This is a start on a group article about welding. Please add any comment you may have. I took the below statements from an earlier thread and have identified the original writer.

Huntsman on brazing:
If I may offer a suggestion, make sure you do a very good job prepping the welds for primer and paint as one of the drawbacks to brazing is that if ALL the flux embedded in the seams is not removed, the paint will eventually turn lose. The other disadvantage, as I am sure you know, is excessive heat. On very stiff cab corners warping is not as obvious, but if you get out on flat metal, it will be there. I have heard of old pros using something called a ‘jewelers torch’ to weld and braze body panels with, benefits being that it produces the desired temp but more focused heat.

Randy Jack on brazing:
Brazing is an interesting solution. We use brazing at my work often. In some joint styles (enough overlap with a minimum gapped seam) the brazed joint is actually stronger than the parent material.

AXracer on brazing:
There's a reason brazing isn't used much for body repair, body putty and paint doesn't stick well to brass and will eventually fail. If you must braze, buy some high tensile nickle silver brazing rod instead of brass. It doesn't actually contain any silver so the price is reasonable and it comes in 1/16" diameter, ideal for thin work. It doesn't come flux coated so you'll need a can of powered flux to dip the hot rod into and/or use paste flux brushed onto the area you're going to braze. Start heating slowly to dry the flux then add the rod when the flux melts and turns glassy.

I oxyAc braze gold every day in my business, precious metal "soldering" is actually a brazing process, but I much prefer my MIG for body work.

From WillyB:
I discovered that I was trying to weld old Ford sheetmetal to new Ford sheetmetal - they changed it, went to higher strength but thinner steel and it don't weld so good. Practicing on new scrap made it a lot easier. I also think I wasn't cleaning the iron good enough for welding.

The big difference was my photogrey glasses - I am so used to wearing them that I never though about it. Between the new auto-darkening helmet I bought and my photogreys, I could not see the weld pool, or even the pieces I was welding once the arc started.

AXracer:
Yes, use mild steel sheet for body repair rather than cutting up newer scrap panels the new alloys are so different and most have some sort of rust resistant coating.

MIG is very sensitive to dirt and rust be sure to sand the metal clean at least a 1/2" on either side of the joint on both sides and the edges. Dirt and/or rust will cause "volcanos" in the bead. A freshly sanded surface can rust enough just from the humidity overnight to affect the smoothness of the bead. Clean the metal again just before welding.

Try this for better visability: if you hold the torch in your right hand tip the torch ~ 20° from vertical so the tip is pointing to the left towards you at the right end of the joint to be welded. Now run your bead by pushing the tip towards yourself while looking at the bead coming towards you. That way the tip is not blocking your vis and the arc is lighting the joint ahead making it much easier to see where you are going.

A flat butt joint is the most difficult to make, outside corners next and inside corners the easiest. Try to plan your work so as to have the least amount of butt joints as possible, welds along or near an edge are much less likely to warp and are easier to clean up.

I like to use a fan disk on my angle grinder to clean up most welds, and use a carbide burr in a die grinder for inside corners.

Keep a stock of sheet metal in 10, 16, 18 , and 20 ga. and try to match the thickness of the patch to the thickness of the panel. The metal fabrication shop where I get my metal usually has a lot of smaller cutoffs they consider scrap. I pick up any pieces that are from ~ 4x4" and larger and they either give it to me for free or charge me a couple dollars for a good handfull of pieces. There's also a heavier metals fabricator in town and I get scrap cutoffs from 1/8" and up there.

From IBeam:
For the last few years, I have been using a wire feed. This is the difference of day and night. There is however a little trick I did not see mentioned. Do use a Shielding Gas. The trick is, the kind of gas. I know Argon is expensive. $80 per bottle, plus $350 lease for 10 years. What I done is dropped my wire to .028 non flux, then went down to the local Coca-Cola company paid a $50 deposit, then $15 for the gas, and got a bottle of Co2. The regulator I bought from a Beer Supply Vendor. The reason for the Beer Vendor is through any Gas or Auto parts distributor, the Regulator was $80 and up. Through the Beer Vendor, it was only $30.

