Eating into 1st weld

[Thrashsmith]

Hi folks, I'm not sure of the correct lingo so please bare with me...and correct me.

I was welding into some V grooves today that required a few bead layers. I've read up on how to layer beads so I'm pretty sure I was going about it the right way but I was having problems with burning too much into the bead below the bead I was laying.

This isn't what I was doing but it's the easiest way to describe it: imagine you laid down a bead, then directly on top you ran another bead to build up the height...well that wasn't happening, I was burning into the lower bead so much that I wasn't really gaining any height from bead number 2.

What could have I been doing wrong? I was running 3.2 rod at 120-125 amps. I don't think I was going too fast or slow with the beads either cos they came out pretty nice looking. How long should I leave between beads 1 and 2?

Cheers for any pointers!

 

[jonjoe]

to high of amps and also you could let the the weld cool between welds

 

[Thrashsmith]

Cheers. Is there a rule of thumb of how long you should leave between layers? I did wonder if i should have been leaving it longer to cool, when i was grinding back the rubbish areas the disc was going through the welds like butter.

 

[jonjoe]

to tell you the truth i dont know but when am doing muti passes i hardly leave any time between welds. the more the weld burns in the better. could you post some pictures.

 

[Thrashsmith]

I can't unfortunately, I just grabbed the angle grinder and ground out any bits that were rubbish and kept repeating the process until it looked right.

I often hear ppl say arc welding is very hard to do on sheet 3mm or below, is that because the arc will burn right through? I'm not planning on welding thin sheet, I just want to get an idea of how much the arc will burn into the base metal.

If that is right then it seems ironic that you can build up bead layers with rods less than 3mm without burning through them, but not weld sheet without burning through???

 

[jonjoe]

yea welding on thin metal with a stick welder is a pain.

 

[jackjosh]

Try about 110 Amps. If your current is a bit high it will tend to burn out any slag you may have left so you can sometimes use it to your advantage but it is still nice to keep it neat. How long to leave it depends on how thick the plate is, if you could get some templesticks they would help. As a general rule you want to have a nice controllable weld pool and if it feels and sounds like you are using a lightsaber then knock it down.