Grahame Collins
18th Aug 2007, 12:30 AM
Hi guys
Further to the thread on positional weld – overhead welding- I have completed the basic information on vertical up welding. I will keep it as basic as possible so keep in mind it is written for a DIYer MMA stick function.
You will see other variations to this around the net ,but I consider this the simplest for beginners.
Please keep firmly in mind the short arc comments I made in the previous Overhead welding posts.
Some basic principles need to be observed when attempting the vertical up weld position.
1. Welding with an electrode type suitable to the position ie; 6012 and 6013 type mild steel electrodes for mild steel parent metal.
2. .Using an electrode diameter of sufficiently small diameter to allow control of a size /volume the molten arc pool.
3. .Using a short arc technique.
4. Observing a pause at each end of the side motion of the electrode.See the diagram below.
5. “Snapping” the electrode between the pause points ,thus minimizing the molten metal build up in the middle of the weld bead
6. Amperage the same or maybe slightly less than standard downhand amps.
Most vertical up welds for DIY are the fillet welds involving welding of two intersecting pieces of metal. Vertical up in general is suitable for heavier plate say 6mm and thicker, It’s a slow moving weld ,so a fairly large heat input is present. Ok got it? Not suitable for sheet thicknesses unless you are into burning through and filling big holes..
Tacks
Don’t do them where you are going to weld over them. This causes finished weld profile problems and potential slag inclusion- holes- gaps –pockets etc. Instead place your tacks on the upper and lower horizontal adjacent surfaces. Placed there ,distortion is also controlled much better.
Electrode Angles
Between 10 to 5 0 below horizontal stops the molten flux from mixing with the molten metal.
Overlapping of Passes
If we consider each left to right and right to left movement a “pass” the amount of overlapping is important. It is like building a brick wall. Each pass is horizontal .Each “pass” should overlap the preceding one by half .Beginners make the mistake of trying to “climb” too quickly and leave big slag holes between passes.
The Upward Movement
Make the upward transition at the pause position. It takes practice to judge how much as the vertical distance is only half a bead width wide.
Stop and Re start
A vertical up bead will consume quite a few electrodes. On running out of electrode, break the arc quickly to leave an egg shaped crater. The re-strike of the new electrode should be done 10mm or so vertically above the crater. Lift and elongate the arc to 7 or 8mm out and move it back to where your last broke the arc on the previous electrode. Done in this fashion the blend in, will be almost undetectable with practice.
Finishing the bead
As the top is reached the heat build will concentrate around the edges of the plate. Stop for a period of time when the last 10 mm or so comes up. Allow the heat to dissipate and restart after a minute or so.
Those with small capacity machines will notice that the circuit breaker is prone to throw. All I can suggest is place a fan behind it to assist cooling.
This weld needs a lot of practice.
Cheers
Grahame
Further to the thread on positional weld – overhead welding- I have completed the basic information on vertical up welding. I will keep it as basic as possible so keep in mind it is written for a DIYer MMA stick function.
You will see other variations to this around the net ,but I consider this the simplest for beginners.
Please keep firmly in mind the short arc comments I made in the previous Overhead welding posts.
Some basic principles need to be observed when attempting the vertical up weld position.
1. Welding with an electrode type suitable to the position ie; 6012 and 6013 type mild steel electrodes for mild steel parent metal.
2. .Using an electrode diameter of sufficiently small diameter to allow control of a size /volume the molten arc pool.
3. .Using a short arc technique.
4. Observing a pause at each end of the side motion of the electrode.See the diagram below.
5. “Snapping” the electrode between the pause points ,thus minimizing the molten metal build up in the middle of the weld bead
6. Amperage the same or maybe slightly less than standard downhand amps.
Most vertical up welds for DIY are the fillet welds involving welding of two intersecting pieces of metal. Vertical up in general is suitable for heavier plate say 6mm and thicker, It’s a slow moving weld ,so a fairly large heat input is present. Ok got it? Not suitable for sheet thicknesses unless you are into burning through and filling big holes..
Tacks
Don’t do them where you are going to weld over them. This causes finished weld profile problems and potential slag inclusion- holes- gaps –pockets etc. Instead place your tacks on the upper and lower horizontal adjacent surfaces. Placed there ,distortion is also controlled much better.
Electrode Angles
Between 10 to 5 0 below horizontal stops the molten flux from mixing with the molten metal.
Overlapping of Passes
If we consider each left to right and right to left movement a “pass” the amount of overlapping is important. It is like building a brick wall. Each pass is horizontal .Each “pass” should overlap the preceding one by half .Beginners make the mistake of trying to “climb” too quickly and leave big slag holes between passes.
The Upward Movement
Make the upward transition at the pause position. It takes practice to judge how much as the vertical distance is only half a bead width wide.
Stop and Re start
A vertical up bead will consume quite a few electrodes. On running out of electrode, break the arc quickly to leave an egg shaped crater. The re-strike of the new electrode should be done 10mm or so vertically above the crater. Lift and elongate the arc to 7 or 8mm out and move it back to where your last broke the arc on the previous electrode. Done in this fashion the blend in, will be almost undetectable with practice.
Finishing the bead
As the top is reached the heat build will concentrate around the edges of the plate. Stop for a period of time when the last 10 mm or so comes up. Allow the heat to dissipate and restart after a minute or so.
Those with small capacity machines will notice that the circuit breaker is prone to throw. All I can suggest is place a fan behind it to assist cooling.
This weld needs a lot of practice.
Cheers
Grahame