Is there a trick to Brazing Copper to Steel or Stainless Steel?
My Machinist buddy needed me to silver braze some copper washers to stainless steel bolts and also a copper block to a swivel foot.
So here is the video with a few tips on silver brazing copper to steel and brazing stainless steel bolts to some copper washers.
I use the term silver brazing instead of silver solder because technically anything over 840 degress F is brazing.
The silver braze filler material I used that day was a BAg-5 class silver braze comparable to Harris easy flo 45 ( I looked it up after I did the video)
It works good with white stay silv flux.
I bent up some rings of silver braze material and pre placed them on the joints to see if I could get an evenly flowed silver braze joint like I show in the video.
Turns out pre placing filler metal works great because it allows the torch heat to be directed on the areas most needed without prematurely melting the silver braze filler rod. You can see a nice collar of silver brazing material on the head of the stainless steel bolt when its done. Thats a good indication that brazing material flowed where it was needed.
All i had on that day was a cutting torch but it allowed for a soft enough flame to get the job done.
Here are basic tips for silver brazing copper to steel, or stainless steel;
* clean and flux the area to be silver brazed
* use a tip that produces a flame that is hot enough to heat the area without taking all day...but not so hot that it is hard to control
* make sure to use a tip that allows for a soft flame that is big enough to wrap around the joint.
* use the right flux for the job. There are manufacturers charts that match silver brazing filler metals with the right flux.
* keep the torch moving to avoid hot spots and direct the heat to the areas the need it most...for example thicker members or copper members that conduct more heat.
* when its possible, using preplaced filler metal can make things go better
* remember to follow your oxyfuel safety rules..(that stuff can hurt you)