birch ply

Hi Im looking into building a boat I've decided on a small canoe or kayak. The problem is my budget is what I can dig out of the couch before my kids. I found some birch underlayment at the local menards store 1/4 inch, 5 ply, zero void with exterior glue; would that be suitible to skin my boat? Is birch a good wood to use in boat building? Thank you for any replies.

 

Birch for boats

Birch ply is very strong and stiff but rots like nothing on earth

 

The exterior glue will not tolerate extended lengths of time in the water, but as a canoe or other light rowing boat, she should be trailered home after a few hours on the water. Encapsulated in epoxy and cloth, kept clean, dry and under cover, she could last a long time. If left to the elements, for even reasonably short amounts of time, she will rot out quickly.

The short of it is, the care you give her will determine the length of life she will have, knowing you have used less then the best materials to plank her up. If well kept she will do fine, if not she dies.

 

Apart from what the other posters have informed you, I think that if it is worth the effort to build any boat, it is a shame to make it much heavier than it should be due to a small cost saving.
One-quarter inch thick ply is probably too thick and heavy for a one-man paddling craft. Okoume is widely used and is much lighter. 3mm or 4 mm is more suitable and will weigh around half of what your Birch ply weighs, and is made for marine use. Still needs proper sealing, preferably with epoxy resin, or sheathed in epoxy/woven fibreglass.
See CLC boats site for indicative price: http://www.clcboats.com/epoxy_plywood.php#plywood