Welding body panels

[72chevylwbmo]

Hey guys, starting to fix some rust on my sons 72. All I have at the moment for welding wire is S.S. wire with the Tri-Mix gas. Do you think this will work fine for welding in body panels?

[72chevylwbmo]

Any Ideas?

[Tinkermc]

I use Argon gas and 35 wire.

[StingRay]

Stainless wire will weld it but any time an area of material is significantly different than the surrounding area it can promote corrosion. Also for bodywork you want the softest weld you can get. I don't know if stainless will give you that. Best to buy the correct wire.

[KMC3420]

I use 75/25 argon/co2, and .023 welding wire. Has worked the best for me on body panels.

[vidman]

Agree with kmc3420. Have been using this setup with ER70 wire for years. When I weld thicker material I will change over to .035 wire..

[67 chevelle]

Originally Posted by vidman

Agree with kmc3420. Have been using this setup with ER70 wire for years. When I weld thicker material I will change over to .035 wire..

agree 23 or 25 for sheet metal going slow , 35 is for frames and thick stuff , allso last time I welded sheet metal it was perfect , then I grinded the welds , totally screwed it grinding , too much heat , take your time grinding also

[Bomp]

Originally Posted by KMC3420

I use 75/25 argon/co2, and .023 welding wire. Has worked the best for me on body panels.

I use this too.
On finer work like roof skins or door skin I switch to Lincoln Electric .025 wire.

[Fitz]

Originally Posted by 72chevylwbmo

Hey guys, starting to fix some rust on my sons 72. All I have at the moment for welding wire is S.S. wire with the Tri-Mix gas. Do you think this will work fine for welding in body panels?

No. 0.023 in mild steel wire and an Argon-Co2 mix is what you want to use.

[hugger6933]

I used to use 0.35 just because i didn't know any better. I use 0.23 and still use the 75/25 argon mix it is SOOO much better than it was. I found out the other wire one day I had a guest in the shop wanting to weld something and asked if he could change the wire and of course wanting to be a good shop host I said sure. Went and got him some small wire and then found out for myself it is the stuff for the small jobs for sure. Jim

[cableguy0]

Stainless wire is usually thick. Thick wire is no good for body work because you build too much heat just melting the wire. Also stainless wire will be a lot harder which makes grinding it more difficult as well as building more heat in the panels. .023 mild steel wire is the way to go as stated.

[FlameOut]

Wow, I'm glad I read this thread. I always have used 0.030 wire. Just today I bought another spool, even though I have a spool of 0.023 in my cabinet. I'm gonna swap to the 0.023 tomorrow and see how it works out

[cableguy0]

Originally Posted by FlameOut

Wow, I'm glad I read this thread. I always have used 0.030 wire. Just today I bought another spool, even though I have a spool of 0.023 in my cabinet. I'm gonna swap to the 0.023 tomorrow and see how it works out

Just remember to turn the heat down a notch or so. The thinner wire melts at a lower temp so you don't need as much heat to actually weld your material.

[dwcsr]

C25 (75/25) and .023 is better but .030 will work well. As for stainless with trimix, the issue is that the bead will have a much higher tensile strength and when it cools it will shirnk quicker and may pull the panel out of shape because its not cooling and shrinking at the same rate as the base metal.

[72chevylwbmo]

Awesome info, thanks guys.

[72chevylwbmo]

With all of this info that you guys have provided. Is there also a good thread on the best way of cutting and fitting the body panels? I was somewhat successful at installing one. But it wasn't as good as I was hoping for. A good tutorial would be helpful.

[KMC3420]

Here is one of my favorites and has great pictures, it will get you in the right direction for sure. MP&C is a member on here as well, but not 100% on his user name on this site.

http://www.garagejournal.com/forum/s...3534&showall=1

[MARTINSR]

Here is a "Basics of Basics" I have been told is very helpful. Print it out and put it by the john read it a few times.

http://www.hotrodders.com/forum/basi...els-44009.html

Here is one on spot weld removal when cutting away old panels.

http://www.hotrodders.com/forum/basi...ls-222549.html

Brian

[72chevylwbmo]

That is good stuff. I will hopefully get better at it with practice.

