MIG for vintage car restoration?

[norlander]

Weld up a welding trolley to take the welder and secure the bottle better, it looks as though it could fall over,that damage the regulator set and maybe the welder as well. If you move the welder around as it is in the picture,hold the bottle and steer the welder with the bottle.

 

[normspanners]

Good news, the MIG has arrived... its a nice piece of kit but frankly they could deliver it with the wheels assembled...

Hi by the way and welcome
I have Just had a thought looking at that photo and the extension lead dont weld with it rolled up like that, you will end up with a pool of melted plastic on the floor !!

 

[scourtaud]

I won't, I know about the extension lead thing, I just plugged it in to feed the wire.

As for the bottle, its actually quite secure, I've tried pushing it and the mig on their side and the back (with my brother making sure it doesn't fall over) and its not falling over anytime soon.
I will be welding a cart because I'd like to be able to better organise the cables and store the mask and other accessories but first I need to learn to weld...

I've tried fitting the correct gas regulator (I could've guessed that) and the B team that served me at the shop for the second time today gave me a left screw nut for the regulator outlet instead of a right screw so I'll be happy to see them again tomorrow... I've got the mig and the gas but right now I'm sooo annoyed....

 

[scourtaud]

So I've finally got all the right pieces and was able to try it out for the first time, first with 0.6 then 0.8 wire and tried every setting while varying the gas flow between 10 and 15 l/min. I only had some cheap supermaket rusted steel plate to play with and lets be honnest, I feel I need a lot more practice.

Only a few of the welds seem ok to me (still not brilliant), some are cleary not deep enough, otheres are soo deep it made holes in the steel (gave me a chance to try filling them up which went ok i think).

As for the L piece and the edge to edge welding, they look horrible and did not go smoothly but they both hold quite strong, couldn't break them with a regular hammer and if I try to bend the edge weld, its the steel that bends which seems like a good sign.

Here are the pictures front and back, please don't make too much fun of me, I still have very little clue of what I'm doing...

 

[mike 109444]

Just remember yo are not going to want to do long runs on car body panels as you will get blow through AND DISTORTION ! You need to do the "thin metal technique" See the tutorial on home page. Note also a backing strip such as a length of flattened copper pipe helps to stop blow through. Good luck with the project.

 

[norlander]

I can't see too well as I am on my phone, but the runs look pretty straight, the beads maybe a bit high?-but that can happen on thin material.
Do some tack welds -say every 50mm, then join them up,try short runs and 'pulse'-sort of repeated spot welds.
Do some runs on thicker material as well to try different settings.
Then get some square /rectangular tubing, 1.5mm wall,and weld up a cart/workstation for your GYS/clamps/tools etc-that will get you welding practice and you will end up with something useful.

 

[Barry-Lowe]

Welcome to the forum:

The GYS is a good choice for your task, in fact within the price range I doubt you will find better, a few members have them and rate them highly.

I'm after buying a Stirling 2500rm to do chassis and car panel work, would that be any good for a novice to get use to and would any one know the market value secondhand please

 

[scourtaud]

I'll be practicing again next week (off this week end) but I was wondering, what do you guys weld on and by that I mean the surface beneath the this you weld?

I need to buy some good steel and get more method on my practices... I just read the whole tutorial again and clearly, it reads under a completely different light now I've played with a MIG... The first reading only left me with notions, that I now understand much better.

 

[marlinspike]

Barry - probably best to post that question as a new thread in the Buying a Mig forum.

Scourtaud - we just practise our welding on an old Black and Decker workmate - which is a small wooden table or bench. Many people on the forum use a metal welding table. Making one yourself would be a good first project.

I bought a thick piece of copper on eBay which has helped with burning through. As already said, it is most helpful to practise on the same thickness as the metal you want to weld. If it is car body metal it is usually around 1mm or 1.2mm in the panels.

 

[scourtaud]

Thanks for the reply, I've managed to squeeze in about an hour of welding after my week end duties and I switched back to 0.6 wire and played with the settings.

I feel like I'm starting to make some progress, I've discovered that even though its better for beads to be in A/Min, for spots (still on only one sheet), its penetrates better on A/Max.

