Building a frame for floor

[jcupo6]

Re: Building a frame for floor

exterior grade plywood
epoxy resin is best
poly is second best

Bah, beat me to it!

 

[jspano]

Re: Building a frame for floor

that a look at the floor on this page (bigger boat \) but you can see the fastners on the 2 stringers in the middle and the along the ends of the ribs

last 2pics

http://forums.iboats.com/showthread.php?t=365995&page=28

check out this entire page

http://forums.iboats.com/showthread.php?t=365995&page=27

 

[geeco1]

Re: Building a frame for floor

I'll point out a couple of things that I recently learned on my resto recently that may be able to help you.

First of all, it you just lay the plywood on the floor and step on it (before screwing it down), it will seem weak. Once it is secured to the stringer and side ribs, it will be solid. How wide is your boat? Most roof trusses on houses are 24 inches, and they hold the weight just fine. My guess is that your span is around 30 inches +/-.

Second, buy some thin, flat aluminum to put under each joint where the sheets of plywood meet. It should be about 2 inches wide.

Third, put two coats of epoxy on the bottom and sides of the ply. Only put one coat on the top. Then, after putting the ply in the boat, secure to the stringer and ribs. Finally, put the second coat of epoxy on the top. Use fiberglass cloth to cover the joints.

Fourth, make sure your fasteners will go through the ply and aluminum. I used 5/8 ply, and the longest rivets that I could find would not reach. I should have used 1/2 ply. I ended up using stainless screws.

As stated before, exterior ply is fine and widely used on restorations. Just make sure that you coat all sides in epoxy or poly.

 

[Educator79]

Re: Building a frame for floor

Thanks for all the help guys! I have a lot of thin aluminum sheeting. The whole underside of the boat was layered with it. Why do I need to put that where the seems meet?

 

[geeco1]

Re: Building a frame for floor

You put the aluminum where the seams meet so that they edges support each other, and flex with each other. Your plywood will have some flex if you step on it between the sides and center stringer. If you don't use the aluminum strip and you step on the edge of a seam, one sheet will flex down and the other sheet will stay in place. This will cause the fiberglass cloth to pull away and crack some.

If you want to try an experiment... put two 2 x 4's on the ground about 2 feet apart. Now lay 2 pieces of scrap plywood over the 2 x 4's with the seam running perpendicular to the 2 x 4's. If you step on one piece of plywood at the seam, you should see it bend down and the other sheet stay in place. Now.... take another small scrap piece of ply and screw it across the seam to both pieces. When you step on it, it should seem firmer and both pieces of ply will flex together.

Keep in mind... that the amount of flex that you have in your experiment will be much greater than what you will have once secured in your boat. This is also assuming that you are using 1/2 or 5/8 inch ply. If you are using something really thick like 3/4 or more then you may not see any flex (but it is still there).

 

[ghamby]

Re: Building a frame for floor

Why was the bottom covered in aluminum sheet? I suggest you pressure wash
out the inside of that boat, and check for leaks before you do anything else.
Are the rivets tight? Do the seams need sealing? Is the transom sound?
Glass the plywood top and bottom. Seal all end and edge grain with resin.
Seal any holes you drill in the plywood. GH

 

[Educator79]

Re: Building a frame for floor

Well I will do that then. Strange though, it didn't seem to me that a thin strip of aluminum would be any support at all. I guess everything is different in the world of boat repar Thanks for the great advice!

 

[Educator79]

Re: Building a frame for floor

The plywood was lined with aluminum, not the bottom of the boat. It has one leak that I saw. I have cleaned the boat thoroughly and will seel it with gluvit. I need to post some new pics. Thanks.

 

[geeco1]

Re: Building a frame for floor

Let me clarify one thing.... I don't know what aluminum that your plywood was lined in, but when I was talking about a thin piece of aluminum, a was talking about some fairly stiff stuff. Probably 1/16 inch or so. Not aluminum like would be on a roll or used as flashing. If you go to Lowes or HD, they carry the aluminum strips in the same section as angle iron. It would be about the same thickness as your stringer is made from.

 

[cedarjunki]

Re: Building a frame for floor

Why was the bottom covered in aluminum sheet? GH

sounds like it may have been redone once and the previous owner either worked or new a buddy that worked on rail cars. (passenger trains)
there was a company here that made these sandwiched panels. unbelievable how strong they were when all glued,and welded all the way around. (still have a few pieces laying around) but wish i had a few full sheets, i would use them on the ss deck.

ive never ran across anyone building a frame in these aluminum boats, and ive been looking through them alot! adding,stiffening maybe but never a full frame. just riveted to the stringers and the ribs. having only one stringer i would use 3/4", unless your actually going to encase the whole deck in layers of glass.

there is endless reading on this subject here with some very usefull help from others...believe me i know. had to buy a bigger monitor so i could read it all easier, and see all the amazing pictures better

 

[Educator79]

Re: Building a frame for floor

Well you are right, there is lots of info. And I have not even gotten to the buying a steering wheel cable set, buying and installing a shifter/throttle box, building a console to mount the steering wheel, and buying hooking up and installing an ignition in the console. . . I may never actually get a chance to use this boat Hey, when I take some updated pics, should I just post them at the end of this thread or should I start a new thread?

 

[ezmobee]

Re: Building a frame for floor

Start a new thread called "16' Starcraft whatever Restoration". You should get enough traffic from us Starcraft nuts to get most of your questions answered.