Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

Welding tips

Started by _Tucks123_ , Aug 16 2015 09:06 PM

Next

Please log in to reply

27 replies to this topic

#1 _Tucks123_

Guests

Posted 16 August 2015 - 09:06 PM

I know, i know, this gets asked all the time and i have used the search forum and looked at those answers as well.

I have a few questions for welding with a mig.

The welder i have is a unimig 180amp, with argon/co2 gas bottle and using mild steel wire. I'm using the lowest amp setting with a wire feed around 3-5 and a bit under 13l/pm of gas.

I'm having a few problems, the main one is blow throughs, which i think is due to me not preparing my metal well enough, trying to weld on bits that have been grinded and are too thin.

Another big problem is porosity, my weld pools look like craters with a lot of little pin holes around them, i've had a play around to try and fix it but can't seem to get the hang of it.

Another thing is that it looks like it isn't penetrating enough, like the welds are sitting on the top of the joins.

Can anyone please give me some hints with welding in particular and the best settings to use on 22gauge panel steel.

Any help right now is appreciated. Cheers.

Back to top

#2 _76lxJAS_

Guests

Posted 16 August 2015 - 09:28 PM

Turn up your amps and move faster if needed.

Not enough wire speed will result in the wire burning away before you get to weld. To much wire speed will result in it wanting to push your hand away from the weld hope that makes sense. ? Don't be scared to adjust things.

If you have a mate with you.
Get a old piece of of something to weld. Have the mate play with upping and downing the amps and the same with the wire speed. U will see the difference as he adjusts it.
Also make sure you welding nice clean steel. U can be chasing rusty areas for a wile before u get to the good clean sections. .

Back to top

#3 wot179

Green Eggs and Spam

Members
6,784 posts

Name:Jesus Bloody Christ
Location:Sunny Santa Maria
Car:Goon
Joined: 06-February 09

Posted 16 August 2015 - 10:36 PM

As well as incorrect surface prep such as Jason mentions above, porosity is often caused by lack of shielding gas.

This could be caused by a number of things.

Without seeing pics, my guess would be you are holding your torch too far away from where you want to weld.

Get in nice and close at an angle of about 30 degrees from perpendicular.

It could also be caused by a nozzle filled with spatter preventing the gas from going where it needs to be,

or a faulty/damaged/incorrectly fitted nozzle or diffuser.

Incorrect prep as described by you could easily be a problem with blowthrough, as well as incorrect technique as described by Jason.

Edited by wot179, 16 August 2015 - 10:38 PM.

Back to top

#4 _Ozzie Picker_

Guests

Posted 16 August 2015 - 10:45 PM

Maybe have a look on youtube at different methods,try searching for vids.This one gives some ideas.

Back to top

#5 N/A-PWR

CABIN ENGINE CONTROLS GALORE

Members
9,595 posts

Name:Dave I
Location:Wooroloo, 65km's East of Perth
Car:'1969' LC RAT TORANA
Joined: 08-December 12

Posted 16 August 2015 - 11:18 PM

A good Tip going around is,

Spot welding, do a spot on a spot as you weld with thin stuff,

I am doing this at work with materials that have big gaps even.

Once you get the hang of it, it is easy.

there is also settings on some welders for Spot.

Back to top

#6 S pack

Scrivet Counter

Members
15,541 posts

Name:Dave
Location:Luggage Point
Car:73 LJ
Joined: 25-January 10

Posted 17 August 2015 - 12:08 AM

You should be using .6mm wire and turn the gas flow up to 15lpm.

Wot179 has some good advice and as others have said experiment with the amps and wire speed.

Back to top

#7 _mikecatts_

Guests

Posted 17 August 2015 - 07:13 AM

try argon/oxygen mix (supergas).. designed for thin metal.. argon/carbon is for thicker metal.. I also use .8 wire with a .9 tip.. better gas flow.. Helped me heaps.

I used a Unimig 180 and had good results.. Play with the settings.. I dont like to use .6 as some times you have to hold the weld to get it to fill.. which inturn creates heat.. so .8 less heat to weld the same gap. Keep the tip about 10mm from work.

