Myth #3 — Everybody Uses the Stainless Steel Tips, so It Must Be the Correct Type to Use for Brazing.
Many people merely “follow the trend”. When asked why they use stainless tips, their answer is typically: “We’ve always done it that way”.
We all know that the crowd is not always right, and this is a case where “the crowd” is indeed wrong. Stainless steel straight tips are NOT best for brazing, and are only being widely used because someone observed someone using it many years ago, assumed it was correct, wrote it into their procedures, and convinced others to do the same.
Myth #4 — I Need a Long Tip to Reach Deep Places, and Only Stainless Tips Offer Long Lengths. There Aren’t Any Long Tapered Plastic Tips out There.
Many people need an extended tip to reach “hard-to-get-at” places, and assume that only stainless tips are made long enough for that purpose. Wrong. Tapered plastic tips are available with long extensions on them to reach such spots, but also have the advantage of flexibility that stainless tips do not have.
Myth #5 — I’ll Just Thin down the Paste so That It’s Much Easier to Extrude Through the Narrow Stainless Steel Tip.
Many people have thinned down the brazing paste in order to get it thin enough to extrude more easily through the stainless tip. Thinning down the paste means adding in more liquid binder, all of which must be volatilized during the brazing process, since the liquid portion of the brazing paste is merely a carrier for the solid brazing filler metal (BFM) powder that is in the paste. So, if you add in more liquid binder, it just means that you have more and more binder that MUST be “burned off” (volatilized) during the brazing process. As long as your furnace atmosphere is such that this increased amount of binder is not an issue, then everything should indeed be fine. But if you are having any kind of difficulty in completely and successfully burning-off all BFM binders from the paste during your brazing cycle, then the thickness of the paste, and the type of cartridge-tip you are using to dispense the BFM paste may become an important consideration for you.
The “Rest of the Story” — What Are Stainless Tips Really For?
Stainless tips were originally invented for dispensing thin liquids, oils, and adhesives. Because of their low viscosity, these liquids could easily and quickly be dispensed through thin stainless needles, and are still the preferred way to dispense these liquids. They were never designed for dispensing heavy, thick pastes.
Question: Have you ever considered removing the tapered plastic tip from a cartridge of caulking paste and replacing that tip with a long thin stainless dispensing tip prior to using it for any of your home repairs? Of course not! If you were to try that, you’d find that your muscles would give out and cramp up before you got an inch of caulk extruded through the stainless tip.
In a similar way, thick brazing pastes are not ideal for extrusion from cartridges using thin stainless needles. Instead, tapered plastic tips are ideally suited for such applications.
Does this mean that you now MUST change from stainless to tapered-plastic tips? No. That’s a decision that is totally yours to make. I just wanted to point out the difference between the types of cartridge tips that are out there for you, and the kind of extrudable materials for which each configuration is optimized. So, although I am not suggesting that you need to switch from what you might be currently using, I do want you to be aware of the reasons why each type of tip exists, and let you then make your own reasoned decision about which type to use.