MIMF

A friend recently asked me to build him a uke out of Douglas Fir. I've had a lot of success with other woods, however this seems to flake and become very brittle. Does anybody know if there's a way to stop it from flaking as shown in the picture? Is it too much water? Too little? Too hot? To cold? Or is it just the nature of Dougla Fir?

How thick is your side material? Did you test it for run out? How hot did you get it? Did you use a metal support strap?

I am amazed by how lightly some ukuleles are built.

I've never bent fir before but I would try more heat for starters. Ukes can be very thin so don't be afraid to thin the sides down; a small decrease in thickness can give you a large increase in bending stiffness. When all else fails, super soft II.

It's 1.8mm, 300F, metal on both sides while bending. It didn't seem hard to bend, like some other woods I've tried, it just flaked like this.

How do you test for runout? (Obviously didn't do this)

1.8mm = .072", not overly thin. 300F is probably not enough to soften the wood.

The test for run out is to split a cut off piece to see how the grain runs.

For a tenor uke, should I go less than 1.8. How thin would still be OK?

I've worked with fir a lot over the years in my finish carpentry work. It is very difficult to work with. It is brittle, splintery, unstable, and definitely not suitable for the making of musical instruments!

Steve Woods wrote:I've worked with fir a lot over the years in my finish carpentry work. It is very difficult to work with. It is brittle, splintery, unstable, and definitely not suitable for the making of musical instruments!

Do you speak of Douglas fir, or some other? I'll agree with brittle and splintery, but not unstable. Well-seasoned DF holds still.

For a uke, I'd use DF for the top. Select the lightest piece you can find - light weight and color, the two usually go hand in hand. Bending doesn't sound like something it will want to do, however, without a fight.