Floor Replacement - Tuffy Marauder

My son bought a first project boat - 1981 Tuffy Marauder fibergalss shallow V with a good 1991 40 HP oil injected Mercury 4 cyl.
The Tuffy has a floor too soft to secure pedestal seats.
Removed carpet - the floor is 43 x 149 inches bewteen the side compartments - it abutts the side compartments but does not go under them. Floor is 1/2 or 5/8 chipboard glassed over (one Matt and resin) to connect to side compartments. everything is bone - dry. No mildew either.
There are two stringers that run fore - aft about 18- 20 inches apart. The floor is 6 -8 inch above keel and even with hull at sides, and has a slight 1 -2 inche rise for last 3 feet towards casting platform.

My brother-in -law (40 yrs carpentry, drywall, construction) says leave old floor (since glassed in) and put 2 layers 1/2 inch exterior plywood . ie. 3 pcs - 4 x 8 ft sheets and run whole sheet (trimmed to width ) from back, continue with 4 ft to front below platform, then reverse for second sheet, and half sheet so seams are offset. he would bond flooring to old and staple to stringers , then reglass in flooring at top to sides of compartments to make water proof.

Is this a good approach? and is 2 layers of 1/2 inch overkill, (3/8 better) the layering is because he said we couldn't bend 3/4 " or 1 " plywood towards front.
???

Re: Floor Replacement - Tuffy Marauder

Deck or sole, Bob. Boats don't have floors.

Re: Floor Replacement - Tuffy Marauder

My family had a couple of Tuffy boats way back when. First a Marauder and then a Rampage. Tuffy didn't use the best wood materials in their boats. The best method would be to rip out the would and rebuild it from the keel up. Yes, that is a lot of work. However, you will do the job correctly the first time and it will be good for as long as you own it and much more.

You can also go the route of the family suggestion, but you are just covering the problem. The suggested approach will work, but you will be adding a lot of weight to the boat.

The answer lies in your overall plans for the boat. Do you plan to keep it for more than a year or two? If yes, then consider doing the job correctly. If not, slap the new floor on it and enjoy the season.

If I were doing the boat, I would rip it out and use 3/8" marine meranti plywood (strong, light, and no-voids) encapsulated with epoxy and covered with a thin glass cloth.

With the other approach, 1/2" ply can still be very tough to bend. You only need more than 3/8" if your plan is to mount the seats directly to the wood with wood screws. In that case, you will want about 1" of materials at least under the seat bases. Another approach (and better in my opinion) is to mount the seats by through bolting them with a backing plate.

Good luck.

Re: Floor Replacement - Tuffy Marauder

my son and i are currently rebuildiing a 1987 Tuffy Custom Rogue. almost the exact same boat you have. it's a project boat we are building into a flats boat for red fishing off the coast of texas. i bought it in april from a dealer in wisconsin thinking it looked really solid. apparently my boat buying skills are just slightly less than my ability to pick winning powerball numbers. from what we have found you have no choice but to tear everything out and start with a bare hull. fortunatly for us the people on this forum have given us the advise and knowledge we have needed. our boat had already had the quick put another piece carpeted plywood over the rotted floor repair. we ripped the casting platform and replacement floor out only to discover what you have. lots of rotted wood. we were lucky in that the wood was so rotted we were able to get our hand under the fiberglass by where the seat pedestal was mounted and pull up. it pulled so far towards the side and stopped. what we found was that there is a solid section of fibergass that runs the length of the boat on both sides. we took a cutting wheel and cut the old floor off to that point. once you see what i am talking about you won't have any trouble following the line to cut. then you can scoop out the rotted wood with a shovel and a shop vac. there was very little foam under the floor just around where the seat pedestal was mounted near the bow. you will get your floor out in a couple of hours. take the transom cap off and look at the top of the wood. if yours has the metal plate that is on the outside of the transom to protect the fiberglass where the motor is mounted take it off and look for indentations or cracks in the fiber glass. take a long screw driver and try shoving it down into the transom from the top. if you can push it in the transom is also rotted. if it is drill the rivets out and pull the Tuffy corner caps off and start digging the wood out of the transom cavity. this will take a while and is a tedious slow job. i bought a cheap long pry bar at menards and ground it down so it was the same width as the thickness of the transom and just kept digging. getting the transom completly out was an ongoing project for several days quitting everytime i got bored with digging. i assume yours has the long boxes built along both sides the length of the boat. peel the carpet up and find what look like corks stuck in the top of the boxes. take a long (18-20in) thin screw driver and push it down through the cork all the way to the bottom into the foam. pull it out and see if it is wet. do this 4-5 times on each side. we not only had wet foam but on 1 side about 4-5 inches of standing water inside of the box. if your foam is wet you will need to cut the top of the boxes open and scrape it all out. we used a 1 x4 for our outline and set the saw just deep enough to cut all the way through and cut the top open. the boat is a fairly light boat with no motor on it so if you go to the back corner and try to lift on side of the boat it should lift fairly easily. if it doesn't you have wet foam. scrapeing the foam out was probably the low point of our rebuild so far. if we put all our time together it probably took 2 of us 2 full weekends to completly strip the boat down to the point we could start to rebuild. since our goal is to rebuild this boat to only use it 5-7 years we used 3/4 treated plywood for the transom. we made a cardboard template and used it to get our rough shape cut. once we had our wood fitted we coated the inside of the cavity with PL premium adhesive and put the wood in and temporally installed all the bolts and clamped the top. after that had dried for a few days we sealed the top with an entire tube of caulking and reinstalled the transom cap and sealed all the bolts in their holes. we cut a 2 in hole in the back of each flotation box to let any future water a place to get out. we replaced the foam with 38 swim noodles. (on sale at Fleet Farm .95) we replaced the top of the boxes with pieces we cut out and sealed them. because of what we wanted to do with the casting decks we chose to go with 2 layers of 1/2 in plywood for the floor using 1 narrow piece of treated plywood glued in on top of the stringers for support and a piece of fiberglassed BCX for the finished floor between the boxes. we using non skid paint to finish the boat so we need a smooth surface to work with. if we were using carpet or vinyl for a finish then we would have used either 5/8 or 3/4 treated plywood for the floor rather than 2 layers. we have been working on this boat since the first of june mostly on weekends with time off for birthday parties, going shooting and the occasional rain delay. someone with more dedication to the project, less time standing around trying to figure out what to do next or remembering what they needed to buy when they went to the store will probably get their boat doen a lot faster than we are.
i have pictures i could send you if you want to see what the hull looks like after the floor is out. just PM me your email address.

Re: Floor Replacement - Tuffy Marauder

Thank You fishingdan for the Tuffy info - I was also concerned about the extra weight. The 3/8 " would sure be easier to work with - but I am not how to access to through-bolt pedestals?
BobSC

Re: Floor Replacement - Tuffy Marauder

That was a really detailed reply - Thanks marquette! I forwarded to my carpenter/tradesman brother-in-law to also digest.
Photos of the hull w/o floor and casting deck would be great - The present casting deck has a fore mounted aluminum plate for a bow mount trolling motor. it doesn't seem soft up there? and I did not understand the narrow strips under the casting patform you mentioned.
e-mail: bob.schmidt@us.abb.com