does doug fir = s. pine for west coast?

[warx]

Hi there,

Building a hull using doorskin construction (ply, foam, wood ribs). Plans call for the 1" ribs to be southern yellow pine which is not available on the west coast. Can I substitute CVG kiln-dried douglass fir instead? They seem similar. It must be gluable and hold fasteners well.

Thanks,
Mike.

[DGreenwood]

The quality of Doug fir really varies. If it is good quality I think it would be a decent replacement for what you are doing. However you must realize that the Doug fir is not as resistant as Yellow Pine. Take steps to protect the end grain especially. I would look for a count of rings per inch up in the teens at least.

[Dr. J]

What type of boat are you building? I use fir extensively in my area, however it is never of the kiln dried variety. Air dried edge grain is the way to go. I have used fir for planking, but never for frames on any sized boat because it is prone to shrinking and swelling in the presence of moisture. In addition, fir will not bend well into the tight curves that are usually required of frames and it will not last long before requiring replacing. In terms of strength and durability,White oak is an excellent wood to use if you are planning to steam bend your frames. It bends well, and is able to withstand the stresses required when supporting the hull.If your boat is of substantial size, then sawn frames can be made with other types of wood,yellow cedar for example. If you post the type and size of your boat and the method of construction then it might be easier to offer more advice.