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<blockquote data-quote="jbtsax" data-source="post: 80275" data-attributes="member: 1801">That was one area that I needed some help from my mentor who is very skilled at doing brass repair.&nbsp; He cut the rib at the top with a jeweler&#039;s saw and unsoldered the portion that was overlapping the severe bend.&nbsp; The reasoning was it is much easier to straighten and remove the dents from one layer of brass rather than two.&nbsp; We then inserted two steel rods in the body one coming from each direction and had them meet at the bend.&nbsp; The metal was very slowly &quot;coaxed&quot; part of the way back into shape by carefully applying pressure using the steel rods as levers.When about 60% of the bend was removed a tapered polished steel mandrel made specifically for Mark VI altos was inserted in the body as far as it would reach. Then the remainder of the crease was tapped using small dent hammers and smoothed with small rollers while inching the tapered mandrel further in as the work progressed.&nbsp; The special mandrel which is ridiculously expensive to have made was rented from the JL Smith Co.&nbsp; The shipping cost more than the rental fee, but a quality repair would have been impossible without it.At first we thought we might have to heat the brass, but it turned out to be malleable enough to straighten without resorting to the torch which made the repair more manageable and less time consuming.&nbsp; Sharp bends in a brass instrument can have a tendency to break or crack when they are bent back the other way even when every precaution is taken.&nbsp; There was a bit of luck involved in having this repair go as well as we had hoped for.</blockquote>

[QUOTE="jbtsax, post: 80275, member: 1801"] That was one area that I needed some help from my mentor who is very skilled at doing brass repair. He cut the rib at the top with a jeweler's saw and unsoldered the portion that was overlapping the severe bend. The reasoning was it is much easier to straighten and remove the dents from one layer of brass rather than two. We then inserted two steel rods in the body one coming from each direction and had them meet at the bend. The metal was very slowly "coaxed" part of the way back into shape by carefully applying pressure using the steel rods as levers. When about 60% of the bend was removed a tapered polished steel mandrel made specifically for Mark VI altos was inserted in the body as far as it would reach. Then the remainder of the crease was tapped using small dent hammers and smoothed with small rollers while inching the tapered mandrel further in as the work progressed. The special mandrel which is ridiculously expensive to have made was rented from the JL Smith Co. The shipping cost more than the rental fee, but a quality repair would have been impossible without it. At first we thought we might have to heat the brass, but it turned out to be malleable enough to straighten without resorting to the torch which made the repair more manageable and less time consuming. Sharp bends in a brass instrument can have a tendency to break or crack when they are bent back the other way even when every precaution is taken. There was a bit of luck involved in having this repair go as well as we had hoped for. [/QUOTE]

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