Double Bass Cross Bars in a Flat back

[basswraith]

What kind of wood can be used to replace the cross bars in a flat back bass?
IS It OK to use the quarter sawn part of the pine lumber found at a commercial building supply? Or should I buy some quarter sawn spruce from a specialized tone wood supplier?
And also if any one has input about gluing in these cross bars with a little bit of spring to them. That info would start a great conversation here.
Thank you.

 

[oldbass]

In looking at wood for cross bars on a flat back that I am rebuilding I picked up a piece of poplar. It appears a bit harder than lumber yard pine and has a nice clear grain. It glues well too. Lumber yard pine can warp or twist over time as it ages and the poplar seems to be more stable. However, while I'm not a luthier I have extensive experience working with good cabinet woods and am simply passing on my observations.

 

[Ken McKay]

Personally, I would stay away from lumberyard wood. It could work out but you don't want to find it warping after you get things buttoned up.

Spruce is a good choice and if you know where to look it can be as cheap as a lumberyard. Poplar is also good, but not the yellow/green poplar sold at Home Depot, that is another wood that is heavier. Willow is good if it is dried and cut the right way.

Best bet is to get straight grained spruce, pine, fir, western red cedar. Look up Aircraft Spruce on the web you can get what you need there.

Putting a little arch in the brace is always a good idea. But not too much 3-5 mm will do wonders to keep the back from caving in during the dry season.

 

[Ken McKay]

I wanted to add something very important, critical in fact. Be sure that the Relative Humidity is about 45% when you glue the brace in. That will insure that it doesnt sink in between the braces in the dry months. It is winter here in the USA so that is probably a good time, but maybe too dry.