Blow back is from dirty metal and original metal from factory had a zinc coat on it which blows back...

and if you are using the supplied wire.. throw it away and get the BOC gasses wire.. Its the best one ive found.

and

you are not using the supplied gassless wire are you?

Im self taught so dont shoot me down guys..

Back to top

#8 mick_in_oz

Forum Fixture

Members
666 posts

Name:Mick
Location:Western QLD
Car:LX Hatchback
Joined: 12-June 11

Posted 17 August 2015 - 07:44 AM

If you are talking panel steel or anything approaching, the 0.6mm mentioned is mandatory. If talking panel steel don't get all excited and try to run a bead as it will get too hot and pull everything, use the above mentioned spot method, place the spots about the place and don't put another one down if you can't hold your hand on it comfortably.

Best bet is to learn to weld on some 1.6 or 3mm steel and then move onto panel steel. This will give you the chance to play with the setting properly and get a feel for it.

The 12LPM of gas flow is plenty, check this with the trigger pulled rather than just static. The gas mix you have is fine.

Good call above about making sure you are not using gassless or innershield wire.

The sound it should make when welding when the wire speed for the amp setting chosen is correct is a sizzling noise, not enough wire = no sizzle, too much wire = HEAPS of sizzle, spitting, and eventually push off (as mentioned above), I've seen it described as the sound of bacon sizzling.

Best bet is some thicker steel, pick a current setting approaching half way and pull the trigger and play with the wire speed from there.

How about some pics? they will tell all of us a LOT to help guide you.

My WIA has a setting chart of current vs wire speed vs wire size chart inside the door, its a good place to start if changing to an unfamiliar wire size.

Back to top

#9 _ChaosWeaver_

Guests

Posted 17 August 2015 - 08:06 AM

I agree with everything said... most important is practice on offcuts of similar steel.. like old car panels your not going to use... when your welding good on them, move on to your job.. that way your not experimenting or frocking things up.... and with welding, preparation is everything, the best welder in the world couldn't / wouldn't weld dirty steel. and if he did he wouldn't expect great results ...

this is what you can do with practice.. TIG and not MIG I know, but pretty damn tidy..

LINK : https://www.facebook...12/?pnref=story

Back to top

#10 _dno_

Guests

Posted 17 August 2015 - 10:26 AM

I'll also add Migs aren't very good when used in breezy area's like door ways or even outdoors, it only takes a light breeze

to loose your gas shielding. Another thing I've found too is a near empty bottle cause's problems.

Back to top

#11 _Tucks123_

Guests

Posted 17 August 2015 - 11:38 AM

Thanks everyone for the replies, I have attempted to prep the metal as well as possible, the gas bottle has plenty of gas and is used inside so I'll just keep practising and practising until I get it right. Lucky there aren't many areas that are on the true exterior of the car so I'm kind of lucky there but still. Thanks heaps again

Back to top

#12 _miki76lx_

Guests

Posted 17 August 2015 - 01:31 PM

https://youtu.be/xhydsdUN1yw hiaye this is arepair me and my son are doing on a hr holden the vid shows the tack sequence and dont weld a continous line. Move around this stops too much heat in one spot. Hope you gets some tips from this.

Back to top

#13 _dno_

Guests

Posted 17 August 2015 - 01:45 PM

I should have worded the near empty bottle comment a bit better, what I've found is once my reg reads around 6 which suggest its about halve empty, it's far closer to empty than the gauge has you believing.

Back to top

#14 _Tucks123_

Guests

Posted 17 August 2015 - 08:36 PM

I will add that i'm not attempting continuous beads, the blow throughs occur even when just doing a small tack weld. i'll keep experimenting anyway. cheers for the help.

Back to top

#15 N/A-PWR

CABIN ENGINE CONTROLS GALORE

Members
9,595 posts

Name:Dave I
Location:Wooroloo, 65km's East of Perth
Car:'1969' LC RAT TORANA
Joined: 08-December 12

Posted 17 August 2015 - 09:20 PM

Hello Tuck,

keep turning the amps down until it does not spot weld,

and then turn the amps up a touch to see if she spot welds,

somewhere there is the right amount of amps.