I've tried joinings to spots with a bead (2 to 3 cm) but I'm having a hard time getting penetration near the spots.
I've tried stitching which turned out note too bad (I think).

I still went through the steel a few times, didn't get penetration another time and was complete rubish another time...



I'me welding on a big bench we've got in the shed with very thick wood pieces on it so I'll stay on that for now...

I'll be buying the correct steel thickness this week but its not that simple, I've got to go and order it and the pick it up the next day and they only come in 1mx2m so it requires my dad's range rover since there's no way it'll fit in my convertible mini. In the meantime, I've played on what must be 0.8 steel of not great quality but if I can make it work on this, it should be ok on the car...

I'll try to find a piece of copper but I'm not sure I'll be able to use it once on the car since not all backings a accessible much less allow me to hold or clamp something there.

I hope to try my first weld on the car (an easy one to begin with) next week end (knowing I'll be praticing ever day between 12 and 2pm).

I have to say this website is quite invaluable in the process, and having read and watched everything about MIG welding, I have a better undestanding of the settings I'm changing and adjusting. Is there a way to donate?

 

[Bill Edwards]

I have to say this website is quite invaluable in the process, and having read and watched everything about MIG welding, I have a better undestanding of the settings I'm changing and adjusting. Is there a way to donate?

You're getting there - lots to learn yet of course, but you're starting out OK.

As to supporting the forum, that's a rare (and nice) question to hear. There's a link on this page, under 'How can you support this website': http://www.mig-welding.co.uk/about.htm

 

[norlander]

remember that when you start off, the job is cold.as you add tacks, it heats up, and if you do not space out your tacks, you will risk going through.Those are spot welds in your photo, tack welds are way smaller,its only a 2-3 second burst for a tack,leaving a spot about the size of a nail head.
Move around the job to avoid local overheating.

 

[scourtaud]

You're getting there - lots to learn yet of course, but you're starting out OK.

As to supporting the forum, that's a rare (and nice) question to hear. There's a link on this page, under 'How can you support this website': http://www.mig-welding.co.uk/about.htm

Thanks, I didn't think to look into the forum, I was looking for a simple paypal button.

remember that when you start off, the job is cold.as you add tacks, it heats up, and if you do not space out your tacks, you will risk going through.Those are spot welds in your photo, tack welds are way smaller,its only a 2-3 second burst for a tack,leaving a spot about the size of a nail head.
Move around the job to avoid local overheating.

That's good to know about the spots Vs tacks, I'll admit it a short bursts but I was moving the torch a little as if to join 2 pieces of steel. I'll try the real thing in a few days with the correct steel.

As for the heat, its incredible (as a beginner) to see what heat does to the metal sheet. For now I don't really care since its scrap practice but I fully plan to do a real practice with the right steel in order to get an idea of how long I should wait and how I should space my tacks (and short beads) before I approache the car with the torch.

I was reading another Thread and saw a magnetic ground so I'm going to be looking for that since not all welds will be close to an edge of the car.

 

[norlander]

Its often surprising for beginners to see how short the trigger press is for a tack,and the speed at which you can zip round the piece to tack it.

I have an earth extension with mag ground, if you search my threads you will see a picture of it. I used flattened copper pipe bent into shape so as to give the earth clamp a good grip on it.
The copper pipe was bought from the plumbing supplies place, I flattened what was left, and those strips are what I use as heat sink strips-but thats when I am doing TIG not MIG,but you might find them of use.
All welding processes benefit from a good,sound,clean earth,close to the part being welded if possible,but sound clean contact wherever the earth is made.
MMA will often work thru a poor earth, but MIG will play up if the earth is not good,so if you have found good settings for the material you are welding and you get problems,look to the earth contact first,then, check the hose to the gun is not in too tight a curve.
One other thing to check occasionally (easy on the GYS) are the connections on the gas/no gas terminals,make sure they are tightened up or they can arc and cause you to chase the wrong problem.
Finally, MIG is normally ok welding close to magnets, (I think thats because its AC?) but just bear in mind that magnets can interfere with the arc but I do not have problems with my magnetic set up/earth clamp kit and MIG.

