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Lacquer Stripper

Posted: Fri Nov 12, 2004 5:12 pm
by Dan Schultz
A tech on the Delphi Repair Forum mentioned the he had been using a product called 'Aircraft Stripper' that is available from some auto parts stores (I won't say which one because I don't want to upset Joe again!) I bought a gallon this morning and used about 1/4 cup on the 'lacquer from hell' (an old Conn baritone). One light coat and the lacquer just about fell off! You repair guys need to pick up some of this stuff before the EPA finds out how good it works and finds some excuse to force it off the market!

Posted: Fri Nov 12, 2004 9:09 pm
by Normal
I used this stuff on an older King that was about half lacquered. It worked well. Like Joe said you need to be careful with it. It will burn skin.

The question I've had since taking off the lacquer is could this remover also affect solder joints. I've had to have someone resolder three or four joints since. Of course it could be that the lacquer was what was holding the horn together.

Posted: Sat Nov 13, 2004 1:00 am
by Chuck(G)
Nothing short of heat, mechanical stress or acid is really going to affect the strength of a soldered joint much.

Posted: Sat Nov 13, 2004 12:35 pm
by Normal
Chuck, You got me curious so I looked up two of the main ingredients of aircraft coating remover. The two ingredients I could find are:

Ammonium Hydroxide - Incompatible with copper, copper alloys, acids, galvanised iron, zinc, aluminium, bronze, dimethyl sulphate, mercury, alkali metals.

Methylene Chloride - Incompatible with alkali metals, aluminium, strong oxidising agents, strong caustics, some forms of plastic, titanium.

From what I read, this material is more a base than an acid, but it still might have an impact on the brass rather than the metals in the solder. Then again I know enough chemistry to be dangerous.

Where I had a problem was with some of the braces. It is possible that when I washed the tuba after using this stripper that I didn't let it soak long enough to dilute the stripper in the brace joints. It also depends on how solid the solder joints were.

Posted: Sat Nov 13, 2004 12:48 pm
by Chuck(G)
Norm, there are some in the clockmaking business who swear that ammonia and brass are a no-no. The claim is made that ammonia will make brass brittle.

AFAIK, however, the lead in solder is pretty much impervious to most common bases and the tin is only sparingly reactive with the strongest of them.

Posted: Sat Nov 13, 2004 6:53 pm
by Dan Schultz
Normal wrote: The question I've had since taking off the lacquer is could this remover also affect solder joints.
As Chuck mentioned... I don't think there is much other that stress or heat that will cause problems with solder joints. I've been into many horns that looked good on the surface only to find that some of the original solder joints were bad. I've found joints where there was no solder at all! Many, many others where the solder did not run around the complete perephery of the joint. I repaired a high school Conn 15J last week that had no solder at all in the upper knuckle of the 3rd valve. The only thing holding the slide tube on was the two braces between the slide tubes. In short... I think there is a something wrong with most horns.... new or old. I have yet to take apart ANYTHING that had perfect solder joints or even straight tubing connections. Bad solder joints usually go un-noticed until working on other things.