: If I had a choice between ash, birch, white oak and maple, which
: would be the best for bending the ribs and coaming for a
: Greenland style SOF?

Just like some others said, pick the best, straightest grain you can find. I *struggled* with steam bending as I'm sure many have, but what I learned was the grain is king. Air-dried wood is best, kiln-dried next, hardwoods better than soft, but a piece of straight grained softwood will work. I've found that ANY runout is going to break there, even if the break is just the start of a split. Small breaks or de-laminations, you can use anyhow, just trim off the "hangnail".

Also like some posters said, smaller steambox is better.

A pre-bending jig for ribs with a nylon strap to back the rib worked well for me.

I could not find any oak with suitable grain in a barn full of air dried stickered wood, but we found some hickory planks that worked absolutely wonderfully.

I've also had good results bending pine, and cypress, except I learned that cypress becomes very brittle after it cools off after steaming, thus, won't use that again. By cypress, I mean Bald Cypress, Taxodium distichum. I've also been able to bend red oak from lowes, but again, getting the grain is key. I've found a big range of bendability with the red oak from lowes though... some bends really nice, other boards didn't seem to want to bend no matter how long I steamed them. The ones that bent well were the redder boards, the yellower/lighter brown ones not so much.

I've also had good luck just heating the wood locally with a regular steam iron. I bent my masik and curved deck beam in the last kayak from a .75 x 3" piece of red oak, by blocking it up on 2x4s, squatting on it on the balls of my feet, and steaming it between my feet with the iron until it sagged to the floor -- about 3.5" of sag. Made a nice arch. It's a tight fitting low volume kayak though.

And that's about all I know about steaming so far. Grain rules.