Strip or Depopulate in hcl?

[dcorley001]

I have about a half dozen boards with some very nice color on them. On the back side of the board it's almost a solid sheet of gold. Is it wise to strip or depopulate these in hcl with the intention of AP processing the boards when clean? How well will the AP work when there is this much gold on the board. (The gold is over copper). Will there be any values in the initial hcl bath. If so how best to recover these after the components are removed?. I'll try to post some pics of the boards..

 

[Geo]

do you have any used AP solution? some people start a new reaction every time with peroxide. if you add the hcl needed and then add some copper chloride from a previous AP reaction there will be no need for peroxide and therefore no dissolved gold.the initial reaction from the peroxide with the gold only puts a trace amount of gold into solution. the problem of dissolved gold in solution arises from the continued addition of peroxide throughout the reaction. people get anxious wanting to see something happen and adds copious amounts of peroxide to the reaction which will dissolve some gold.

use a small plastic tub just big enough to hold the boards. dilute muriatic acid 50/50 with water and add this to the tub just to cover the boards. a reaction will start in a few minutes. let the reaction proceed until the components start coming loose. be sure to remove any aluminum components before you start.

 

[damezbullion]

do you have any used AP solution? some people start a new reaction every time with peroxide. if you add the hcl needed and then add some copper chloride from a previous AP reaction there will be no need for peroxide and therefore no dissolved gold.the initial reaction from the peroxide with the gold only puts a trace amount of gold into solution. the problem of dissolved gold in solution arises from the continued addition of peroxide throughout the reaction. people get anxious wanting to see something happen and adds copious amounts of peroxide to the reaction which will dissolve some gold.

use a small plastic tub just big enough to hold the boards. dilute muriatic acid 50/50 with water and add this to the tub just to cover the boards. a reaction will start in a few minutes. let the reaction proceed until the components start coming loose. be sure to remove any aluminum components before you start.

just what iv been looking for i could do this with memory/ram sticks to right? and it will COMPLETLY remove solder and depopulate board without heating it up?, i take it i doesnt take out the silver in the solder tho?

 

[Geo]

yes to the first two questions and the silver will be left in the black powder from the process and maybe even a little silver chloride depending on how much oxidizer you use.

 

[damezbullion]

Love it! thanks man