So I'm in the process of bending a harpsichord bridge. The hard maple bridge is 60" long and tapers in height and width from 1/2" in the front to 11/16" in the rear. I thoroughly wet the bridge with water and then wrap it in wet towels for an overnight soaking. The next morning, I put it in the steam box for 45 minutes. After removing it from the steam box, I secure it to a drying jig and let it dry for a month.
A month later, when inspecting the bridge, I realized that I used the wrong drying jig. The jig I used was for a smaller instrument - one more instance of encroaching senility. However, since the bridge can be bent somewhat during installation, I hoped I could persuade the bridge to follow its intended path. No such luck! Facing the decision to make a new bridge or trying to save the old one, I decided I had little to lose by trying to save it rather than replace it. I set up my steambox and found that I could still get the front end of the bridge (the part with the severe curve) into it. So I repeated the process - wetting the bridge and soaking it in towels overnight. The next morning, I got the steam box up to the proper temperature and removed the bridge from the soaking towels. I was surprised to find that the bridge had almost completely straightened out from the overnight soak. It now fit all the way into the steam box. After a 45 minute baking, I put it in the correct drying jig and it looks like all will be well.
I'm amazed to realize that, after building these instruments for over 30 years, I still capable of finding new ways to make stupid mistakes. There appears to be no limits to my ability to find new ways to make life interesting. Still, I never thought that a steam bent piece would straighten out almost completely the way it did, but it's comforting to know that a mistake like this can be re-bent. I'm wondering if a thicker piece of wood would react the same way to water.
Ernie
A month later, when inspecting the bridge, I realized that I used the wrong drying jig. The jig I used was for a smaller instrument - one more instance of encroaching senility. However, since the bridge can be bent somewhat during installation, I hoped I could persuade the bridge to follow its intended path. No such luck! Facing the decision to make a new bridge or trying to save the old one, I decided I had little to lose by trying to save it rather than replace it. I set up my steambox and found that I could still get the front end of the bridge (the part with the severe curve) into it. So I repeated the process - wetting the bridge and soaking it in towels overnight. The next morning, I got the steam box up to the proper temperature and removed the bridge from the soaking towels. I was surprised to find that the bridge had almost completely straightened out from the overnight soak. It now fit all the way into the steam box. After a 45 minute baking, I put it in the correct drying jig and it looks like all will be well.
I'm amazed to realize that, after building these instruments for over 30 years, I still capable of finding new ways to make stupid mistakes. There appears to be no limits to my ability to find new ways to make life interesting. Still, I never thought that a steam bent piece would straighten out almost completely the way it did, but it's comforting to know that a mistake like this can be re-bent. I'm wondering if a thicker piece of wood would react the same way to water.
Ernie