Wont weld the joint - SOLVED

itchyback · #1 07-18-2010, 12:32 AM

Hey,
I'm using an arc welder to weld to pieces of steel together but the weld bead just sits either side of the join and the join fills up with slag. I'm new to welding so i suspect i'm doing something wrong. THe pieces have been in an L shape should they be in a V shape? i tried 80 amps but it just blew a hole. there is at most a 1mm (less than 1/16) gap is that too much? I've ground everything back to bare metal with an angle grinder. I did do a short course in welding but it hasnt helped me very much, it was a little too basic.

material is 30mmx30mmx1.6mm (1'1/4 x 1'1/4 RHS 1/16) thick
settings are about 60amps
rods are E4113/ E6013 - according to the box they can weld in all positions.

Thanks for your help

wyoming9 · #2 07-18-2010, 04:26 AM

Are you sure what you are trying to weld is in fact steel??

While SMAW is not the best choice for thin metal the 6013 electrode is about the best one to use.

does your job need a butt joint?? if so the use of a copper backing strip.With something that thin there is no need for a gap are you needing to hold an over all dimension??

A lap joint clamped and tacked as needed .

Pictures ??

I know of some off brand AC only welders that don`t work to well any time .

Are your electrodes damp or are they new??

All things to look at

Good luck

itchyback · #3 07-22-2010, 05:22 PM

Thanks for the reply
I'm positive its steel
How would you hold a copper backing strip inside a sealed tube? i havent tried that before and where would i find a suitable copper strip to do that?
The gap is there because i need to keep an overall dimension and some parts i chewed out too much with a grinder.
The electrodes are about a month old and after i used them i wrapped them in glad wrap/ plastic cling film/ that stuff you wrap your sandwiches in for lunch (what do you guys call it?) that said it did have a bit of a white powder on the sticks, i cant remember if that was there when i got them or not.

If someone can direct me as to how to post photos that would be great.

4play · #4 07-22-2010, 06:43 PM

Id say you did pretty good on protecting the rods. At a month old, even in an open atmosphere they should still be ok to use. If they possibly were effected by moisture. you can put them in an oven at about 120*F (48*C) for about 4 hours. I know you can in an electric oven but im not sure on a gas oven, something about it is throwing up a red flag in my head. From what you have described in your first post, my guess would be that you have one piece that is magnetized. Easy way to check is to sweep up some grinder shavings and sprinkle them over the joint and if they stick its magnetized. This can happen easily with tubing and rod. To demagnetize the tube, place it lengthwise in the east and west direction and strike it with a hammer. Cast Iron works better but a regular hammer works too. If you don't believe me take a piece of round stock and drag it through grinder shavings see if it picks up any. If not hold it in the north to south position strike it with a hammer and run it through shavings again Ill bet it does pick some up. Turn it east and west and try it all again. Sorry about a long post I was just trying to point out how simple it is to accidently magnetize something.

itchyback · #5 07-22-2010, 11:39 PM

Magnetised ?! i'd never thought of that, nor thought it would affect things. I'll give it a crack. now you mention it a few bits and pieces have been picking up metal shavings.

Wicked one · #6 07-23-2010, 09:48 PM

Quote:

Originally Posted by itchyback

Hey,
I'm using an arc welder to weld to pieces of steel together but the weld bead just sits either side of the join and the join fills up with slag. I'm new to welding so i suspect i'm doing something wrong. THe pieces have been in an L shape should they be in a V shape? i tried 80 amps but it just blew a hole. there is at most a 1mm (less than 1/16) gap is that too much? I've ground everything back to bare metal with an angle grinder. I did do a short course in welding but it hasnt helped me very much, it was a little too basic.

material is 30mmx30mmx1.6mm (1'1/4 x 1'1/4 RHS 1/16) thick
settings are about 60amps
rods are E4113/ E6013 - according to the box they can weld in all positions.

Thanks for your help

Is your welder AC or DC? If it's DC your polarity is wrong. Switch your leads and it should work fine. If it's AC your machine could have a problem

wyoming9 · #7 07-23-2010, 10:13 PM

Be nice to know what kind of welder.

Would it hurt anything to leave a copper strip inside the piece after it is finished . In the past I have made copper backing for pipe yours would just be made to fit your tube

You should be holding a short arc to keep the voltage as low as possible. If all else fails run a stringer bead down both sides even if you must run two to a side till you can close the gap.

Another old trick is to use aluminum heat sinks to soak up the extra heat on both sides of your joint

SomeGuyFromOlympia · #8 07-24-2010, 01:13 AM

Rod angle?
Arc Length?
Ground?
He never mentioned these....

itchyback · #9 07-24-2010, 06:43 PM

THe welder is a cheap GMC 140amp welder (bought 2nd hand). I assume its AC as there is no option to swap the leads but i could be wrong. How do you know/ check?
Rod length is 30cm
arc length was 2-5mm
ground?? connected about 12-20inches away? (i'm not sure what this question is about?)

SomeGuyFromOlympia · #10 07-25-2010, 02:02 AM

Quote:

Originally Posted by itchyback

THe welder is a cheap GMC 140amp welder (bought 2nd hand). I assume its AC as there is no option to swap the leads but i could be wrong. How do you know/ check?
Rod length is 30cm
arc length was 2-5mm
ground?? connected about 12-20inches away? (i'm not sure what this question is about?)

your ground location can affect arc blow if you have it

Wicked one · #11 07-25-2010, 09:15 PM

Try welding away from the ground instead of towards.

itchyback · #12 07-31-2010, 03:18 AM

I think i've cracked it gents.
in lou of being able to post pictures here is a text version of my sitaution

__l or __/ (these are the angles of the two pieces of metal, 90d perpendicular)
a cross section of the join would look like this [MMM WW sssGs WWW MMMM]
m = metal, w = weld, s = slag, g = gap, one letter = 1/32inch

I had had a few blow throughs on my first attempts at welding which has made me weld too quickly. So i slowed down and presto - i nice looking weld. I'm quite surprised at how much of the weld pool appears to be molten slag. Originally once i'd finished the weld the slag coating looked to cover it nicely but when i chipped it away there was very little weld in place. Now the slag bulges a bit and chips off to reveal a nice weld. I also changed my angle somewhat which i think has helped. I have some trouble keeping the arc so i'm going to get some skinnier rods, i'm hoping this will give me a more solid arc at lower amps and therefore less blow through on the metal which is 1/16 thick
I'm also getting better at welding blow through back together.

SomeGuyFromOlympia · #13 07-31-2010, 04:16 AM

Right on!!
Get the right rod, slow down, let your puddle 'talk to you'
You will learn that the metal and the slag look different.

'drag' your stick behind you a little and it will help with the slag

to use your 'drafting' --> (this direction) rod angle like this: /

your arc length should be about your rod diameter (general rule)