Question about welding sheetmetal

[fla 66 cuda]

How do you do it? This is my first attempt at doing sheetmetal replacement [i guess i shoulda taken some welding classes back in the day] I have a flux core welder[that was loaned to me] 110 house current .035 wire i have played with the feed [have no idea what's right] don't have an amp. adjustment just a b c d e [chart in door says B and 1.5 speed burns thru most times]. I'm not having any luck, keep burning holes in the damn metal. I have this evening aquired another loaner, gas shielded mig welder that i hope will help make things a little easer[won't help my welding inexperiance] any sugestions will gladly be accepted,my son is loseing hope on this project and i'm bound and determined to fix this damn car[what i learn on this one i will use on mine] my son does not want a 100 point restoration just a nice daily driver for weekend cruise ins.

 

[moparpoor]

Flux core a no no.Use the gas shielded welder for sure.Use 023 wire with about 20cfh for flow.Grab some scrap sheet metal to practice.Look at what the welder calls for and practice.For spot welding use the next higher heat setting and adjust wire speed as needed.Practice and take your time.

 

[fla 66 cuda]

Thank's i know welding is an art and taking your time is key i thought the flux was a bad idea but trying to keep costs down i took advantage of the offer of a welder, i have not done too much damage and what i have done i'll probly cut out and do again after i get better at it.Iwas going to purchase the gas add on kit for this welder i have but another person offered theirs that has gas.

 

[moparpoor]

Once you start welding on some pactice metal shoot some pics.Then load them up so we can help fine tune them for ya.Good luck!!

 

[Patrick]

I've never had a problem with flux, so long as I used a good one that turned the power to the wire off when I released the trigger.

 

[Coledavis01]

I recently took up welding after having not touched one in 9 years...wasn't like riding a bike! Helping a buddy on his car and recently bought a decent welder that's set up for flux core or gas shielded MIG, kit came with a spool of the flux and had trouble with it at first. Make sure the metal your welding to isn't thin from rust on the backside or the burn through won't end. Also, don't try to run a bead on thin body panels, make tacks every few inches which will give the metal time to cool and help prevent it from warping badly. I've noticed the closer and better of a ground (bare metal) you can get will also help.

Good luck!

Cole

 

[fla 66 cuda]

The ground proximity did cross my mind today as well as the metal issues some of the burn thru could be thin metal,i try to remove all the rusted area when cutting it out it's possible i missed some.I'm going to give the gas shielded welder a try, i'm sure it's 75% my inexperiance and 25% impatence that's causing my problems. A friend who is a welder said that ,035 is too heavy and will burn thru due to heating the sheetmetal faster than the wire i don't have any idea if thats right but it sounds like whats happening to me,he sugessted smaller guage wire and gas shielding. Thanks again for the info. i would like to acomplish something on this car instead of spinning my wheels.

 

[northerndave]

As to the .035 being too big and contributing to burn through... well... no and no.
kind of a 2 part there, I'll try to explain.

.035 flux core wire is quite a bit different than .035 solid wire. Solid .035 wire just has more metal in it, .035 flux core is probably more comparable to .023 solid as far as the amount of filler metal in the wire per inch.

So your .035 flux wasn't "too big" for the job. It just sounds like you were using too much heat, or zapped a thin spot (possibly ground too thin, possibly rusted thin from the opposite side) or you are just staying on the trigger too long in one spot.

Flux core will work, I just don't care for it personally.

As to part 2 (my second "no") even if it was .035 solid I’d have to say that the wire still isn't "too big" You can do a lot with .035 wire on sheet metal by just using less wire speed and less heat.

Personally I do prefer .023 for sheet metal welding, I feel that it lends itself better to the low heat settings with a quicker arc to puddle time when you hit the trigger. (it just starts a little faster) The .035 wire will go from initial arc to puddle at low heat settings fairly well but I find it a bit more clumsy than the .023 in this respect.

Run your heat as low as you can for your sheet metal to sheet metal welds. Run a little hotter for sheet metal to structure welds (plug welding to simulate/replace factory spot welds)

Start with floor repairs if that is part of your project. You get to practice on an area that will be covered up with a carpet lol! Get your initial experience with areas like that before you jump into body panel patching or partial replacement.

Burning holes and "burning back" usually means not enough wire speed. If you feel the wire pushing and popping/sputtering you may be trying to feed too much wire for the heat setting you are using.

As others have said, do NOT try to run constant beads of weld on body panel areas, you will warp the hell out of the metal. Tack weld in areas like that, tack and move, tack and move. Keep landing tack welds centered between tacks you previously placed until you have eliminated all the space between the tacks. The end result might not be as pretty as a steady weld but it will greatly reduce your warping.

here's a quarter skin going on, tack..

tack, tack..

tack, tack, tack..

Eventually it all becomes one weld. Carefully grind the area and it's ready for some filler to conceal the seam and help blend out the minor warping you will get even with the tack-tack method.

 

[chrisd]

I'm following closely here, because I never welded before I started my project. On the last picture, it looks like there are some pits where it wasn't tacked? Maybe as thick? Would you reweld those spots to fill them in with welds or a body filler?

 

[northerndave]

Yeah there are a couple of weld voids in that last photo. I'll be looking that whole seam over before i seal it with metal to metal filler. It's a 7' 4" long seam in this case

But I'll be looking for spots like that to buzz a little tack into and re-grind. The problem with that tack weld method is that in the end it gets hard to see what's going on as you are nearly stacking tacks on top of each other. But you just have to do it that way or it will warp all to hell on you.

