AX, I have done floor panels and cab corners in my 56 Ford F-100. I have also fabricated patches for my running boards. I have two more 56 Fords in line to work on. My next big project is the rear window conversion making a small window 56 into a big window. Im really imtinidated by this one because of the big long cut across the back of the cab. Three sides of the patch are spot welded like the original. The bottom cut involves cutting a straight line in the middle of the rear cab wall from one end to the other. Cutting the perfect line to butt weld in the replacement patch is what has me scared. Thats probably close to six feet of line to cut and weld. I dont want to flange weld it and I dont want to use the flange adhesive method, although that would be my second choice. Being a novice hobby welder, I think this project may be a little challenging for me.

Any suggestions for making that perfect cut?

 

Ax Your tutorials are always very much appreciated, Thank you.

 

What a great thread. Fantastic information, thanks for taking the time to do this.

One note that I did not see mentioned in the safety information. DO NOT use chlorinated solvents to clean parts you are going to weld. This means most aerosol brake cleaners. If you are using Argon or Argon mix as your shielding gas the chlorine residue reacts with the argon under the welding heat (arc) and forms phosgene gas. Phosgene gas was a nerve agent used in WW1 and it WILL seriously injure you (nerve damage) and can easily KILL you.

I know we all use brake clean as it is such a convenient way to clean old parts but if you aren't sure if a part has been cleaned with brake clean, clean it again with another solvent such as alcohol or just good old soap and water before welding.

 

Sorry, something went haywire with my browser so I couldn't post for a couple days. Here's the reply I tried to post: If you go thru the fender rust repair post you'll see my method: cut the cab a little smaller than the filler panel Use dykem blue on the new panel in the area of the cut. Put the panel in place tightly (clecos would be a real good investment!) and carefully scribe the cut with a steel scribe. Go slow, and only make a single accurate scribe line. remove the panel and cut just outside the line with a 0.040 cut off wheel on a 3 or 4" angle grinder. Use the cut off wheel like a chop saw not like a circular saw cutting plywood, i.e. don't try to push it along the line in a continuous cut, instead hold the cutoff wheel next to the line and swing it down into the metal until you have cut 2-3". Raise the wheel up out of the metal, advance the grinder ahead to the edge of the cut, line it up and swing it down again. Repeat until you have completed the cut. (if you need a source for the ultra thin cutoff wheel at an excellent price let me know.) Switch the cutoff wheel to a red fiber 40 grit disk with a rubber backing wheel (or better yet buy 2 4" angle grinders so you don't have to keep stopping to change the tool.) And use it near flat to the cut and with light long strokes, refine the cut to the line. deburr the panel, give it another coat of dykem and test the fit. rescribe the overlap spots and re-grind it. Hopefully you worked with patience and didn't overcut leaving gaps larger than the 0.023 Easy Grind filler wire.
Try to refine to a perfect butt joint, patience is the key here time taken to get a perfect seam will be saved several fold in the metal finishing stage. Butt if you should miss-cut it a little wide in a couple places, all is not lost. (see below) Butt (pun intended), no overlaps!
Remember using point tacks with full penetration and allowing them to cool completely to the touch before adding any additional tacks within 6" is key to reducing warpage. and adjusting and refining the seam alignment as you go is also important. Read the patch welding information in my fender rust repair tutorial for detailed information and pictures. A long seam may take a couple days to fully weld, have some other projects to work on at the same time will help keep you from losing patience. NEVER rush it by force cooling with water or compressed air!!!
Tack where the fit is perfect first working from the center towards the ends.

