Tig or Mig patch panels? Pro & cons ?

[mikhett]

I plan on doing some rust Repair on my 56 Ford Victoria and I have a mig welder but no Tig.Is it worth it to learn Tig for auto panel patch panels or should I stick with mig? thanks

 

[txvwnut]

Re: Tig or might patch panels? Pro & cons ?

If you got the mig use it. If you just want to spend the coin on a tig unit and learn how to use it then go that route.

 

[willymakeit]

Re: Tig or might patch panels? Pro & cons ?

Mug for me. I used a wire called easy grind. It’s a little softer .

 

[Kaizen]

Re: Tig or might patch panels? Pro & cons ?

Used mig with .023 wire for **** welds and .030 for plug welds/spot welds. Gotta take your time. Keep it cool.


Sent from my iPhone using Tapatalk

 

[cgrutt]

Re: Tig or might patch panels? Pro & cons ?

I welded in a patch panel on my F150 a couple years ago with a 120v MIG and the Easy Grind wire still holding up... wasn't bad for my first welding project. Just take it slow. I spaced together a bunch of tack welds until it formed a continuous weld. I'd love to learn how to TIG weld but not in the cards at the moment...

 

[Ohmthis]

Re: Tig or might patch panels? Pro & cons ?

OP, do a search on here for welding body panels. Robert (MP&C) shows how to weld in panels with a mig. He is an excellent teacher and his work clearly shows he knows what he is talking about. His thread is really full of good info too. Hope this helps. Here I did the leg work for you.
https://www.garagejournal.com/forum/showthread.php?t=53534

 

[sqznby]

Re: Tig or might patch panels? Pro & cons ?

Stick with Mig, because you have it already.

 

[59 wagon man]

Re: Tig or might patch panels? Pro & cons ?

todays 2 part epoxys maybe just what you need. if your replacing a panel it offers strength, no warping from heat and a few other benefits

 

[joe_padavano]

Re: Tig or might patch panels? Pro & cons ?

The answer really depends on the quality of work you want. If this is patch panels for a farm truck with lap joints, MIG. If this is a 1000 point restoration with extensive metal finishing, TIG.

 

[Partsguy57]

Re: Tig or might patch panels? Pro & cons ?

Mig... if you have no experience with a tig without a ton of practice you will only make a mess......

Sent from my SM-G965U using Tapatalk

 

[Retlaw 66]

Re: Tig or might patch panels? Pro & cons ?

I've used a mig for 30 years but just bought my first tig this year. I prefer the tig for much of the sheetmetal work I do. You have far more control, and can add a minimal amount of filler rod which produces a weld bead which requires less grinding to finish. A huge benefit of tig (for me) is it does not produce a shower of sparks, an advantage if you will be welding indoors.
I still use the mig for plug welds, on thicker metal where a thicker weld bead is preferred for strength, a joint where I want to add more filler, or areas that are difficult to reach with a tig torch. The tig does require much more attention to technique than mig, but I feel results can be superior.
I'm a hobbyist, I don't do this for a living.

 

[Partsguy57]

Re: Tig or might patch panels? Pro & cons ?

I've used a mig for 30 years but just bought my first tig this year. I prefer the tig for much of the sheetmetal work I do. You have far more control, and can add a minimal amount of filler rod which produces a weld bead which requires less grinding to finish. A huge benefit of tig (for me) is it does not produce a shower of sparks, an advantage if you will be welding indoors.
I still use the mig for plug welds, on thicker metal where a thicker weld bead is preferred for strength, a joint where I want to add more filler, or areas that are difficult to reach with a tig torch. The tig does require much more attention to technique than mig, but I feel results can be superior.
I'm a hobbyist, I don't do this for a living.

You are correct, but the attention to detail (as you said)is the rub( lots of practice and
some pick it up faster then others) hence making a mess with a tig without experience....

Sent from my SM-G965U using Tapatalk

 

[BD1]

Re: Tig or might patch panels? Pro & cons ?

