I cleaned with alcohol, but it was isopropyl so not much sense in drinking that. Sanded, cleaned, soldered; cleaned in soap and water and used file to trim the copper wire per suggestion above (post pic). I painted the metal but taped over the solder joints just in case they break and need to be re-soldered; would be impossible if painted.

Took the plane with new floats up on Sunday but it was hard to stear without a rudder in the water (I had hoped the plane's rudder would be enough). Spent Monday building the new rudder. All hooked up but with 40 mph winds, might be a while before the final test.