Multiplying by 2 will give you the correct outlines. However, the sized of wood will not scale up by 2. Since my expertise is in planes, I'll reference them. If your plane has a 1/4" square spar, and you scale the plane up by 2, your spar would scale to 1/2" square. This is overkill. A better size for the spar would be 3/8" square or possibly 3/8"x1/4". Sheeting is the same way. If you have 1/16" sheet and scale up by 2, you would end up with 1/8" sheet. This is probably too thick. A more correct size would be 3/32".

When scaling up a plan with no referenced sizes, it's best to study some existing designs of your craft, be it boat or plane.

Dr.1