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Tony Sestito
Tony Sestito PowerDork
6/29/17 2:45 p.m.

I'm staring down infinity with my 1979 Trans Am project, and I've come to the conclusion that I need to shape up my welding skills to the point where I'm not afraid to tackle the job.

I've dabbled in welding before when I had my Shelby CSX. I borrowed a friend's Hobart Handler 110V welder and did some flux core boogers, and that's probably the machine I'll be using this time around. I know that 220V is better, but that's not an option, and this welder did a fine job before, so let's not get into that.

Here's the way I look at welding: it's like playing an instrument. When I first picked up a pair of drum sticks at age 10, I had no idea what I was doing. I got basic guidance from the school band teacher, but my interest grew and I wanted to learn more. I listened to bands and watched videos until I got some basic technique down, and got a drum kit. I got better and better until I hit a wall. I signed up for private lessons and my skills grew exponentially to to point where I could be considered "good".

What I'm looking to do now is the "listen and watch" phase of learning, with a bit of the "doing" mixed in.

I'm doing relatively thin metal (heaviest is 16 gauge) and will be dabbling with MIG gas for the 1st time. I know the basics: good ground, prepping surfaces, and all that. I have gloves and a helmet already. Anyone have tips or good resources to help me out?

NEALSMO
NEALSMO UberDork
6/29/17 2:51 p.m.

Good thing is that using gas instead of flux core will improve your welds 1000% on it's own.

Youtube has plenty of tutorial resources at your fingertips. Watch some vids, grab some scrap metal, then have some burn time.

Have any Junior Colleges or adult classes nearby? I learned some basic skills (brazing and stick welding) from shop class in college. Never had any formal MIG training, but can stick two pieces of metal together pretty well. Sometimes I don't even need to grind my welds when done

Dusterbd13
Dusterbd13 UltimaDork
6/29/17 3:07 p.m.

Community college is where i learned the basics. Then just sheer practice.

Also, with sheetmetal repair, you will have to grind. So almost all the ugly goes away.

I prefer my 89 dollar harbor freight flux core for sheetmetal work. Just seems to do better with less blow through for me. Then, dress with a flap wheel on a 4 inch grinder.

stuart in mn
stuart in mn UltimaDork
6/29/17 3:10 p.m.

I second the idea of an adult class. I did one a few years back at a local community college; one night a week for eight weeks, and the cost was very reasonable. We had a pro welder for an instructor (his day job was welding at a nuclear power plant), ~1 hour class time each night, followed by ~2 hours of shop time with good quality equipment. It was well worth it.

For sheet metal a 120vac welder should be fine.

Driven5
Driven5 Dork
6/29/17 3:18 p.m.

If this is a musical instrument, it's a recorder. Sure a talented musician can always impress with what one can really do, but at the same time, just about anybody can teach themselves to play 'hot cross buns' on one. I tend to think of MIG as a Hot Melt Metal Gun. Just watch a few YouTube tutorials, get some scrap metal, and start practicing. Destructive testing along the way is good for validating your results. If you can take a class/lessons, that's always going to be the quickest means to proficiency at anything.

RevRico
RevRico SuperDork
6/29/17 3:18 p.m.

Weld.com has a really good YouTube channel, and weldingtipsandtricks is another good reference channel.

My local community college only offers welding in a certification program, but the local high school technical school has adult classes at night in spring and fall semesters.

Get some scrap about the size you'll be welding, like from a junk yard, and practice with it instead of just jumping onto the car and screwing up.

Otherwise, I'm following along, because of similar interest.

BrokenYugo
BrokenYugo MegaDork
6/29/17 3:28 p.m.

120 volt welders are sensitive to power quality, do your best to prevent voltage drop. 20 amp circuits, no extension cords or very heavy (10 gauge) extension cords of minimal length, etc.

With thin bodywork type stuff you're usually best off just tacking over and over until done, good guide on it towards the bottom of this thread.

https://grassrootsmotorsports.com/forum/grm/best-way-for-inexperienced-welder-to-weld-in-replacement-floor-pans/111784/page1/

pilotbraden
pilotbraden UltraDork
6/29/17 3:31 p.m.

I teach might and base metal prep for a work force development program at a community college. Practice is everything. When I learned to weld my mentor told my class that you can't be consistent until you have laid a mile of weld bead. Get in touch with me and I can talk you through a lot of the problems. I don't have time to type a long response right now

NOHOME
NOHOME UltimaDork
6/29/17 4:18 p.m.

The problem I have with flux core is that sheet-metal requires a stop-start method of welding. In essence, connecting a series of dots to form a long scar.

The reason that this wont work with the flux core is because the bead is covered in slag (flux) when you stop. This slag would contaminate the nest dot of weld.

But...I see where you are willing to go for gas. Get MigMix: that being argon CO2 mix.Below is a quick tutorial on a process that works for me. It revolves getting your rig dialed in so that a short burst with the gun held in one position will give you a weld dot that almost falls out the backside. You then start welding off the front sloping face of that first dot and let the molten metal slide/flow into the seam.

Hope this helps.

The other thing I will mention is clean metal. When you grind or flap wheel the seam, you need at least 1" either side to be clean shiny metal. And the backside is just as important as the front side.If the molten metal comes in contact with anyting that it can vaporize, it pollutes your gas shield and the boiling/evaporating smegma turns your puddle into fizzy pop that just drops out the backside of the seam. Wiping the seam with acetone to remove any grease makes a huge difference.

pilotbraden
pilotbraden UltraDork
6/29/17 9:01 p.m.

Do not clean the metal with brake cleaner it can kill you.

asoduk
asoduk HalfDork
6/29/17 9:14 p.m.