I can now butt match the panel edges, no overlap, and tack them into place. Then I come back and do a series of 1/2 inch welds so I do not heat warp, then grind it off. In places like door jams and stiff areas, you do not even have to use putty after grinding. You can take a dent on a corner, split it with a Die Grinder cutter, then pull it out, and weld it up again.

The Co2 mixture does give a bit of splatter, but welding with the wire feed is a pleasure it is so easy. Also I can not stress strong enough that prepping the surface by grinding off all contaminates (rust, paint) so it will flow out. Also on metals over 1/8, take a torch and preheat it, and you can weld up to 1/4 thick easy with a small wire feed.

I know there may be some that disagree with this, but it works very well for me.

From Randy Jack:
"Old steel" is just your basic cold rolled (1018) steel sheet, available everywhere for next to nothing. "New steel" refers to the alloyed steel car makers switched to in later years. It has better formability and is stiffer so that the thinner sheet they use now will stand up (almost) similar to the heavy gage stuff our trucks are made of. Our trucks are the old steel.

Patching with the new steel is trying to mix different alloys with different melting points and ingredients, which can cause some problems for weld strength and warping. The new steel also has carbon in it which causes it to harden when cooled after heating, making working (hammering) of the weld really difficult even when still hot and impossible when fully cooled.

Again from Randy Jack:
The "olde steel" is the common 1018 steel alloy - same then as now. That is the alloy used on our truck's sheet metal. If you use a piece of an old fender, it is still 1018 steel.

I buy the pieces I need from a local metal supplier. I buy what are called "drop offs", or the pieces left over when he shears an order for someone else. They are always in odd sizes, usually rectangular. They are cheap because they are scrap unless someone like me wants them. Works well for all concerned. I usually keep some pieces of 16, 18 and 20 gage around in sizes from 1 X 4 up to 18 X 48.

The possible benefit of using old sheet metal in lieu of new 1018 sheet might be the very small differences in alloying that have occured over the years. There also have been changes in the method smelting which tend to give newer steel more consistent qualities, but, because of standards, the differences are really small.

I have used new pieces of 1018 to MIG all the body mods and patches on my 56 with excellent results. My gallery will show some of those projects.

I do kinda like the nostalgia of resurrecting a piece from the old fender to be in the new patch, though. But without a sand blaster, I'm just too lazy to do the cleanup required for prep.

From Fatfenders 56:
Back in the old days when we had to gas weld or braze everything I/we found that a good thorough sandblasting made body work stick, have not had a come back for body work lifting off of brazing since.

From Huntsman:
Agreed, a lot of folks like to wire brush seams but my experiance is that wire brushing anything tends to shine the metal, closing up what the paint has to stick to.

From IBeam:
I have used the Brazing rod trick to reduce warpage. I run my own body shop for 6 years, but have done body and paint my entire life. What they say about body repair sticking to a braze is true. I have seen a few pieces of work come back on me. After that, I went back to mild steel and extra putty. It may not be perfect, but done right, it does not crack or come apart.

 

From WillyB
I purchased a book at the store where I buy my welding supplies - "Welder's Handbook" by Richard Finch. One subject he covers is gas welding aluminum. I have no experance with aluminum, but he states that you use an aluminum rod with aluminum welding flux, and a colbalt blue lens on your welding goggles.

You do not use acetylene gas, but instead use hydrogen to mix with the oxygen. You use the same torch, but need a bigger tip than what you would use for the same thickness of steel.

Both the flame and the weld pools are different colors than you are used to - you look for aluminum to get "shiny" just before it melts.

Other than that, it is the same process as oxyacetylene welding steel.

