6013 on Aluminized Steel

[Wes C]

Howdy, first post here. I have been using the Miller Site and forum as a resource for quite a while. I'm new here but I'm definitely glad to be here! Obligatory words out of the way...

I am building a custom exhaust for my project car and I'm planning to do it mostly with stick. I picked up a used Thunderbolt XL earlier this year and I've been practicing quite a bit on scrap tubing but I'm still very much a beginner. I'll just say I built a similar exhaust a year ago and did the whole thing with oxy-acetylene and got decent results but I'm trying to learn stick a little better and not use quite as much heat as the torch!

Vitals on my project: 16 ga. and 14 ga. aluminized steel tubing (2.25"), 1/16" 6013 (Lincoln FW 37) @ 30-40 Amps; 409SS mufflers and cat, plan to use 309L

I've spent hours searching and reading everyone's opinions on 6013 and aluminized steel, and they run the gamut. Some hate 6013 and some use it almost exclusively with good results. Some weld aluminized as-is while others grind the coating off at the joint.

Nevertheless, I'm looking for a little more guidance or opinions, anyways, on how best to do these welds. All the aluminized-to-aluminized are butt welds and the aluminized to 409 are all laps.

I have been doing all my practice welds without grinding the aluminum off and running the electrodes downhand @ about 33 amps DCEN on my better welds with slight to no weave. I chose 1/16" 6013 because everything I've read said it's the choice for sheet metal due to low penetration. I feel like I've got it pretty much dialed-in and I'm getting pretty good beads (for me) and good penetration and I'm not blowing through the pipe... as long as I have perfect fit up.

Main concerns are: My slag isn't coming off real nice - is that normal for this situation or is it due to the aluminized (oxides contaminating the weld)? Is there a better 1/16" electrode to be using on this pipe? And last but not least, of course, would you expect significantly better results with the aluminum removed around the joint?

Thanks for listening!
-wes

[walker]

I'd prefer MIG for that, but since you don't have it, and you seem to be comfortable with stick, just go for it. The aluminum coating is so thin it won't make a bit of difference to your weld. For the slag to come off easier you need to run it hotter. I'd keep it where you are successful at it and just use a wire wheel to clean the welds off.

[Sberry]

You might actually find it easier with larger electrode, that is so tiny I would need binoculars to see it at arms length. Bigger wire fills across gaps easier.

[Wes C]

I'd prefer MIG for that, but since you don't have it, and you seem to be comfortable with stick, just go for it. The aluminum coating is so thin it won't make a bit of difference to your weld. For the slag to come off easier you need to run it hotter. I'd keep it where you are successful at it and just use a wire wheel to clean the welds off.

I used a wire brush - by hand - after chipping the slag and gave me a pretty good look at what I came out with, pretty clean really. So, yeah, I'll stick with it for now. (seriously, that pun was unintentional)
I figured running it hotter would help with the slag, but I'm finding I can't run it much hotter or I start to go through, but as you said, no big deal.

You might actually find it easier with larger electrode, that is so tiny I would need binoculars to see it at arms length. Bigger wire fills across gaps easier.

I also have tried with 1/8" 6011 which was sort of a disaster. It welded, but it was not pretty and I was burning through till I had to turn the power down to where I couldn't start the arc.

I could try with some 3/32" - might do that. As long as I'm going electrode shopping, anything other than 6013 I should look at? I don't think the 6011 is the way to go here...

Thanks, I appreciate it guys. Recognize your names from some of what I've already read.

[kevin]

You are ok with the size electrode for that job, all position butt welds, you will be better served with 6011, with is a fast freeze electrode where as the 6013 is leaning to the fast fill group, which means, there is a small amount of iron powder in the flux, used to increase the amount of deposited metal, but with this, the fast fill rods are designed for the flat position, the 6011, being a fast freeze, will solidify very quickly making out of position welding a much easier task. Also with a fast freeze rod, the cleaning of the aluminum can be welded as is. I know some one will bark up, i can run 6013 uphill, that is not the point, this poster is just learning, he is having issues with trapped flux, which is common with fast fill rods..... Use 6011 or 6010, it looks a little rougher but will give you better results, then next time around, get a mig.

