brazing mufflers question

[o8f150]

i am wanting to get a welding setup to weld my own mufflers,,, i hate paying someone to weld them or use dhibbs75 welder all the time,,, what i was told from an elderly guy that welds said that brazing them will not hold up becasue of the heat,,, i have done a lot of welding in my days even brazing,, ii can get everything to braze for next to nothing around here,,, or should i buy a low amp wire feed welder to do my mufflers,, i wanting your alls feedback on this

 

[thomasjf]

Braze away

his problem may have been from the rod he used or other problems with design.
Wire feed on tin gets pretty touchy, and can be a bit sloppy.
I've know guys that torched most everything with great results. More depends on the choice of filler than heat source.
If I was to change methods, I'd go Tig.

 

[hanniedog]

Local saw shop brazed the muffler on a 242xp I picked up. So far so good but time will tell if it holds or not.

 

[nmurph]

I braze my mufflers when I split them to remove the CAT. I can also use the MIG set to low and slow, and just over-lap the spots. To braze i use a jeweler's torch that makes it easy to get a very tiny area very hot. I have actually used flux cored MIG wire to torch weld, but I found that the fluxed brazing rods work very well. The only problem with doing it with fluxed rod is that I have to chip the flux off if I want to paint the muffler.

 

[redheadwoodshed]

I've been brazeing and welding for 20+ years and I have never had a braze come apart because of heat, unless I put a torch to it.I like them flux coated rods, on a muffler the smaller rods work better(3/32").

 

[o8f150]

your alls thinking is what i had in mind too,, i have brazed a lot in the past and never had a problem,,,,i never thought the muffler would get hot enough to melt it,, dang muffler would have to be glowing red to do that, by then the piston would have had a melt down

 

[Axlerod74]

Though I have never used braze on a muffler, I have used it on lots of other stuff. It should hold up very well. If it gets hot enough to melt the braze it is cherry red............I mean hot and though I have seen mufflers get hot, never that hot. You will melt your saw if your meffler gets that hot. I agree with nmurph, the flux rods flow well but the flux leaves a hard resin behind that you have to chip off to paint. I have found that most times a wire wheel on a bench grinder does a good job of removing it without the blows from a chipping hammer.

 

[Rustynutz]

Don't listen to old farts telling you not to braze exhausts "there idiots"
brazing is by far the best way.
TIG is to expensive and with any electric weld there's an undercut each side of the weld, and that's where its gona crack. not to mention making the weld area brittle!

over the years i have tried to disassemble brazed parts and its not that easy even with a hot torch

 

[CJ1]

Don't listen to old farts telling you not to braze exhausts "there idiots"
brazing is by far the best way.
TIG is to expensive and with any electric weld there's an undercut each side of the weld, and that's where its gona crack. not to mention making the weld area brittle!

over the years i have tried to disassemble brazed parts and its not that easy even with a hot torch

The only way you get undercut is if the weld was not done right, in any welding process. Braze will hold fine on a 2 stroke chainsaw muffler. CJ

 

[Rustynutz]

The only way you get undercut is if the weld was not done right, in any welding process. Braze will hold fine on a 2 stroke chainsaw muffler. CJ

agree but where talking shop welding here not some specialist with 20 years welding thin wall, most modern mufflers are press formed with a wall thickness of no more than 0.5, welding this thickness would be like dolphins "every one's got a blow-hole"

 

[Somesawguy]

agree but where talking shop welding here not some specialist with 20 years welding thin wall, most modern mufflers are press formed with a wall thickness of no more than 0.5, welding this thickness would be like dolphins "every one's got a blow-hole"

I wouldn't even attempt to MIG a saw muffler. Like you say, they are way too thin.

Brazing or TIG is probably the only reasonable way to go.

 

[Simonizer]

3/32" flux-coated bronze brazing rod has worked great on the last 2000+ mufflers I have done. Use a #0 tip, set regs at 5psi acetylene, 5psi oxygen. If you buy rod in 3 ft lengths, take your flame and cut them in half, easier to work with. When you get down to short pieces, butt them up and braze them together so you never waste rod.

 

[nmurph]

I wouldn't even attempt to MIG a saw muffler. Like you say, they are way too thin.

Brazing or TIG is probably the only reasonable way to go.

They can be MIG'ed, but you need to go low and slow. Don't try to run a continuous bead. Over-lapping the beads keeps the metal from getting too hot. I just braze bc it is faster and holds well.

 

[rms61moparman]

The only problem with brazing is getting your surface CLEAN to start!
Many times a used muffler will be "cigarette paper" thin by the time you get it clean enough to do a good job.
I work in a factory that makes automotive exhaust systems and as a boss I had said to me once..."It's kinda like welding a snowflake to a piece of cellophane!"LOL


Mike

 

[buzz sawyer]

The only problem with brazing is getting your surface CLEAN to start!
Many times a used muffler will be "cigarette paper" thin by the time you get it clean enough to do a good job.
I work in a factory that makes automotive exhaust systems and as a boss I had said to me once..."It's kinda like welding a snowflake to a piece of cellophane!"LOL


Mike

When I get thin ones, I try to lay down a perimeter of brass and then make a sheet metal patch to cover the thin area, then braze it in place. Doing that now on a 2MG.

 

[Bob Wright]

Braze will be fine. Get yourself one of those little 110v migs that uses gas and some .023 mig wire...Bob

 

[parrisw]

I've done it everyway, they all work fine, if done properly. Get the best welder you can afford.

This is what I use now.

 

[Bob Wright]

My best is Blue...Bob

 

[parrisw]

My best is Blue...Bob

Nice. Miller makes some nice stuff. I really like their line of Tig welders now.