Brazing carbide

What grade of carbide are you using, and why?

I finally have grinders with diamond wheels to resharpen brazed tools and inserts.

I don't know if regular brazing flux is going to do it, I use one intended for brazing tips and stainless steel as it is formulated to deal with the more tenacious oxides.

I plan to use slices of the shank of a half inch carbide router bit . Somewhere here I have a few carbide inserts that are candidates if I can find them . I have diamond blades for the Dremel and a tile saw with a diamond blade and a green stone on my bench grinder

In a couple of the videos I watched they were using straight borax ... I also have some flux intended for use with molten brass and aluminum .

Let us know what you choose, and how it works. Please.

My second-hand example of the Baldor clone is good enough for hobby use.

I was talking about the block/collet holder I made to hold end mills to sharpen the ends . I have some kind of bonded grinding disc that was meant for sharpening circular saw blades - I don't know what that stuff is but it cut the diamond point that I tried to true it with .

I was talking about the block/collet holder I made to hold end mills to sharpen the ends . I have some kind of bonded grinding disc that was meant for sharpening circular saw blades - I don't know what that stuff is but it cut the diamond point that I tried to true it with . Snag

------------------------------ CBN?

I do remember them, left and right handed. I made an adapter for mine to hold S&D drill bit shanks centered in the 5C collet to be sharpened at the back relief angle setting.

I don't know , I'll look at the ebay purchase info to see what the grind medium is - the closest match I can find is a diamond bonded grinding media . My fixture has 2 angles on the bottom , cutting edge and back relief . The collet holder is indexed for 2 3 4 and 6 flutes . Does a right fine job too . I did find the carbide cutters I was looking for . I can cut chunks oversize with a diamond blade and grind to final shape after brazing them to the shank .

I wonder it it would be simpler to braze the end of the carbide shank to the steel tool and then cut it off, giving you an area out of the flame to fixture the carbide securely in place.

I've got a couple of diamond wheels and the one on the machine at the moment is a metal matrix diamond wheel and it had been badly worn so the face wasn't square due to years of use without truing. I posted here probably a couple of decades ago and got a guy that used to run a precision grinding shop and he gave me suitable advice for truing it. Most of the exchanges ended up being private not on the news feed. Basically the bulk of the material was removed using a SiC dressing stick to rip back the surface diamonds and then a BN dressing stick to clean back further, IIRC that last bit helped remove the matrix around the diamonds and get a good new working surface. That said it is a slow process so I didn't completely true it square but far better than when I got it.

I expect using a diamond point will wear the dressing point like diamonds are cut and polished on a CI lap with diamond paste.

I bought a small diamond cut off wheel that fits on my d-bit grinder. since my D-bit grinder has a native 5C tool holder its dead easy (more or less) to slice chowdered tips off of carbide end mills. That's actually what I bought it for. Converting end mills into side mills. LOL.

Something like that might work for slicing little discs off the than k end mills for brazed carbide insert tooling. If you pregrind you can get bottom rake, and if you accept some side wear on the wheel you can get slight top rake before fully removing the piece from the stock.

That is an interesting approach.

A quick read tells me silver solder 45% silver or higher is considered "best".

Silfos (typically 15) is for copper to copper or copper to bronze. I have a couple pieces I used for soldering copper tube on an AC unit. Silfos is nice for copper as it is supposed to be self fluxing, making out of position work easier in theory. In reality I only got good joints on the bench.

Brass can work, but it doesn't stick to the carbide as well as silver.

I have a small section of 45% silver solder around somewhere and I can tell you it was expensive. I bought it at the a local welding store, the better one, that doesn't usually gouge me. It was NOT good enough for repairing band saw blades. But there should be no flex in your carbide to steel connection. If you want it you know how to reach me, to remind me of your address. (If I can find it.)

There are light fluxes and dark fluxes, and I think those with boron (black brazing flux) is best, but borax might be a poor man's alternative. They use borax at forging temperatures afterall, (and for some heat treating operations) so it probably won't burn off.

Some I recalled, some I got from an old This Old Tony Video, and some I double checked using Goggle's AI search function.

Sounds like to old go to Easyflo no2 at about 50% would do it or its Cadmium free alternative at about 55%. I have some in various sizes and it will roll out to a thin strip if you have a rolling mill although if required really thin it'll need annealing and I've used it for this type of job where I wanted a thin shim of solder in place in the joint.

I haven't tried to use it to repair a broken bandsaw blade but have read that it should be suitable if a scarf joint is used.

I have suitable flux for use with the silver solder for tool tips and stainless steel.

Silfos (typically 15) is for copper to copper or copper to bronze. I have a couple pieces I used for soldering copper tube on an AC unit. Silfos is nice for copper as it is supposed to be self fluxing, making out of position work easier in theory. In reality I only got good joints on the bench.

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On steel Silfos forms brittle iron phosphide that weakens the joint.

I have some silver solder I bought expressly for repairing/making bandsaw blades . Haven't seen it in several years ... I'll look into getting some more (*wallet gonna take a hit) as well as some black flux . There's no rush , this is one of those "one of these days when I get a wild hare" projects . OK just ordered some 47% silver solder (old stuff with cadmium) and some black flux . Bet y'all a nickel the solver solder I already have shows up before the stuff I just ordered arrives ... the damn flux cost twice what the silver solder (10 feet of .016/26 ga wire) cost , but I'd bet it's more than a lifetime supply for me in both cases . *I don't worry too much about cost these days . My wants/needs are simple and for the most part well under a hundred bucks . About the only thing I run past the wife (got one of the rare "good ones") is guns or tools over a couple hundred .

I wasn't planning on using it , just tossed in the fact that I have some ... got it at a yard sale for about 10% of it's value . I love yard sales even more than my wife does !

I wasn't planning on using it , just tossed in the fact that I have some ... got it at a yard sale for about 10% of it's value . I love yard sales even more than my wife does ! Snag

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I acquired mine similarly cheaply at a flea market. The price of Silver is bouncing around $80 per Troy ounce of 31.10 grams after peaking over $100. A standard ounce is 28.35 grams, a pound is 453.6g. Thus a pound of Silfos contains $175 +/- in Silver.