Welding tips and suggestions?

[RallyBob]

Originally Posted by azopelnut What is the opinion of the welders on the forum of "flux core" wire? I just picked up a used Lincoln Welder that doesn't have gas. I want to attack some panels on my GT and Ascona (both midwest cars with some rusty panels)

Use caution, since not only is it more difficult to get a clean weld with flux-core wire on thin materials, it can also leave a layer of flux which is corrosive (like brazing). If you paint over the flux, it's only a matter of time before the repair will 'undo' itself, as the flux itself will corrode the repair. That said, it's ill-advised for permanent body panel repairs.

bob

[tunepipe911]

My opinion;(28 years experience),welding is a passion,some can learn it ,some will learn it ,some are born as a welder others will never be able to weld
mig welding is the best for car-repair,in other cases,the position off the arc is verry important to start the welding(aprox 70 degrees)
have fun!

[neuropel]

Paul,

I'm pretty new to welding, but even with my limited experience I'd say you won't like the flux-core at all. Even a good weld with the flux core tends to leave splatter everywhere. I had no idea that it also left a corrosive residue behind as Bob pointed out! I think the flux core might serve well where you're out in the field with no provision/space for gas bottles, but if you're working in a shop and have the space for it, I'd definitely go the gas route. Does your new welder accept gas (Id' be surprised if not)? If you didn't get a regulator with it, you can pick up a good quality one cheap on ebay.

One other thing I've been amazed at is how much sheet metal can warp. The recommendation by many to use "stitch" welds for sheetmetal patch repairs works great. I have a Henrob Oxy/Acy torch that I'm learning to use fairly well. It takes a lot more practice to get decent welds with it, but I can definitely see why everyone recommends learning with O/A systems. With the small Henrob tip and some tig rod, the process gets very similar to tig welding. Additionally, I've noticed that the gas welds are much more malleable afterward than mig welds. Plus, it works awesome with aluminum if you have the correct lenses that allow you to see the puddle!

Todd

[Paul]

Okay, just to pacify my anal, technical engineering self.....

Its "Spatter" not Splatter.... ya know... with out the "L"

[neuropel]

Correct! And to think I was more worried about "malleable"...

I should keep the following in mind:

Metal "spatters"
Brains "splatter"

[Washout]

Originally Posted by Paul Okay, just to pacify my anal, technical engineering self..... Its "Spatter" not Splatter.... ya know... with out the "L"

Whatever helps you sleep at night.

Once again the entire point is ignored so we can pick the fly speck from the pepper.

[namba209]

Originally Posted by Washout Whatever helps you sleep at night. Once again the entire point is ignored so we can pick the fly speck from the pepper.

Not really. It's being grammatically correct, the idea is so that if anyone uses the search engine, types in the correct word/phraseology, they get the info they're after. Nit-picking? Sure, but the search engine doesn't decipher typos, like we do in the Chat Room.

Now to get this back on topic, when I was in A & P school, I had to use/learn all the metal bonding techniques. After the instructor saw my various attempts, my "practical task" was to braze a couple of sheets of metal together. I can assure you that was an embarassing moment, and the reason I had a "pro" do the welding on Willit? With a uni-body, structual integrity is paramount and a half-a$$ed job just won't get it.

[RallyBob]

Originally Posted by neuropel One other thing I've been amazed at is how much sheet metal can warp. Additionally, I've noticed that the gas welds are much more malleable afterward than mig welds.

Very much worth noting Todd.

As of last week, I'm back to doing some part-time restoration for a local shop. On my first job last Friday I had to repair a floor pan on a 1926 Buick, just the edges were rusted. I chose to TIG weld the new 20 gauge steel to the old 20 gauge (slightly rusted, therefore thinner). I put a tack-weld every 3-4 inches for starters, then lightly planish (hammer) the HAZ (heat affected zones). Even with the low heat of a TIG (I was using 20-30 amps), there is always shrinkage from heat, causing warpage at the new welded seam. But a light planishing will re-stretch the metal to it's original shape. Be careful not to get too carried away with the stretching.

Then I will use a .040" filler rod and weld 1" sections every 3-4 inches. After every two of these welds, I will again lightly planish the HAZ. I continue this sequence until the panel is fully welded, and when I'm finished it is barely warped. Yes, it definitely does take time, but this is pretty standard procedure for restoration work and high level fabrication. Almost nobody uses a MIG anymore for higher-end body repair and fabrication, other than for tacking purposes. Lest you think this time is wasted, imagine the countless hours you can potentially spend trying to make the warped panel straight again if you didn't weld carefully, or the process of applying and sanding bondo trying to cover up the warpage!

Since I'm butting the panels up tight before welding, and using low amperage and small filler rods, the surface of the weld merely needs to be sanded with a 90 degree grinder fitted with an abrasive flap wheel. The back side of the panel needs even less sanding BTW.

These abrasive flap type wheels remove material quickly (made easier by the soft welds), but they don't produce as much heat as a hard sanding disc or grinding wheel. This is important! If you turn the area blue in color from sanding/grinding, you've shrunk the metal again and warped it once more!

Off my pedestal now, sorry for the long speech!

Bob

[baz]

fine words of wisdom as always bob

i love what can be done with a flap wheel so much better than just having an angle grinder and cutting discs

[CoriolisSTORM]

Well, update:
The sticks we were using were I think 6010 (that seems right) We got the 7018 in today and that is a lot easier to get started, but if you get it stuck, it sticks good! And unfortunately, I have also discovered that the coating is sort of brittle on the rods as well. That being said, these are nicer welds without a lot of spatter around the piece. Thank you all for the help so far, listening is a must I know, as is watching closely. We do not have auto darkening helmets, so those are out of the question. 8 straight hours of welding a day, 10 days straight, and I'm just finishing with my second. I think I'll figure it out by then. Boy am I tired too.

[Paul]

Hobart has a good web site that might be of interest.

Hobart Welders: The Power to Change Your World

The Weld Tech link has a very active discussion forum, even a thread on headers. Also check out the Weld Links page.

[CoriolisSTORM]

Thank you Paul, that is a good, useful link.

[namba209]

Originally Posted by CoriolisSTORM We do not have auto darkening helmets, so those are out of the question. 8 straight hours of welding a day, 10 days straight, and I'm just finishing with my second. I think I'll figure it out by then. Boy am I tired too.

Just a suggestion here. If your gonna do extensive welding or just on the odd job that comes up, do yourslef a favor and get the auto-darkening welding helmet. Check with your instructor to see if you can use it in class. They're your eyes and permanent spot blindness can occur from cumulative exposure to the arc.

[CoriolisSTORM]

Yep, I've flashed myself once or twice, and its not fun. I am all for protecting my eyesight.

[CoriolisSTORM]

Okay gents, I have a welding project I have to do tomorrow, and we are free to choose our own. Only things are, it has to be kind of small, and it cant use too much stock. (We have a limited amount on hand at any given time.) Any Opelish ideas or otherwise? Or any other really good ideas? Jeep ideas?

[roadings]

just to add a few thoughts... something that was taught to me was if your root pass sounds like frying bacon its' "going in" properly, of course that was on sch40 carbon steel pipe. i've seen welders take their eyes completely off of the weld in progress, hold a conversation and still get the weld to penetrate properly. the said weld wat then cut out of the system and used for the welders yearly test. he passed. of course the man had been welding for 45 years and had grown very aware of the sounds that he should hear.

[jerseyopel]

The weld engineer we had at the shipyard has his own site worth checking out. It is Ed Craig's WeldReality.com