Engine Compartment Bracing

[Drax240z]

Sorry shock, there is no way to get a MIG weld to look like that. Close maybe, but that is distinctly TIG.

 

Hopefully by the time I get to welding our race car frame this year, my welds will be close to that! Getting there! TIG is so addictive too, once you start getting decent welds, you just never want to stop welding with it.

[Mikelly]

Unfortunately, I have to agree with DRAX, and I'm making a chunk of change off selling you guys MIG welded stuff... That I weld up. Those welds are awesome and it would depend on some seriously perfect construction material, and the right welding equipment AND a skilled welder to get anything close to those kinds of welds.

 

Mike

[Guest Anonymous]

I had a friend that could both tig and mig, and while his mig work was darn nice, it didn't equal the tig welds in appearance EVER, he was a excellent welder with all the certs so I have to agree with Drax and Mike. Theres nothing wrong with MIG on steel, or even aluminum if its heavy enough (no lighter than 1/8" matl' with migging aluminum or its a mess to deal with, but fast on thick aluminum parts), but it will always look like a mig weld no matter how pretty you try and gussy it up. Strength wise, arguably the mig might actually have better penetration but that is down to the TIG operators ability to use the machine properly.

 

Regards,

 

Lone

[Guest Perry]

I agree definetly TIG. A really clean aircraft quality MIG weld will be messier than that, but also MIG weld beads are usually larger and a bit more convex in shape (when it's not a flat but weld). TIG welds leave a bit less filler on the surface resulting in the concave appearance at joints, plus it is cleaner. I've gotta get a TIG for my shop, although I'd probably still use the MIG a lot for convenience when I don't care what it looks like.

Perry

[ZROSSA]

While we are on the subject of welders;

 

I am new to mig welding and spent last weekend playing around with one. I am doing mostly body panels (1mm) and some bracing with nothing thicker than 3mm. I seem to be getting good penetration but my welds look a mess with a big bead left over the welded area. I have the wire feed down really low and have even tried pulseing the weld to try to get a flater weld. This works a little better. The gas is argo sheild and is set at around 4 psi. I really would like to get the welds flater so i can but weld sheet with out to much clean up. Also is it beter to push into the the weld (hand is over what you just welded) or pull away from it( hand is over what you are about to weld). Any other good advise?

 

Thanks Guys

 

Douglas

[blueovalz]

I had the same problem, so I went to an .023 wire (smaller) and it helped a lot.

[Guest Anonymous]

As far as the direction, personally I think it matters what hand you use. If your right handed, going to right to left works well, left handed the other direction. The reason, your left hand (if your right handed) will be moving over still cool metal, where as if you went the other way your left hand (which I use to steady the end of the torch and I rest my left outside hand on the piece or table) will be on hot just welded metal.

Technically my welder friend used to say to me 'Drag a stick, Push a mig', he was refering to dragging a arc welder rod to weld, and pushing a mig torch to weld away from you or the torch as it were.

As long as the speed is right, either direction will yield results.

I agree with Terry, smaller wire will help, if your using like .035 like my lincoln comes with (shielded unfortunately, I'll fix that soon, already have the gas) going down to .023 like Terry suggested will put less fill into the weld flattening it. By doing that you should find you may even need to turn the wire speed up as you'll have less heat too.

 

Regards,

 

Lone

[Brad-ManQ45]

FWIW - not much I'm sure -

 

I will have to disagree with some of you who say mig can't look as good as tig.

 

I have examples in my garage from the class I took(T, butt and lap) that look like the "stack of dimes".

 

I WILL agree that the bead will tend to be somewhat bigger.

 

Having control over both current and wirespeed helps.

 

I personally prefer to pull when welding flat and go from left to right. It's a little harder to see where you're going, but the benefits of the better view of the puddle outweigh this.

 

As I will be welding on a rotisserie, I will be flat as much as possible.

 

When I finally get a digital camera, I'll take some pictures....

 

I chose MIG because I will never be welding thin aluminum - a trailer mayber, but mostly body panels and tubing.

 

I started having a blast in class when my welds started looking decent consistently - getting the settings on the machine right was a BIG factor.

[johnc]

Douglas,

 

4 psi for the shielding gas sounds very low. I run mine at 30 psi. As the others have said, a smaller diameter wire helps a lot.