The old way (and still a good way) is to flux and lead solder this seam at this point to fill any pin holes then start with polyester body filler over that.

I've done as many have done and opted for using products such as "metal 2 metal" as a replacement for lead.

 

[northerndave]

Also what I didn't show you is that this was an overlap weld with a flanged edge using a flanging tool. It ads strength, it gives you a nice target area to lay your weld into if done correctly, it gives you backer material to weld to and the step flange helps possition the new panel material "on plane" or level with the original surface area you are mating the new panel to.

This is how i like them to fit prior to welding, notice the slight gap between the new panel edge and the flanged "shoulder", this gives me a nice target area to land my weld into.

 

[Finallygotmine]

This is freaking fantastic, just like getting a welding course. Im ready to purchase my welder today. Does that make me a welder? Just kidding. I used to say "just because a guy has a hammer, doesn't mean he's a carpenter" This is fascinating with all the inside thoughts on the welds. you pay good stuff for this kind of guidance folks in technical college. (Daryn taking furious notes) no sh*t

 

[greenmonsta79]

Dave, putting that flange on the top of the quarter like that did it want to distort the natural curve of the panel?? When I do my quarter skins I was thinking about butt welding them on the outside of the quarter since I don't plan on using the door jam section, I would be interested in the reasoning why you went with that seam instead of a butt weld?

 

[northerndave]

The thing is, it's a 7'4" weld seam. it's really tough to stitch the whole thing on without creating "some" distortion.

I've done long body seams down the side before just below the top body line. And I've feathered the minor distortion out with body filler along the sides accordingly.

I decided this time to try it up top.

My reasons were for a more favorable presentation of the weld area to myself. Both for welding and for the body work that follows. But mostly for the body work that follows.

See, it's a lot of hand sanding with a long board and I prefer to do that on a topside horizontal area rather than being confined to a narrow strip between the upper body line "spear" and the top of the panel down that 7'4" length of mopar.

I really focus on the sides of a car when I look at a finished product. To me the quarters on these cars are like a display billboard for style. I want them straight as a laser with minimal body filler to achieve it.

Of course I want the top straight too but I felt I had more to work with up top between the trunk gutter and the outer long edge of the quarter, it's also convex there which lends itself better to the long board sanding/straightening in my opinion.

The flange and overlay vs a butt weld... Well it's extremely forgiving for blow through, I feel it may add some strength with the formed flange under the weld, and the location of this overlay is very well hidden from the inside trunk view.

These are just my personal thoughts on quarter skinning b-bodies. It don't mean it's the "right way". It's just what I arrived at based on past experience with quarter skins and based on the curves/shapes in and around the areas I had to choose from for my seam placement.

If I find difficulties in the finishing of these quarters I will certainly let my mopar buddies know about it.

This is a little bit different from standard practice on hanging a quarter skin I suppose. but I put a lot of thought into it and I felt comfortable enough with this idea to try it on MY OWN car, and so far it's looking good.

 

[MoparBill]

I agree with NorthernDave.. Having a flange on the backside of a weld is a very good thing! If you try to fit up that same seam without a flange you wouldn't have as nice of a finished product, not to mention the inside would look like a porcupine!
I am a sheetmetal worker by trade, and have been since '87. I have welded quite a bit of sheet metal over the years, and my advice is to practice! Buy a good name brand machine (Lincoln, Hobart, or Miller), use shielding gas, and practice on scrap before you turn loose on your car. When possible put a heat soak behind your joint, preferrably copper but aluminum will do just fine. Weld vertical seams downhand as heat rises. Take your time, weld a little and let things cool down. Same with grinding down the weld; grinding generates more than enough heat to warp a panel! When prepping a panel to weld, be careful on the angle of your grinder. You can 'knife edge' a panel and make it way thinner than it was by gringing it at an angle. This make blowing through much easier. The gas you use is important too. C25 will run a little cooler than Stargon, just throwing that out there. Again...practice!

 

[greenmonsta79]

Dave, I really kind of like the way you did it better than on the outside of the panel because I have done skins on the outside and was never really happy with them, only problem I might run into would be on the driver side near the flip top gas cap hole since it is pretty close to the edge? Did you use the door jam section? Got any pics of that section?

 

[northerndave]

Bill those are awesome tips. I've been wanting to try some of that heat soak/heat sink putty to help with welds like this but I haven't yet. Do you know what I'm talking about? kind of like modeling clay? You can roll it into "ropes" and flank your weld areas with it, I guess it's supposed to help a lot.

greenmosta79, yes I did use the lip that reaches in to the door jam area.

I separated the old ones by drilling the spot welds which we are all very familiar with.

I use a fairly inexpensive "bullet point" drill bit rather than the expensive spot weld cutters that seem to break so easily.

I try to only drill through the first layer with the shoulder of the bit, this way only the 1/8" pilot point of the bit goes all the way through.

I guess I don't have any really good photos right now of this area after fitting the new skins but I do have this one shot of the RH side where I was using a pickle fork handle to dolly the corner radius out a little better to match the shape of the corner of the door.

 

[Coronet 500]

Look at a refrigeration or HVAC supply for heat absorbtion materials. One I use is UNI-COOL heat block compound, it's in a can like a putty after use it turns hard then add water work it into the consistency you want and reuse or put back in can. I use it to pack around refrigeration valve bodies when I braze weld them. You might try a plumbing supply too.

 

[northerndave]

Thanks for the tip!