Question for our metal fabricators!!!
 

I would like to know the ''KEY'' to this type of weld. Is it metal thickness,welder settings, technique,mig ,tig ?????? I have really been struggling with this and I'm at wits end. I have to do some work to my outter wheel wells and I'm not at all happy with the final result. I need to get this dialed in so any pointers would really help. I used Jasons car (WAR) as an example of the type weld I'm struggling with..... My welders are Miller 210 mig Lincoln 110 mig I do have a new Hobart Tig but I have no Idea how to use it yet......

Fit up is the start, get it lined up perfect! Sheetmetal clamps help alot too. Mig works for me. If you have any questions feel free to call. DeWayne

This type of welding is driving me nuts too. I have a flux core mig and it just seems to blast through the metal even on a low setting. I gave up for the day and will probably end up replacing the part I was trying to salvage. I figure by the end of the project I'll be a novice sheet metal welder.

One thing that did help a little is making sure I try to keep a shallow angle between the MIG tip and the metal to be welded. If that angle gets too steep, it seems to just blast through the metal. Just an observation on my side but I'm a beginner.

Once you have the gas/wire speed/heat setting dialed in and butted panels have small gap,it should come out like you want ,has worked for me. Obviously you will need correct size wire for thick/thin steel

Though there is a noticable difference between machines,you still should be able to manage to get a good weld. I've had a Miller for about 13-15 years of dependable service,it finally gave up and needed some sort of switch ,so I retired it and replaced it with my back up Lincoln welder ,which had better penetration,overall cleaner,smoother welds,but after couple months of use I decided to get Hobart because Lincoln kept acting up,wire kept slipping,getting stuck,I called independent repair shop and the tech told me to buy Miller or Hobart,because they very rarely come in for service,but always fix Lincolns, so I will never buy another Lincoln.

I use a Miller 210 for almost everything with .030" wire.

I also use a Miller 210. I use .023 wire for sheet metal and .030 for heavier items. Gas for everything. Adjust your gas flow and play around with the heat and wire speeds. The chart on the machine isn't alway nuts on. For plug welds I usually adjust the machine up to the next thicker gauge of metal, so if it's really 20g I'll go 18g etc. I little hotter.

Make sure the area is ground bare and clean it if you need nice welds.

If the gap is too big it is easy to burn through. Like others have said take your time to "fit" the metal and gaps.

Wes

same here, except i get lazy and hate changing wire so small sheet metal projects get .030. if i know im doing a lot, i usually change to the .023.

i love my 210, but now wish i would have spent the extra for the 251. there are projects where i need the 2.5 tap which doesnt exist.

What you are looking at is a mig or tig tack then ground. I mig tack in place, and then tig if sheetmetal as in the pic.

Mario --


Welding has very little to do with the "machine" and very much to do with the operator... It's like a golf swing -- if you suck -- no amount of money spent on clubs will help. If you're good - you can hit any club. Having said that there are a few things that you can do to help.

CLEAN CLEAN CLEAN not only the side you can see - but the back side too! CLEAN!

Fit up is critical! Poor fitting pieces are a nightmare and the increase in skill required to weld them increases exponentially!

When tacking - I snip the wire at an angle - like 45* This make a good initial contact and actually takes less voltage to get the weld started. It also makes the tack with pure clean fill metal. I snip - tack - snip - tack.... Wire is CHEAP. Watch your "stick out" - tacking is best done (for me) with a little shorter stick out than if I'm running a bead...

I like to tack CORNERS first. Heat runs to the corners... and by the time you get there - they're already way hotter and tend to just blow.... So I go all the corners - then the middle of the piece centered between the corners so the metal doesn't start to bow or warp.... cooling as I go -- then in between each of those tacks until I'm down to an inch between tacks or less....

TACKING is one of those things where you really really need to be able to SEE!! If you can't see your work and see exactly where your tack is going and what is happening to the metal then it's hard to do. Once you're really good at welding - then you don't even need to look - but until then you need to be able to really see your weld! Play with the darkness of your helmet. Too dark and you can't see and too light and you're seeing spots all day! LOL.
Practice these settings on scrap at the wire feed and settings you're going to use to do your work.

I usually angle my MIG wire at the BIG PIECE of the work -- rather than trying to aim for the gap... the big piece is more "solid" and usually your GROUND is connected to the big work... so your tack will get off quicker -- and the puddle will gap over to the edge of the filler piece... if that makes sense...

