[welder0109]

Can anyone give me some tips on how to weld lap joints with a 6011 electrode without getting any undercut or cold lap, on 3/16 plate, flat position, using a Miller Dynasty 280

[Poland308]

What size 6011 and how many amps are you running? Why 6011? And are you cleaning off the mill flake before you weld the plate?

[Mike]

0109. welcome to the forum.

[Boomer63]

Watch your amperage setting. Your rod angle is going to be super critical, but rod angle is super critical for any process. Also, the rod angle you are using here for SMAW will also be the same angle used for GMAW or GTAW. Try a very slight whip and pause, moving forward a tiny bit, then back and holding while the puddle fills out. Your angle should be around 50 degrees. Another manipulation you might try is a modification of a 'Z' weave; making a pattern like a backwards leaning "W". As you manipulate and go 'up', lean backwards and as you manipulate 'down' lean forwards. I don't know if that modified 'Z' weave will help you with the 3/16, but it will come in handy on thicker metals.

Make sure you have a drag angle of something like 5 to 20 degrees. Keep your arc length tight! Pause enough to fill in the weld; watch the back part of the puddle and keep your weld size consistent. A tight arc length will keep down weld spatter. If you see lots of spatter, your arc length is too long. If you are getting a lot of undercut on the top plate, check your rod angle, amperage setting or amount of time you are pausing to allow the weld to fill in.

I hope this helps!
Gary

[Lightning]

I would focus the heat on the "bottom" plate, create a puddle, then "wash" it over to the edge of the top plate.

If you focus the heat on the edge of the top plate, it will just melt back and never fuse with the bottom plate.

Try to make the bead flush with the top of the edge of the top plate without melting it back.

Rod manipulation, if I used any, would probably look like a bandsaw blade, like this (moving left-to-right): |\|\|\|\

[Boomer63]

I would focus the heat on the "bottom" plate, create a puddle, then "wash" it over to the edge of the top plate.

If you focus the heat on the edge of the top plate, it will just melt back and never fuse with the bottom plate.

Try to make the bead flush with the top of the edge of the top plate without melting it back.

Rod manipulation, if I used any, would probably look like a bandsaw blade, like this (moving left-to-right): |\|\|\|\

Lightning expressed in much fewer words what I was trying to say. Also, I LOVE his illustration! Remember, this is also the same 'manipulation' that you will use for a "T" joint (fillet weld). Don't manipulate too high on the joint to fill in the top. Remember that the edge of your puddle is NOT where your rod is; but is out away from the rod.
Gary