[260DET]

Gee all you experts with modern equipment I've got an old stick welder and have recently 'discovered' 2mm (14gauge?) rods which are good for most automotive type work, except thin sheet metal, lots of penetration. But if its plainly visible, off to a pro I go.

[ZROSSA]

Thanks for the reply's,

 

I have been useing .8 ml which is .032 inch i think. I will turn up the gas and see what happens. The guys at the shop said to turn it down untill it started to spatter a lot then turn it up a bit. I have books on welding but havent been able to find them yet. I am having a great time using it though. I have to stop myself from making unnessesary brackets and overdoing the chassis reinforcements. This is on a race car so looks are not all that important but strenght is. I just want to get better so it is easier when i start on the z body.

 

Thanks again. Have a good w/end all.

 

Douglas

[Drax240z]

Brad you can get the stack of dimes look with a MIG, no doubt. However, those welds are definately TIG, just from colour and shape. I'm not trying to say you can't have nice MIG welds, I did our whole racecar frame with MIG welds and they can turn out great with the proper settings. (which are a huge factor!)

 

As for left to right or right to left, its really personal preferance. As long as you know what the results are of each, then you can adjust to make a good quality weld. Once you start TIGing though, its really hard to go left to right if you are right handed and still use filler rod!

[Guest Anonymous]

Funny that this turned into a welding discussion, because I just completed a MIG/TIG class at the local community college. One thing we did there that nobody here has mentioned is MIG with a flux-cored wire that requires gas. It's awesome! Penetrates better and is stronger than either normal MIG or flux-core wire. And it's prettier! I neglected to find out what it's called, but you can bet I'm going to get some for my Miller 175.

Mitch

[Z-TARD]

ZROSSA, For MIG welding, you should be pushing into the weld area (hand over top of what you have already welded) There are a few ways to gett flatter beads: 1) turn your argon purge gas up, it can flatten the weld just by the extra pressure. If you have too much argon flowing through your gas cup, it will begin sucking oxygen in with it, a venturi effect similar to a carburator sucking in gasoline- This is a bad thing. You may want to find an argon gauge with a flow-meter built into it. It should flow at about 15-20 CFH (Cubic Feet/Hour) You can also flatten your welds by turning up your amperage, although if you are welding on sheetmetal you are very limited on how high you can go. As you turn your amps up, you will probably notice that you will need to turn up you feed rate for the wire as well to keep it from spattering (pidgeon $hit) all over the place. Another way is to manipulate the mig gun from side to side as you progress forward, spreading the weld out over a wider area.The best way by far however, is to take a step away from the mig welder, request permission from your signifigant other, and go out and buy a TIG machine....

[Brad-ManQ45]

I had no doubt that it was TIG, just wanted to dispute the "ugly" part of the comments. MIG doesn't HAVE to be ugly, you just need to practice and adjust to the machine and its' capacities.

 

Hey Mitch - I've got a Miller 175 too! Haven't used it yet (wiring garage this weekend - got put on hold by honey - do's). Then the rotisserrie.

 

All my welding in class this year was stick and MIG - the MIG on big Lincoln machines w/separate wirefeeder. Loved it when jerks would monkey w/the settings between classes (noone supposed to be in there) - a little tweek made a BIG difference.

 

Machine to machine made a difference also.

 

As hard as stick was with TWO hands to steady the stick, I can just imagine TIG, and would have to agree on right to left for right handers - pulling. I really DO like seeing the puddle as much as possible.

 

After I got pretty good w/stick they turned me loose on the MIG and once I adjusted my speed and caught on to adjusting the amps and wirespeed, I was pretty proud of (some) of the welds the first 4 hour class. This got a lot more consistent the next 4 weeks.

 

OK that's enough, jusat wanted to offer some tips to those MIG'ing from someone who just got out of classes and knew NOTHING going in - if I can do it ANYONE can.

 

I would like to mention the Hobart Welding Talk forum as an excellent source of info for people starting out - it helped me while I was in classes. Hobart and Miller are made on the same assembly lines for those that don't know...

 

Hobart Welding Talk

 

Keep up the GOOD welding!

