When a part fails to meet service requirements, the brazing personnel are surprised and often can’t understand why the parts failed because the outside surfaces came out of their brazing furnace looking shiny, clean and bright. Based on the nice-looking outside surfaces of the parts, should they not assume that the inside of the brazed joints were also similarly cleaned and therefore probably brazed well? Unfortunately, no! 

There are a number of very important steps that must be followed in order to ensure good brazing, one of which is that the parts to be joined must be clean before being assembled for brazing.   

Two methods can be used to prevent the base-metal erosion discussed last time in part 1.

How can we prevent the erosion of thin stainless tubes that we need to braze into several through-holes in some thick stainless plates during our furnace brazing operations?

Here is the third and final part of Dan Kay's blog series about the purpose of a braze fillet. Part 2 can be found here.

Here is part 2 of Dan Kay's blog about the purpose of a braze fillet.

When visiting a brazing job-shop recently, I was told that one of the shop’s clients insisted that some of their components be re-brazed because the braze fillets were not large enough, according to that client. When I examined the component myself, the braze fillet was actually perfectly OK, but the shop’s client thought that all fillets – welded or brazed – needed to be large.

Brazing expert Dan Kay answers a detailed reader question about brazing 304L stainless steel. They are seeing a few dark spots on the product being brazed. Find out what Dan says the problem(s) might be.

Question: I've heard that argon can be a dangerous gas to work with in my brazing operations. I don't understand how this can be since argon is known to be an inert gas and appears to be quite safe to use. How can it be dangerous?

Let’s finish the discussion we started last time. As shown in Table 1, it is important that you look at the surfaces that you want to braze together and decide if they meet the design criteria needed for brazing.