Most of the reading I have done implies that silver bearing soft solder (tin based) creates a better join than hard solder (silver/copper based), as along with being more difficult, hard solder requires temperatures which are close to that which cause sensitization (a type of metal weakness) of the stainless steel. One person also claimed that soft solder is better as it creates a bigger fillet due to its wider liquid/solid temperature range. On the other hand, I have read many posts where home distillers use hard solder for this purpose; with some claiming that the bond is stronger than that of soft solder.
Sometime next week I hope to have a go at attaching a 4" ferrule to my keg boiler as a column connection (I might also attached the column to a wall for extra support). I already have sticks of hard solder (copper based with 15% silver), so would rather not have to buy a roll of StayBrite 8 (or whatever similar product I can source in Australia) if I can avoid it. Apparently the Ezi-Weld 801 flux we can get off the shelf here in Australia has been tried and tested to work as a substitute for Stay-Clean (it doesnt look as good as Saty-Silv Black for hard soldering).
So my question is; assuming correct technique is used, does silver bearing soft solder ( tin based, with low silver content) create stronger / better stainless to stainless joins than hard solder (copper based with 15% silver content)?
CS
Last edited by Cletus_Spuckler on Fri Apr 27, 2018 10:27 am, edited 3 times in total.
CS