Author Topic: Removing Lead Solder  (Read 3621 times)

Offline Mark Elliott

  • Hero Member
  • *****
  • Posts: 5191
    • Mark Elliott  Artist & Craftsman
Removing Lead Solder
« on: July 04, 2014, 01:29:07 AM »
I have a broken trigger guard that someone else tried to fix with lead solder.    I need some suggestions as to how to remove the lead from the broken joint.   I have tried heating the solder and brushing it out with a bronze brush, but that only worked but so well.   I thought about vaporizing it with a torch, but that is a little risky.   I ended up with lead poisoning that way when I was a teenager.    I hate to do that on purpose.   Other suggestions would be appreciated.
 

coutios

  • Guest
Re: Removing Lead Solder
« Reply #1 on: July 04, 2014, 01:59:46 AM »
    When I was still working the electronics dept. used a thin woven strip of pure copper about .187 wide by .09 in thickness.. We called it wicking... It was used to remove solder from where it was not needed..

     The "wicking" was fluxed laid against the solder and a hot iron was pressed against the wicking...  It would melt the solder and draw it into the wicking.. Seemed to work well..  May or may not work well enough for what you need.. Sorry but don't know where to get it today...

Lot's of luck
Dave

Offline Mark Elliott

  • Hero Member
  • *****
  • Posts: 5191
    • Mark Elliott  Artist & Craftsman
Re: Removing Lead Solder
« Reply #2 on: July 04, 2014, 02:25:54 AM »
I have used the copper braid before as well as a vaccum desolderer.   I have those items, but they only work to remove most of the solder so that you can remove an electronic component.   In that case, the leads and wires are still left tinned.   That has already been done.   What is left is a thin layer of lead in the joint.   Given that the joint is an uneven break,  there are many microscopic nooks and crannies in which solder resides.    I am willing to bet that the solder is only a few molecules thick in the joint.   I am afraid that it is enough to destroy any joint I try to create with silver solder.   

Offline davec2

  • Hero Member
  • *****
  • Posts: 2959
    • The Lucky Bag
Re: Removing Lead Solder
« Reply #3 on: July 04, 2014, 02:26:53 AM »
Hydrochloric acid (muriatic) will remove the lead and not bother the brass.  Don't try to silver solder with ANY lead in the joint.  It will fall apart.  Either etch it clean (down to the molecular level) with acid or mechanically cut away the contaminated brass and make a new joint.  If cutting away some of the joint leaves the TG short, you may have to add back in a replacement piece of brass.  I also use a silver solder that I get from Rio Grande that is brass yellow.  HCL is a little slow, but if you have removed most of the lead, the thin remaining layer will come off relatively quickly.

Or, you can use Acetic acid and hydrogen peroxide.  The lead dissolves quickly. Use a 1:1 mixture of 5% acetic acid and 3% hydrogen peroxide.
 
« Last Edit: July 04, 2014, 02:36:00 AM by davec2 »
"No man will be a sailor who has contrivance enough to get himself into a jail; for being in a ship is being in a jail, with the chance of being drowned... a man in a jail has more room, better food, and commonly better company."
Dr. Samuel Johnson, 1780

Offline frogwalking

  • Hero Member
  • *****
  • Posts: 1044
Re: Removing Lead Solder
« Reply #4 on: July 04, 2014, 02:38:32 AM »
Radio Shack sells the desoldering braid.
Quality, schedule, price; Pick any two.

Offline Mark Elliott

  • Hero Member
  • *****
  • Posts: 5191
    • Mark Elliott  Artist & Craftsman
Re: Removing Lead Solder
« Reply #5 on: July 04, 2014, 02:56:47 AM »
Thanks Dave.   I suspected what you said, but didn't know if the acid was safe for brass.   

Offline davec2

  • Hero Member
  • *****
  • Posts: 2959
    • The Lucky Bag
Re: Removing Lead Solder
« Reply #6 on: July 04, 2014, 05:16:29 AM »
Mark,

Yes, I use HCL to pickle brass parts (and gold, silver, copper, etc.) to remove flux after silver soldering.  No harm to the brass.
"No man will be a sailor who has contrivance enough to get himself into a jail; for being in a ship is being in a jail, with the chance of being drowned... a man in a jail has more room, better food, and commonly better company."
Dr. Samuel Johnson, 1780

Offline Mark Elliott

  • Hero Member
  • *****
  • Posts: 5191
    • Mark Elliott  Artist & Craftsman
Re: Removing Lead Solder
« Reply #7 on: July 04, 2014, 05:50:52 AM »
I used the acetic acid and hydrogen peroxide.    I only let it go for 2 hours tonight.   I was afraid to leave it overnight.   It was bubbling and frothing and turning very bluish-green.   It was obviously taking some of the copper.   It etched part of the bow so that I could see the crystal structure.   I still have lead to come off.   I will work on it more tomorrow.


kaintuck

  • Guest
Re: Removing Lead Solder
« Reply #8 on: July 04, 2014, 01:19:43 PM »
And any left over Acetic acid will kill them stubborn weeds!!!

I bet your shop smells nice now...... ;D

Marc