Back to top

#16 TerrA LX

Fulcrum Fixture

Members
14,241 posts

Location:Sid 'n' knee
Joined: 31-May 06

Posted 18 August 2015 - 06:10 AM

I will add that i'm not attempting continuous beads, the blow throughs occur even when just doing a small tack weld. i'll keep experimenting anyway. cheers for the help.

Welding, any form of welding, whether it be Arc, MIG, soldering, brazing etc etc must be done on a clean sound surface, if you are trying to weld thin, rusty, dirty or contaminated steel you will fail every time.

Back to top

#17 _ChaosWeaver_

Guests

Posted 18 August 2015 - 08:07 AM

I will add that i'm not attempting continuous beads, the blow throughs occur even when just doing a small tack weld. i'll keep experimenting anyway. cheers for the help.

I may have missed it, but what thickness wire are you using ?? as said, go the finest wire you can.. that way you have a lot more control over the Amp's & Wire Speed available on your machine . If it is an old welder, you could have a gas solenoid issue, or something as simple as a gas leak some where in the welder hand piece or lead... pull the trigger, and listen for leaks.. At 11-12 LPM of gas, you should hear a fairly strong sound of gas at the shroud...

Also make sure you have the right length wire tip, for the gas shroud your using... the wire tip needs to be about 5-6 mm inside the shroud... goodluck mate.....

Back to top

#18 Shtstr

Formerly lcxu105

Members
1,809 posts

Name:Mmmmmmm
Location:Brisbane
Car:lx hatchback lc gtr
Joined: 18-June 10

Posted 18 August 2015 - 10:36 AM

Your gas flow should be around 20 and easy way to get the feed right for wire is to look at the point of contact when welding. It should look like the fan you get when spray painting.

Back to top

#19 wot179

Green Eggs and Spam

Members
6,784 posts

Name:Jesus Bloody Christ
Location:Sunny Santa Maria
Car:Goon
Joined: 06-February 09

Posted 18 August 2015 - 11:11 AM

Gasflow should be 12-15 l/m Dave

Back to top

#20 _Tucks123_

Guests

Posted 19 August 2015 - 08:31 AM

cheers for all the help guys, have welded another panel in and it has come up better then the last. I'm slowly getting the hang of it. Will continue to practise and use the tips given to me.

We are going to change the wire i'm using and look at getting .6 rather than .8 and hopefully that will help with the welding. Will post up pictures soon of the panels.

Back to top

#21 _ChaosWeaver_

Guests

Posted 19 August 2015 - 09:06 AM

Good stuff mate... practice is everything .... Just one other thing, you must keep your wire dry, it takes bugga all for it to start to form rust on the wire, and then the rusty wire will give you problems too... if not using it for a while, take it off the machine and wrap it up so moisture cant get at it... and if you have a compressor, blow the wire liner out from time to time... :spoton:

Back to top

#22 mick_in_oz

Forum Fixture

Members
666 posts

Name:Mick
Location:Western QLD
Car:LX Hatchback
Joined: 12-June 11

Posted 19 August 2015 - 08:56 PM

Old school lazy mans solution to rusty wire. Get the cap off an aerosol can, and put in a small rag soaked in a small bit of engine oil, and store it inside the same compartment that the wire is house in inside the welder. The ever so slightly oily vapour stops the surface rust starting, and doesn't cause any welding trouble.

Back to top

#23 S pack

Scrivet Counter

Members
15,541 posts

Name:Dave
Location:Luggage Point
Car:73 LJ
Joined: 25-January 10

Posted 19 August 2015 - 10:48 PM

cheers for all the help guys, have welded another panel in and it has come up better then the last. I'm slowly getting the hang of it. Will continue to practise and use the tips given to me.

We are going to change the wire i'm using and look at getting .6 rather than .8 and hopefully that will help with the welding. Will post up pictures soon of the panels.

Make sure you also get a couple of packs of .6mm tips for the torch.