White buildup on immersed lead-free solder?!?

[etiennedesrosiers]

Hi all,

I've soldered a stainless fitting on a stainless kettle using a cheap lead-free with silver bearing with the harris stay-clean flux. I know that the strenght of this kind of solder is not great but since it is not stressed, I decided to try.

The solder works well (strenght and water tight) but after only 20 minutes immersed in filtered tap water, white stuff appers over it.

It seems to be a kind of corrosion since if I let it in distilled water (no mineral, thus low electrical conductivity) nothing happen.

I know that many people solder with the harris stay brite which is basically the same but with a higher silver content. Have you ever see that?

Thanks

 

[BargainFittings]

Yes I see it with plumbing solder or low silver solder like you describe.

The higher silver content solder stays bright and shiny

 

[Ben58]

Lead free solder normally contains tin and antimony. The white you see is an oxide layer on the tin.