Dealing with miss-fits: should you miss-cut so the seam has a few (hopefully only a few) short gaps between, DO NOT try to weld across the gap, or blow outs will ensue. If very short and narrow (no wider than the wire diameter), and the back is accessible to you or a helper Back up the gap with a copper spoon or aluminum bar held tight (you will likely need to sand any nearby weld bead flat, the backer must fit tight) to the back side while you make a quick short bead starting on top one side (not right on the edge!)and across the gap at the center. The weld will not stick to the backer. For a slightly wider or longer gap, cut a suitable length off the spool of 0.030 Easy Grind wire (you did take my advice and bought a spool of the two diameters of Easy Grind wire didn't you?) Lay it in the gap and hold in place with a welding magnet from the back while tacking over it. be sure to keep it and the seam aligned with light hammer and dolly work as you go. Finally for wider gaps still or accidental overlaps. VERY carefully make a cut along the seam with a 0.040 very thin cut off disk. And slip in a narrow strip of 18 ga sheet metal into the kerf until nearly flush with the outside. I save some of the narrow strips my electric sheet metal shears make just for this purpose. The slight burr on the edge and slight waviness from straightening with fingers help hold it in place. If your welder is set properly you will be able to grind off the excess filler strip on the back after the weld is complete without issue. If the gap is larger yet (SHAME on you!) weld the rest of the seam then drill the gap at each end with a step drill to 1/2" centered on the seam, cut between CAREFULLY with the cutoff disk making a 1/2" wide mail slot with rounded ends. Sand the adjacent welded seam flat on the back. Hold a strip of dykem blue sprayed sheet metal on the back and CAREFULLY scribe and cut a well fitted patch and weld in like any patch. See the fender repair tutorial for info on metal finishing the seam with mallet and block, hammer and dolly and bullseye pick work.

 

What a great response! I have two small makita grinders already. I will look for the easy grind wire .023 and .030, ultra thin cut off disks, dykem blue. I always use .023 and sometimes .030 but they are not "easy grind". I checked out several of the highlighted links for this wire but the pages did not come up, so I am still looking.

I have a good selection of clecos (clamps and pins).

I also have a good collection of the welding clamps that make a perfect (approximate) 1/16" space between metal when butt welding. The clamps have a little bar that goes behind the weld joint to keep both pieces of metal perfectly alligned up and down and spaced to maintain the 1/16" gap.

I could use a good source for the thin cut off disks and wire. Im not sure what "dyke, blue is"?

I read thru your articles but before I start, I will study them.

I am also interested in your bulls eye picks. I will pm you with my email address.

Thanks for all your effort in helping with my project.

 

I think "Easy Grind" is now "All-State Easy Grind" (someone correct me quick if I'm wrong and I'll edit this post)

Here is a link to Airgas: https://www.airgas.com/product/Weldi.../p/ESA69130058

And from weldingsupply.com: https://weldingsupply.com/cgi-bin/ei...DEF:OR:130PS43

 

Not to take the welding subject off topic but don't use chlorinated solvents around any open flame heat source. It was long ago but I was using using Brakleen in winter in a small garage (CRC brand chlorinated version, it is clearly marked). I was suddenly overcome when vapor felt like it was sucking my lungs out. I crawled out of the garage and wondered if I would make it. I laid in a snowbank puking and gasping for air for several minutes) After I semi recovered I looked through the garage window and could see the vapor drifting over a Kerosene heater 15 feet away. It was cooking off into phosgene gas like Mike mentions. It was no joke. If you get it near flame there is 100% chance it will begin to convert to a toxic gas. If there isn't excellent ventilation it will take you to your knees. Argon is not required. Only chlorinated solvent and flame or extreme heat which is common to welding of course..

 

ET, you are correct, ESAB is changing their wire brand name to All-State, same wire. I get mine from welding supply.com. Once you try the Easy Grind wire you won't use any other. It lays a flatter bead, is softer so doesn't crack when hammered on, and definitely grinds easier which reduces heat. Grinding heat can cause more warpage than welding so go slowly allowing the area to cool frequently, if the metal turns blue you are overheating it, use 30 or 40 grit red fiber sanding disks with a light touch. Pressure does not make it go any faster but can cause a lot of damage! Change disks when needed, they are not expensive, save the worn ones for deburring etc.