I MIG Tack and TIG to fill the gaps -- because grinding TIG fill rod is far easier! But TIG takes far more skill so just figure you'll have to be careful grinding... :_paranoid TIG can also be hammer and dollied to flatten and control the warpage and the amount of grinding required.... and MIG wire is just too hard to do that with.

Tacking is all about heat control and most "newbs" I've tried to teach are just on the weld too long so they burn thru.... It's kind of a timing issue... and just takes a bit to master but it's not hard that's for sure. If I can do it - you sure as heck can!
:thumbsup:

Dude! There is only one thing to say here - and it's not meant to hurt your feelings -- but FLUX CORE is for farmers repairing tractors in a field where carting gas out there is too much of a chore. Stop using FLUX CORE to do car repair welding unless you're just welding up a jalopy frame.

I'm aware and I will stop once able. No worries. :thumbsup:

I'm no expert, but flux core can weld fine for beginners. Not all of us can buy all the best tools at one time. You'll find you can weld thinner materials easier when you switch to the bottle. :cheers:

Hopefully, not too much of a hi- jack....if so, please disregard.

I have also done the mig to tack, then tig to fill in with good results. As Greg said the ability to more easily grind the tig filler and hammer and dolly it helps a ton. I'm very far from great at this BTW, but I try.

Has anyone used "ez grind" mig wire before? I haven't, but am curious about it. It supposedly has properties closer to the tig weld for grinding and hammer and dolly work.

Oh and fit up, fit up, fit up is huge........i struggle sometimes to pitch a patch in the trash, but if it isn't right......do it and make one that fits right. You will be better off in the end.

How does Lincoln's Superarc L-56 wire perform in the OP's situation?

Some folks aren't aware of the limits of flux core -- so I'm glad you are. I know it's an extra expense etc to go gas --- but is truly worth it. Flux core is just kind of a crude way to try to do thin materials that hot rodders have to work on. :cheers:

Bottle lease and gas is cheap. I own my bottles, but that also limits who will fill them for me.

LOL but I so agree. Get the gas and get to welding some nice stuff!!!
Wes

I am using the ESAB ez grind. It does seem a little easier to work with than standard mig wire. I found out about it from a fabricator at a rod shop.

Talked to Jason (WAR) yesterday and he set me straight. I was making MANY mistakes. But he has me dialed in now, so it should go a little smoother . Will see, if not he's getting a plane ticket real soon!!!:D

Good to hear buddy!

It is one of those "ah ha" moments when all finally goes as it should.... and then you're off and running! Today a patch panel - tomorrow an entire tube chassis!
:rofl:

Ya..... All I have to do is apply it now Greg!!:D

Any tips for the rest of us newbies?

I'm always looking to learn some tips and tricks....dont be shy Mario....

Well my mistakes were numerous! First the wire I'm using is .35 I had to change that to .23. My gas preasure was to hi I had it at 40 brought it down to 20. I also learned.... SLOW DOWN and keep everthing cool, very important.. Jason also told me that he prefers not to but the metal up to tight he likes to leave a little gap. It gives the metal a little room to move around. I will start with the recomended settings on the machine and then adjust from there. I was all over the place with my wire speed and voltage. Make sure you can see what your welding!!! This is one of MY biggest problems, it sounds crazy but it sure does make a difference I tried it a little yesterday. Bought some new lights and man I can see!!!! Then we got into grinding the welds and I never thought of this. Jason uses a angle grinder with a cut off wheel instead of a grinding disc to first grind his welds. This knocks down the high spots of the weld with out thinning the surrounding metal. A big problem I was having,as I was grinding the weld to knock it down I was thinning the metal around it so when I wanted to fill a little spot I would blow right through and then start wandering all over the place chasing the holes I kept making. Next thing you know I have this big blob of sh^t . Now I have more of a mess!! I really liked this tip from Jason I think this is going to help me alot.. This may be basic stuff for alot of you guys,but it really set me straight and gave me direction instead of being all over the place. I have a starting point now. Now its up to me. I can't say enuff about Jason he was a huge help to me.

Awesome! THanks for taking the time to summarize!

