How to Braze- part 1
How to braze- A 4-part series on how to braze carbide tips
Welcome to our series on how to braze! We have put together a tutorial on how to braze and broken it up into 4 parts. We will be adding a new post every few days so be sure to check in and visit us often so you can take advantage of this valuable information. In part 1 of this series we will be discussing saw plate and how to prepare the saw plate for brazing.
When brazing carbide tips you will need:
- Braze Alloy or silver solder
- Brazing Flux
- Carbide tips
- Saw plate
- Also, you will need a tool to heat the braze alloy
- And you will also need a tool to help guide the carbide tip onto the saw plate.
*For successful brazing the quality of the materials used is very important and can have a significant effect on reducing the amount of tip loss and breakage you experience. We proudly sell what we believe to be some of the best brazing flux, Braze alloy, and Carbide Tips in the industry.
Part 1: Choosing a saw plate:
A steel saw plate is laser cut. The laser cutting causes a heat affected and burnt and oxidized edge on the saw plate. This edge must be ground back to clean steel. Probably the safest figure to use is 0.010”. If you do not grind the edge on the saw plate back, the tips may still stick to the burnt steel but it will be a very weak bond.
Steel saw plate typically comes with some sort of a protectant to prevent rust. This must be removed from the saw tip seat as well as the adjoining shoulders. The best way to do this is with some sort of a caustic solution (sodium hydroxide, NaOH). A strong caustic solution breaks the oils and greases done into soaps which are easily removed. A solvent will dilute the oils and greases but will not remove them completely. Either cleaning method can work successfully but the caustic method is surer and more complete. For more tips you can read our blog on cleaning steel.
See our videos below on preparing steel plate for brazing
How to Prepare Saw Plate for Brazing
Broken and Ripped Shoulders
Broken and ripped shoulders are two separate things.
Broken (Snapped) Shoulders
During brazing it is possible to get the steel saw plate so hot that a change in structure takes place. This change in structure can cause a change of hardness of as much as 20 points Rockwell C. This makes the saw plate very hard and very brittle. If the saw plate is not correctly tempered back to the correct Rockwell and the correct toughness then it can snap during use. This is typically a very clean break.
I have seen instances, with an improperly maintained automatic brazer, where the heat affected zone continued into the saw plate as much as an inch below the bottom of the gullets. In this case a customer returned the saw blade that had a whole section missing. A section of five tips, gullets and all, had come off as a single piece to a depth of about an inch below the bottom of the gullets.
Ripped Shoulders
Ripped shoulders are different than snapped or broken shoulders. With ripped shoulders the steel is tempered correctly but the saw tip gets hit so hard that it actually pulls the steel apart. These are typically not clean breaks. They will often leave deformed steel.
Watch our video on:
Saw Steel Embrittlement
Tags: Brazing, carbide tips, cleaning steel, how to braze, saw plate
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