From Randy Jack:
Welding aluminum in aerospace work is always done using TIG and aluminum rod. No flux is required. Shielding gasses are usually helium and Argon. Unlike MIG, the gasses are usually in separate tanks and mixed at the weld site rather than pre-mixed in one tank.

There are more variables to TIG than any other method. The tungsten tip shape and gap to the work piece, the shielding gas mixture and pressure, the tip coolant temperature and water volume, the power applied, the speed of the pass and the rod alloy are all variables that must be balanced. Really good TIG welding is truly an art. That said, TIG is, in my opinion (and Ron Covell's), the ultimate welding system. It produces very controlled and beautiful welds. Many times, the beads are left as welded, since there is little or no spatter to clean up. A good example would be most custom motorcycle frames. Controlling very small tacks or beads and how much heat goes into the part is easier. It is a more complicated and awkward system to use compared to MIG, since it is difficult to use in all positions and requires both hands and one foot (or knee) to work the power pedal.

TIG is very sensitive to any contamination on the parts to be welded. They must be very clean. Aluminum details see a hot and strong alkali bath to remove any oxidation and then are welded literally within minutes. Steel isn't as fussy, but still needs to be mechanically well prepped. That said, I would love to have a TIG setup some day.

MIG is inexpensive to buy and use and is an easy system to learn. (I think arc/stick welding is the least expensive and easiest, but is clearly the messiest). MIG is a one-handed point and shoot system which (with enough amps) will weld any thickness at pretty much the same speed (quickly) at any attitude (even overhead). Better welds require similar joint and part prep, although MIG tends to be less fussy about that. I have tacked some pretty funky looking parts together. It always requires some cleanup, since there is usually some spatter (as much as arc/stick when using flux core wire).

I don't yet own an oxy-acetylene setup, but want one, especially for brazing, cutting (gas axe) and heating/bending (gas wrench). The Welder's Handbook recommends oxy/acetylene as the preferred starter setup because it is more forgiving and so useful and learning it is a good key to mastering the other methods. You learn to use the changes in metal color to see when to fuse the parent edges, add rod and fuse the puddle. Most welding classes will teach gas welding first for those reasons. I've seen some oxy/acetylene welds that were as pretty as TIG. It is very versatile in that gas welding can be used to join almost any material.

Welding has been the most fun and rewarding process of all the things I have done to my truck. (Although making horsepower is pretty cool too). The kick I get out of welding is that you actually CREATE stuff welding, rather than just fix, replace or adjust stuff. Welding is way cool! I picked MIG as my first and primary system because I could do the sheet metal patching and mods I wanted and it was within striking range of my credit card. Even though my system is a very inexpensive one with few whistles or bells, I have been very pleased with it. I probably have less that $500 total in my system including the welder, cart, auto-dark helmet, coat, gloves, etc.

 

***** - here's a thread from the Paint & Body section that you may be able to dig more info from.

Patch Panel/Rust Repair

Oh, and thanks for the invite guys. I think this is great.

 

Carlene - I have mixed emotions about Rosati's repair. It is great, and a very good demonstration of how to do a proper repair. My problem is that now I see how poor my repairs have been, and know I should cut them out and start again.

Great post, and many thanks for the link!

(I don't think I will ever be able to write "finished" on any aspect of my project!)

 

Here's a copy of a post I made to Rosati's topic over there:
For typical body repair work we do on our trucks, I have found the video (or DVD) put out by Ron Covell www.covell.biz titled "Basic Techniques for Working With Steel" one of the best investments you can make. He show how to do rust repair, hole filling, panel shaping, wire edging, heat shrinking, and on and off dolly hammer and dolly work. The latter alone is worth the price, so many novices actually do more damage than good when they start trying to straighten a panel with a hammer and dolly using the wrong technique. Especially LISTEN to the difference in sound the hammer makes when striking the panel when working on dolly (rings) and off dolly (dull). Unless you are trying to stretch a panel (rarely) you should be working off dolly.