I learned at the local trade school. It was a great class and so much fun that I took it 4 times. The instructor didn't care and would help me with exactly what I wanted to learn.

Miller has some great videos online. They are what my instructor would show parts of in our classes.

The new welders out there are awesome too. The new Millers have pretty much autopilot for setting up for a weld. There is even a new Miller that can do Mig, Tig and stick all in one $1800 welder! (I have a Miller because that is what my local welding supply sells. I'm sure Lincoln has something similar. Hobart=Miller in a different color).

As others have said, use gas. Flux core is useful when you run out of gas and need to fix ___ right away.

Have fun! I love welding and probably take on way too many "help a buddy" projects.

Also, buy good safety gear. Never weld in flip flops. Always use a mask!

ClemSparks
ClemSparks PowerDork
6/29/17 9:20 p.m.

In reply to pilotbraden:

Is the concern here fire or inhaling poisonous gas or...? Just curious because Brake Clean is what I have seen used and used sometimes myself. And yeah...fire happens for sure.

ClemSparks
ClemSparks PowerDork
6/29/17 9:23 p.m.
asoduk wrote: Never weld in flip flops.

Damn...I can't use brake clean OR flip flops?! I guess I'm out of the welding business

fasted58
fasted58 MegaDork
6/29/17 9:23 p.m.

In reply to ClemSparks:

Phosgene

bearmtnmartin
bearmtnmartin SuperDork
6/29/17 9:38 p.m.

Push the puddle don't pull, keep the feed cable as bend free as possible, and done right it will sound like bacon frying.

stuart in mn
stuart in mn UltimaDork
6/29/17 9:45 p.m.
ClemSparks wrote: In reply to pilotbraden: Is the concern here fire or inhaling poisonous gas or...? Just curious because Brake Clean is what I have seen used and used sometimes myself. And yeah...fire happens for sure.

It's chlorinated brake clean you have to be careful of. They also sell non-chlorinated brake clean that is okay for use prior to welding.

jimbbski
jimbbski Dork
6/29/17 9:48 p.m.

The problem with brake clean is that some people with start to weld without wiping the metal clean and dry. If you do that you should be OK but it's best to not even use it.

BrokenYugo
BrokenYugo MegaDork
6/29/17 9:52 p.m.
ClemSparks wrote: In reply to pilotbraden: Is the concern here fire or inhaling poisonous gas or...? Just curious because Brake Clean is what I have seen used and used sometimes myself. And yeah...fire happens for sure.

You can use NON CHLORINATED brake cleaner, though it's not recommended to avoid any chance of mixup. DO NOT USE CHLORINATED brake cleaner, in the intense heat and UV light of the welding arc the chlorinated solvent decomposes to phosgene gas, yes, WW1 chemical warfare phosgene gas, it doesn't take much of it to destroy your lungs.

ClemSparks
ClemSparks PowerDork
6/29/17 10:07 p.m.

Cool. So I oughta be alright with non-chlorinated brake clean and flip flops. Game on!

I do refer to them regularly as "safety flops."

And the musty hay smell at our place is actually musty hay. Geez...I really need to stop welding in these conditions.

fasted58
fasted58 MegaDork
6/29/17 10:09 p.m.
ClemSparks wrote: Cool. So I oughta be alright with non-chlorinated brake clean and flip flops. Game on! I do refer to them regularly as "safety flops."

Or, to step it up a notch... Crocs

Tony Sestito
Tony Sestito PowerDork
6/30/17 7:44 a.m.

In reply to wheels777:

I'm probably about an hour from there. I'd be using Greg's welder, so there's a good chance it's the same one.

Tony Sestito
Tony Sestito PowerDork
6/30/17 7:46 a.m.

Thanks for all the responses! I'll be watching videos all weekend now.

icaneat50eggs
icaneat50eggs Dork
6/30/17 12:32 p.m.

I got a nothtern tool that does mig tig and stick for $600.

I used to say I welded, now I work in a chemical plant with real welders. it's not a welding rod in there hand, it's a freaking magic wand. Now I say they weld, and I make metal stick together.

JBasham
JBasham Reader
6/30/17 2:51 p.m.

NOHOME's technique works great for thinner metals, AND it's dead easy to get good at if you have a gas MIG rig. It just takes patience. But you still need to do the stuff you see in the videos about stitching, and get some experience how "big" the stitch gaps need to be if you want to avoid warps. But it doesn't take the same kind of practice needed to, say, MIG frame components or cage tubes.

NOHOME
NOHOME UltimaDork
6/30/17 6:48 p.m.
JBasham wrote: NOHOME's technique works great for thinner metals, AND it's dead easy to get good at if you have a gas MIG rig. It just takes patience. But you still need to do the stuff you see in the videos about stitching, and get some experience how "big" the stitch gaps need to be if you want to avoid warps. But it doesn't take the same kind of practice needed to, say, MIG frame components or cage tubes.

You are correct that this applies to sheet metal welding. I imagine it could work for structural if you wanted to run one mother of a powerful welder!

You mention warping the panel. Did some testing, and found out that the conventional method of jumping around, doing short stitches and letting cool in between was not as effective as just tacking the work with enough tacks to keep the gap, then going from one end of the seam to the other. The key was that I try to keep the HAZ an even width for the entire panel. You can get a rhythm going that will give you a uniform HAZ.

You will always get warp in a sheetmetal panel because it is mostly a factor of the molten metal shrinking across the gap as it goes from liquid to solid state and then even more as it cools.

Metal finishing a panel to a no-filler state is a beoch. I pretty much cant bring myself to care that much about a skim of filler.

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