Board logo

sooty deposit when welding
locoboy - 28/10/04 at 01:25 PM

Hi all,

I had a crack with the welder last weekend - my first go might i add. Practiced for about an hour and by the end i would say that 50% of my welds were acceptable visually and in terms of penetration and strength.

However..... if i try to tack weld anything i get a sooty deposit around the tack (this is the same when i finish a normal weld run too). is this normal?

If it is normal, does it need cleaning off with a wire brush before i try to weld over the top of it?

Many thanks


locoboy - 28/10/04 at 06:32 PM

come on chaps, about 90% of the reguar posters on here will know exactly what i am talking about and will have experienced the same thing at some point.

any anwsers yet? - please!


theconrodkid - 28/10/04 at 06:43 PM

sounds like something on the metal,its not galvanised is it?


Surrey Dave - 28/10/04 at 07:00 PM

Have you got a good flow of gas when welding , 'cos when the gas runs out the welding tends to look sooty and cruddy, and no thats not a new childrens TV prog.......



[Edited on 28/10/04 by Surrey Dave]


blueshift - 28/10/04 at 07:08 PM

I get a bit of a sooty deposit around my tack welds too sometimes. generally the welds fairly often end up with some kind of black / brown / grey dusting around them that wipes off with a finger. I don't really worry about it.


locoboy - 28/10/04 at 07:21 PM

cheers guys, it was outside fo it could have been the gas blowing away a little.

Blueshift, do you just weld over the top or wipe it off?

Conrod, its just erw non galv cleaned with a grinder.


JoelP - 28/10/04 at 07:25 PM

i get discolouration, but not what i would describe as soot. Comes off with wire brush, and i weld over it if required. No apparent probems for me, but an experienced welder might know more.


Mark Allanson - 28/10/04 at 08:42 PM

Does the steel have a protective film of oil?


locoboy - 29/10/04 at 07:53 AM

No mark, its ERW that has been in my outdoor shed for months so has surface rust, gave it a belt with the grinder then away i went.


blueshift - 29/10/04 at 10:02 AM

Mine probably has a bit of original oil / wd40 / rust on it. I give things a wire brush before I weld them if they look mucky or if I'm feeling keen and don't forget.

If I'm welding again in the sooty area I'll give it a quick scoosh over with a wire brush, though I have welded through it once or twice and don't remember any obvious effects.

The only thing I'm not happy about now with my welding is that occasionaly for no reason I can understand, the weld goes crackly and bubbly and lays down porus "shells" instead of a nice molten bead. It has happened welding outside which I attribute to gusts of wind, but sometimes inside as well, at the beginning of a weld. hum.


locoboy - 29/10/04 at 10:25 AM

Blueshift,

I have managed my fair share of 'aero' style welds too but seeing as all my welding was done outside it was probably the wind - well thats my excuse anyway