[kaycee]

I have been using 023 wire on some body braces and such was having a hard time seeing the wire (yeah age has something to do with it).I had to weld some thicker stuff recently and put in some 035 decided to try and weld some sheet metal just turned down heat and it's working great personal preference there is no wire YOU HAVE TO USE experiment and use what makes you happy

[MARTINSR]

Originally Posted by kaycee

I have been using 023 wire on some body braces and such was having a hard time seeing the wire (yeah age has something to do with it).I had to weld some thicker stuff recently and put in some 035 decided to try and weld some sheet metal just turned down heat and it's working great personal preference there is no wire YOU HAVE TO USE experiment and use what makes you happy

How about bi-focals! OMG did that change things, holy crap. I just started gas welding again just for old times sake, and it's very cool! Anyway, I really had a problem with the welding goggles and ended up getting one of these with a tinted lense for welding. Man what a difference, this old man can see the weld now!

And no, that's not me, it's some OTHER stud.



But for my MIG welding, I got one of these years ago and never looked back. I can't stand the auto dark, this thing has really worked well for me. And forget all the weird stuff about forgetting and your chin hurting using it to open and close the lense and what ever, unless you have a medical condition where you have a problem with your chin this thing works GREAT and it is second nature you don't even think about it just minutes into using it. It has a very large lense so you can really see what you are doing.


http://www.accustrike.com/



Brian

[blazer2007]

Originally Posted by MARTINSR

How about bi-focals! OMG did that change things, holy crap. I just started gas welding again just for old times sake, and it's very cool! Anyway, I really had a problem with the welding goggles and ended up getting one of these with a tinted lense for welding. Man what a difference, this old man can see the weld now!

And no, that's not me, it's some OTHER stud.



But for my MIG welding, I got one of these years ago and never looked back. I can't stand the auto dark, this thing has really worked well for me. And forget all the weird stuff about forgetting and your chin hurting using it to open and close the lense and what ever, unless you have a medical condition where you have a problem with your chin this thing works GREAT and it is second nature you don't even think about it just minutes into using it. It has a very large lense so you can really see what you are doing.


http://www.accustrike.com/



Brian

how does it get dark ?

[MP&C]

Originally Posted by KMC3420

Here is one of my favorites and has great pictures, it will get you in the right direction for sure. MP&C is a member on here as well, but not 100% on his user name on this site.

http://www.garagejournal.com/forum/s...3534&showall=1

Same user name everywhere, except where forum software does not permit characters (&) . Then it's MPandC.
Thanks for sharing the link, quite a bit of info in there..

Originally Posted by 72chevylwbmo

Well as much as I hate to do this, I'm going to post pictures of the panel I installed last night. Go ahead, tell me how bad of a job I did. But also tell me how to fix and make it look good, please.

I'll add some comments, but please don't take this as criticism. I've done some of the same things myself, and it's all part of the learning curve. My intent is to pass on some of the things you may see as you continue with your panel install, so you can better understand what it occurring that you can deal with any of the issues (reactions) that crop up.

Fitment looks good on the panel, except for the added strip on the end. I will say that some panel movement does tend to occur as welds shrink and push/pull at the surrounding area. With any added strip like that, you may find is easier to better keep the panel shape in check if you weld the strip onto the panel off the vehicle, do the weld planishing and dressing, re-trim to fit the opening and then weld to the vehicle. Having a strip in between two panels puts two weld seams in close proximity, which compounds those shrinking effects in a confined space. Not that they can't be dealt with, but it may be more of a challenge. Having the panel off the vehicle to correct any mis-cuts allows better opportunity for any panel deformity to be worked off the end of the panel. Welded in as you've shown with the strip between two panels will tend to lock things in place, where any deformation that may occur is more work to get things back in check. (food for thought) At this point I'm not suggesting to cut anything out, it's more of an awareness thing so you can better monitor panel movement.


Most quarter panel installs involve a somewhat flat crown in both the horizontal and vertical directions. Regardless of appearance, all body panels will have crown in at least one direction to help hold the shape of that panel. A flat sheet of metal has no support and will flap in the breeze, so ALL panels will have crown somewhere. If we were to look at your top seam along the weld in a cross-section view (top-down) you would see that despite appearing flat, that panel actually has crown from front to back. It looks like a slight arc. Now, anytime you apply the heat from welding, you are going to get a shrink as that weld cools. When we weld one dot at a time, each and every dot is going to pull at the metal around it, from all directions, causing a shrink. Once you've added all those shrinks from all those weld dots together, along the entire weld seam, it adds up to a substantial amount of shrink such that what used to look like an arc is now more closely resembling a straight line. So given a weld seam like that, without any planishing to counteract the shrinking, you will see the panel pulling inward, as the crown at the weld is shrinking. Looking at the panel as a whole, unchecked shrinking would appear as a pronounced valley, where the weld seam is shrinking and pulling the adjacent panels along for the ride.


