TOPIC: How thick the sole?

So how thick of plywood should I use to replace the floor in my 68 mfg chevron 17 foot?


I have not ripped out the old floor to measure the thickness so I don't know what's there. might take it out another time or two.


but I want to order my plywood. is 3/4 too thick?


cheers


dan

Yes, 3/4" is way overkill. A lot of the original flooring is 3/8" but I use 1/2" okoume marine plywood for all my restorations. It's reasonably priced and really does the job right...nice and rigid, no give under foot. Call Al Jernigan at World panel products in Windsor, NC: (252)794-2036.

Unfortunately, the shipping for these panels can be a little scary so be sure to buy all you need at one shot. You can usually ship three sheets for the price of one.

I used 3/4 but as stated above, it is overkill. But my floor is not like most, Mine has good air circulation under it. When I put mine in it replaced 1/2 inch exterior plywood that was only covered with paint and no primer some years before. It was warped and rotted. I used it as is for the first year. No seats ,just a lawn chair. I was using a plastic chair when it broke through the floor. Leg busted off and I fell backwards in the boat. I'd of paid money to see that. So overkill was OK. I'm laughing at the memory right now. I was in shallow water. My first reaction was to throw the chair overboard, which I did only to pic it out of the water and take my trash back home. Next time I took an aluminum one. God that was so long ago. That is when I put the pedestal seats in with cheap plastic seats. At that time I just wanted a functional boat that kept the water mostly on the outside of the boat. I painted it blue and thought I had the world. When I got the 9.8 Mercury I was as happy as a poor guy with a fishing boat could be. I still have the same boat. It's now black with better seats and the red carpet was worn out and replaced with gray. Boat had lights added and a for-deck. These pics of it blue was in 06 right before I painted it black and got my Honda. Now I have to finish my 59 Winner.

dlatshaw,

The "old-timers" here KNOW that I'm going to tell you to use 1/2" MDO, as it's CHEAP (I LIKE CHEAP.) and will last darn near forever with a coat of un-thickened epoxy (I use the CHEAP stuff there, too.)

MDO is what the Highway Department makes "big green signs" out of & just painted those signs will last a LONG time.

Unless you need "ballast", there is NO need for 3/4" ply in our boats.

yours, satx

I'm using 1/2" fir marine plywood on my 59 Glastron floor. If you go to a higher end lumber yard (where good contractors go - not the box stores), you can probably find it. It should be available in your area and you could probably locate it with a couple of phone calls or a web search. You don't need mahogany or anything like that, just the basic stuff. It was actually about $10 per sheet more than MDO where I got it.

Dan, I prefer the Marine Plywood. My boats had 1/4 inch marine plywood that lasted for 40 plus years. I used 3/8 inch when I replaced them. It was over kill. Question in 68 MFG had a fiberglass floor (see the Library). Was yours replaced or repaired once before? I know the 64 Sea Cruiser Paul just got has a Fiberglass floor. Only wood we found was in the transom. I guess I am just curious. Al

There is one good reason to use the same thickness of what was in there.
It will install in the same place and you are less likely to have to make changes due to different thicknesses. Weight will also be close.

morris wrote:

Dan, I prefer the Marine Plywood. My boats had 1/4 inch marine plywood that lasted for 40 plus years. I used 3/8 inch when I replaced them. It was over kill. Question in 68 MFG had a fiberglass floor (see the Library). Was yours replaced or repaired once before? I know the 64 Sea Cruiser Paul just got has a Fiberglass floor. Only wood we found was in the transom. I guess I am just curious. Al

Well what i've been told is there have never been any major fiberglass repairs to the boat...

It looks like the original vinyl floor covering that was glued to the floor. Under that is a layer of what appears to be fiberglass.

Maybe i'll just get out a hole saw when i get home and drill an exploratory plug and see what's what.

The seats were attached into the floor with those rubber-surrounded nuts with bolts (sorry, don't know the name) While i'm mentioning attaching the seats, how can i do that without drilling holes in my new floor? They are the back-to-back lounge seats that fold out and lay flat. I planned on attaching some kind of cleat to the floor using 3m and fiberglass and attaching them to the cleat.

How about the plastic (pvc?) marine board. It's about $100 more per sheet retail but i have a buddy that owes me one that owns a cabinet shop.

If you could get them for the same price, would it be a better choice?

