the muffler shops welded them up for years with a brazing torch and coat hanger's. :thumbup: As far as your machine you have to set it best for you,I like to weld hot,But I know how to work a hot machine.People are different.Play with your machine on a piece of pipe.It will come to you,You want to have it hot enough to get good penetration. :thumbup:

 

what all is needed to brazing. I have a BernzOmatic welding kit which has mapp gas and O2.

 

exhaust

You will never do it with the bernzo, Not that it won't braze, it will get hot enough but time consuming, you need to use gas with the welder, that flux crap is well.....crap. get gas, practice, your probably moving to slow, ya gotta practice, a good weld does not come with out it........

 

i borrowed the welder so i have use the flux

 

I use oxygen/acetylene to do my brazing (welding with a coat hanger),With a brazing torch. :thumbup:

 

Hi,
Brazing an exhaust system isn't a good idea imo
as it isn't very strong, It's better used in joints like soldering, brazing is don at less then a thousand* (using the coat hanger is welding,)
Good luck,
Rich
Checkout what these guys did
http://www.ford-trucks.com/forums/45580-how-to-weld-exhaust-pipes.html

 

i did a peice with a liclon handy core, wire speed seemed to help with burn through(higher was less burnthough gotta keep it the fire fed), low heat as well. if you burn through tap the trigger just long enough to lay down some metal and cool then go again until the hole is filled. little more grinding with flux but it worth it i guess

as for mig i havent had the pleasure to use one, as im still livin with the parents and making very little cashola.

 

Sorry let me rephrase what I have said!!! I have welded some with a coat hanger and a brazing torch.( Years ago):nono: :nono: Now I MIG weld mine. :thumbup:

 

An Oxy/Acetylene torch works great for welding exhaust and although hanger wire is often used a good gas welding rod works a heck of a lot better. Brazing (using a Bronze rod, not steel) should work ok for slip fit connections but it would not work very well where the weld has to carry the load, I suppose a slip fit should just be clamped anyway. As far as the heat affecting brazing with the bronze that should not be a problem as cast iron exhaust manifolds are brazed all the time. That flux core is junk for what you are doing, not saying it can't be done just that it is more trouble than it is worth to get a sound weld and forget about it looking decent! If you are trying to get a good sound weld that looks neat you really should try to get a MIG instead of that flux core welder or try to get a torch (Oxy/Acetylene) with the right size tip and some real welding rods not hanger wire.

 

Brazing (using a Bronze rod, not steel) should work ok for slip fit connections but it would not work very well where the weld has to carry the load, I suppose a slip fit should just be clamped anyway. As far as the heat affecting brazing with the bronze that should not be a problem as cast iron exhaust manifolds are brazed all the time.

Oldred: Don't you mean "brass rod" for brazing? You know I don't have even a fraction of the experience welding that you do, so if there is such a thing as using a bronze rod I'd be happy to get your info on it. Bronze = copper + tin alloy.

That slip fit is a good reminder -- I've seen people try to make brazed butt joints. Of course the joint then has the tensile strength of brass instead of steel. A proper brazed joint will be stronger than the base metals it joins.

If you are trying to get a good sound weld that looks neat you really should try to get a MIG instead of that flux core welder or try to get a torch (Oxy/Acetylene) with the right size tip and some real welding rods not hanger wire.

I'm still amazed at the difference in ease and quality of welds between that flux-only welder and MIG. Glad you and others kept urging me to try it or I'd still be grabbing the oxy-acetylene every time I wanted to weld thin stuff.

Maybe the common use of coat hangers for oxy-acetylene welding while calling it brazing is why the myth still persists that brazing isn't very strong.

 

Nope, they are are Bronze. Of course there are different alloys of Bronze available as well Silver brazing alloys, etc. Another point about brazing, and this is just my opinion, is to avoid the popular flux coated rods because they simply contain too much flux and although it does not harm anything it does get in the way. I buy bare rods and bulk flux in a can, this way I can just dip the rod and use only as much flux as I need then once the area is throughly "tinned" I leave off any more flux making for a cleaner joint and easier to see welding (brazing). If you are doing build-up work or any brazing that requires a heavy deposit those flux covered rods become a PITA and besides the bulk flux is really good for prepping the weld area prior to brazing which you can't do with covered rods.

 

Thanks for the info on the bronze; I've only ever used brass rods.

I've seen those flux covered rods but don't see a need for them. Heat and dip just doesn't seem that much a chore to me.

Last spring I was at a farm auction scarfing up scrap steel. My wife came hurrying up all excited about getting a new ignition cable repair kit (plastic box filled with cables, boots, terminals, etc.) for my diesel tractor (yep, she meant well). Inside was a 1 lb can of "Forney Brazing Flux"; looks like the label was printed at least 40 years ago, maybe longer. I just grinned and told her if I live long enough to finish off the 1 lb can of flux I already have, I'll start on that one.

