Hammered Dulcimer design, construction, and unrelated stuff

Thursday, May 23, 2013

Darkening Cherry With UV Light

At upwards of $12.00 per board foot for the good stuff, Walnut has gotten too expensive.  We used walnut for all our bridges and the rails of the Phoebe hammered dulcimers for 20 years.  Wood prices run in a cycle based on whether dark woods are in style, or light woods.  For the last 20 years, light furniture, light kitchens, pickled woods, white on white were the vogue, so walnut was affordable.  But now the trend has reversed.

So we had to find another wood that could contrast well with the birch top of the Phoebe, as well as sound good.  We had used cherry bridges many times, and it sounds great, but when new is sort of a bland salmon color, but darkens with time to a rich dark red which is beautiful.  Cherry is one of my all time favorite woods.  Trouble is we send out brand new dulcimers, but want them to look nice right away.  The bridges are unfinished, at our price point, a finish is out of the question, so the bridges need to just look good the way they are.

My wood dealer, Mark Hill of Hill Hardwoods in Iowa City, Iowa suggested that I might be able to darken cherry quickly with UV light.  He didn't know the particulars, but I was intrigued.  So I went to the internet, and there wasn't much out there, but lots of folks asking the same question I was.  I did find one mention that UVA was what you needed.

After much searching around, I found that a bug zapper bulb produces UVA.  UVB is what gives you a tan.  UVA is what causes cancer, so this is something to be very careful with.  Don't look at it without  eye protection.

Since the bridges are less than 20 inches long, I bought a 15 watt 18 inch bug zapper bulb on eBay, and got an 18 inch fluorescent fixture at Menard's.  The bulb was $15.00, and the fixture was $10.00.  I built a wood long enough to contain the bridges, mounted the fixture on the lid, and lined the whole thing with aluminum foil to keep the light bouncing around in there.  It works slick!  The lid fits tight, so no light escapes.   3 or 4 days in the box, and cherry gets quite a tan!  They look great on the dulcimers, and the position marks show up nicely.  It really is too cool!