 

[scourtaud]

So another day, a little more practice (but not much), I tried a little tack welding on two pieces of steel and even though the tack par went ok I think (0.6mm wire).

But as soon as I tried to do beads (even very short ones), It had a tendency to melt the metal and no cooling time or shortness would help, even on the lowest power setting. I have no idea how to overcome this but to maybe try with the 0.8 wire (having read that for an equal setting, thicker wire would produce less heat or something like that). I haven't made a picture of this but I will tomorrow if needed.

Any tips to overcome the melting?

 

[Bill Edwards]

Sometimes when the metal is too thin the only way to weld it is a series of (overlapping) tacks, as proper runs will just melt through.

 

[norlander]

As Bill says, use the same short burst you used to tack the job up,but join them together, and do sections of maybe 25mm in length before switching to another part.
Looking not too bad, it will come with practice,you are progressing quite well.
One technique I have seen, but not really used myself, is (if you have a compressor), is to blow compressed air on the job, you weld a small section with the tack weld technique, then give it a go over with a blow gun.

 

[mike 109444]

If you get a length of copper pipe and flatten one end then create a slight crease along the first 3 inches this will then allow it to sit into the area/slit where the welding will take place. IF you can get a light source to shine from the rear you can then see when the copper is in the right position. Think the "Tig" users of a backing piece are more looking for something to soak up the heat where migging it's more to stop the blow through. Note you may find from time to time that the copper will stick to the under side of the weld (stick rather that weld as it's copper to steel!) a slight twist should break it loose. Try to have at least 10 inches of pipe as it will soak up the heat and soon warm you hand, ouch !!
Once you have the patch tacked then try to add more tacks as norlander has said as the heat build up will run in front of the weld and blow through. (max 1/2 inch runs) 0.8 should/would put more heat in! To get good pressure on the copper pipe you will need to secure your test piece to the bench (a fair bit of force may be needed to hold it in the right spot)

 

[mike 109444]

Its often surprising for beginners to see how short the trigger press is for a tack,and the speed at which you can zip round the piece to tack it.

I have an earth extension with mag ground, if you search my threads you will see a picture of it. I used flattened copper pipe bent into shape so as to give the earth clamp a good grip on it.
The copper pipe was bought from the plumbing supplies place, I flattened what was left, and those strips are what I use as heat sink strips-but thats when I am doing TIG not MIG,but you might find them of use.
All welding processes benefit from a good,sound,clean earth,close to the part being welded if possible,but sound clean contact wherever the earth is made.
MMA will often work thru a poor earth, but MIG will play up if the earth is not good,so if you have found good settings for the material you are welding and you get problems,look to the earth contact first,then, check the hose to the gun is not in too tight a curve.
One other thing to check occasionally (easy on the GYS) are the connections on the gas/no gas terminals,make sure they are tightened up or they can arc and cause you to chase the wrong problem.
Finally, MIG is normally ok welding close to magnets, (I think thats because its AC?) but just bear in mind that magnets can interfere with the arc but I do not have problems with my magnetic set up/earth clamp kit and MIG.

FYI Mig is DC (have seen ONE mention by a usa member of a dirt cheep mig that was AC)
Some members have mentioned that they have issues when welding near the clamping type magnets (large red triangles) and since I read those post I have noticed it as well.

 

[scourtaud]

Thanks to all for the replies, this really is a great community and I can't thank you enough for your advice without which I'd be completely lost.

The copper pipe seems like a good idea and I'll try it since I have some scrap pieces from my fuel lines but it won't be doable on the car so I'll have to figure this out without the copper before I start on the car.

I'll try the stitching between tacks rather than beads (event the very short ones were an issue today).

I'll try the compressor trick but I'll need to find a way to keep the airgun open without holding it since I'm not ready to weld with one hand just yet.

as for the Red triangle magnet, I used it for the first two tacks but the removed it since it was taking a lot of space.

I should be able to practice some more tomorrow and I'll order some 1.0 and 1.2 steel instead of the 0.8 I'm using right now since its what I'll be doing the car with.