Back to Silver00V6's exhaust... Would those bronze rods be better on the "aluminized steel" than brass for brazing?

 

Are really sure what you have been using is brass? Seems almost everyone refers to the bronze rod as brass, the bronze rods are the commonly used brazing rods sold everywhere from welding suppliers to auto parts houses.

 

Are really sure what you have been using is brass? Seems almost everyone refers to the bronze rod as brass, the bronze rods are the commonly used brazing rods sold everywhere from welding suppliers to auto parts houses.

I've never checked the melting temperature, but they sure look and act like brass. If these pictures are reasonably accurate in color, the rods I use are brass:
bronze sax with clear lacquer
brass sax with clear lacquer

Do you know of a way I can test to know for sure? Just curious -- nothing I've brazed has come apart yet.

 

Almost everyone calls brazing rods brass but just for fun I tried to find "brass brazing rods" listed at several welding supplier sites but the only thing a search of the sites will bring up is alloys for brazing brass items and not a single listing for a brass rod, not saying there are not any out there just that I did not find any listed. Bronze brazing rods however are easily found at all the sites in various alloys both bare and flux coated along with the various silver and other brazing alloys.

 

Ok im building my own exhaust. I have 2.5 inch 16 gauge aluminized steel. I borrowed my buddies welder wich is a Lincoln Weld Pack 2500hd. According to Licolns site its a Weld Pack 155. Its the non gas its using .30 Flux core wire. Well i started welding some today and was blowing holes in my exhuast. Setting was on B-2 which is what they chart said for 16 gauge mild steel. Well my question is whats a better setting for this welder to quit blowing holes or Is there a type of brazing to use for exhuast and what all is needed for brazin. Thanks for the help.

If it's a combo welder shield gas and/or flux wire (no gas) make sure the polarities are right. You have to set it up on the negative side for Flux wire. You will see instructions inside the unit on what to do. Read it... all usually on the door to access the wire spool. Also dont try and run a steady bead. Stitch it so to speak until you get the hang of it.

Good luck but don't be discouraged it's tough to get pretty welds with flux wire and alloy pipe but it can be done.

 

Also dont try and run a steady bead. Stitch it so to speak until you get the hang of it.

That was where I screwed up with my flux-core only welder on sheet metal. When I posted pictures here, several people instantly recognized that problem along with other goofs I was making and gave good coaching. To me, it's much touchier than using stick, torch or MIG but practice helps "get the hang of it".

 

Brazing Is An Art - Muffler Brazing

Hello folks. I have brazed for many years and it's all about the heat and the type of rod! I have brazed galvanized pipe together with high water pressure and it holds and will continue to hold! And I have brazed brass pressure valves together for pressure sprayers! No problem! As I have said quote "It's all about the heat and the rod"! I have found that it's nearly impossible to get the correct amount of heat without wearing the goggles that come with most brazing outfits! The fellow that mentioned the bronze rods is 100per cent correct! Most of the hardware and welding supply houses sell the bronze rods as a general rule! The trick is that you have to get the metal to a point that it is just before liquifying and then the weld will hold with never a problem! You cannot see it correctly without the goggles! It's a special cherry red color that you must look for and that comes with practice! I hope this helps you!

 

Hello folks. I have brazed for many years and it's all about the heat and the type of rod!

thank you for adding value to this 6 yr old thread on your first post

 

Just to add a bit more to what was said there I think one of the biggest failures of braze joints is failure to get the entire mating surfaces on both parts hot enough. often parts will be placed together and then heated until the rod appears to flow but in reality the brazing filler metal will just be mostly applied to the outside, if the interior surfaces of the mated parts are heated correctly the brazing filler will "wick" into the entire area. That works well for relatively small parts but larger parts may require "tinning" the area first by covering the entire surfaces with a light layer the brazing filler prior to assembly, this makes it MUCH easier to get a 100% joint.

 

I didn't read every word so if this has been covered forgive me. Lets clarify something here, "Brazing" is melting a brass rod to "glue" two pieces of metal together. I say "glue" because that is literally what it is doing, it's simply bonding them with brass which melts at a much lower temp than the metal. The metal is NOT melted together like welding. Where as welding is literally melting them together and making them one piece, brazing is not.

Brazing and welding are two completely different things, but use the same tool, a "torch", it is used for both brazing and welding with a metal rod (or no rod at all if you have a tight enough fit). It uses oxygen and acetylene gas to create a fire at the tip that is hot enough to melt the brass or metal.

