Intro into Brazing

[charlessenf]

I would like to learn to braze. I have been looking at the benzomatic kit that uses a small mapp and oxygen tank.

GOOGOL YOUTUBE for "benzomatic mapp gas brazing"

I hit on a couple of good ones. Of course you can always go bigger - if you're into a lot of it, the price of those non-refillable tiny tanks will justify a set of PONY TANKS and torches ($295-$420 New Home Depot today). I could NOT find the Mapp/Oxy combo at Lowes or HD to day!

Look at the videos, see how it is done (regardless the torch/setup employed). That at your expectations/intended projects should help you decide if the MAPP GASS approach would be worth the learning curve

 

[WranglerX]

Umm...Can we get back on track, first off TIG is only going to solve problems for a few welders with equipment and skill..... MIG is probably best for intermediate welding for most small farm and hobby farm applications.... Brazing is entry level for small repair usually for people with Oxy/Acet rigs.... I personally only have Hobart Handler 140 for welding and it does really well for most all my needs, my Oxy/Acet rig has been relegated to mostly heating and "some" cutting.... Tried TIG, its to demanding for old eyes and not to steady hands.... As pro welder at demo stated, I was pretty good at balling up tungsten tip....

 

[bgr]

Your local voc/tec evening class is the best way to learn. They would also know how to get and fill welding cylinders.

For soldering, silver soldering, and brazing a clean, rust free surface and the right flux for the material is all important. A company called Eutectic makes really good flux.

They used to make a kit for silver soldering with a few rods and flux. If you have a local welding supply shop, they would have it. Not expensive. They could also tell you if you could use Mapp gas for it.

 

[etpm]

I am currently running .030 flux in my welder but I do have gas hook up capabilities. Will gas MIG work better on thinner material than flux?

I dunno which machine you have but with my Lincoln SP125+ and SP100 machines I can weld sheet metal easily. Normally when you switch from flux core to MIG you also need to switch polarity. But Lincoln says for sheet metal the polarity should be the same as for flux core welding. Of course the voltage and wire speed must also be reduced quite a ways. And you need to use .023 wire. With my old Lincoln machines this is easy since they have infinite wire speed and voltage controls. I don't know if your machine has this flexibility.
Eric

 

[Lavender Valley]

IF you are half way serious about oxy/acet brazing you really need serious torch set.... THE the big box store sets with 16 oz oxy and mapp gas are just enough to make you really frustrated..... Personally I would not go smaller than the style shown of graphic below..... To learn to braze, there is a dozen or more videos on u-tube to show you how.... The problem with smaller sets is finding a gas supplier that will work with you handling such small cylinders.....

I totally agree, once you have the bottles and torch your world will open before your eyes, brazing, light steel welding, welding copper with silfos, heating and bending, cutting and more. Here in New Zealand Bunnings hires the bottles, one lifetime cost and when my blood stops pumping my Kids take the bottles back and they get that payment back. the bottles are alot bigger than pictured above.

 

[eddieirvine]

you mentioned having a hard time brazing a hole one thing a lot do wrong is just heat the hole, you have to generate a lot of heat around a hole and test your brazing rod for even flow when that starts around your hole keep everything hot and push the rod in the hole it will fill nicely I was a maintenance machinist for 35 years we use to repair all kinds of things wore out shafts were one thing we did a lot of or wore out bores for a bearing, we would undercut the shafts and build them back up, same on outer bores for outer race of bearing worked very well with brazing rod and silver solder repaired a ton of equipment saved them a ton of down time and money

 

[rScotty]

Your local voc/tec evening class is the best way to learn. They would also know how to get and fill welding cylinders.

For soldering, silver soldering, and brazing a clean, rust free surface and the right flux for the material is all important. A company called Eutectic makes really good flux.

They used to make a kit for silver soldering with a few rods and flux. If you have a local welding supply shop, they would have it. Not expensive. They could also tell you if you could use Mapp gas for it.

For all types of soldering, brazing, or welding, I enjoy the oxy/acetylene torch the most. It is so versatile and relaxing. It can add or subtract metal, join weird alloys together, heat treat, and stress relieve. What a marvelous tool.
rScotty

 

[eddieirvine]

you mentioned having a hard time brazing a hole one thing a lot do wrong is just heat the hole, you have to generate a lot of heat around a hole and test your brazing rod for even flow when that starts around your hole keep everything hot and push the rod in the hole it will fill nicely I was a maintenance machinist for 35 years we use to repair all kinds of things wore out shafts were one thing we did a lot of or wore out bores for a bearing, we would undercut the shafts and build them back up, same on outer bores for outer race of bearing worked very well with brazing rod and silver solder repaired a ton of equipment saved them a ton of down time and money

This was before wire welding came out also and this could be done nicely with a wire welder also

 

[AnotherBueller]

I do eventually want to get my hands on a torch set. Just hasn't been a big enough push to need it. Since I already have a MAPP torch and all I would need it flux and rod, I may just play around with it before investing any more. If this set up is enough to do a chainsaw exhaust, it may really be all I ever need.

Look for a victor style torch set on marketplace or craigslist or at your local pawn shop. I bought a used 'Victor Journeyman' torch kit for ~$100 3 or 4 years ago from ebay. Had everything I needed but the bottles.

 

[charlessenf]

Would that kit be enough to braze something like a chainsaw muffler?

How about a picture of what you're talking about? Is it mounted on the saw - or can you remove it to do the work? Brazing thin to thick (or vise versa) can be a bit difficult. Since you need to heat the material red hot +/- the thicker the material the more MAPP gas required and the kit tanks only hold 14oz - since you can't change out a tank before the metal cools . . .

