Thread: arc welding 90 degree joints - lots of trouble

Originally Posted by jatt

The best thing I ever did was to replace my old helmet with an auto darkening unit. The $115 Unimig one I picked up has the 3 adjustments (delay, shade level, sensitivity).

It really has helped me improve my technique.

I agree fully, I bought one a few weeks ago

I second all of that Lou has said and in particular the bit about the arms.

The arms need to be close to the body as far afar as comfort will allow.

One can greatly reducing shakes and wobbles byusing two hands in the following fashion.

Hold the electrode holder in you gloved dominant hand but resting on the bench.The other golved hand comes is brought in close and the electrode can be suported across the top of the the first finger.

This hand is usually closest to the arc ,so don't try to be stingy by burning the electrode all the way down.

Another point to make is that the joint line needs to be straddled by the arc puddle,ie a bit above the line and a bit below.

A short arc and slightly higher amps are the way to.

As Lou says get some scrap bits and get into it.
Finally a word on tacking. Tack on the intended start/finish ends of the bead, not in the bloody middle of the bead run GRRR??

The bead can be started on one tack and finished on the other and you won't even notice the tacks later as they are absorbed into the bead.

Grahame

Thanks for all the hints and tips guys, i'm going to make a bench for a bench grinder soon and will try all this out on it. Although I probably cut a few off cuts up and have a crack at welding better this time around.

On 40x40x3mm tube would a 2.6mm (E6013) or 3.2mm (E7016) be better to use ??

Matt.

I watched an arc welding vid the other day and it recommended pretty much what others have said here... although one tip I found useful was that if it is only a short weld run to be made, and you aren't the steadiest person around, use a shorter electrode or one that has been half used before... Longer electrodes amplify your shakes, shorter ones not so much And yeah, get a good helmet... I brought a auto-darkening cheapy one a while back with fixed shade DIN 11... Only recently just realised this is a bit too dark for low amp arc welding so I brought a filter lens of DIN 9 for my other non darkening helmet. Now I could see the weld pool much better and greatly improved my results... So if you do get an auto-darkening helmet, make sure it is one of those with adjustable shades, and not a fixed shade

Originally Posted by Matty5700

On 40x40x3mm tube would a 2.6mm (E6013) or 3.2mm (E7016) be better to use ??.

A 2.6mm 6013 electrode is fine.


Grahame

Originally Posted by Matty5700

Thanks for all the hints and tips guys, i'm going to make a bench for a bench grinder soon and will try all this out on it. Although I probably cut a few off cuts up and have a crack at welding better this time around.

On 40x40x3mm tube would a 2.6mm (E6013) or 3.2mm (E7016) be better to use ??

Matt.

Hi Matt

As mentioned in one of the replies, you have to keep the electrode at a 45 deg angle between the two pieces you are welding together, regardless of whether you are welding from above or below the join. As a beginner, it is easier if the join is below you and the two right angle pieces are at a 45 deg angle to the horizontal. Then all you have to do is keep the electrode at about 15 degrees to the vertical in the direction of the welding. The other critical factor is the current (amperage) setting you use in relation to the thickness of your metal. If you are using a small oil welder, you do not have much control unless you have an Inverter type welder. Please note that it is also easier to weld when your metal is warmed by the sun than if it has been standing overnight in winter. I mainly use 2.5mm E6013 electrodes for 1.6mm thick tubing to 16mm steel bars. If you have a problem with steadiness of the hand, then try using your spare gloved hand to steady and guide the electrode as you are welding. Some people also bend a new electrode to prevent it from whipping around, although I do not believe in doing that except when I have to weld in hard to reach places. Welding is not difficult, it just takes a lot of practice. I went throught about 5 kgs of electrodes before I becames sufficiently proficient. Good luck with your projects.

Regards
Ernest

Thanks Ernest & Grahame, I might go out to the shed in a minute and give it a try, i'll cut up a few bits of scrap (after I change my bandsaw blade, but thats a different thread !!)

Matt.

Originally Posted by Matty5700

i'm going to make a bench for a bench grinder soon and will try all this out on it.

Ok! the following are some things which are good to know before you start welding your bench.

Some things I would keep in mind in making a bench,or any frame for that matter,are :

• Do all the of tacking before you lay a single bead of weld.
  
• If there are long sections (of unbraced legs for example) tack on some temporary braces while all the welding beads are being laid down.This stops the welds distorting the angles (square ,hopefully)
  
• When laying the beads don't do all the welding in one section.
• Weld a straight bead ,then go to the diagonal opposite on the frame
  this will balance the heat input to use the heat input created distortion to balance each welded portion against its opposite member.

The offers a much better chance of ending up with straight and square frame.

If you need a diagram ,sing out and I shall put something together.

Grahame

Thanks for all that Grahame, I think I should probably have asked for advice earlier, I already made a workbench frame that is 2200xx900dx800h mm and it has ........... a few imperfections !! I got tired of trying to patch up holes I blew in it (trying to weld at 90 degrees, flat join weld are beautiful !!) I just left a few and painted the whole thing in a nice black hammer tone paint. I may get around to repairing it eventually, but if it works ok I doubt this will happen any time soon.

I have noticed that it isnt quite square, this heat distortion and a few other problems, but all in all not bad for my very first attempt.

With this bit of experiece I would definately say making a trailer is off the cards for a while until I can confidently make bits of furniture sucessfully (things like shelves are next)

EDIT: no pic required, I know exactly what you mean. I sort of knew some of this before I started but got a little to excited and just started welding long beads , lol.

Matt.

I had a lot of similar troubles as a recent trainee welder.
I fixed/improved it by;
-inceasing amps a bit to get better penetration
-starting the arc and pool on the lower (horizontal) peice then moving to the higher (vertical) peice and getting a good "bridge" of molten metal under the slag before moving down the weld line

I reasoned that if i started on the vertical peice the slag runs under the metal pool and makes it a bit harder to get a weld pool to connect to the lower peice

I noticed I also tended to rush down the weld line after striking an arc, so I slowed myself down to make sure I developed a good weld pool across the fillet before i started moving.

Good luck!