[kevin]

Forgot to mention, 6010 and 6011 use a whipping technique

[Wes C]

You are ok with the size electrode for that job, all position butt welds, you will be better served with 6011, with is a fast freeze electrode where as the 6013 is leaning to the fast fill group, which means, there is a small amount of iron powder in the flux, used to increase the amount of deposited metal, but with this, the fast fill rods are designed for the flat position, the 6011, being a fast freeze, will solidify very quickly making out of position welding a much easier task. Also with a fast freeze rod, the cleaning of the aluminum can be welded as is. I know some one will bark up, i can run 6013 uphill, that is not the point, this poster is just learning, he is having issues with trapped flux, which is common with fast fill rods..... Use 6011 or 6010, it looks a little rougher but will give you better results, then next time around, get a mig.

Right, I've noticed that the 6013 has about 10-15% iron powder... that must be what holds the extra heat making them not fast freezing. I do get quite a bit of filler (probably more than needed) when I use the 6013. I guess I've always wondered why 6010 & 6011 are fast freezing - maybe the absence if iron powder in the flux, and probably the alloy they are too. But why wouldn't 7018 be fast freeze (doesn't have extra iron?)... Anyway.

I think I can find some smaller 6010/11 rods to try out. After reading the Lincoln catalog again, I can see how they might make sense for my situation. I guess I've shied away from them because I've always been worried that the deep penetration characteristics would blow through my pipe. I'll try them with the weave (saw your other post) and see.
Thanks again.

[Sberry]

You will not be able to weave this rod here, its whip and for 14 ga and 16 we wouldn't even bother dropping from 1/8 with 6011,, maybe if I was running it all day for some special reason but those tiny rods add to the difficulty. I remember when the economy was in the tank back in the day took a sheet metal test, 20ga galv with 3/32 6011 running DCRP, I don't recall the reason they didn't even change polarity.

This winter if I get a chance am going to stick my head in the booth and run some for pics of these common joints that are routine questions on the forums. Many are trying to make up for poor technique with small electrodes and low currents, no matter how hard they try its not going to get much better.

[bills53]

Lincoln has a 5/64 6013 electrode which worked decent for my exhaust

[Wes C]

You will not be able to weave this rod here, its whip and for 14 ga and 16 we wouldn't even bother dropping from 1/8 with 6011,, maybe if I was running it all day for some special reason but those tiny rods add to the difficulty. I remember when the economy was in the tank back in the day took a sheet metal test, 20ga galv with 3/32 6011 running DCRP, I don't recall the reason they didn't even change polarity.

Yep, I meant "whip" not weave, in response to kevin. It was late.

This winter if I get a chance am going to stick my head in the booth and run some for pics of these common joints that are routine questions on the forums. Many are trying to make up for poor technique with small electrodes and low currents, no matter how hard they try its not going to get much better.

That's a good idea, the questions do come up alot. By the way, I'm not trying to make up for poor technique with the low amps and diameter - I'm just a beginner, as I stated. I think we all know that low current and smaller electrodes are easier for a beginner to manipulate. You might tell me to learn on a larger rod because I'll learn faster but, I assure you, by choosing to practice on thin gauge pipe it is plenty challenging.
Besides that, our machines go down to 20 or 30 amps for a reason, they make 1/16" electrodes for a reason. I'm just sayin'. You don't water your petunias with a fire hose, do you?

Lincoln has a 5/64 6013 electrode which worked decent for my exhaust

Cool. Yeah, that's just 1/64" bigger than the Lincoln 6013 I have been using. Is your exhaust aluminized? Were you doing mostly butt welds or lap joints?