Dykem blue (Dykem is most common brand, sometimes called layout blue or layout fluid) is a very fast drying thin spray or brush lacquer used by machinists when scribing out a piece for machining. You can find it online, but I bought a can at my local industrial supply/metals supplier and I think I may have also seen it at my local NAPA store recently. If all else fails, buy a super fat black permanent ink marker at an office supply store and use that to paint out the area where you'll scribe mark.

Those panel clamps are WRONG IMHO. 1/16" (0.0625 or 16 ga) is a HUGE gap 3x what I recommended as max without adding a filler! Re-read last post. You'll blow a lot of holes using them! If you need something like them, cut some 3/4" x 1" tabs of 16 or 14 ga metal and drill two 1/8" holes in it. Straddle the seam, drill corresponding holes and use clecos to clamp it in place. Remove after tacking on each side, tack and fill the holes using a backer spoon.If you insist on using them, buy some 1/16" soft steel wire and insert it into the gap between clamps before welding, but you are making a lot of extra work for yourself and increasing likelihood of warpage.

I buy my 0.040 ultra thin kerf cutoff disks in packs of 25 or 50 here: http://www.ebay.com/itm/25-4-x-040-x5-8-Stainless-Steel-Metal-Cut-off-Wheels-Cutting-Disc-/261231248599?hash=item3cd29884d7These are for 4" angle grinder, be sure to buy the right ones for your grinder. They sell a LOT of different wheels and abrasives, so be sure you are buying 0.040 thick flat disks (type 1).

 

A friend of mine looked into this deeper after I sent him Mike's post. It isn't the argon gas (which is inert) that causes the problems. Like "Fatfenders" described so well, it is the fumes from the evaporating chlorine. Brakleen evaporates very fast leaving no residue. So if you clean a part in a well ventilated area, let it dry thoroughly and then weld it you are OK. Just don't heat up the fumes from Brakleen or any other chlorine-based cleaner/solvent (Chlorox).

slightly: That makes me wonder about used on electric dryers. If your washer doesn't rinse out all of the Chlorox or other chlorine bleach would this cause a problem?

Here are important facts from CDC on Phosgene.
CDC | Facts About Phosgene

 

Thanks Effie, ordered the easy grind off the weldersupply.com, its on its way. Thanks for the link.

 

AX, thanks for posting the links to the cut off disks. I have 100 on the way. What an awesome price when you buy them in a box of 100.

When I read your post on making the perfect cut, I questioned if the gap in the clamps I have would be too wide and sure enough, you came right back with a red flag. You confirmed what I was afraid might be too wide.

I will revisit that and save those clamps for thicker material. Right now my focus is 100% on welding sheet metal and making the perfect cut to provide a good butt joint.

Thanks for being patient and pointing that out!

 

I am no chemist but I know Chlorine is an element. Trichlorethane 1.1.1. or whatever version is legal now is the common variant that is dangerous when improperly used. IMO best just to pre-clean with something else if there are any ventilation and heat source issues. There are safe products made specifically for pre-cleaning welds.

Back on topic. For those of you using the ESAB wire, how much easier does it grind than other brands of wire? I have a lot of bodywork to do soon. I also have a multi-year supply of wire already on hand so I don't want to buy more for a small difference. Most wire I have ever used does not grind easily at all.

 

Im wondering of the mig welding tip Eastwood sells for making plug welds would be a good aid for making the tack welds. Its allows the user to hold the tip of the wire the same distance from the metal weld after weld. I want to try one for spot welding anyway so I guess its worth a try. Looking for that consistent 3/8" stinger to use on thin sheetmetal to make a series of tack welds side by side. For those who dont know what Im talking about, its a mig welding cup that replaces the stock welding cup on your mig handle. It has a uniform spacer on each side (like a pair of legs). When you place it above a spot weld, its designed to keep the tip the correct distance from the metal to make a consistent spot weld.

 

The difference isn't small. It grinds more like the sheet metal than a weld. And, as Ax noted before, you can bump it around with a hammer and dolly.

You mean this?:

 

Yes. Watching the on line video of it, it looks like it might be good for a spot weld, but too close for a tack weld.