 

brad

[ZROSSA]

Thanks fellas,

 

You are the best. Turns out that the gauge was in bar and something else. I just talked everyone into the mig so a tig is out of the question. The guy that put my cage in did it with a mig and his welds are not that far or the guys that tig welded Ross'. I will work at it, after all it only a corolla and a race car. Will save the good stuff for the Z.

 

Douglas

[Pop N Wood]

Zrossa

 

I am experiencing the same problem you are. I don't know how to make flat MIG welds. I wonder if it is even possible. It seems like the only way to get a decent MIG weld ends up leaving a nice round bead. If you have DC welder you can try reversing the polarity. This helps some. But even with that, you still have to adjust the wire speed to make the buzz "sing". This seems to add more filler than I want. None of this is really a problem since the welds are plenty strong, but it would be nice to get prettier welds.

 

When I was a kid I welded everything with a torch. I use to get nice flat welds with evenly sized puddles ("laying down quarters" as my brother use to say). This was possible because I could move and angle the torch to place the heat where I wanted it (actually move the puddle) and then dip the welding rod in and out to only add as much filler as I wanted. TIG is a lot like a torch in that you can back the rod out and really work the bead. MIG welders don't give you separate control of the heat and filler.

[Guest Anonymous]

Well actually, migs do provide adjustment of heat and filler material, I assume you meant real time like tig where you can back out of the trigger or footpedal to lose a bit of heat or lay off the rod if you want. Mig is set via knobs as you know.

I personally don't like straight argon for Mig, I know others say, hey its the cleanest blah blah blah, perhaps they're right, but the buzzing and weirdness of a argon shielded weld I just don't dig.

 

If I had to use argon, I'd get a mix of that and carbon dioxide, and personally we used straight c02 and the welds looked beautiful and were still plenty strong and you get more of a 'crackle' sound out of the welding instead of this weird buzzing sound and heavy splattering of material.

 

Granted it may have been a adjustment problem as I wasn't used to welding with argon, the times I did was usually because they delivered the wrong gas.

 

I know I did manage to burn a dime sized hole in the top of my foot (snuck around the tongue in my boot, talk about dance party) using Argon, after that I lost a bit of respect for it. For my money in a non-professional home use situation, C02 is much cheaper and the way I'll go, an opinion to be sure.

 

Regards,

 

Lone

[johnc]

Be careful about trying to get a MIG weld to look like a TIG weld. They are two different processes and have different results. There's a good change you'll compromise MIG weld strength by trying to get it flat and looking like a "stack of dimes."

 

I've noticed that the welding world (at least in the motorsports arena) there's a lot of emphasis placed on asthetics. You generally pay a lot more for the nice TIG welds and in most cases the welded part is a little lighter (based on material choice) but not any stronger.

 

A good example is the roll bar my wife and I just put into her Miata. We paid $450 for a MIG welded, 1.75" .120 wall DOM bolt in bar. A fabricator friend looked at it and made some comments about the MIG welds.

 

I asked him how much he would charge for a similar roll bar. He said $1,500 to $2,000. It would not save much weight because the SCCA Solo1 rules specific .120 wall for ERW, DOM, and CroMo.

 

So, I asked him if he was paying for it out of his pocket, which would he choose? He said our bar looked pretty good.

[peej410]

Originally posted by johnc:

Be careful about trying to get a MIG weld to look like a TIG weld. They are two different processes and have different results. There's a good change you'll compromise MIG weld strength by trying to get it flat and looking like a "stack of dimes."

 

I've noticed that the welding world (at least in the motorsports arena) there's a lot of emphasis placed on asthetics. You generally pay a lot more for the nice TIG welds and in most cases the welded part is a little lighter (based on material choice) but not any stronger.

 

A good example is the roll bar my wife and I just put into her Miata. We paid $450 for a MIG welded, 1.75" .120 wall DOM bolt in bar. A fabricator friend looked at it and made some comments about the MIG welds.

 

I asked him how much he would charge for a similar roll bar. He said $1,500 to $2,000. It would not save much weight because the SCCA Solo1 rules specific .120 wall for ERW, DOM, and CroMo.

 

So, I asked him if he was paying for it out of his pocket, which would he choose? He said our bar looked pretty good.

john where did u meet your wife, i need a girl that is that into motorsports