If you use 6-mm glass inside and out, you won't have any problems. For the keel, use multiple (4-5) layers of glass to protect the edge or do as I did and add a brass stem band. The brass band can be screwed and glued into the keel as long as there is a fillet of thickened epoxy on the inside of the keel. Another option is to use a strip of ash along the keel. Ash can be heated with a heat gun to make it very flexible and easy to screw or glue onto the keel. A 4-mm wrap of glass will give the ash an extra bit of protection when hitting logs, gravel, etc. The ash is easily sanded to shape once it has been installed on the keel.

Robert N Pruden