How do I weld up a sump without making it look like crap?

[thechuckster]

i think you should move a bit faster with the tip across the work peice - and steady your welding hand by resting it on something. The earlier welds do look like a lot of excess metal being laid down.

[matty12]

you have to push with mig and not drag (the reverse to stick)otherwise you end up with porosity in you welds as the gas doesnt cover

[superstylin]

i would suggest using a wire wheel over the entire area you are welding both on the inside of the sump and outside. as soon as you start burning into the sump the old caked on oil on the other side will heat and run back into the weld- any impurities are gonna cause you problems.
we weld up a lot of cast alum sumps and we need them blasted before hand to remove any shit. also clean the area you want to weld with metho just before welding to remove any dirt, dust or crap from the grinding discs.

if you are pulsing or stitching the weld increase the amps(this will give a hotter flatter weld-be careful as u will get more chance of leaks pulsing it via pin holes) and use a piece of alum on the inside of the sump to help remove some of the heat and stop blowing holes in it.
with 0.8 wire you are gonna struggle without putting excess heat into the thinner metal.
0.6 is the go for thin shit. or worst case if plate over the area you are welding.
i have shaved countless doors and done a lot of custom sheet metal using 0.6 wire. it is much more controllable and leaves a much smaller weld.

ideally tigging it would be nice but if it is dirty/rusty or oily its not gonna happen.

[marc280]

So long as you hold the torch at the right angle you shouldn't have any problems with gas coverage... I'm not an expert welder but I've done a few MIG courses at tafe and we were always taught to pull torch except for vertical up, and I've never had a problem with porosity... (by the way I highly recommend the TAFE courses, they only cost about $150 and even just the metal/welding consumables you use would cost more than that...) But then again if you find pushing works for you then that might be the best way.

If you find your blowing through, then yep you'll need to lower the voltage back down. Just try to get the voltage to a setting where your getting good penetration without blowing through, then it is a matter of adjusting the wire speed and travel speed to suit (I know easier said than done sometimes).

Also what angle are you holding the torch at? It should usually be in the range from about 15 to 30 degrees in the direction of travel. The page below has a couple of good tips...
http://www.thefabricator.com/ArcWeld...cle.cfm?ID=301

One other thing I just thought of is I'm assuming that you have the polarity set right? If you get this around the wrong way then it causes all sorts of trouble. I'm trying to remember off the top of my head what it should be and I'm pretty sure it is DC+ (i.e. electrode +) when running bare wire with gas and electrode negative when using a flux cored wire.

[RAd28]

superstylin - I've been using a flapper wheel to prep surfaces before welding, and on the practice pieces atleast, i've been able to access both sides to clean them both, but that's not helping on the practice pieces... once i've got that down pat, i'll certainly keep it in mind when doing the final job. I've heard someone suggest mig welding it, then running the oxy over it quickly to fix up any small pin holes etc... I still haven't had a chance to use the 0.6mm wire, hopefully i'll track down a new tip for it during the week.

marc280 - I've been trying to hold the torch about 45deg from the work piece... when you say 15-30, are you refering to the angle between vertical, and the gun? or workpiece and the gun? I've been trying to keep the gun closer to the work piece in an attempt to direct the heat more at the weld bead rather then the new metal...
As for the polarity... I have no idea, I haven't seen any polarity settings on the welder...

[superstylin]

So long as you hold the torch at the right angle you shouldn't have any problems with gas coverage... I'm not an expert welder but I've done a few MIG courses at tafe and we were always taught to pull torch except for vertical up, and I've never had a problem with porosity... (by the way I highly recommend the TAFE courses, they only cost about $150 and even just the metal/welding consumables you use would cost more than that...) But then again if you find pushing works for you then that might be the best way.

If you find your blowing through, then yep you'll need to lower the voltage back down. Just try to get the voltage to a setting where your getting good penetration without blowing through, then it is a matter of adjusting the wire speed and travel speed to suit (I know easier said than done sometimes).

Also what angle are you holding the torch at? It should usually be in the range from about 15 to 30 degrees in the direction of travel. The page below has a couple of good tips...
http://www.thefabricator.com/ArcWeld...cle.cfm?ID=301

One other thing I just thought of is I'm assuming that you have the polarity set right? If you get this around the wrong way then it causes all sorts of trouble. I'm trying to remember off the top of my head what it should be and I'm pretty sure it is DC+ (i.e. electrode +) when running bare wire with gas and electrode negative when using a flux cored wire.

the only time you pull is with stick welding.
pulling a mig will give u no penetration and a lack of fusion.
if they taught you that at tafe, i'd go ask for a refund and learn from someone who knows.

[marc280]

I was just looking at those photos you posted up earlier again and some of the first practice welds actually look quite good. Do you know what you changed between those and the other welds?

When I said an angle of 15-30 I meant between vertical and the gun (for a butt weld anyway). Increasing the stick-out length by moving the gun away from the workpiece a little results in a slightly lower heat input, although if you move it too far you'll find that it will start sputtering. The reverse is also true in that decreasing the stick-out will input a little more heat. Although changing the stickout length should be more of a fine tuning thing. Holding the gun a little higher to reduce the angle between the vertical may help a little although just remember it will increase the heat input a little too....

