Posted by Lee Stofer on March 09, 2002 at 11:06:41:
Hello all,
I received a UMI Dent Eraser kit yesterday, and I thought I'd report my findings thus far on this system.
At this point, I think it will be a useful tool here in the shop, but it will not make any of my other tools obsolete. It will sometimes prevent me from having to "open-up" an instrument for repairs, but not nearly all the time.
This morning, I decided to try de-denting my Cerveny F. All the dents on it were shallow, the sort of thing you'd really rather not take the horn apart to remove, since the horns plays so well and looks pretty good. The Cerveny was essentially completely de-dented in about an hour, and I did not have to un-solder anything.
I found that the larger balls do the best job, and shallow dents can be removed with about the same amount of effort necessary with traditional methods. I did some additional experimenting on a larger horn with deeper dents, too, and found that use of this system in conjunction with judicious use of a dent hammer yielded good results, to a point. If a tube is badly dented, or is very thick, or is work-hardened, it will still need to come apart to be right again.
So, it is not the be-all and end-all of tuba repair, and can be quite dangerous if not used very carefully. But, on minor-to-moderate play-condition repairs, I think it will be useful.