[Shansh]

hopefully this is a worthwhile question, here goes;

when i am welding, I am getting a dark grey colour to my welds, in some spots the nice silver colour shows through but mostly its the dull greay colour, looks a little like slag but not all horrible & rough, i am also getting penetration issues, am only welding 3mm RHS. i am using

150A WIA MIG
argoshield light

set on low range 2,2 or high 1,1 depending on if its a butt weld or fillet
wire feed 5-7
gas is at 16 l/m
0.8 solid wire

i am running the wire ahead of the weld, ie pushing rather than dragging, taking my time to make sure there is a nice puddle and using a "cursive e" type motion as i am welding. does anyone have any idea why i am not getting a nice bright silver weld? does this mean my welds are porous? i want to start fabbing front & rear bar & a cage in the near future & really want to get some confidence in my welding.

any help would be very appreciated.

[ball]

Throw a pic up if you can. Easier to see rather than explain.

[Fatzook]

The dark spots can indicate contamination like Mill scale from the steel. Make sure your steel is clean before starting.

A porous weld will be full of little holes. To check, do a test weld, then cut the material in half so you can see the cross section of the weld. You will be able to see if there is any porousity, and you MAY be able to see penetration. Otherwise, get a flap disc on your grinder, and linish your way through the test weld a few mm at a time and check for any pin sized holes. A magnifying glass will make them easier to see.

[ajsr]

pics will help a lot

[dank]

it's been around the blocks but it's worth noting....be careful using brake cleaner to prep your steel...i

http://www.brewracingframes.com/id75.htm

I've always had issues with porous welds...would love to do a welding course one day when time permits.

[Shansh]

i hear ya on the welding course, closest one to me is over an hour away, too far for after work, found out late last week there is a mobile tafeSA van that might do it, that could be cool

[Shansh]

heres a couple of pics, i dont have any of the welds on the job, as you can see they have been ground back & painted. the other pic is when i first started & was trying to get the settings right for the job





jeez it looks bad so close up, didnt look anywhere this shitty seeing it sitting on the bench

[Fatzook]

Looks like there may be some porousity in the crater at the end of the bead..... but its hard to tell with that blurry pic. The rest of the weld surface looks normal. I get the occasional dark, or coffee coloured finish on the top of a hot weld, but usually when I have not bothered to 'clean' the surface.

just keep practicing.

[Shansh]

no worries pete, thanks, none of the welds on the job had any of that porosity, just the dark colour, i was expecting the welds to come out shiny.

will keep at it

cheers

[monley]

Fatzook wrote:

Looks like there may be some porousity in the crater at the end of the bead..... but its hard to tell with that blurry pic. The rest of the weld surface looks normal. I get the occasional dark, or coffee coloured finish on the top of a hot weld, but usually when I have not bothered to 'clean' the surface.

just keep practicing.

x2989527092

Even watch some youtube vids on welding

It could even be worth going to TAFE and buying the welding books that us apprentices learn out of at TAFE.

[Shansh]

a mate at work has the modules from tafe, he reckons he is gonna pass em on.

have watched a few vids there is some good stuff there.
getting the settings right is the real hard part if find, but i guess thats just experience & practice.

hopefully the mobile tafe runs a course, that would be very cool

thanks for the help guys

[Fatzook]

Shansh wrote:

i was expecting the welds to come out shiny.

Don't worry about the colour. Different grades of steel, gas mixes and wire compositions can yield different coloured welds.

I generally find that MIG welding with ER70S-6, which is the most common wire for GP welding gives a puter colour weld, where as MMA (stick) with low hydrogen 7018 rods gives a bright silver finish more often than not.

Just look for a consistant bead, without undercutting, or cold edges, and work on making them pretty with practice.

[Shansh]

too easy, the pewter colour is what i was getting today, its good to know thats normal. found some courses tonight to apply for, turns out the local tafe runs them after all!!
im more concerned about good penetration & strength rather than them being really flash looking, though i wouldnt complain if i got both results in one go.......

practice it is

[britvit]

I did a basic welding course at TAFE (SA) last year it was fantastic, all new gear and very good teachers. I'd highly recommend it.

[Shansh]

britvit wrote:

I did a basic welding course at TAFE (SA) last year it was fantastic, all new gear and very good teachers. I'd highly recommend it.

x2

especially if i am going to be making stuff for my car, i want to at least have a good idea of how i am supposed to be going about welding stuff properly

[Pubic]

Gas coverage is a big part in the final colour.

but as stated, heat, wire feed and speed at which you move will all contribute to the final colour.

a good, nice even bead is definately what you should be aiming for.

[jdk81]

Shansh wrote:

heres a couple of pics, i dont have any of the welds on the job, as you can see they have been ground back & painted. the other pic is when i first started & was trying to get the settings right for the job

jeez it looks bad so close up, didnt look anywhere this shitty seeing it sitting on the bench

I found your problem.

Theres not enough empty beer bottles.
Theres a fine line between not enough beer, and too much beer whilst welding.
Big bonus points for not learning on a gasless, with 1/2 slab of beer in you.

If you get sick of burning yourself, get a welding jacket from a welding supply store (best $55 I spent).

