Welding Tips and Tricks

I work for a HVAC manufacturing plant and we make heating and cooling coils. If anyone is familiar with that area of the industry you'll know there is a little bit of everything going on all at once. We're not a huge company so the bosses count on a few of us to do everything. I've brazed brass distributors the size of a gorrilas fist with 34 leads coming out 3/16" dia. 44" long and make that sucker shine by 6:27 am, pull out a die on a fin press to retrue the arc or replace a broken punch and have it back in by lunch, MIG weld some square tubing into rolling tables and whatever else is needed by 4:30, and then TIG some drain pans made of either stainless or galvanized 18-12 gauge sheet metal. All the while answering questions as I walk past people en route to the bathroom. Time is a major factor with us and for some unknown reason the when has replaced the how when people try and make a product. I try and read forums and ask other trades people and ask salesmen and just straight up try stuff to see what happens. We had an order for 18 large fan units that have galvanized housings and drain pans, and three phase fans that I terminate and then run in a panel in the junction box. I have to weld the corners of all the pans and put a length of Schedule 40 black pipe I thread NPT. The sizes often vary but what kills me and really busts my balls is when I get my tungstens all nice and sharp, set my aluminum blocks behind in the corner, wire brush the area real nice with a brush I only use for whatever material, I have like seven designated brushes, and when I roll my pedal the zinc leaps from the steel and into my cup and on my electrode making it look like a melted candle. I have found that the nicer, cleaner set up I get the more consistently nice it goes. For 18g I was running at 60v through 2% thoriated (red band) and gave the control to my foot. Also turned my post flow to 9 seconds and gas readout was up to about 20 pfa. I found that welding for a couple seconds and then stopping while keeping my torch in position really helped. And after I hammer everything square and tight and have my blocks and clamps in place I can just fuse and use my left hand as a gas trap and that works better still. Always in tight with a back angle blowing gas forward, sometimes have to rotate and whip it and add filler it I pop a void, and sometimes will keep my arc usable out of some sideways lump until I can't keep a puddle. I braze, I weld, I do electrical, I fix machines. A millwright on speed. Never enough hours in the day and I was trained to be a machinist first. There has to be a smarter, better way to get solid welds with out all the hassle. I expect to resharpen more so I set out a few prior to striking an arc but sometimes it gets crazy. I'm not a ticketed TIG Weldor but can read and learn.

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Hey,

Sounds like you have alot on your plate, and hopefully the pay you well for it.

As for tigging gal, as far as i know, you will not be able to find an easy way of doing it. Tig is so sensitive to contaminants, that you are going to struggle getting a weld down, its not your fault, just the fact that the zinc melts, then burns at a far lower temp than the steel. End of story.

The easiest and most common way of doing it is standard steel mig. If the steel is gal sheet folded into a tray, you can just weld it as the coating will be thin. If it is hot dipped AFTER it was folded, the coating will likely be very thick and may need to be ground off a bit.

Other way to do it is with a 6012/13 stick rod, and should provide an acceptable bead.

Silicon bronze can be used in a mig, but that not practical for small jobs. ( although sil bro tig rod may work for you)

Hope this helps, Mick

Welcome to the forum Observe and Adapt.

Thanks a lot. The material is pre-galvanized sheet metal, comes on flats , have all sorts of sheet metal in various gauges and types from .125 copper to punch end caps for headers, Aluminum for some large fan housings, Stainless and galvanized is mostly used. We have an old beater Lincoln MIG welder but getting the bossman to get other wire or proper tooling is like dealing with insurance companies. Nearly everything I have in the way of tools I bought because they use home tools for production and wonder why they produce garbage work. I have a little arc welder on my cart but not familiar with running a stick through my TIG setup nor am I sure about the type of wire or settings for MIG. I'll get my own wire or stinger if I need, but not sure what would be best. The TIG works alright, I have gotten decent but seems like an over kill to put all that technology into fusing the corners of 18g. Thanks a lot for your suggestions, I always have lots of questions because almost anything I do somebody has already done and made it through. I'll get a few rods and try with my welder on some samples and get some silicon bronze wire and see how I fare.

