Hi all,

I'm a novice welder, to say the least!
I am looking for any good tips you can give me.

I was having a lot of trouble getting the (spot) welds to take an the floorpan / tunnel join this weekend, although I'm doing nothing different to previously where they were fine. They just wouldn't 'bond' to the tunnel.

Also I was getting many welds with bubbles bursting out during cooling - why is this? Not that it is a problem as such, but it wasn't happening before!

Thanks in advance
P

What type of welder are you using, stick, mig, gas etc.

I never welded before I did my pans and I learned quickly. A MIG set up with gas is a good thing to have. Just helps you get those clean welds you want with no splatter. Beyond that here are a few points:

1. Get to know your welder. Know what each setting does differently (wire speed, voltage, etc.) It will help when it comes to the thinner pan metal vs. welding thicker metal for heavy duty brackets.
2. Practice on a few pieces to get the speed and motion down. The ideal motion for a continuous weld is a zig zag that pushes the weld along, not pulls it.
3. Make sure your surfaces are clean, both the new pan and the tunnel lip.
4. Make sure the surfaces are touching, you will get a lot less burn through if they are touching than if you are trying to weld two pieces together with a gap in between.
5. This kind of goes along with 1, but learn what different size welding wire does and which would be best. I tried to use .035 wire and I had a heck of a time. I swapped to .023 wire and it made a huge difference.

Now let me state that I am in no way, shape, or form a great welder or that all of my welds are perfect. That being said they were all looked over by a professional and he said that they looked good to him so I have a little clue.

Hi Paddy,
Yep, we need a little more info on your welding setup. I've done both stick welding and MIG welding, and can confidently say I can push a bead just as well with either one, and I taught myself. It takes a little practice like Pog mentioned, and getting to know your equipment. Surface contamination is the number one cause of bubbles and "globby" weld lines. Make sure that both surfaces are absolutely spotless and sanded or ground down to the bare metal - and wiped again with acetone or other fast dissolving thinner to get rid of any trace oils. Start on the heavier gauge steel and as the weld heats up, move to the thinner steel (like your pan to tunnel weld - start the weld on the tunnel, then as the metal gets molten, slide the torch to the pan and repeat in a back and forth motion).

He's got a Clarke Mig in his photos, so thats a reasonable start! Best bet for all round welding advice would be to mosey over to the Mig Welding Forum, it's a bit like this only welding is their business!

From my experience, it looks like your welds are a bit lacking in amps Paddy, or the metal isn't cleaned back enough (so you're getting contamination), or possibly the gas flow is a little low (or being blown away in the wind). You're getting a build up of weld but it doesn't look to be burning in well..... Get good at running a bead on the flat before trying to do verticals, which are much harder - and if you can get away without welding overhead you'll be doing yourself a favour!

Vpogv's got a point about wire size too - 0.6mm always seems to be a pig, whilst 0.8 gives very few problems! CO2/Argon mix gives better welds than straight CO2 - this year I invested in a BIG cylinder contract (with several Mogs to keep on the road the disposables I'd of got through would have been at least three times as expensive.) The little disposables only seem to last five minutes.........

practice, practice & then practice a little bt more. On scrap steel. I wont repeat all that has gone before & get hold of the mig welders hand book from CIG or BOC or who ever they are. & if the weld sounds like sizzling bacon while you are doing it, you are doing it right (hope your not a vegi)

Bushboy

Bacon is the sound that stuck with me when I welded. Definitely practice, cut up the old pans and test a few pieces of that. You'll get the hang of it quickly.

Thanks all!

Yes it is a Clarke Mig, but no gas variety.
I am currently using 0.9mm flux cored wire - different brand to previous, but same specs, and the results i'm getting are nowhere near what the older (and cheaper brand) wire was giving.
I've player around with the power (4settings) and feed speed (dial 1-10, or is it 11...)

I will clean everything back a little more before trying to seam weld, as i suspect you are correct in thinking everything could be cleaner ;) Will pinch some acetone from work.

For the floors, have you just been welding from above, or below also?

Cheers
P

From the factory the pants are held in with rosette welds - holes drilled into the pans then a spot weld in each - every 2 inches or so. I on the other hand did not get good welds doing it this way so I ended up with small beads above and below the pans to make sure it was plenty strong.

Good - as thats what I'm planning to do!

Small beads and alternating sections of the pan so you don't get part of the pan too hot. It'll warp quickly if you keep a bead going or stay in one spot too long.

Too true there vpog! I learned this mistake the hard way. Lots of spot welds. It takes longer but the result is worth it!

My last weld job was a backyard necessity. My muffler fell apart on my old (now gone) celica. So I nabbed a spare muffler from the dead cavalier in the backyard, and fashioned a new muffler for the car using the spare metal/parts.

Took all day, but it work beautifully.

Haste makes waste in this process! Take your time, and do it right!

Like everyone said grab your self some scrap metal! old fenders, exhaust pipes, what ever you can nab cheaply. And practice till your fingers hurt! Once your rested, then go back to your car, get ALL flammables out of the area, and even then make sure you have a fire extinguisher handy! Oil can be found in the most obscure places in a cars chassis! Make sure your ready to put it out, if a stray spark finds it!
Dont want your gem going up in flames!

That must hurt

Bin there, done that!!

Until you mentioned Flux Cored wire in one of your posts I would have bet on it being a gas feed problem or trying to weld rust!! I tried flux cored wire and couldn't get on with it.

Suggest you wire brush the area well and then spray it with weld-through primer which stops the corrosion and helps get a good weld going. I used the same process to fit my floorpans and with a bit of practice with the settings it was easy.

Mick

i was taught to weld with oxy/acet from the age of 17, then after that using the stick method. Only used a Mig when I got the Nova, after a mod to the feed mechanism i was happy with it.
1st Rule use clean metal and make sure it is sound, don't mess around with bad metal just cut it away or renew it all. The as every one say's practice, even if you use £30+ of the stuff doing it; the finished job will be well worth it