"The seats were attached into the floor with those rubber-surrounded nuts with bolts (sorry, don't know the name) While i'm mentioning attaching the seats, how can i do that without drilling holes in my new floor? They are the back-to-back lounge seats that fold out and lay flat. I planned on attaching some kind of cleat to the floor using 3m and fiberglass and attaching them to the cleat."

Some manufacturers would glass wood to the floor just inside the box and run screws thru the face so they were flush mounted and no floor holes. The only bad thing is it uses wood.

I have always wanted to try PVC board but it is expensive.

Al

I have some spare aluminum angle supports left over from a solar panel project. Maybe i could cut those to size and glass them in place.

so I finally took a core sample. looks like they used 1/8 inch plywood or it has vastly deterioated.

my money is on rotted.


so it was probably 1/4 with fiber on one side.


so I'm thinking 3/8 with glass on both sides. or just resin on the bottom.

dlatshaw wrote:

so I finally took a core sample. looks like they used 1/8 inch plywood or it has vastly deterioated.

my money is on rotted.


so it was probably 1/4 with fiber on one side.


so I'm thinking 3/8 with glass on both sides. or just resin on the bottom.

Gotta tell ya Dan that looks like wood to me. I guess the 68 brochure is incorrect for certain models.

I glassed both sides of the g3's I have done. The V-165 I just used resin on the underside and of course I glassed the floor side. I am not sure if glassing the underside was overkill or not. I know it will last long
enough for my grandsons to worry about it and I will be long gone (I hope).
At this point I am sure no matter what you decide, the boat will be
structurally sound. Have you given any more consideration to HDPE or PVC board?

Al

dlatshaw wrote:

How about the plastic (pvc?) marine board. It's about $100 more per sheet retail but i have a buddy that owes me one that owns a cabinet shop.

If you could get them for the same price, would it be a better choice?

I really like to use expanded PVC foam sheets. It is so much nicer to work with than plywood. It is a little stronger and about 24% lighter than marine plywood. You'll save time and money because it does not need to be sealed with resin like wood. It does need to be protected from UV, paint or carpet would be needed.

A product like Starboard is UV tolerant but cost is double. It is very heavy, took 3 guys to pick up a sheet of 3/4", sheets are smaller 3'x7'. Nothing will stick to it, it cannot be painted, resins and glues will not stick, even 3M 5200 will not stick.

I get my plastics from a local Piedmont Plastics store www.piedmontplastics.com/locations.aspx A white 4'x8' sheet of 3/8" was $78.00 and a 4'x8' sheet of 3/4" was $120.00. If I remember the 1/4" sheets where around $50.00 in white.

Do it once and forget about it, it has a landfill life of about 500,000 years give or take.

Hi guys, I'm a newcomer to the site. I have just finished restoring a '61 Alumacraft Torino (14') . My father won the boat in a 'sales' contest when it was new and it has been in the family ever since! I replaced the sole with 3/4" marine ply as I wanted no flex. I wanted to install the lounge seats with bolts coming up from underneath rather than lags from up above. First I cut and fit the sole feathering the edges about 6" to fit the angle of the bottom. Then I measured and positioned the seats where I wanted them and marked the bolt holes. I pulled the sole back out, drilled 1/4" holes from the top flipped it and countersunk and tapped in 3/8" machine bolts securing the last 3/4" with 4200 . Then I liberally coated with West System epoxy. The next step was to secure the sole to the boat with a thick coating of 5200 and covering it with marine carpet. Bolting in the seats was a breeze with studs, fender washers and nuts. I might add that I recently retired from 35 years as a yacht carpenter.
Thank you,
Capt. George MacMillan
100 ton Master Captain

Rustydusty,

WELCOME ABOARD, Captain.

Sounds like your work may last into the 23rd Century. - Most of "the tin boats" had 1/4 or 3/8 plywood (if anything) for soles when they were built, as those that HAD soles had them only to put the carpet upon.

yours, satx

Hi , thanks for the welcome! My Alumacraft is a fiberglass boat and never had a plywood sole to begin with. What it has is a foam filled fiberglassed sole angled to the keel approximately 1" thick in the center which didn't give me a secure way to fasten the seats. Originally it was equipped with bench seats with backs whose seat bases were glassed to the hull which acted as stiffeners. I cut out the bases (I wanted lounge seats for more fishing space at the rear) and used 3/4" to get back the rigidity. As it turned out, my wife had me add 2 jump seats to the rear so I lost the extra space anyway! I will add pictures when I get some downloaded to the 'puter.

Ordered 2 4x8 sheets of 1/2 inch PVC...

Should be here in the next week or two.