I have a Hobart 140 Mig (<500.00 at Northern Tool), highest amp 115V shielded MIG available, and haven't found anything I wanted to weld on my truck that it was too low powered for, and I can pick it up and carry it around. Like someone said, distance from the weld to the torch and wire feed speed is more critical than power setting. Keep the distance consistant by dragging the shield cup on the metal as you weld, and adjust the wire feed to give you the penetration you need. When working on sheet metal, one trick to reduce burn thru is to slow down the feed just enough that the arc makes and breaks with a stuttering sound as you move along just fast enough to maintain the bead. If you do blow a hole or have a hole 1/2" or smaller to fill, grind off any metal build up on the rear of the area from the burn thru then back the hole with a piece of copper (I use the flattened end of a length of copper waterpipe bent like a small spatula) Hold the copper tight against the back of the hole, and start the weld ON TOP of the surrounding metal NOT at the edge and work back and forth or around the hole towards the center until it's filled. The weld will not stick to the copper which act like a heat sink and backer.

 

Tig for body panels and light sheetmetal, I use .030 or .035 mig wire off of 1# spools. You can cut it any length you want and it straightens real easy. Mig wire and tig wire for mild steel should be ER70S. For stainless should be 309, while 309 is a touch more expensive than 308, 309 can be used for joining stainless to steel by AWS standards, 308 may not. I also use 309 in 1# spools. Aluminum I highly recomend 5356 over the 4043. While 4043 flows a little better, it is produces a weaker weld. 4043 works better for a root pass on cast alum, it pulls the trash out of the cast (oil and grease that is trapped) better, then grind or buff it up and use 5356 out from there. For body work I would recomend 1/16 tungsten. Steel or Stainless use 2% thoriated (red on the end) for alum use pure tungsten (green on the end) One other trick that works well for aluminum is use the biggest cup you can and turn your gas up to about 25-30 CFH and DO NOT pull your filler rod out of the shielding gas, keep it as close to the cup or below the cup as possible.

Grinding tungsten is a pain in the butt sometimes, but an uncontaminated tungsten welds much better and cleaner. I found a small threaded back drill chuck and installed a long arbor in it to hold on to, now makes it easy to grind without burning your hand. Balling the tungsten for aluminum welding is another pain in the butt sometimes. All you need is a heavy piece of brass or copper. It shines up easy, and will not contaminate, or leave arc marks on what you are welding. For any tig welder out there, I highly recomend chucking your foot pedal in favor of a rotary torch mounted control. Makes welding roll cages, motorcycle frames, ect. ect. much easier, due to not having to drag around a foot pedal, or having room or position to operate it with your foot. Scotch brite pads work really well to clean filler rod before use. Acetone also works well to clean aluminum after it is brushed. Caution it is flamable and works good with a rag that wont leave a lot of lint behind.

Better-Built truck tool boxes (Daws MFG.) produces their super shiny (clean) welds by using the same material as filler rod. So for any of you doing any home projects out of sheet aluminum that you will polish or anodize afterwords, do yourself a favor. Buy a larger piece of sheet than you need, take it to a sheetmetal shop and have them shear you off 1/8" wide strips to use as your filler metal for welding said project together. Daws actually bought a de-coiler and precision shear just to make thier own filler rods, it is just one of the ways they reduced their bottom line to increase profits. 5' long filler rods vs. 3' that they pay for buy the roll and not the pound.

Ryan

 

Whenever welding anything, use common sense. Remove the paint from the area on both sides, if you can get to it. The smoke from the paints Ford used is pretty noxious, and the paint can burn if you get it hot enough. Be especially careful installing cab corners and cab pillar repair pieces- I almost burned my truck up because a fast-food wrapper had gotten stuck in between the body panels, plus the foam or hair in the seat is pretty flammable. You should always have somebody with you while welding, to watch for sparks and fire. Invest in a welding blanket, too.
With MIG welding, you can use straight argon gas or a blend of argon and CO2. I wouldn't use pure CO2, it holds the weld heat in and can cause burn-through problems.
Don't use a little 110 MIG welding machine for anything structural, they simply don't have the power to burn into the steel properly. Any frame repairs should be made by stick or TIG, depending on what's available.
When using 7018 stick rods, be sure to keep them dry. They need to be heated in an oven to about 400º for two hours, then kept in a sealed airtight container until you use them. If excess moisture gets into the rods, it will cause major porosity problems with the welds.