Mig with easy grind as mentioned is best.

 

[bad_idea]

Re: Tig or might patch panels? Pro & cons ?

One more vote for MIG. So much easier and will net quality results.

 

[EdT]

Re: Tig or might patch panels? Pro & cons ?

Check out MP&C thread on this site. More info there about mig welding sheet metal than you will be able to absorb. Lots of how to shots, setting up, tests etc. If you've never done it, get a junk yard panel from someplace and try it out before you do it for real. As with all kinds of welding, it takes practice and it's better to practice on something that doesn't matter.

 

[Certified Drunk]

Re: Tig or might patch panels? Pro & cons ?

Make a spot weld with the mig welder, then spray it with compressed air to cool it off. Repeat till it's completely welded.
This will help from distorting the panel.

 

[Certified Drunk]

Re: Tig or might patch panels? Pro & cons ?

MP&C thread...
https://www.garagejournal.com/forum/showthread.php?t=182565

 

[MP&C]

Re: Tig or might patch panels? Pro & cons ?

Mike, this is something I did this weekend:

Note full penetration weld:

Dressed and media blasted:

This was done with the TIG. The weld is softer for easier planishing, which by the way was minimal required, weld splatter is non-existent, I do not need a cut off wheel to grind welds down as I do with mig, and from start to finish (cut, trim, weld, dress) is about 1/3 to 1/2 the amount of time involved as compared to MIG. TIG normally requires more attention to detail in cutting out a panel and trimming/filing to final size before welding, as adding heat without automatic fill wire (as with MIG) may cause any slight gap to burn back the edges or blow a hole, so to speak. So yes, it does require more finesse. But in the long run, it will take less time and will give better results.



When I started using TIG a couple decades ago is was a Miller Econotig, which was not very accommodating with thin sheet metal as it did not have the lower range needed. It was better suited to 1/8" and thicker. So most of my rust repair work was done using the MIG, and the process you see me using in the above linked thread has focused on using a precise, methodical process that it can be easily duplicated by anyone to achieve acceptable results. Follow the process and you are side stepping many years of trial and error.

The process in a nutshell: Understand we are welding only ONE weld dot at a time. Set welder at higher heat for full penetration weld, adjust wire feed faster if needed to overcome blowouts. Start weld dots at one end of the seam and tack about every 1-1/2", aligning the panels together as you go. While the weld dots are spaced and more accessible, planish each weld dot individually to help stretch back out the shrinking that occurs as the weld cools. Then grind each weld dot, both front and back, to just above panel height. This gets the area back as close as possible to the original thickness without getting too close to thinning the area. The panel thickness is what we based our heat settings. (leave weld dots and now you have metal up to 4X or more thicker than the sheet metal. This affects heat required and will result in colder joints, or insufficient weld penetration) Any sanding/final dressing I normally leave until the end to avoid any excessive removal of parent metal based on all the weld cleanup work required. Once you get done grinding welds, now go back to where you started and weld the next set of weld dots, overlapping the first set by about 1/3. This will help to eliminate the missed spots that occur from jumping around, as some advise you to do. This also explains why you start tacking from one side and work toward the other, if you jumped completely to the other end of the weld to "keep things cool", then you have more chance of panel mis-alignment which may result in more metal between welds on one side than the other, ie: instant pucker. So to recap, tack, align panel, space about 1-1/2", tack, repeat until the end of the seam. Go back to start and planish each weld dot individually, start to finish. Go back to start and grind each weld dot, FRONT AND BACK, start to finish. (this also gets welds out of the way for planishing the next set of weld dots). Then 1/3 overlap, and repeat each step.