Honestly, get some scrap, clean it up and just practice pad welds. (laying straight lines no weaving or cursive e's etc).
Try it on the bench, inspect it every now and then.
Later you can make the plate sit vertical, and practice on it (weld horizontal and vertical etc)
Then try upside down etc.

[Derzky]

Fatzook wrote:

Shansh wrote:

i was expecting the welds to come out shiny.

Don't worry about the colour. Different grades of steel, gas mixes and wire compositions can yield different coloured welds.....

Just look for a consistant bead, without undercutting, or cold edges, and work on making them pretty with practice.

x2

Every machine is different so it hard to tell you what settings you need for your welder to do each job, so practice is the key.

If you are having penetration issues you may need to crank the voltage a bit but in saying that you don't want to blow holes in the job or cause undercutting as both of these will cause the job to be just as weak as having no penetration.

You can do test welds and by cross cutting the welds and using acid you can see the depth of penetration (the acid will show a yellowish line around the weld) but this is a bit difficult with 3mm steel.

You could always do a test weld and then take to it with a lump hammer and see how much persuasion is needed to break the "weld", you should be able fold the steel over the weld without breaking the weld = good penetration. The steel may break but the weld should be stonger than the steel and you may find that it breaks on the edge of the weld, if so, inspect the break and it should give you an indication of the depth of penetration.

If you do a welding course they will probably give you a similar test with approx 12mm plate butt weld to withstand 10 tonne in a press, the 12mm plate will bend but the weld should not break.

The puddle at the end of the weld is more than likely just contaminants in the weld and not an indication of it being porus as it is not along the length fo the weld.

A welding course will help alot but there are also a large number of books available inc haymes from repco which may help or make friends with your local steel fab shop owner

[wolf_rt]

welding with a 'cursive e' pattern is likely to lead to crappier looking welds....

try just going straight back and forward, or just doing some straight runs.

also don't lift the nozzle straight off the job at the end of the run, to help avoid porosity at the end of the weld. Gas will continue to flow for 0.5 sec or so after you release the trigger.

[Shansh]

this looks ok though, will keep practising, thanks for the tips guys

[Fatzook]

Yeah thats a good vid. I saw that a few years ago.

[Pubic]

In the weld you showed above, I would try bumping up your heat very slightly and lowering your wire feed slightly too, as stated, also keep your nozzle above the weld once you stop for a couple seconds.

Your weld looks a little cool with a little too much wire.

Try doing one step at a time....

bump the heat up... weld.

bump the heat back to where it was, then bump the wire feed down.. .weld.

inspect the two to see how each change effected the weld.

then go from there.

[Shansh]

thanks mate, will give it a go this arvo, will let you know how i do

[ainzy]

Is your job perfectally (spelling) from breeze due to fact the porosity is intermitant it could be happening when getting a gust of wind or have you checked your wire it could have rust on it that will cause issues if your reel is rusting give it lite hit with cooking spray but dont let the oil get dirty or it will kill your liner

[BlueSuzy]

Not that it will change what your doing, 10-15l/m. Anything over is a waste of gas.

I run mine with 10l/m all welds.

If windy, up it, because you gas is blowing away..

And 3mm plate, up the power and wire abit more, Let it burn in. Those welds look abit cold.

[Damo]

BlueSuzy wrote:

Not that it will change what your doing, 10-15l/m. Anything over is a waste of gas.

I run mine with 10l/m all welds.

If windy, up it, because you gas is blowing away..

And 3mm plate, up the power and wire abit more, Let it burn in. Those welds look abit cold.

Adding to the gas flow point, if you give it TOO MUCH gas it will actually pull air in. I use 14lpm as that's what I was taught at TAFE.

There are some good tutorials here, I especially like MIG Power Settings and Setting Wire Feed Speed

[Fatzook]

Damo wrote:

BlueSuzy wrote:

Not that it will change what your doing, 10-15l/m. Anything over is a waste of gas.

I run mine with 10l/m all welds.

If windy, up it, because you gas is blowing away..

And 3mm plate, up the power and wire abit more, Let it burn in. Those welds look abit cold.

Adding to the gas flow point, if you give it TOO MUCH gas it will actually pull air in. I use 14lpm as that's what I was taught at TAFE.

There are some good tutorials here, I especially like MIG Power Settings and Setting Wire Feed Speed

I use 12-13lpm. I mostly weld in an open air environment, so if its windy, and I can't sheild the job, I do something else. Nothing worse than having to grind porous welds out

[JrZook]

Fatzook wrote:

I use 12-13lpm. I mostly weld in an open air environment, so if its windy, and I can't sheild the job, I do something else. Nothing worse than having to grind porous welds out

Just lay another one over the top! WIN!

[Damo]

JrZook wrote:

Fatzook wrote:

I use 12-13lpm. I mostly weld in an open air environment, so if its windy, and I can't sheild the job, I do something else. Nothing worse than having to grind porous welds out

Just lay another one over the top! WIN!

SIKA

[BlueSuzy]

JrZook wrote:

Fatzook wrote:

I use 12-13lpm. I mostly weld in an open air environment, so if its windy, and I can't sheild the job, I do something else. Nothing worse than having to grind porous welds out

Just lay another one over the top! WIN!

No win! Then you have a big double aero bar weld.