On 05/29/2010 10:34 AM, Paul K. Dickman wrote:
"Tim wrote in message
...
On 05/28/2010 07:25 AM, Roger Shoaf wrote:
"Ned wrote in message
...
On Thu, 27 May 2010 22:17:36 -0700, Tim
wrote:
Oops.
After finishing soldering my Very First model airplane fuel tank, I
went
to do the last step of any soldering project -- cleaning off the flux.
Unfortunately, while I know that the flux I use yields to scrubbing
with
hot soapy water, I don't know what -- if anything -- will just take it
off. I'm experimenting.
Jeweler's pickle?
http://www.ganoksin.com/borisat/nena...ling-notes.htm
--
Ned Simmons
Won't the acid be a problem? While not stated, I had assumed that the
fuel
tank was made of copper or brass. If you look at the last part of the
cited
article it indicated that the acid pickle eats copper.
Actually the tank is made out of poor-man's tinplate -- it's a Dole chunk
pineapple can, cut up and bent on a Harbor Fright brake.
So, if I use any pickling solution that'll eat steel, I want to not leave
things in there for long.
If you used a pineapple can, your problem might not be the flux residue.
Modern food cans have the interiors coated with a resin. It is difficult to
remove in the best case and it is impossible to remove after it gets
roasted.
If your problem is a crusty residue near the joint that thins out to a
transparent brown, then that is what you have.
When I need tinplate I scrounge it from gallon lacquer thinner cans. The
interior isn't usually coated and you can remove the paint on the exterior
with paint remover before you start working.
It's not showing that at all -- I chose those cans because they're
obviously galvanized on the inside. They certainly soldered up like
there's nothing in between the solder and the can. All of the other tin
cans that we go through are obviously coated with some sort of plastic,
which I'd have to clean off, and which may not leave me with a nice
surface to which to solder.
I'm mostly concerned with leaving acid residue inside my nice model
airplane motors after running them with a tank made with this flux.
--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com