better when I go to sell it to the next person looking for a good boat to go and spend a little time on the water.

 

[109jb]

Re: to glass or to marine polyurethane

...I fixed mine by cutting back to good wood and spanning the whole thing covering the whole thing with 5 coats of enamel paint and then covering the whole thing with a single piece of aluminum. You can get old highway signs at the scrap yard pretty cheap. I just beveled the edges of mine, drilled countersunk holes and covered the entire floor with AL. Something like that might or might not be applicable to your situation. Mine has been fine ever since though I do keep it out of the rain.

What you describe here is not a "repair", but a patch. This can work for a time, but without removing all the wet and rotted wood will not last. Using aluminum signs and scrap to cover the wood isn't a solution either.

...It just seems that ripping the whole deck up to fix one spot when the rest is otherwise completely sound can mean a lot of unnecessary work....

The problem is that the one spot is likely the tip of the iceberg. Taking core samples of the wood floor can answer the question, but judging by the pictures the damage is going to be pretty widespread. If core samples show that surrounding wood is not wet or rotted, the cutting out the wet/rotted sections and replacing with new wood glassed in is OK, but again my bet would be that the damaged area is widespread enough that I would want to replace the whole thing.

As I said before, I did a patch job on my Sea Ray to get through the 2008 season, but will be replacing the whole floor this winter. The soft spot on my floor was also only about 1 foot diameter, but I replaced about a 3' x 4' piece of floor and I was still not to dry wood. I got to wood that did not appear rotted yet, just wet, but I know the rot would eventually be there and the only way to get rid of it is to replace a much larger portion of the floor. Large enough that I decided it was worth it to just replace all the floor/stringers.

1955, I think your decision is a good one as you will know when done that you have a good solid boat. Good luck.

 

[oops!]

Re: to glass or to marine polyurethane

sorry man....im not buyin it.....!.....the rot in that floor is too wide spread in a bliner for it just to be the wood......decks rot from the bottom up.....thats why we glass the bottom of our decks......

read ondarvrs post again....there is more there than you can see.

search core sample......

i truly think you also have foam issues.

if you are short on cash....just use exterior grade ply......the marine is really expencive.....after the ply is encapsulated......youll get 20 years out of it....
rot does not care if its marine grade ply or ext.....if it gets wet.....it rots !

 

[1955]

Re: to glass or to marine polyurethane

Thank you sir. I found core sample and will do it. I found marine ply for $45-4x8 sheet is that good? I am thinking I will just take all the wood out and replace. 2 sheet of ply will do it. ( this may sound stupid but)if I use ex-grade ply should I cover both sides with resin and glass after I cut to size and then put it in and glass to the rest of the boat for support? I also noticed that the stringers have no glass on them at all just bare wood, if these are stringers I only see 3. two under the seat platform 14"wx5"hx width of beam one and one in back just before the bildge. they are suspended about 1" above the bottom of boat???

 

[1955]

Re: to glass or to marine polyurethane

I am one happy bugger just pulled 7 core samples on transom and all is good hard wood. I think I did not mention to all you but this boat was stored with is bow down. The person I got it from left it at his kids house all the the gear on it just went away, fish finder, trolling motor and I'm sure other stuff. I have not pulled samples from bow yet , not until I pull up floor boards????????????

 

[i386]

Re: to glass or to marine polyurethane

The stringer in the 1st and 2nd pic looks rotten to me.

 

[fishrdan]

Re: to glass or to marine polyurethane

I found marine ply for $45-4x8 sheet is that good?

Yes a good price for 1/2", but I think you are going to be using more than 2 sheets once all is said and done, stringers, deck, etc... If you are trying to cut corners 1/2" 5 ply exterior plywood will cost half of the marine plywood. I paid $60/sheet for 3/4 marine ply and bought 6 sheets for my rebuilt $$$ I could have bought the cheaper plywood, but I intend to keep the boat for 10+ years.

Have you core sampled the foam yet? I think once the decks are removed you will find more rot and wet foam, only 1 way to tell...