# Desoldreing boards



## Sunspot (Sep 1, 2013)

I'm curious on this one as I have not seen it mentioned. 

I have access to a system which enables me to completely disolve the solder on boards en masse. Motherboards, graphics card and memory can be put in and the various compents will drop off. I intend to sort through all this stuff for the valuablw parts but I need someone to tell me if this will cause trouble for recovering the various metals. It's a standard flow oven, the solder melts, the components are left over. 

I want to be clear, all this is is a high temperature furnace that is used to melt the solder holding the components. My friends will sort out the various components and hand them to me to chemically sort out. I just want to make sure this melting of the solder won't cause me trouble. I'll be left with intact monolithic capacitors, black chips, fingers and what have you. I mean basically all the components drop off and then someone sorts through them. 

I have not seen this mentioned on the forum and I just need some opinions as to whether it's an acceptable process. It's basically just a flow process in the same way they create circuits.


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## Smack (Sep 1, 2013)

Try searching Depopulating Boards :idea:


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## Sunspot (Sep 1, 2013)

Yeah I see depolulating boards, this isn't quit the same thing.

The deal here would be basically causing all of the compnents to drop from the boards as the solver would be melted and then they would sort thourgh the components. I'm just wondering if this would have any effect of the recovery of the metals. This is essentially the same as the flowing process used to create the boards in the first place. 

I just need a bit of guidance on this one before I say yes to them removing every complent from a board in this way and sorting through them.


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## everydayisalesson (Sep 1, 2013)

Geo has a very good video on depopulating cell phone boards which is basically the same thing you are proposing just on a larger scale. Check it out, its very informative.

Mike


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## Smack (Sep 1, 2013)

Sunspot said:


> Yeah I see depolulating boards, this isn't quit the same thing.
> 
> The deal here would be basically causing all of the compnents to drop from the boards as the solver would be melted and then they would sort thourgh the components. I'm just wondering if this would have any effect of the recovery of the metals. This is essentially the same as the flowing process used to create the boards in the first place.
> 
> I just need a bit of guidance on this one before I say yes to them removing every complent from a board in this way and sorting through them.




Yes, but they don't have trouble with tin in acid during the manufacturing process. Your going to have solder all over the components if you heat and then knock them off into a container. You could try a solder bath (with proper ventilation of course) by having a pan on a hot plate with molten solder in it and big enough to put circuit boards in right side up, when the solder on the boards melts you lift the board off and the surface tension and gravity is supposed to suck the solder off the boards, then hitting them upside down in a container. I don't see that process getting every component though. I've never tried this technique, but always wanted to. You know shearing off the surface mount devices would leave much of the unwanted tin behind.


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## pimpneightez (Sep 2, 2013)

I think a hot HCL bath will remove solder. Maybe someone with more experience can verify.


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## masonwebb (Sep 24, 2013)

Heat gun all the way! It may take more time, but it is cheaper than using chemicals.


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