I was tutoring someone on another forum recently in using the MIG and the process I've laid out in the thread linked above, stressing the planish and grind steps between each step. His pictures show many weld dots next to each other, no flat spots that would indicate planishing occurred, and yes, that would also indicate no grinding occurred. He posted pictures to find out why all the warping occurred, and why it didn't fix it when he used a shrinking disc. MIG is a pain in the *** to use but if any steps are skipped, the panel gets away from you so much quicker. If you're not used to seeing metal deforming after welding, it starts forming a wave, and people automatically think this is excess metal and they want to shrink something. SHRINKING is what caused this, it will never be fixed by more shrinking. The weld is pulling at the surrounding metal as it shrinks and the puckers form just outside the heat affected zone. The weld and HAZ must be STRETCHED to relieve the pull that the weld has on the surrounding adjacent metal.


The individual weld dots with MIG are used so we can set our welder HOT for a full penetration weld. Unfortunately this results in a weld that pulls from all directions. The easiest way to stretch it back out in all directions is while the weld is all lonesome, by itself, or while any adjacent weld dots have been ground down out of the way. As a comparison to TIG, you have better localized control of the heat with a TIG, so one can do a full pass, or as far as the length of filler rod will allow. This basically lets the weld and HAZ heat up gradually and cool down gradually as you work your way across the panel, for less shrink occurring over all the start and stop welds in using the MIG.



So my recommendation is to get proficient enough in cutting and trimming your patches for a tight joint so you will have better luck with the TIG, and use that machine. If you already have a MIG and don't see yourself buying anything else, please follow the process I've laid out to help in your success, it comes with plenty of learning curve already built in for you. Deviate from the process, you are now into trial and error.


Mike, I know we're more than a couple hours away, but if you would like to come down one Saturday when we're in the shop, You can try both methods and see for yourself..

 

[Stooge]

Re: Tig or might patch panels? Pro & cons ?

Hard to follow MP&C, but Im still a newbie with tig, and although I really like it, admittedly im still more confident and comfortable with using mig for a lot of my bigger rust repairs

Miller 211, regular er703-6 .030 wire that I use for everything, doors are around 44" wide if I remember correctly. Cleco pins aren't connected to anything underneath, (they were leftover from when I was making the new panel) and I ground those **** clamps down a bit so they are quite thin, although I could have held it with just those magnets. It does take a bit longer to dress the welds, but its not bad if you have a little system/ method.

3 by Dan Haas, on Flickr

5 by Dan Haas, on Flickr

8 by Dan Haas, on Flickr

 

[MoonRise]

Re: Tig or might patch panels? Pro & cons ?

MIG.

You have the machine already.

It will need some skill and finesse to do. If you haven't welded sheet metal before, PRACTICE first. Lots of practice. Use 0.023 solid wire and C25 gas. Pure CO2 is usually going to be too 'hot' for most folks to weld sheet metal with, same with 0.030 wire. Do NOT use FCAW. As Robert mentioned, you need to weld a series of completely fused individual weld 'dots', NOT a continuous weld bead. Make a weld 'dot', move to a different place on the joint, make another weld 'dot', let the sheet cool, make a few more 'dots', grind and planish as needed, repeat until the joint is complete. Cooling and grinding and planishing will take longer than the actual arc welding time.

TIG can give a skilled operator good to very good results. The key word there is "skilled". If you are not already at least minimally proficient and skilled with TIG welding, never mind not already having a TIG machine, forget about it IMNSHO.

 

[Capt Chrysler]

Re: Tig or might patch panels? Pro & cons ?

todays 2 part epoxys maybe just what you need. if your replacing a panel it offers strength, no warping from heat and a few other benefits

I don't think panel bond is rated for floor pans.

Capt. Chrysler

 

[MP&C]

Re: Tig or might patch panels? Pro & cons ?

todays 2 part epoxys maybe just what you need. if your replacing a panel it offers strength, no warping from heat and a few other benefits

A lapped seam using Panel bond in the middle of a panel may also result in a ghost line in the paint, as shown in this video...

.

 

[willymakeit]

I also gas weld. As with any process watching heat and puddle is critical.
Beauty of gas is you can heat and bend or cut. Torch and tip size means a lot.