Any experience with using CLR?

I just (finally) upgraded my endoscope and looked inside the slide of my 1947 Olds Standard. I no longer believe that the inners are replacements. :lol: I suppose they could be. Given that the thing is 76 years old, that would provide ample time for someone to trash and run through several sets of inners. But the horn was not in otherwise bad condition when I got it, and so I now suspect that these are the original inners. The outsides of them appear to be pristine. The insides? Not so much. Of course, the insides are particularly critical, but I would like to clean them up.

There is a LOT of surface corrosion, and a lot of deposits. I had, of course, cleaned it a number of times already. So "normal" cleaning hasn't done the trick. I'm thinking I need to approach it in the same way as cleaning the outer, plus a lot more brushing (probably with appropriately sized gun barrel brushes -- .45 or .50 cal. should work), maybe with a low-speed electric drill to drive it rotationally. As I think of going the vinegar-soak or citric cleaner route, I'm wondering if CLR might be a better approach. It works especially well on calcium deposits.

Thoughts and experience?

Well, I found this thread on a subsequent search. Don't know why it didn't show up earlier. It's encouraging, and with some other good pointers as well:

[url]<LINK_TEXT text="viewtopic.php?t=15025">https://trombonechat.com/viewtopic.php?t=15025</LINK_TEXT>

There is a reason that an experienced trombone tech asks what they do for an hourly shop rate. CLR may remove mineral deposits, you may also miscalculate the dilution ratio and damage the brass, there may be other factors to take into account that CLR may not address.

Years of experience working on brass instruments every day counts for something.

Thanks. The CLR worked well for me.