HCL bath

[rpg]

I'm doing a learning test on a HCL bath for future pin process. I put a few cards in it and an aquarium heater (to 80 degrees). It has been working outside for 10 hours or so (temperature outside is above freezing still here in Mass) and the parts are breaking off easy, meaning the acid is doing its job on the Tin and Lead. One of the cards had gold plated pins that are now white. I remember reading in the forum that this maybe due to Tin or Lead plating on top of the gold and the gold should still be under. Now I'm afraid of doing a batch of pins and having the Tin plated back into the Pin.

My questions are:
- is 80 degrees too low for a HCL batch and that is what is causing the plating of Tin on top of the Gold? (if indeed is what I'm seeing)
- at the right temperature, how long should the process take?

TIA

 

[Lino1406]

The lead part of solder with HCl
gives white precipitate

 

[rpg]

thank you Lino. After a day and a half 99% of the parts fell of the boards but a light blue substance has formed. It sticks to the boards and components, although it comes off with a light finger scrub. The black layer that forms over golden pins also comes off with a light scrub. Some places a white layer also forms on top of plated gold. Any idea what this is? Do I really need to take the stinky HCL close to boiling temperature for the solder removal to work to perfection? TIA