N10-N11A Expandable Dent Removal Tools
A tool of specific size such as an N53 Mandrel cannot work equally well on both the beginning section and the bottom section of the slide. This is because the first 4 inches of the slide is from .002” to .010” (.05mm to .15mm) smaller than the rest of the slide on 90% of all trombones. This is caused by shrinkage of the tubing when the hand brace or outer sleeve is soldered on. This can also be caused by the slide being jarred in such a way that the hand brace is pushed slightly into the slide. Using the tool is simple.
First, clean the trombone slide thoroughly with F7 Brasso, Z10 Cold Cleaner and a dry cheesecloth rag as per our standard process. Put the tool in the vise and slide the trombone slide loosely over the tool. Turn the adjusting nut until the expandable working part of the tool is snug under a portion of the tubing that is dent free. Then, merely slide the trombone slide back and forth over the working part of the tool with a slightly rotating movement. This will produce a smooth burnishing action. The tool is polished chromed steel. It will not burr or scrape the inside tubing. Rotate until the slide feels smooth. Remove the slide and wipe it out with a clean length of X50 Cheesecloth. The dent will probably have disappeared; if not, repeat the operation with the adjusting nut a little tighter.
N10 For tenor inner slides
N11 For tenor outer slides
N11A For bass trombone outer slides
Can be used with N12 ring (on page 49 in the 2008 Ferree's Tools Catalog).