 

[AnotherBueller]

How about a picture of what you're talking about? Is it mounted on the saw - or can you remove it to do the work? Brazing thin to thick (or vise versa) can be a bit difficult. Since you need to heat the material red hot +/- the thicker the material the more MAPP gas required and the kit tanks only hold 14oz - since you can't change out a tank before the metal cools . . .

That kit will do anything yo will probably ever want to do.
For your muffler a very small torch a 000 or 00 tip would work. I don't know if you would need to up to a 0 tip. You will need to practice on some thin stuff first. unless you take a class at a tech school or Jr collage.
I learned as part of my air craft mechanic training and 40 years later when I wanted to start doing stuff I went to the local Jr Collage for refresher training. It was well worth it . Ok some more thoughts on the kit: I bought a 80CuFt acetylene bottle which means I can not use any gas large tips because that small a tank can't produce enough acetylene for a large tip (>3 or maybe 4 size for welding and a size 1 rose bud for heating) I kept the sizes small because I loose tract of time and acetylene production drops to a lower level after a few minuets.
I welcome any corrections from the better than me guys here.

 

[lobsta1]

I don't normally comment, however I had jump in here. About 18 years ago I took an intro to welding class at the local tech high school. Course was 2 nights a week for 8 weeks. Covered O/A stick & mig. Both flux & gas. Cost was $220. Now it is a four week class that has been split into two separate courses. The kicker is that EACH course costs $999. Two grand for an intro class is a little too steep for me.
A few years ago I was interested in taking the course again, but was then about $650.
Al

 

[yomax4]

I think with common sense, a bit of hands on and a few U-tube vids most people can get the just of it.

 

[walhondingMF]

I can weld ok for a I guy who learned on a stick in the farm shop as a kid. I've done some learning in our schools AG shop. I just like having the option to have the freedom to do my own work. My grandpa didn't buy something until he could make it or fix it. Junk and scrape all around just waiting to be turned into something. I inherited that gene.

 

[Flogger]

I do eventually want to get my hands on a torch set. Just hasn't been a big enough push to need it. Since I already have a MAPP torch and all I would need it flux and rod, I may just play around with it before investing any more. If this set up is enough to do a chainsaw exhaust, it may really be all I ever need.

It would likely do the job for you. If you are referring to the muffler that would be a challenging first job unless you have a lot of soldering experience. It involves getting the workpiece to just the right temp and then applying the rod. The thinner the workpiece the shorter the window between just right and oops I have a big hole now!

 

[Flogger]

I didn't know this thread existed. I mainly use my Oxy-acetylene kit for cutting or heating metals with a Rosebud. Now that I have a Plasma cutter, I cut more with it. I have a gate that is made out of Aluminum, and a buddy of mine who teaches welding fixed a crack with a tig, but it didn't hold, so another buddy told me to try and braise it, so I just started looking into it. I haven't braised in over 30 years and don't remember any of it so will be watching some videos. I use a heavy-duty Victor-style torch set. Does anyone know what Braising tip size is needed for Aluminum? I have none...thx

Plate Thickness	Tip Size
1/8 inches	000
1/4 inches	00
3/8 inches	0
1/2 inches	0
3/4 inches	1
1 inch	2
2 inches	3
3 inches	4
4 inches	5

 

[Flogger]

I once employed a guy that could weld anything from eggshells to the crack of dawn!! That may be a slight exaggeration but I learned a whole lot from him. I would estimate about .06% of his knowledge. Amazing is an understatement for his abilities.

 

[jaxs]

I can weld ok for a I guy who learned on a stick in the farm shop as a kid. I've done some learning in our schools AG shop. I just like having the option to have the freedom to do my own work. My grandpa didn't buy something until he could make it or fix it. Junk and scrape all around just waiting to be turned into something. I inherited that gene.

You and I might be related because that describes me and my grandpa to a tee.
Bad news first, all the kings horses and men can not successfully braze the chainsaw muffler. The tiniest bit oxidation/rust makes it imposable to braze and I assure you the muffler has pits that will not grind out before grinding through material.

The good news is you map/air torch works great on propane. Real mapp is no longer available and even if it was it's far more expensive and not much hotter than propane. You can buy a hose that will connect your Bernzomatic torch to a grill bottle and one grill bottle would last you 20 years. Buy a can of flux (half pint size will last nearly long as the grill bottle plus you will use the flux for something in addition to what i'm about to suggest. 20 Mule Team Borax is also a good flux. There are dozens of heat ranges in Bernzomatic torches and unfortunatly it's difficult to know heat capabilities unless bought new in package. Strip out 14 ga and multistrand copper wires to find what size your torch can melt. Geather pieces of scrap steel for pratice and determine what size piece your torch can handle.

Ok lets get started. Begin with thin wire and a piece of steel the size of a knife blade. Briefly hold wire in outer flame then quickly dip into flux. Secondary flame of propane is hottest part (acty is inner flame). Hold flame near end of material until color changes then begin touching fluxed wire to material until flux melts and spreads followed by wire melting. Move along material while intremittenly adding wire (don't forget to dip wire in flux as needed). This costs next to nothing so pratice and experiment to your heart's content.

 

[charlessenf]

14.1 oz. Handheld Map-Pro Gas Cylinder - The Home Depot​

$14.97

• Ideal for a variety of tasks that need higher heat than propane
• In-air flame temperature of 3,730 degrees Fahrenheit
• Compatible with a wide range of hand torches

 

[California]

Ignorant novice question: My ancient 230a-AC stick welder came with a carbon arc torch. Is this usable for brazing, or for heating/bending steel? I've never used it for anything.