Welding mufflers

[Jasonrkba]

Im teaching myself how to weld. I have a harbor freight mig welder chepo. I am trying to weld a small piece of pipe to a cover I made for a 10-10. The welder has two heat settings min and max. I had the heat on max and the wire at 3.5. I just dont seem to be getting enough penetration. I know my weld looks bad as I said learning. Any ideas what Im doing wrong?

 

[ammoaddict]

Looks like some of my welding. I probably have the same welder in the Northern tool brand. I didn't have any luck with the spool of wire that came with the welder. I bought some name brand wire and it did a lot better. It still looked like crap but it held.

Sent from my moto g(7) power using Tapatalk

 

[Pioneer]

The cheap flux core wire welders penetrate best at the highest heat setting together with the fastest wire speed. Assuming you don't keep blowing the breaker at this setting.
And yes, I also found aftermarket wire spools are better quality, much less spatter for one thing.
For light gauge metal like mufflers, I actually prefer brazing, more control and nicer finish.

 

[heimannm]

Nice cover, it will be nice to see a photo of it installed on your saw.

What diameter wire? For lighter gauge material .025 or .030 is better.

You say mig, but I suspect yours used flux core wire rather than shielding gas. The flux creates a cloud around the weld to prevent air (oxygen) from interacting with the molten metal. The base metal must be very clean, and you have to clean very thoroughly after welding to get rid of any residual flux before you try to weld any further. Stick welding can burn through a lot of paint, dirt, debris, etc. but with wire the weld area must be very clean in order for the process to work.

Mig refers to Metal Inert Gas with a gas shield that leaves almost no residue on the weld surface, and welder are sometimes very sensitive if we use the improper terms to describe the process/equipment. From Google: Metal Inert Gas (MIG) welding is an arc welding process that uses a continuous solid wire electrode heated and fed into the weld pool from a welding gun. ... The gun feeds a shielding gas alongside the electrode helping protect the weld pool from airborne contaminants.

Mark

 

[Jasonrkba]

You are correct mark. Flux core. Im using .030 And hobart wire.

 

[U&A]

Lincoln or Hobart wire (or rod) only for me.



Wow.

Ill leave that joke open for ya


Sent while firmly grasping my Redline lubed Ram [emoji231]

 

[Jasonrkba]

It may not have been clean enough. Iv made a couple of these just to learn with. I have a couple ideas for different designs once i get the welding part down.

 

[Ted Jenkins]

A muffler is not an easy learned project but keep on it. I took a weld class before turning a teenager and have thousands of projects behind me. I do pretty well with all my units but after sixty years can not say my success was over night. I would use higher heat setting and direct the torch always towards the largest mass of metal. The exact opposite of letting the torch near any of the thinner metal. The thinner the metal the more likely to burn through it. You could spend some time grinding back the weld and redo it or let it go. It appears that it will hold. Thanks

 

[pioneerguy600]

Higher heat setting and keep the tip as close to the metal being welded as possible for penetration. I prefer 25ga Lincoln wire but its more what one gets used to using. Clean metal, no contamination or rust is best.

 

[Jasonrkba]

I used the max heat setting but i could have been cleaner. I have family coming in for Thanksgiving tomorrow so it may be a few days before I can get back to it.

 

[thenne1713]

Im teaching myself how to weld. I have a harbor freight mig welder chepo. I am trying to weld a small piece of pipe to a cover I made for a 10-10. The welder has two heat settings min and max. I had the heat on max and the wire at 3.5. I just dont seem to be getting enough penetration. I know my weld looks bad as I said learning. Any ideas what Im doing wrong?

Youtube has GREAT videos instrucs on welding thin metals w/ wirefeed; basic = overlapping spotweld puddles, the slight pause between allows enough cooling to prevent blowout/ warp of thin metals.

 

[torch]

The base metal must be very clean, and you have to clean very thoroughly after welding to get rid of any residual flux before you try to weld any further. Stick welding can burn through a lot of paint, dirt, debris, etc. but with wire the weld area must be very clean in order for the process to work.

X2. That includes the wire itself and the ground clamp location.

I will add that you should avoid the use of magnetic clamps and jigs as well. Use them just long enough to tack things in place and keep the tacks as far from the magnets as possible. On thin material such as a muffler, consider backing the joint with a layer of either sacrificial steel or a piece of copper to help prevent burn-through. Use a series of short welds rather than try for one long weld for both distortion control and to reduce burn-through.

As already noted, flux core wire tends to spatter as the boiling flux tries to get from inside the wire to outside the weld, so don't expect things to be as neat as gas-shielded wire. But the other difference is the polarity. If your machine is convertible, make sure the electrode is set to negative when using flux core wire. Electrode positive is used for gas shielding only.

 

[J D]

Helps to have the steel thickness as close to the same as you can get too

 

[frank_]

flux cored wire sucks, anti spatter spray helps tho

 

[Jasonrkba]

Here is the unit I have.

https://www.harborfreight.com/flux-125-welder-63582.html

 

[Ronie]

Try increasing the wire speed to get more penetration. I'm not the best welder but the way I do it if the metal is thick enough to keep it from burning through is to start a puddle, then I move it along moving the torch tip like I'm writing an e. If the metal is thin, then I'll do spot welds

 

[Canyon Angler]

I do a lot of welding (mainly stick and tig) but I've found it easiest to braze mufflers, using brazing rod and oxy-acetylene. I know that doesn't help you with your mig rig, but it might be an excuse to get a O/A rig. They're handy as hell for heating, brazing, cutting, etc...you'll get plenty of use out of it!

I don't have a lot of hood time on mig, but in general, if you're welding pieces with different thicknesses, you want to start your puddle on the thicker piece, then "wash" it over to the thinner piece. And if doing a lap joint, start your puddle on the lower piece, then wash it over to the top piece. (If you start on the top piece in a lap weld, you'll just melt back the edge without fusing it to the lower piece.) HTH...

 

[Old2stroke]

Damn. After reading these posts, I miss the TIG welder I had in the lab before I retired. Best welder for doing sit down work that requires better control of arc energy and is ideal for thin metal welding and actually looks good when you are finished.

 

[Jasent]

One thing I’ve learned with flux core is the flux needs to pre heat. Run a longer tail (head farther from the work) so the flux gets heated before it’s needed to protect the weld. About 1.5-2” seems about perfect. I used to have that same welder. I bought the other brand from harbor freight (green unit) can’t remember the name. It’s dc and welds so much better!!! With the new setup I can weld muffler on the lowest heat and about 1/3 max speed and not have any blow through. Get good Penetration. And much less splatter

I just got tired of trying to get the Chicago to work for me

this is the one I went with. Night and day difference!

https://www.harborfreight.com/easy-flux-125-amp-welder-56355.html

 

[esshup]

Push with the gun rather than pull with the gun when welding.

Or get away from flux/wire and go TIG for the thin stuff.