Mario, to clarify, I do fit up everything tight, Tig Or Mig. Fit up and lots of tacks as you go so the two planes of the metal are perfect and hold dimension is the most important thing. I said I like to tig everything and hammer and dollie the weld as I go. If you don't the heat and cooling will draw them together and start warping panels. Thats why you need to stretch the metal. But,If you can't tig or just have a Mig It can be done. You want to set the machine as low as you can but still get a good bead and penetration. And I don't mean pull the trigger and take off. On off on off and cool the weld. Trigger in the right hand blower in the left. If you start with a gap and just start tacking away the cooling will just draw the part closer as you move down the piece. Just try to fit it tight and lightly score it with the edge of your cut off wheel after it's tacked up if you need to . If your blowing through it's to hot or your torch angle or approach to the weld is wrong. If it bird turd and poor penetration it's to cold. I found you can get good results with the mig if thats all you have but the welds will be more brittle to hammer and dollie. A good 110 mig and 023 wire (no flux core)is all you need. Those 180's and 210's are just to big for light gauge work, they like alot of heat to work.

The mandrels you want to use are the Matco part #HMANF15.

Hope this helps. Don't know if info is right or wrong but works for me.

I did'nt have my notes.:_paranoid I was just going to change that. I think your results speak for them self Jason:wow:

These pictures from Tyler's 50/50 car might give you some idea of how it is done. The fit is CRUCIAL for Tig welding. You cannot get great results with a Mig. You can do OK, but not what you can with a Tig. The fit up is super important. Then you need an air hose and and lots of patience.

Practice, Practice, Practice, Practice..... You can always improve
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super cool-whiz-bang- Michelin slicks. Rims are ugly though.
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As for a gap.... I was told that with MIG you should have a gap about the same size as the wire diameter....always seemed a tad wide to me.... I try to shoot a bit less than that.....

So for MIG stuff....when do you hammer and dolly it? say you are doing a square patch panel 6 x 6 inches..... do 4-5 tacks per side and then hammer and dolly?....do you grind down those first tacks before you do it? hammer and dolly direct on the welds....all along the edges? work from the middle and work out.....I dont have much experiecne on the hammer and dolly stuff....

Ned ---

Nobody hammer and dollies MIG... it's too hard. You end up just wrecking a perfectly good body hammer. LOL

If you do this -- you have to be QUICK -- weld an inch - drop the torch - grab the hammer and dolly and work the weld flat. The dolly is an "anvil". Doing this wrong and the metal grows and you have warpage... hot metal tends to be more pliable... it's why we heat stuff cherry red to bend it etc... when you apply this principle to thin sheet -- it becomes an "art form".

It's a skill that needs to be "acquired"... ya have to mess up a few panels and have someone with you to show you how it should be done.

It's like grinding welds.... there are some that can see what they're doing and only knock the weld down -- and others that just run the grinder and end up with a places the thickness of tinfoil... they just don't know it. LOL

Funny about this hobby.... it actually takes some skill to do some of these things and we all - including me - want to be fabricators - welders - suspension engineers - engine builders... and do all of this one hour per week with no prior experience. <belly laugh inserted here>

Try long enough - and you can get the hang of it. That's why it's a great hobby!

I'm saying this not because I can actually DO any of it -- I'm saying it because I've tried and failed enough to know some of the pitfalls and the learning curve can be quite steep. I only wish I could be a clone of Tim... or others here. It's why I keep telling the shops "I'll work for free - I'll sweep the floors - just so I can hang out and learn some of this stuff". So far... no takers. They seem to be smarter than that. :faint:

I shoot for almost no significant gap when making patch / filler panels...Maybe .010" all around... You just don't want the filler piece to be tight in the hole when "cold", since it can bind/distort when it expands when you start welding on it...

You also want to dial in your heat and wire feed such that your weld bead lays out almost flat, as opposed to being a big "log" of welding wire bead that is sitting way up high that you will have to grind a lot down. As GW already said you don't want to be trying to hammer and dolly to manipulate weld sites.

To avoid distortion make many small tacks to get things in position, carefully grind those tacks flush, then clean all of it and prepare for the actual welding...Do about an inch of bead length at a time, let it cool, keep a wet rag nearby to help cool off the nearby areas...

.023" wire all the way... That one change will probably be the biggest help... You also probably only need between 12-15 CFH on your shielding gas. You only need enough to create the shielding environment, no more than that.

Thanx for all the input guys!!!!! I have a LOOOONG road ahead of me so I really need to get this right.

