Dumb, dumber, dumberest questions

Most of the time there is no flux involved either. It’s when you get to 45% when you need flux. I am not sure if jewelry has torches or not. Metal shop does not. We don’t have acetylene due to the high hazards associated with it. For a few people it’s not a problem. It’s when you get to the size we are is when it becomes hazardous/dangerous. Like you are not supposed to turn the regular above 15 psi, use 1/7th the volume in an hour, not laying the cylinder on its side. Things like that most don’t know about. That’s what makes it hazardous/ dangerous.

Does MAPP gas heat around the same temps as acetylene? Between propane and MAPP, which is closer?

Propane 3600
MAPP 3730
Acetylene 5720 (!)

According to my quick Googling.

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I’ve done brazing with all 3 gasses. It all depends on the torch & operator on your results. Mapp is hotter than propane and acetylene is hotter than them both.

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Acetylene cheats. The hottest inner flame is acetylene combusting by itself. The outer, cooler flame is further combustion with the oxygen.

Honestly, use propane or propane-oxy 99% of the time. Acetylene isn’t really needed for much and is a PITA from a safety standpoint.

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That was kinda my thought – the less expensive torch options, or the whole oxy-acetylene rig that we don’t have at DMS.

The pipe is only 1/2 inch and from what I’ve read, size matters. :wink: At least in regards to how the copper will dissipate the heat. Does it seem reasonable that a Lowes propane and torch could melt a brazing rod? I don’t really need to do lengthy brazing, just kind of a spot weld is what I’m thinking.

It will do just fine. Ive done 1 1/8" with propane before.

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I’ve left you 3 sticks of Stay Silv 15 on the HAAS table in Machine Shop.


Wow, thank you Tim! That is very generous of you! Thank you all for your input and advice, this place rocks!

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Pickup up just now. Thanks again Tim. I’m looking forard to trying my hand at brazing!

@TBJK well, I am a new convert to copper brazing! It is way easier than silver soldering because of the lack of flux and is seriously strong.

I had to use MAPP gas, as my skills with Propane are just not there, but MAPP gas is kinda fun (and cheap) too. I did some research and got lost in the weeds looking for a source to buy more of the same 15 sil-sol sticks you gave me. Where do you purchase from? I found it at Supply House but if you look around prices are all over the place.

Also, you said this, and I didn’t listen, and you were right… It doesn’t work on dissimilar metals. I tried to braze a 30 inch brass coated steel piano hinge to the side of one of those copper pipes. it stuck to the pipe alright but the brass just peeled off, and when I re-tried it after stripping it down to bare steel that definitely didn’t work. Any suggestions for either a source for pure copper piano hinges that are 24+ inches long, or is there a brazing rod that will let me attach steel to copper?

TIA to everyone who has helped with this project. I never thought it would take over a month, LOL

Would screws and JBWeld epoxy on the back work?

I thought about the ole trusty JB-Weld but not sure how it would hold up over time since the hinge will have a lot of pressure to hold the acrylic doors. What hoping for a more permanent situation.

JBWeld is 5000+ PSI strength once cured. The screws would help with any possible stability/vibration issues. I could see an advantage using a putty in mating the flat hinge to a round tube.

I’m not going to lie, I see the appeal of the putty mating the flat hinge to a round pipe, and maybe that is the best method in the end, we shall see. I appreciate the suggestion. But this is a good excuse to learn some new metalworking skills so if the right metal solution is out there and I can get my arms around it without it costing a fortune, I want to give that a shot first. This project was supposed to be sooo simple. ha ha ha. Version 2 will probably be built up at the MS.

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You can get it I believe at Home Depot & Lowes. They sell it with just a few sticks in a tube. I have also seen some that was square in shape.

Regarding the dis-similar metals. You can use 45% silver solder with white brazing flux to do that. Technically its white brazing but we just use the slang term silver solder. We use it to braze pressure piping to compressor, which is normally steel to copper. They sell a flux coated 45% rod, however I’m not a fan of it. It pops, spits & makes a damn mess. I use 45% non-flux coated sticks. I will give you a stick or two if you would like to try it. You will need white brazing flux for it. The base metal needs to be clean, IE no plating.

Thanks Tim, I did get some Lowes brazing rods but I don’t think they were the same composition as the ones you shared. If you are willing to share a couple of the 45%, it would be greatly appreciated and I have cash to offer. My research has educated me on how expensive these rods are. LOL. Have you ever bought from Supply House? I found the 15% * .050" x 1/8" x 20" rods for 28 rods for $119. It was the best deal per rod I have found so far on the 15%. They don’t seem to have the 45% non-fluxed in rod form but do have it is spool form. Is that the same?

The rod & spooled form is the same. The rod is easier to deal with. One of my frequented supply houses didn’t know about the 45% rod, he was just used to the blue or orange flux coated rod. Uncoiling while brazing can be a pain in the ass, that why I use the rod. Nothing like squeezed into an awkward as hell position while holding a torch, trying to unspool some more wire type, trying not to burn yourself or the equipment.

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