 

I do not claim to know much of anything about patching a panel. I only know what I am reading on this forum. I do know a little bit about welding though. I have welded small rips in car bodies (usually floorboards from accidents or popped spot welds) is about all.

I currently use a 220 V Lincoln MIG with a mix gas. I believe its argon and CO2. I have used a small guage solid wire (.030) and weld fairly thin sheet metal (16 GA) using the tack and let cool methods everyone else on here talks about. I have not done this on a car body, just light steel fabrication jobs in the shop. TIG of couse is better for thin stuff, but costs a lot more.

I can also increase the heat and wire size (remember the 220 V) to weld fairly heavy steel. I happen to use .045, but you can use up to 1/6" with this particular machine. I have used it to weld 1/4" plate. I don't think anything on a typical truck is any heavier than that. All material must be clean and I prefer to bevel everything thats possible when using a small MIG to improve penetration and strength. Once the beveled side is welded, you can grind back into the first weld from the other side. 100% weld that way. (frames might be a good application for this method)

I have not chopped up a frame, but I have used this particular MIG many times for frame repairs.

Now for the scary stuff (to me anyway). I belong to a website where SAS (straight axle swaps) are fairly common for the off-road crowd. The street guys also like to "C" notch the frames for lowering. With the SAS, I see guys weld spring buckets on downhill. In the "C" notch plates I see the same thing. Downhill makes a pretty weld, but it won't hold worth anything.

In every shop I have been around its considered illegal and can get you fired. Do not weld downhill! It can get you and anyone around you killed going down the interstate when something breaks. Either turn the material to weld flat or weld uphill.

Above all, if something looks unsafe, don't do it!


EDIT: I just though I might add that with this machine and the correct wire/gas combos, I am also supposed to be able to weld aluminum and stainless. I have not tried it, but according to lincoln I can. Typically I take aluminum and stainless to where my dad works.

 

I would not weld anything structural that could be dangerous if it broke, myself. I would tack it in place and take it to a certified welder to finish weld. My life is worth more than the few bucks to have it done. If you have the welding skills to do structural repairs or mods you should probably be adding to this discussion, if you are a novice, DON'T DO STRUCTURAL WELDS!!! As far as 115V machines are concerned, my Hobart 140 has plenty of power to weld even frames, after all frame metal is relatively thin, ~ 10ga. I wouldn't even hesitate to use it to weld in boxing plates for example. I use .025 ESAB EZgrind wire with Ar/CO2 for sheetmetal welding.

 

Thats excellent advice for those novice welders out there for any structural members. Fit it up and take to a pro who knows whats hes doing. Get it done right. Don't take chances. Not only is it your life in your hands, but your families, and anyone elses on the road.

I am not sure how this thread would apply to a pro. If they know what they are doing already, they don't need someone telling them how to prep a weld or how to weld it. They (like me) need to know about the patching and repairs.

 

Okguys, when its time to weld....the practice time makes the difference. sheetmetal//try mig welds with paint on the back. try them with wire brushed/ try them with sanded down toclean metal. then check your ground, file some of the teeth flat for more contact area, clean the ground and the metal area it clamps to, check that your ground clamp has its jaw with the attached wire on the clean side///frame repairs,stiffining plates, there are design issues that engineers study ...for us rust des******s, its about cleaning the metal ....and the preheat of the metal when using mig.. after welding on structures,bridges etc for a few decadesI got to recomend a weld book that is the most practical set of hints from an engineer for repairs and tricks.ONE SHORT CHAPTER ON VEHICLE WELDING/ MOSTLY FRAME REPAIR.'Welding Fabrication and repair- questions and answers' by Frank Marlow,P.E. a book cheap/ by industrial press. its on the web.

