Stick Welding 8mm channel to 30mm plate - mild steel - cracked weld when cooling

[ELL]

So at the moment I have no way to preheat the plate. Is it possible to weld 8mm channel to 30mm plate without the weld cracking straight after the weld is done? At the moment I am getting a crack all along the length of the weld after welding.

 

[BrokenBiker]

i have limited experience with that thickness, but id say its more than likely going to need a preheat...the 30mm section will suck the heat away from the weld far quicker than the 8mm will

ive only ever really stitched little guide blocks to stuff that thick with a 6013 and i rememeber some of those cracking but the guy i was working with welded them again and was fine, but thinking about it, my welds would have put some heat into the plate and he ground them out and re-welded pretty quickly

 

[Robert Weaver]

is access the reason for not preheat, or lack of gas? could you weld a pad, then quickly grind it back, using that as a heat source?

 

[tom2207]

I take it your stick welding it ?

 

[ELL]

I take it your stick welding it ?

I am, yes.

 

[ELL]

is access the reason for not preheat, or lack of gas? could you weld a pad, then quickly grind it back, using that as a heat source?

I'm not sure how to weld a pad then grind it back to use as a heat source to be honest. Also, I have no equipment to heat the plate with at the moment.

 

[wyn]

Shouldn't crack. What rods are you using?

What is the plate...........mild steel or something a bit more exotic?

 

[BrokenBiker]

I'm not sure how to weld a pad then grind it back to use as a heat source to be honest. Also, I have no equipment to heat the plate with at the moment.

i think the suggestion is to weld the joint, then quickly grind it out and weld it agian while its still hot...may require welding smaller sections at a time

 

[ELL]

Shouldn't crack. What rods are you using?

What is the plate...........mild steel or something a bit more exotic?

mild steel plate 30mm thick. I have tried 3.2mm rods, mild steel - non-marked, and esab 6013 3.2mm mild steel.

 

[tom2207]

mild steel plate 30mm thick. I have tried 3.2mm rods, mild steel - non-marked, and esab 6013 3.2mm mild steel.

is the plate clean , plenty of amps , your not picking up dirt ,. is there porosity , is the weld cracking down the center or are you maybe getting cold lap

 

[zzr1200]

mild steel plate 30mm thick. I have tried 3.2mm rods, mild steel - non-marked, and esab 6013 3.2mm mild steel.

At what ampage?

Ground all the joint area?

And are the rods damp?

 

[premmington]

If you not got two many to do - do it in 312 mma rods.

 

[Bornfree]

4mm rods around 150-160 amps concentrate most of the heat on the 30mm and flick the puddle onto the 8mm channel, you shouldn't get cracking weld.

 

[Bsmith]

Use higher tesile rods such as e7016 or e7018s

 

[tom2207]

post a pic , lets see whats going on

 

[Kram]

Its going to be a great high quality welding bench product.

 

[premmington]

post a pic , lets see whats going on

Yes - picture please @ELL

 

[ELL]

Its going to be a great high quality welding bench product.

It's going to be a 30mm plate in the nearest scrap yard with 50 hammer dents in it if I can't get these welds sorted!

 

[ELL]

Yes - picture please @ELL

I'll have a go with @Bornfree 's Idea and then will post a pic. Not sure when I will have time to do it though.

 

[ELL]

Its going to be a great high quality welding bench product.

Listen pal. I just welded a friggin steel bar to a spanner. Surely that puts me in the top tier of welders round here.