Antique Brass Flange: Problem with cleaning off Gobbets Of Solder

[Drew Bedo]

I have an antique brass Petzval lens (un-marked, No-Name) that is now off to SK Grimes for a CLA. However they report a frozen on mounting flange. The inner surface of this flange has lumps of solder on it. I have asked them to not do anything with the flange to keep the cost within limits.

I will avoid using heroic amounts of torque and leave the flange threaded to the lens body. The problem will be to remove the solder to allow the flange and lens to be mounted to a lens board.

I am thinking of first going at it with grinding burs on a Dremel tool. I don't want to use heat to avoid issues with the glass elements.

Any suggestions or alternative methods?

[domaz]

I kind of think the solder would melt pretty quickly with a directly applied soldering iron, especially if you used a soldering wick.This would prevent the heat from being transmitted to the rest of the lens, it might be worth a try anyways as removing the solder is probably the cleanest way to fix this. I'm sure the old solder contains lead, so do it outside if you try.

[BrianShaw]

What’s the ultimate goal? Does the flange really need to be removed?

[Tracy Storer]

You DON'T want to overheat the barrel, it is most likely fabricated from multiple pieces of brass..

[Daniel Unkefer]

I would leave the flange on the lens as it is, get some brass hobby modeling screws (proper size or buy an assortment if not sure) for assembly, mark the board for mounting the flange, then cut the mounting holes. Ask Grimes to flatten the back of the flange where the solder has blobbed through. Good enough. Or use a fine flat file to smooth out excess solder

[Jim C.]

If you don't want to use heat all types of solder are soft, a wood chisel and some light tapping should shave most the solder off
use Dremels abrasive buffs ( EZ511HP ) they're essentially scotch brite wheels, the tan one is about
180 grit to abrade down any high spots.

If Grimes has the lens apart it would be best to have them desolder it, but that may oepn up a can of worms
the only reason that a lens would be soldered to the flange would be -
- it's the wrong flange
- the flange threads are stripped

[Tin Can]

Soon I will solder an old lens to save from dropping

A free Petzval

Some threads are way too loose

Low temp solder and flame

[Daniel Unkefer]

I have glued olde lenses into close-fitting flanges with JB Weld. Works great and will support some weight. Just sayin'.

[Tin Can]

Never used it. I need to test it.

I have glued olde lenses into close-fitting flanges with JB Weld. Works great and will support some weight. Just sayin'.

[BrianShaw]

JB Weld is good stuff for situations where the bond is intended to be permanent. Seems a bit extreme, just like solder. For loose flanges I’ve used paper shims or Teflon plumbing tape to fill minor gap in threads. I’d even consider using pipe dope long before epoxies or solder!