: Hi,
: I am planning to build a chesapeake 16 and use lauan for budged reasons.
: I will use 1/4" lauan for the botton panels and 1/8" lauan for the
: sides and deck with a 8 foot long and 2" wide 1/8" lauan

In my neighborhood there is little difference in price between nominal 1/4 inch lauan (5.5mm) and 1/8th inch meranti (which is similar to lauan, and used for floor underlayments) In fact, sometimes sales on the more commonly available 1/4 inch material make it cheaper.

If your budget is a big concern, do the whole boat with 1/4 inch lauan. it will be cheaper and faster to build.

Your reinforcement strip on the sides is going to take at least an extra hour or two to cut and assemble. Then, you'll probably have to give up work for the night while the glue bonding that reinforcement strip to the main side panel sets up.

Double check your cutting diagrams and see if any hull and deck pieces are to be cut from the same panel. Since you'll be using two different thicknesses you can't scarf scraps left over from cutting the hull onto panel for the deck -- or vice versa -- so you may have to buy an extra panel. Or maybe buy an extra panel of each size! Since the cutting diagrams do not include your reinforcement strip, you should make allowances for this, too when you plan on how many plywood panels to buy.

If you use 1/4 inch for the deck, which probably has less bend to it than the hull, you may be able to get away without having to glass the inside of the deck. This eliminates the cost of the resin and glass cloth, as well as the time involved in doing the work. If ou are going to glass the inside of the deck, consider where in the building process you will do this task. If you glass the plywood before you apply the plywood you can do the work more easily -- it will be flat -- but you'll use a bit more materials. If you put the glass on after the deck is attached, then you'll be working in a dim, confined area.

If you use 1/8th inch for the sides, will ou be covering the inside with fiberglass cloth and resin? If so, your costs will increase. In adition, you'll have to work to get your cloth to fit neatly over that 1/8th inch high reinforcement strip. Even if you fair the edges, of fill them with a fillet, the cloth going over the reinforcement strip is going to be a bit longer than the cloth going over the unreinforced area. Consider how you will make a nip or tuck in the cloth to get it to lay flat so you avoid wrinkles. Actually, a layer of fiberglass on the inside might be a better reinforcement for your 1/8th inch lauan than the strip of plywood.

The downside, of course is that the 1/4 inch plywood is twice the thickness, and twice the weight of the 1/8th inch material. This could add a few pounds to your boat -- but the tradeoff is weight vs. dollars. It won't make your boat much heavier.

Just a few thoughts.

PGJ