Notched Tube Joints

[PSweeney]

I'm having some issues welding in some tubes on my dragster chassis. The main structure of the chassis is tig'd by a pro but I'm adding brackets and some extra tubes with my MIG. I have a Sealey / Siegen 150. It's OK, far better then the little SIP piece of crap I had before. I get good results welding pieces up on the bench but just can't seem to get a decent welds on tube "in position". The torch and liner is new, earth clamp fine.

It's 3.2mm CDS tube, welder is on 4 of 4 heat setting and nearly full whack on the wire feed. The set never really has the bacon frying sound, but I have got a good stable arc, just doesn't crackle ! Wire diameter is 0.6mm and gas is Argon/CO2 mix. When welding in position on tube, I'm struggling to maintain torch angle and I'm getting spatter as a result. I'm seeing the end of the wire ball up whilst running a bead as well. I dropped down to 0.6mm wire ages ago simple because I found it easier to produce neater welds as I'm a bit slow running the bead and because my previous set struggled with it.

Should I be using 0.8mm wire ? and what technique can I use to help maintain a torch angle when welding tubes around 32mm ? I've turned and flipped the chassis to get the best position, but I seem to be fluctuating between pushing and pulling beads based on access and result are inconsistant.

Anybody got any pointers ?

 

[overload]

Pics would help.

 

[pedrobedro]

Get plenty of light on the job and do a dry run round the joint to see where you might have problems keeping the gun in position before you commit to welding. Try the .8 wire it might give you a bit more time to move the torch, keep the tip in close and if you get a ball clip the end of the wire before you start again.

 

[Engineer1964]

Practice on scrap tubes and push rather than pull for a stronger weld. Turn the set up max and work down the settings as opposed to the other way

 

[F.J.]

It sounds like the wire speed needs turning down a bit and you need to slow your movement. If you see the wire ball up then it isn't in a puddle, once you arc just concentrate on keeping the end of the wire in the puddle pushing it as you go. Possibly the best position for tube though is to start at the top and work down one side then stop at the bottom, move around to the other side and repeat.