On the panel fitment, you will likely find that the sharp 90 degree corners on the patch will help to add a bit of distortion. As your welds shrink, a tight inside corner gets those effects from two different directions, where the shrinking effects will compound in the inside corner, normally as a pucker that is a bit challenging to remove. On the corners a large sweeping radius helps to balance out the shrinking effects on either side of the weld, where the planishing efforts don't need to focus on puckers or deformity on one side only.


As to addressing the welds:


I have found that due to the manner in which each weld dot shrink pulls from ALL directions, you will have better luck in planishing to remove said shrinking effects if you can planish the weld dots while they are singular, sitting all by their lonesome. This will more effectively STRETCH that weld dot back out in all directions. And by stretching as you go, you help eliminate the panel being pulled into a valley on those long welds. As far as tacking the panel in place, (FYI) I normally would start the tacks at one end and work toward the other. I know many people will tell you to skip around to minimize heat buildup, and I have been one of those. But if you tack one end and then move to the opposite end, you run a greater risk that one panel may have more material than the other due to misalignment. Once things get all tacked up, this results in a panel bulge on one side of the weld. So tacking from one end and working progressively to the other will help to eliminate this by being able to align the panels together as you go. Now that the panel is tacked and weld dots are spaced about (2 or 3"), go back and planish each weld dot individually, to add a bit of stretch. At this point, I use a 3" cutoff wheel to grind down the dots to just above flush. This gets them out of the way for planishing the next sets of dots, and by leaving them just above flush, you can do the final cleanup with a roloc sander all at once. By trying to grind things down to perfectly smooth after each, you run a greater risk of inadvertent sanding of the metal to the sides of the welds, which may thin and weaken the panel. So I hold off on this until the end. For your grinding disc, I prefer to use cutoff wheels about 1/16 thick. This gives a much smaller contact area than most any other method, so you will have less heat buildup from the grinding process. It also gives the best unobstructed view of what you're doing, so again, less chance of inadvertent abrading/thinning of the parent metal to the sides of the weld. Other grinding methods, such as using a flap disc, hide most of what you're doing, and generate too much heat. Here is a link showing the grinding method on a plug weld, again, sanding on a weld seam I would wait until the end.

https://www.youtube.com/watch?v=V2WHT_zMOE8

Once these initial welds are planished and ground down just above surface, then continue, adding a weld between each one until your welds are spaced about 1" apart. At this point (still planishing and grinding after each time) instead of hitting the center between for weld location, start overlapping by about 1/3 of the last welds. By overlapping, you will have less risk of missed spots or pin holes. Continue with the weld, planish, grind, repeat until the seam is done. I typically weld from start to finish using weld dots only, none of the longer passes at the end, in order to keep everything consistent throughout the process.


For the cutoff wheels, I spend the extra coin and get ones rated for stainless steel. This makes them last longer and put less of that brown haze in the air that you see from the cheap HF or swap meet specials. By the time you figure out the cost of how quickly the cheap ones wear away, you haven't saved a thing. For the roloc sanding disc, the bulk of the welds are being removed by a cutoff wheel, we are only dressing what little remains of the weld and blending that into the parent metal. This is easily accomplished using a 60 or 80 grit, that should be as coarse as you need to go..

[72chevylwbmo]

Well as much as I hate to do this, I'm going to post pictures of the panel I installed last night. Go ahead, tell me how bad of a job I did. But also tell me how to fix and make it look good, please.

[MARTINSR]

Originally Posted by 72chevylwbmo

Well as much as I hate to do this, I'm going to post pictures of the panel I installed last night. Go ahead, tell me how bad of a job I did. But also tell me how to fix and make it look good, please.

What you have done there is fine, just take it easy! Read what I posted on this thread about this, take your time or you will end up with a warped mess.

http://67-72chevytrucks.com/vboard/s...d.php?t=634624

Brian