Brazed and Confused

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Completely new to the task of brazing, I'm quickly finding the process trickier to accomplish than initially believed. I've not met many highly familiar with it, but those with experience have been mostly plumbers. Perhaps thats where my problems are arising, given the fact I'm using conventional copper pipe, but trying to braze it in unconventional ways,  underscoring what I may have wrongly assumed in the first place. Can brazing be done by similar means of a puddle, as in welding steel, or is it strickly limited to capillary action, and with copper pipe, the closely formed tolerances of the fittings used to join them?Thus far, my attempts to bond copper pipe, either sculpturally or structurally suggest the latter.Last edited by KutNKornerz; 01-22-2015 at 03:04 AM.
Reply:It is not limited to capillary action, silver solder is geerally good for capillary action but other types may be more or less handicapped in that respect and pretty much stay where you put them.
Reply:OMG, the work of a wizard. I'm using Stay-Silv 5 filler metal I believe 5% silver, and while I was told to use flux, it appeared to send this type everywhere other than where I wanted it. Its easier to control without flux, but I'm just not getting any adhesion. Using mapp gas and a turbo torch, I may well be wrong but it appears to deliver sufficient heat.Last edited by KutNKornerz; 01-22-2015 at 05:20 AM.
Reply:GD man that is amazing work.-Niche
Reply:Originally Posted by G-sonIt is not limited to capillary action, silver solder is geerally good for capillary action but other types may be more or less handicapped in that respect and pretty much stay where you put them.
Reply:KnK   More precise information on exactly you are trying to do may bring better responses(pictures save your keyboard).    Cleanliness is next to godliness. Very, very clean and do not touch a clean joint with your fingers. Brazing does not melt the base metal(like steel welding does) only the filler which should have a lower melting point than the base metal. Not all fluxes are created equal. What flux are you using and is it he correct one for the job at hand? Do you need lead-free joints? What size of pipe? Strength required? Forces applied?---Meltedmetal
Reply:Actually a good braze weld with the right filler can have a tensile strength around 60k psi, about the same as steel.
Reply:Pork, Bicycles have been brazed for many many years.  Yes, most modern al or steel frames are tigged, but brazing is a very valid way to build a bike.  Adding lugs can help with joint strength, but is not required.  That said, I wouldn't want to use a brazed bike for modern downhill mountain bike racing, but that has more to do with flex than strength.Multimatic 200Ellis 1800Haberle S225 9" cold sawMM 300;  Spoolmate 30A w/ WC-24TB 302GDynasty 280 DX Tigrunner
Reply:Originally Posted by porkncheeseIs that brazed? It looks very neat but correct me if im wrong, a brazed bike frame will most likley fall apart under load. A type of fusion weld is far better. Just look at brand new bikes. They are tig welded not brazed. Why. Because braze is like silicone. Great for sealing low pressure tube but definetely not good at taking loads
Reply:Originally Posted by iongarActually a good braze weld with the right filler can have a tensile strength around 60k psi, about the same as steel.
Reply:Man that looks excellent!!
Reply:Nobody is saying that brazing is superior to tig welding.However it can be more than adequate in many applications.HAZ is not necessarily bigger compared to tig since brazing is done on much lower temperatures.Another example of a demanding application in which brazing is applied is the Ariel Atom.The fact that brazing is less popular to tig welding also has to do with the availability of skilled personnel among other reasons, not many can produce this:
Reply:[QUOTE=taz00;5304461]Nobody is saying that brazing is superior to tig welding.However it can be more than adequate in many applications.HAZ is not necessarily bigger compared to tig since brazing is done on much lower temperatures.Another example of a demanding application in which brazing is applied is the Ariel Atom.The fact that brazing is less popular to tig welding also has to do with the availability of skilled personnel among other reasons, not many can produce this:[QUOTE]Good explianation. I can hardly believe it is used on a road chassis. Perhaps i underestimated how adequate brazing can be. I suppose it is a decent alternative with some applications. Its also good for the backyard welder who cannot justify the cost of TIG as it is fairly expensive. Especially for a 1 off project
Reply:All of the older road bikes were brazed, they have been building them that way since before there was welding.Unless you count black smith type welding.
Reply:Originally Posted by taz00Nobody is saying that brazing is superior to tig welding.However it can be more than adequate in many applications.HAZ is not necessarily bigger compared to tig since brazing is done on much lower temperatures.Another example of a demanding application in which brazing is applied is the Ariel Atom.The fact that brazing is less popular to tig welding also has to do with the availability of skilled personnel among other reasons, not many can produce this:
Reply:Some of you may remember this but I have some Nassau Brutus/G brazing rod that has a 100,000 psi rating.  For all ferrous and non-ferrous metals, exceptionally good for high strength thin joints, (no white metal). 1575 degree F. I can think of many welding joints that do not come close to this.  Just my thoughts, best regards Bob.
Reply:Sweet work ! Beautiful stuff there.
Reply:The entire front ends of jag E-types are brazed together.12v battery, jumper cables, and a 6013.I only have a facebook page. https://www.facebook.com/pages/VPT/244788508917829
Reply:Originally Posted by porkncheeseGood explianation. I can hardly believe it is used on a road chassis. Perhaps i underestimated how adequate brazing can be. I suppose it is a decent alternative with some applications. Its also good for the backyard welder who cannot justify the cost of TIG as it is fairly expensive. Especially for a 1 off project