floor and stringer replacement

[man5]

Hello, i have been reading the forums on and off for almost a year and really have enjoyed them. I have never added any input because of lack of experience with fiberglass boats, but it looks like I am going to get it. Last fall i bought a 76 205 gulfstream. I got it for a good price knowing the floor and stringers needed redone. The problem arised from the pedestal seats rocking and cracked the floor where the non-skid met the carpeted plywood under the seats. My kids and I took out the fuel tank and all the foam in that area. QUESTION 1- the fuel tank had something like epoxy on it which i believe was to protect it and it did a good job but most of it peeled off with the foam. does anyone know what i should put back on when i refoam? QUESTION 2- we did the fuel tank removal through a hatch in the floor, i now want to cut the floor to get to the stringers. it looks like there are only 4 stringers total made out of 1/2 or 3/4 plywood. how/where would i cut the floor so that when i install new it will rest on something. (this boat is what i call a wet deck, the sides are sealed to the floor and that area seems to be in good condition all the way around)QUESTION 3 why are the stringers only plywood? thank you for reading. sorry so long just trying to be specific.

[man5]

adding to the above post: the flooring question that is how do i connect the old floor to the new if the joint doesnt land on a stringer? i wont be able to get underneath it to bottom glass it. should i fiberglass a lip around the old floor? any suggestions are appreciated and will help me to plan the cut out of the floor. thank you

[jimslade]

1. repaint with epoxy paint 2. Most likely the stringers are gone too. You should do one side of the stringers at a time to avoid structural twist. to mate the floors together use a support block under the lip. screw together and glass.Use dried out pressure treated ply.DONT ALLOW THE WOOD TO TOUCH ANY EDGES OF THE FIBERGLASS BOTTOM OR SIDES.

[buckknekkid]

try this for size, we just completed the re construction of the transom knees, tabbing of the aft bulkhead and NOW I find a crack in the roving on one of the stringers

[man5]

Thanks jimslade for the info, I'm trying to get pics posted of the tear out.

[Waterwolf]

Ok, help. I have a 88' Citation 19ft. open bow. Yes, I am new to all this, and not to mechanically inclined. My floor is completely rotted, and the top layer of most of the stringers are trashed to. I have pulled the carpet and most of the glassed floor, that was a little tuff to cut out too. I am stuck on how to replace the half rotted stringers and floor. Anyone in the chicago area want to make a few bucks helping me repair? I have been taking photos of the status. At least this was a good idea.

Frustrated but still interested.

[buckknekkid]

this is your result

[buckknekkid]

here we have epoxied the subfloor

[buckknekkid]

now the serious work begins

[jalbee]

Originally Posted by jimslade

1. repaint with epoxy paint 2. Most likely the stringers are gone too. You should do one side of the stringers at a time to avoid structural twist. to mate the floors together use a support block under the lip. screw together and glass.Use dried out pressure treated ply.DONT ALLOW THE WOOD TO TOUCH ANY EDGES OF THE FIBERGLASS BOTTOM OR SIDES.

Hello, sorry I can't quite get it here but I am in deep concern over the all caps statement about the PTP not touching the edges of the fiberglass bottom. "edges" So I could use the PTP to lay right on the pottom but not the edges, I am not trying to be thick here Unfortunately I come by it quite naturally, as they say. Please elaborate on why the PTP can't touch the edges of the bottom or sides. please use small words and possibly pictures if you have any!

[jimslade]

use 1/8 inch foam strip under the ptp and glass the sides of the ptp to the hull.If the stringer touches the bottom it will set up a localized stress point that will eventually crack the glass hull in that spot. By separating the stress points there is no localizing of the stress on the glass.

[jalbee]

Thanks for the responce ! Now I understand and can move forward with the project. I am looking very forward to getting this boat back in the Water!

[MadMallard]

It seems to be a common thread within this thread that we all have either just started or just completed a stringer/floor/motor mount repair! In my case, the stringers, floor and motor mounts were all rotton. When you see a small, tiny, miniscule hole in your floor, repair it very quickly or else disaster is on the horizon. I have removed the floor, the foam, the two stringers on either side of the gas tank and the motor mounts on both sides. What fun. Needless to say, I have spent many hours searching for answers to the many questions I had/have. Reading this particular thread has brought forward a new question regarding the 1/4" layer of foam between the stringer and the hull: I am fortunate that I did not remove the foam below where the old stringer sat and it has the foam still there and I can also use the foam edge where the stringer lined up with (but was also seperated by a 1/2" foam layer from) the fuel tank as template for the new installation. I was planning on putting in new stringers that will be approximately 12'' longer than the previous ones and having them tabbed to the hull with an alternating layer of mat and cloth over the full length of the epoxy coated stringer. From what I saw during the removal was that the stringers were only tabbed on one side to the hull - shouldn't this glass tab layer go out onto the floor and up over the stringer for at least some increase in strength?

I have built multiple layers of plywood into a plug that will act as the new motor mounts. These plugs are currently drying from their third coat of epoxy awaiting installation. From the foam leftover from the previous installation, I can see that the 1/4" foam seperation rule also applies here. As in the stringer install, is it advisable to tab the motor mount to the hull and transom with the same mat, glass, and epoxy combination for strength?

As for the floor, I will replace it in sections with 3/4" plywood coated with a barrier coating of epoxy (both sides and all edges). In my case, the floor did rest on the stringers and it did extend to touch the hull on all sides. I will be tabbing in the floor and covering with a layer of mat before putting a finish on it.

I just realized that I haven't mentioned that the boat under repair is a 1974 Reinell 2500 with a MCM 888 (Ford 302) in it. For sentimental reasons and financial considerations (just ask my wife), I am undertaking this project. It also didn't hurt that my brother told me I was nuts and I would never finish. Any suggestions or criticisms would be most appreciated. Sorry for the length of the post.