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No worries mate. Seems like they want it all for nothing.

Mick

Haha, you got it. A Mickey Mouse shop that wants you take take a pile of dog crap and make it a Mona Lisa. Well sometimes no matter how much polish it, it's still just dog crap. And do it for nothing and we bank overtime. It's more me wanting to do things right and make what I produce the shinest crap crap I can, with a chamfered edge and a little Dias for it to melt on.

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I can't ask anybody any questions because most of the time they don't know so a lot of it is reading manuals, watching videos, and reading forums. I try and take pride in my work and as much as I try and explain to others I seem to be alone there in my thinking.

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Observe and Adapt wrote:I can't ask anybody any questions because most of the time they don't know so a lot of it is reading manuals, watching videos, and reading forums. I try and take pride in my work and as much as I try and explain to others I seem to be alone there in my thinking.

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Here, you're not alone. We don't have members who don't put pride in their efforts. I've said it before, I'll say it again;

We like to call ourselves craftsmen, so we tend to be our own worst critics.

Steve S

Galvanized is easy to solder and if you take a strong solder the connection will be very strong and air\water tight. If there is no ROHS limitation - use regular plumbers led based solder. If there are use led-free one. Plumber's flux works very well. And solder will not rust... To solder the steel(and zinc) use zinc chloride as a flux (watch for the fumes).

Clearly you can not WELD pieces that are made of metals with such a huge difference in melting temperatures. When the steel core melted to the puddle zinc is already evaporated and shitted all around. The only case is if the steel core is thick and allows you to hold the puddle long enough to burn all zinc and drive it away with the slag(stick, flux core). But the weld will rust in any case.

I am not saying... I am just saying.

OK, I'll ask the dumb question, having never tried this...

Why can't the zinc be removed from the weld area during prep, then re-applied to the entire joint after welding? I recall reading about spray-on galvanizing finish - I don't imagine it's as effective, but is it a practical option? What makes something like that a bad option?

Cheers,
Richard

That's actually something that I do after I weld on the drain pipe and finish all the edges. There is a cold galvanizing spray I coat my welds with. I found that the sheet metal is so thing, removing the zinc coating from both sides leaves me with little materi to work with and I don't want to take away from the strength of the pan, have it just fall right out.

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What I found yielded the best results was just putting a wire wheel on a diegrinder and zipping up the area, fit my pipe and put aluminum blocks behind in the corners and blocking off the hole, and a thinner block on top of the pipe to close it in and bessy clamp them together and hit with the wire brush again. I have my gas way to high so I waste a lot but it seems to keep a nice atmosphere around my tip and less pops.

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Did up another drain pain for a coil housing. Have a larger ss pan for tomorrow morning and then build the framework, mount the fans and wire it up.[attachment=-1]uploadfromtaptalk1400194257234.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194274330.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194292302.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194310234.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194328659.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194342794.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194357507.jpg[/attachment][attachment=-1]uploadfromtaptalk1400194378400.jpg[/attachment]

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Was it a success???

Nice work with the galvanized. I get to work with it once and a while, almost always mig. I hate the stuff. Like you said with tig the zinc will almost always jump right to the tungsten...so frustrating!! With mig I will have an awesome bead running and it will overheat and explode almost always landing behind my ear.
I found if you can cleaning the zinc off that works well, but it is not practical for most production work. Recently found with my mig that running a forward and back motion helps the bead not get overheated while helping burn off the zinc. Please make sure to wear a respirator.

Yes it was a success. Cold galvanized the weld and coated the inside with an asphalt spray incase there are any cracks in the bends or joints. I have a respirator and a fan blowing the fumes away, but thanks for the concern. Making up one out of stainless now, will have pics for criticism, so feel free to input.

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