As superstylin suggested, using 0.6 wire on thinner metal will really help, as you'll need less heat input and won't have the weld bunch up giving a big hump as easily, so that might be your best bet to start.

So long as my memory is right about the correct polarity and you have the torch connected to the positive and the earth lead to the negative you should be right. I just thought it may be worth checking as if it was setup for flux cored wire to start with it could be giving you trouble.

As for pushing or pulling the gun, you could dedicate a whole tread to the benefits of each in different situations. There are quite a few threads on the forum 'welding web' which discuss' this and these two have some good info.
http://weldingweb.com/showthread.php...=push+pull+Mig
and
http://weldingweb.com/showthread.php...push+pull+gmaw
The way I see it is, each person uses a slightly different technique and if it gets a good weld and I works for you, then that is what matters....

Maybe it might help to look at one weld at a time in the photos to try to work out what is going on? For 23 of 25 the 'cold' weld sitting up on the workpiece can be caused by travelling too quickly. Perhaps try slowing the travel speed and see what effect that has. Don't know if that really helps much as it is kinda hard to tell what is going on just through photos and descriptions....

[mullett]

More power! I tend to weld very hot, personal preference is to have a very deep weld without much filler metal...like I mentioned before though, that's a real trick for thin metal, it takes patience waiting for the metal to cool between each burst, and it could result in extra warpage.

Welding is very much personal preference though, whatever you feel most comfortable with (and gives you the greatest control), go with that...

Good call about the flux-cored wire, although I think that welder was probably built before that was popular, and being a higher-end machine, it might not have provision for it. It's worth noting for anyone reading this thread later though, as most welders aren't very clear about it unless you read the instructions (and when you decide to change to flux-less wire 12 months after you buy it, do you still know where they are?)

-RM.

[RAd28]

marc280 - When you mention the earlier welds, are you refering to the first of the welds on the sump? or the ones with the gal steel and blue steel?

Still need to track down a 0.6mm tip for the gun before I can give it a crack.. will post progress shots when I do.

In that shot 23/25, I think you'll find it's sitting up because i'm using such low heat, and I've already welded on the other side, so it didn't heat up enough to really fuse... but it could easily be travel speed, or a combination...

mullet - i'll definately have a shot doing the hot tack technique you speak off...

Does anyone know where I might find a good chunk of a suitable heat sink type material? Copper or aluminium etc?

[RA35GT]

non-ferrous scrap dealer would be best bet. They might let you scrounge around for a small piece.

[RAd28]

I can't believe how friggin hard it is to track down a 0.6mm tip for my welder!! First stop was BOC Gas 'n' Gear, but they were sold out... Next stop was Bunnings, but they only had 0.8 and 0.9mm, finally half way back across town in peak hour traffic I found them in the bottom of a dusty box at Trade Tools Direct. Also picked up a new earth clamp while I was there..

Anyways, Long story short, I got my 0.6mm tip, and swapped the earth clamp, jimmied up some ghetto wire reel holder with a few zip ties 'cause the mini spool was way too small for the reel holder in the welder (the zip tie solution worked perfectly, I can even control the tension! )

So I did a couple of nice long butt welds, they started out pretty average, I tried running short runs, but it just blew holes, and I couldn't really pick when it was about to go, I tried welding on the 2nd setting, but I couldn't keep the wire up to it, just popped the wire like it was a fuse. So I ended up settling on the spotting technique, using the lowest heat setting. I found that I could leave a nice spot, but if i held the trigger for a fraction of a second longer, i got a much flatter bead with much nicer penetration, when I over lapped these spots i ended up with some pretty nice welds, I also found that a small gap (approx sheet thickness) between the two plates made the weld much flatter again, very neat. Consistency was still an issue, but as you'll be able to see from the pics (link below) that was improving as I progressed...

In conclusion, 0.6mm wire is the shiz new earth lead clamp can't be doing any harm either... Need more practice just to improve consistency, but I think i've got the technique good enough, I couldn't see any pin hole welds, so that's good news.

Take a look at the pics, and let me know what you think (The run in the bottom of the pics is the first one, and I progressed left to right in both...)

Link to the pics => Photos 1-7 are todays efforts, but ignore #1 it doesn't fit in chronologically...

HUGE thanks to everyone who offered advice... I tried to rep you all, forgive me if I missed you

[roadkill]

Hi,

from what i've been told brass is great as a heat sync. Dunno where you'd get it though....

Looking good though. I'm in the same boat as you, have welder, can't use for shite. Tafe next year i'm thinking......

bEn

[RAd28]

ben - I've had this welder for a little over a month... If I can make a half decent weld in that time, then anyone can... just need more practice... which is where i'm heading now... more practice...

[takai]

For the SIP welders you can get the tips and shields at Repco

[essaysixtythree]

Wow excellent thread. Heaps of great advice here. I wish I read this before the start of the week. Ive just made my full exhaust and intake using the mig. I struggled welding some of the bends in the thin pipe. Some welds were bird crap and blowing holes but others were just gorgeous. Practice and fiddling with amperage and wire feed settings makes good welds I have found. I was using .8mm wire with a 1mm tip. Boc argo shield light gas.