You could braze with a TIG I assume, I have never used one but I assume. You can also braze with a MIG. We have one a work, a MIG (which of course it isn't a "MIG" anymore but that is a whole different thread) converted to braze. It's pretty cool, we use it on cars that had stock joints that were brazed as some late model cars still use it here and there.

Here is a little video on the subject. I am not saying everything is correct, I haven't watched the whole video but just to get an idea of what the differences are.

And yes, mufflers were gas welded on for years. In fact I had a shop next to a muffler shop and saw it every day for years. I am gas welding again a little and dig the trip back in time. And yes it was done years ago with coat hanger, I welded a lot of stuff using coat hanger.

Brian

 

I didn't read every word so if this has been covered forgive me. Lets clarify something here, "Brazing" is melting a brass rod to "glue" two pieces of metal together. I say "glue" because that is literally what it is doing, it's simply bonding them with brass which melts at a much lower temp than the metal. The metal is NOT melted together like welding. Where as welding is literally melting them together and making them one piece, brazing is not.

Brazing and welding are two completely different things, but use the same tool, a "torch", it is used for both brazing and welding with a metal rod (or no rod at all if you have a tight enough fit). It uses oxygen and acetylene gas to create a fire at the tip that is hot enough to melt the brass or metal.

You could braze with a TIG I assume, I have never used one but I assume. You can also braze with a MIG. We have one a work, a MIG (which of course it isn't a "MIG" anymore but that is a whole different thread) converted to braze. It's pretty cool, we use it on cars that had stock joints that were brazed as some late model cars still use it here and there.

Here is a little video on the subject. I am not saying everything is correct, I haven't watched the whole video but just to get an idea of what the differences are.

Braze vs. Weld - YouTube

And yes, mufflers were gas welded on for years. In fact I had a shop next to a muffler shop and saw it every day for years. I am gas welding again a little and dig the trip back in time. And yes it was done years ago with coat hanger, I welded a lot of stuff using coat hanger.

Brian

I agree with the much bigger things , but when I first started brazing I had a high failure rate because I did not understand that what I was needing to do is weld it together instead of gluing it together as you mentioned, and I did it like soldering something together! Just because the heat may be high enough to melt the rod doesn't mean that it's to be applied at that said time!

Latter on I realized that the rod must be melted into the metal just like you would with an electrical welder! Heat is heat regardless of the source. I'm not tooting my horn, but I have brazed 1 and a half inch galvanized pipe together that never came apart under pressure simply by melting/welding it together with a brazing outfit and brazing rod!

I have ran into people who would send people away from them, telling them that their item could not be brazed and the people have come to me and asked what I thought. I told them I'd give it a shot and to this day the brazing has held! Soldering is gluing together and true brazing is welding! The right heat needs to be applied and the rod melted into the metal and not over the metal! I do not even place my rod near the project until the metal is starting to puddle and it turns a certain color of red that's only detectable by wearing the brazing goggles and with practice.

But everyone prefers or has their own technique that works best for them! And yes some types of welding equipment work better than other methods depending on what the job is! I will say though that there is not many things that I braze together that I do not feel 100 per cent safe and secure about the weld holding! And a muffler to me is actually pretty simple to brazed and trust if the right technique is used.

Thanks!

 

LOLOL, damn we get hooked by this every time! LOL It's so weird, when I go to a new forum I scan the recent postings and join them. I have never thought about doing a search on a subject then posting to an old thread, it makes no sense to me.

Brian

 

alloy rod

A friend got out of the welding profession and gave me several pounds of various alloy brazing rods. they are different colors. and they all react differently. Another guy I worked with Did the shut down of the Old Mustang plant in SJ calif. He gave me a couple containers of Ford spec brazing rod. They were flux coated and have very good flow out at a lower temp than most rod I have bought. The rod was used in the early mustang production on the quarter to lock pillar and on the rear of the quarter under the tailight. Assembly line welding had to be fast and no buggers. They were gas welded with oxy-fuel mix not straight oxy-acety, and the welders used a long flame with their torch.

 

Flux core isn't great but you can certainly weld 16 gauge exhaust pipe with it. Hold your electrode at about a 45 to the surface you're welding. Get close with the electrode too. Make sure your work is really clean and you have a good ground. You may find you need more speed if you're popping and blowing through. Don't just shoot it into one point, work the electrode around in a small circle and get a pool going. When you've got the pool you can lap or butt a joint. Knock the slag off right after you cool it. Brush it up and lay another lap down if you have any holes or weak points.

You can use what you have, that's what the flux core stuff was made for. Light duty field repairs. Unlike O/A you can get in some tight spots with it too. Its all about getting a pool rolling.

K