What's wrong with my welding?

[rogerowen]

I'm going to run this up as a new topic as it's more of a scream for help than a simple debate. What on Earth is wrong with my welding? The wire is melting and sticking to the new metal plates but it's not sticking to the old metal. I'm cleaning back to good metal but my welds always end up looking like rabbit droppings! All and any advise appreciated. Photos to follow.

[bmcecosse]

More POWER - and faster wire feed... What size wire are you using? I found 0.6mm to be useless - 0.8 mm better and as before - the 0.9mm gasless much better......

[ian.mcdougall]

have you looked at this website

http://www.mig-welding.co.uk/‎

[LouiseM]

Here are the photos:[frame][/frame][frame][/frame]

[rogerowen]

More POWER - and faster wire feed... What size wire are you using? I found 0.6mm to be useless - 0.8 mm better and as before - the 0.9mm gasless much better......

I got a reel of .8 Gasless, think you are right about more power, and having taken off my lousy first attempts - I've cut the bodywork back further to thicker stronger metal . I think I was Pussy-Footing here.

[rogerowen]

have you looked at this website

http://www.mig-welding.co.uk/‎

Yes, I joined their forum too now.

[beero]

Are you cleaning front and back on the old metal?

[rogerowen]

Are you cleaning front and back on the old metal?

Can only access the front of the old metal as the back is inside a box section (MG Midget vertical bit just behind the seat back). I was overlaying a patch, but how I've hacked out further past the rust and will attempt to butt weld a new piece in. My new metal was going rusty - so I wiped it over the WD40, then I give it a brushing over with the grinder before welding. I'm also spraying masses of Jenolite inside the hole, and lots of weld-through primer in a hope to delay further rusting. I bought some rust encapsulator but I cant get to much of the internal box section.

[PaulTubby]

Are you cleaning front and back on the old metal?

Can only access the front of the old metal as the back is inside a box section (MG Midget vertical bit just behind the seat back). I was overlaying a patch, but how I've hacked out further past the rust and will attempt to butt weld a new piece in. My new metal was going rusty - so I wiped it over the WD40, then I give it a brushing over with the grinder before welding. I'm also spraying masses of Jenolite inside the hole, and lots of weld-through primer in a hope to delay further rusting. I bought some rust encapsulator but I cant get to much of the internal box section.[/quote

DONT use wd40 to clean the metal! and do all the waxoyl -injecting after the welding, you will cause a fire in the box section if you weld near it! and to get to the internal box section, drill some holes and insert a prob and spray in then grommet over... when cars was new they did that back in the day with zeibarting etc... it works, but only do the cavitity and rust proofing AFTER the welding process! trust me

[rogerowen]

Are you cleaning front and back on the old metal?

Can only access the front of the old metal as the back is inside a box section (MG Midget vertical bit just behind the seat back). I was overlaying a patch, but how I've hacked out further past the rust and will attempt to butt weld a new piece in. My new metal was going rusty - so I wiped it over the WD40, then I give it a brushing over with the grinder before welding. I'm also spraying masses of Jenolite inside the hole, and lots of weld-through primer in a hope to delay further rusting. I bought some rust encapsulator but I cant get to much of the internal box section.[/quote

DONT use wd40 to clean the metal! and do all the waxoyl -injecting after the welding, you will cause a fire in the box section if you weld near it! and to get to the internal box section, drill some holes and insert a prob and spray in then grommet over... when cars was new they did that back in the day with zeibarting etc... it works, but only do the cavitity and rust proofing AFTER the welding process! trust me

Much wisdom, thanks.

[les]

Looking at the welds Roger, I'm thinking you're not 'pushing' the wire into the metal for long enough before moving along, and experiment with the wire speed you may be running too fast causing a build up.

[rogerowen]

Looking at the welds Roger, I'm thinking you're not 'pushing' the wire into the metal for long enough before moving along, and experiment with the wire speed you may be running too fast causing a build up.

This rings true! I think I'm so nervous about burning through that I'm moving a bit too fast. Gonna practice loads! Cheers

[les]

I think most of us have been there Roger, you could get a spare similar thickness piece of metal and burn through on purpose, it may give you an indication of how long it takes, then bear that in mind when you do the real thing.

[rogerowen]

I think most of us have been there Roger, you could get a spare similar thickness piece of metal and burn through on purpose, it may give you an indication of how long it takes, then bear that in mind when you do the real thing.

Brilliant idea, thanks. Lot and lots of practice me thinks!

[drivewasher]

are you useing gas? Co2 or argoshield. Those welds look like not enough shielding gas. Is the polarity right?

[bmcecosse]

I didn't (couldn't easily ?) change the polarity for gasless use. Does it really matter? Has anyone done a direct comparison? What's the logic for changing the polarity??

[rogerowen]

are you useing gas? Co2 or argoshield. Those welds look like not enough shielding gas. Is the polarity right?

Argon mix till it ran out and then Co2. Polarity correct. Wondering if power was too low.

[Kinsley96]

i use gasless as well, (only because i go for the cheap stuff), had the same problems today, and your welds look all too familiar.

when practicing my welding works a treat on 2 mm. however get to the car and it burns through the thinner (previously rusty) metal so had to build it back up. bloody pain!

i reversed polarity today and worked slightly better

meanwhile, I might invest in a quality welder.

[kennatt]

I use gassless,/gas and many times have just not bothered to change polarity never seen any difference in the weld.

[rogerowen]

i use gasless as well, (only because i go for the cheap stuff), had the same problems today, and your welds look all too familiar.

when practicing my welding works a treat on 2 mm. however get to the car and it burns through the thinner (previously rusty) metal so had to build it back up. bloody pain!

i reversed polarity today and worked slightly better

meanwhile, I might invest in a quality welder.

I get the feeling that it's all down to getting the settings correct for the particular job in hand. If you are moving from 2mm to something much less, then the power will need to go down to avoid blowing holes. I think one of my problems is trying to weld where the metal is just TOO thin. I spent yesterday pulling off the plates I had welded to the car (disgusted with my work!), and they came off remarkably easily. I'm now cutting back further than where the rot just ends in the hope that I'm getting back to thicker metal and thereby be able to notch the power up a bit. Basically, I need to melt the old metal as well as the new plate and the wire. Will report back on progress.