 

Any chance you might devote one page to an overview of which type of welder is best which type of welding/repair. Like just a few sentences on each type. And feel free to explain whether stitch welders are any good for sheet metal ...

 

My opinion:

Welders:

OX-AC torch:
Thin steel: v. good
Thick steel: Fair-good
High tensile steel: No
Aluminum: v. good-excellent
Stainless: No
Advantages: inexpensive, versatile, portable, can be used for brazing, general heating and flame cutting
Disadvantages: steep learning curve especially with thin metal, when you run out of gas you're done until you can get new filled cylinder, cylinders must be purchased or leased from a supply house, clumsy to move around without a cart, tanks can be a safety hazzard if they fall or leak and are heavy.

Arc or stick welder (buzz box):
thin steel: poor
thick steel: v. good- excellent
ht steel: no
aluminum: no
SS: no
Advantages: inexpensive, no gas required, supplies readily available, only realistic home shop choice for heavy steel, easy to learn to use, can weld rusty or dirty metal
Disadvantages: requires a nearby 220V outlet, lots of sparks and splatter, welds require chipping of flux.

MIG:
Thin steel: good to v. good
Thick steel: v. good-excellent (requires high amp box which is less useful for thin material)
ht steel: fair-good
aluminum: v. good
SS: excellent
Advantages: moderate priced, versatile, 115V units available with sufficient power to do most automotive related welding, 220V units will weld thin to mod thick materials, v. easy to learn, smaller units v. portable run off household outlet, can be used without shielding gas, tacking pieces in place very easy to do, minimal spatter clean welds, low heat distortion
Disadvantages: requires changing shielding gasses/filler wire for different metals (involved process), adjusting power/wire feed/ gas flow for each job can be fussy, gas cylinders can be heavy and hazardous if knocked over, flux core wire welds must be chipped, metal must be clean, spoolgun required for much aluminum welding, smallest units do not have provision for shielding gas use and may be underpowered for all but the lightest materials.

TIG (heliarc):
thin steel: excellent
Thick steel: v. good-fair
ht steel: excellent
aluminum: excellent
SS: excellent
Advantages: Very versatile welding different metals may only require picking up the right filler rod. very clean low profile welds require little to no dressing, power is variable at the torch by footpedal or thumb slide, so little-no adjustment at machine is needed, best machine for light steel/aluminum especially if equipped with high frequency phase inverter (stitch welder), nearly no spatter making overhead welding easier, very low heat distortion, welds can be bathed in shielding gas as they cool
Disadvantages: Expensive especially when options are added (some new less expensive units coming onto the market), steeper learning curve than stick or MIG, requires two hands and possibly a foot to weld making tacking and some working positions awkward, same shielding gas cylinder issues as MIG

Spot welder:
light steel: good
other metals: no
Advantages: V inexpensive, no consumables used, no appreciable heat distortion, instant proficiency
Disadvantages: not useful for much more than tacking together two sheets of metal along an edge.

 

Thats welder types (covered very well), but are you covering the cutting as well? Plasma.

 

Ax,

Thank you. That was EXACTLY what I mean't.

The last one you listed - spot welder. Would that be the same as "stitch welder" i.e. Eastwood's part # 19045 per their catalog/website ?

I have a lot of sheet metal to weld in the next 8 mths or so. I have a flux core welder (not able to adapt gas to it). My son - Ramsay can stitch it with said welder (and get good penatration) but I'm worried about burning out the welder with the constant stop and start. ( I just blow holes in sheet metal, but he's actually in college to become a welder so it stands to reason he'd be better than me).

I'm on a very tight budget and a new MIG with gas is outa the question....

Thanks,