Constructive criticism

[KimB]

Nice welds

One of the other mods who is more of a professional welder than myself once mentioned when welding box section you should go from middle of the straight to the middle of the next one and not corner to corner, it's a stronger way of doing the weld, something I did not know and probably not critical on hobby welding but I am always willing to learn the correct way.

I'll try that, Have a few long welds to do when I Cut the other bit of steel out. Thanks Steve

 

[Richard.]

Your limits are your welder. In order to achieve good strength on hefty gear like that you need a relatively hefty Mig. What is your material thickness and power available at your welder?

 

[KimB]

Your limits are your welder. In order to achieve good strength on hefty gear like that you need a relatively hefty Mig. What is your material thickness and power available at your welder?

Oh off course, it's a 220 mig, Sealey. I need to weld 10mm plate to the 5mm thick box. to do the 5mm box to the 8mm plate I was a bit cautious of it burning through. it looked like it was getting close to going and that wasn't and full power.

 

[KimB]

 

[Richard.]

It’s a touch on the light side really for the 8-10mm
You’ll be spending the whole job with it maxed out.

 

[KimB]

It’s a touch on the light side really for the 8-10mm
You’ll be spending the whole job with it maxed out.

Yeah i know. Problem is, for home use, you're not gonna get much bigger with a mig. Unless I go to a proffesional set up but that can wait. Rather get tig and MMA welding first.

 

[Richard.]

That’s gonna be ok with 220 amps but it’s just gonna be right on the limits of your machine and supply. It looks like it’s going to be holding some weight so the welding needs to be good.
Mma yeah that would be my preferred way to attack it. It’s got 3.2 7018 written all over it.

 

[Sarto]

Why 3,2 and not 4mm on a weld like this?
Is it a power supply problem again?

 

[KimB]

That’s gonna be ok with 220 amps but it’s just gonna be right on the limits of your machine and supply. It looks like it’s going to be holding some weight so the welding needs to be good.
Mma yeah that would be my preferred way to attack it. It’s got 3.2 7018 written all over it.

Haha, you bet. Mine also.

Why 3,2 and not 4mm on a weld like this?
Is it a power supply problem again?

If that's a comment to me?

 

[Richard.]

Why 3,2 and not 4mm on a weld like this?
Is it a power supply problem again?

5-8/10mm. 3.2 would be perfect imo.

 

[Richard.]

Haha, you bet. Mine also.

If that's a comment to me?

Remind me on closer to the time as I don’t keep hefty gage in stock usually but if you haven’t had much to do with sticks and you do bring the unit over for a bit of tuition/familiarisation we can briefly cover a bit of MMA also.

 

[KimB]

Remind me on closer to the time as I don’t keep hefty gage in stock usually but if you haven’t had much to do with sticks and you do bring the unit over for a bit of tuition/familiarisation we can briefly cover a bit of MMA also.

Sure okay. I have a load of big stuff here. Can bring some too if need be. I’ve only ever MMA welder once but I hated the welder so never did it again. Was one of the cheapo screw type one.

 

[Richard.]

dc MMA from an inverter is night and day nicer than an ac box.
See how you get on.

 

[arther dailey]

I used to stear clear of stick after using old unit,tried inverter and its a completely differant story,as richard sez night an day. picked up a second hand inverter and would part with it.

 

[Scruffywelder]

Don't 7018's need a higher OCV than most inverters are capable of giving?

I can just about get a decent weld with 2.5 7018 on my old Oxford RT140 on the 80V setting but my mates 160A Parweld produces horrible porous crap with the same rods.

 

[DTS]

It’s cellulosic you might be thinking of needing a higher voltage.

 

[Richard.]

produces horrible porous crap with the same rods.

It will either strike them up or it won’t. Most actually will nowadays.
Porosity is a different problem and I doubt it’s been caused by the power source.

 

[Paul G]

Hi Kim,
Everyones being so polite but the thread title is constructive criticism so here goes.

Your welds look ok but you are starting too far along the joint and stoping too quickly. Welds on box should roll right round the corner.

In Your photo that I have used as an example your wire extension has run < A > leaving an edge still showing to the right.

You should have nicked that previous start off with a grinder and ran < B > .


I find that by welding right to left for the 1st weld then turn the job clockwise and weld the 2nd weld so that it finishes where the 1st one started.
Turn clockwise again for the 3rd and finish on the 2nd start. Turn and weld 4th side. This will give corners with the right build up and seal any cold lap starts.

Your 220 is more that capable to do this fabrication. I use a Lincoln 210 and have done similar many times.

HTH
Paul G

 

[Richard.]

Your 220 is more that capable to do this fabrication. I use a Lincoln 210 and have done similar many times.

Sticking something together and actually welding with sufficient fusion and penetration for the material gage are two different things Paul.
210 or 220 amps is not powerful enough to properly weld 8-10mm thick gage.

 

[Paul G]

Sticking something together and actually welding with sufficient fusion and penetration for the material gage are two different things Paul.
210 or 220 amps is not powerful enough to properly weld 8-10mm thick gage.

The nice thing about forums is that everyone can voice their opinion.
In this case our opinions differ, but that's not a bad thing.

Paul G