I couldn't agree more. I've tried both Mig and Tig many times and the Tig is simply the best for this. Cooling the tacks with the air hose helps greatly as well.

Mike

Everything that has been sad here about purity, tight caps and useing tig is 100% true.
But if you still do burn it through with mig, this is the tool/ a way that will rescue you.

http://www.harborfreight.com/media/c...image_7944.jpg

Put this flatly and tightly behind your coming big cap weld and tack. Maeby little longer that normal, you need more stuff cos bigger cap. You just have to practice how to use it.
If and when it burn through molten weld will be flatten in the surface of the copper and sence mig welds wount stick on copper, it will spread around and stick arounding sheetmetal edges and you will be saved. And sence copper is good sucking heat it will cool the weld after as well.

You can weld up big caps and grind them flat after.

Or you can use a piece of aluminium flat or block for withdrawing heat from welds. They work also. If you have a straight edge block of Al, you can use it as welding helpper for 90' angle and heat remover.

Again, this is not the way you want to do it, put its the way you can save stuff when you screw them up.

As myself, I havent never ever needed to use this.:lol: I have heard all this from a friend ;) ,have not :lol: :lol:

For cooling welds, I have use this kind of simple but effective device:
Take a normal (coke) bottle, 0.5 litre is just fine.
Take the cap and drill a hole on the top of it, just little pit smaller that the hole in the bottle it self.
Then put a piece of fabric, welding blanket or something that is not likely to set on fire or melt instantly when comes contacting hot weld.
Fill the bottle with cold water and screw the modified cap on. Now you got a welding cooler ready.

Put a tack and with other hand press the bottle (cap first) on that tack and squeeze a bit, cool water will cooled to spot and no excess water all over workplace and yourself.

[QUOTE=ironworks;326384]These pictures from Tyler's 50/50 car might give you some idea of how it is done. The fit is CRUCIAL for Tig welding. You cannot get great results with a Mig. You can do OK, but not what you can with a Tig. The fit up is super important. Then you need an air hose and and lots of patience.

Practice, Practice, Practice, Practice..... You can always improve


What rod are you guys using for this ?

Thanks,
Brian

[QUOTE=speedfreak;330743]I'm learning that you have to get the metal as tight as possible. I found this out real fast. You try and fill gaps with the mig and you always wind up with small pin holes from a hot edge. I'm on my third set of wheel house's I better learn this fast its getting expensive! I have a new tig but I'm not even thinking of pulling this out until I learn how to get this mig thing figured out....

I've made these for years - but I use copper plate (thin) which you can just cut or bend to your need -- or I smash the end of a piece of copper pipe. Not having a handle that is at a preset angle and length, is handier for me than a tool like this. Works the same either way -- there's just handier "versions" getting the same job done.

Once you really have a handle on welding you find you don't need this kind of stuff 98% of the time I can buzz a hole up without this aid... but these kinds of tools (homemade or otherwise)... can help a guy out in a hurry.

If you're by yourself -- a small piece of copper just snipped off a sheet - can be held in place using a magnet spanning the copper (since copper isn't magnetic) as a backer... Finding something - or someone - to hold this tool takes more time than my quickie fix. LOL That has worked for me if I'm trying to slick a firewall where your arms won't quite get there from here. :_paranoid and the area you're plugging is too small to make a fill piece.

GregWeld, your right on the money.
This is a handy tool if you weld some thin or damaged material.
Sure it can be duss hole close but this do it faster and most important that this draw a lot of heat away.

I also use a piece of coppertubing, 1/2" hammered the other end flat and have bendet to fit what every I do with it.

I have seen somebody to use those hold-down toggle clamps combined with a piece of copper tin for one mans working.

Again, I'm not a pro just a everyday welder how wants to get better doing it.

[QUOTE=DOOM;331644]Honestly, Trying to get it figured out with a MIG is totally different then a TIG. If you scribe tight light to trim and fit you can tack it up with the MIG. But learning how to weld sheetmetal is like trying to learn how to ride a bicycle when you want to ride a unicycyle. Just start now with the tig on 20amps and maybe buy some MIG wire to not build up your welds to much while your learning. The TIG welders out number MIG welders 5-2 in my shop and all my MIG welders are 110 volt except 1. I have 1 220 volt MIG.

Spend your time learning how to trim and fit sheetmetal very tight. Then learn to tack with the TIG.

Learn to cut gap and fit like this
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