Hello again. This is another publication on the Stick Rod Series. Today we will look at Fast Freeze Rods/Uphill/Downhill.
As we discussed last time, the fast freeze rod is a common stick rod that has been a stable rod and around the welding trade from the beginning since flux coated rods have existed.
Our focus today will be the uphill and downhill positions of the fast freeze rod.
The best place to start with any rod is of course the flat position, but I want to focus on a little harder area today.
Depending on what you will be welding and in what code (if any) you will be accountable too, the two most common applications will either be uphill welding or downhill welding. Some like to refer to the downhill as downhand. I don’t but some do.
In general industry standards, there is very little acceptable downhill welding outside of the pipeline welding code 1101.
Most procedures nation and world wide will focus on the uphill root pass, hot pass, and cover pass. From experience where there is a fast freeze rod root pass and or hot pass, the cover pass will usually be with a low-hydrogen rod like 7018 or something similar.
Uphill welding is very different from the downhill welding. When welding there is a natural effect of heat that is fighting against the welder. Heat rises. You say, hey, that guy is smart. Thanks. Just kidding. Keep this basic principle in mind at all times when you are welding and it will help you redirect your weld when necessary because of what happens with radiant heat transfer.
Uphill welding has more penetration because the rod is burning the surface metal out of the way before the puddle comes behind to fill in giving more weld deposit deeper into the parent metal. It is easier to overcome a gap welding uphill; especially with fast freeze rod because while moving up and away from the area where the metal is being deposited, the weld has frozen or solidified by the time you come back down to deposit more metal. You are not fighting the tendancy of the metal to outrun you like downhill can do at high heat since gravity is pulling on the metal. Uphill welding is not as fast as downhill welding therefore you rarely see uphill welding on a pipeline weld. The pipeline weld is almost always all downhill from start to finish.
Sometimes it is necessary to stop and let the metal cool if the gap is too big. It is better to do this than to keep welding and run the risk of pushing to much metal through on the root pass. Now if you are welding plate to plate with no gap between the metal, then this is not usually a problem.
Uphill welding requires less amperage heat to weld than the downhill procedure. Not something drastic, but slightly different.
The reason for this is that downhill welding is more a dragging the rod than whipping or stepping the rod like the row of dimes we discussed from our last article and because gravity is working against you, the slag, or impurities that are cooking out of the weld while the process is going on, are following and often trying to overtake the downhill weld. Due to the nature of the gravity and slag feature on downhill the heat setting is usually higher than uphill welding. This extra heat is needed to keep the rod burning while fighting the slag trying to consume the rod arc. It could be upto as much as 10 amps higher.
One thing to be aware of when welding a gap uphill like on a pipe or but weld plate is this: it is easy to put too much metal into the weld joint because of higher deposition rate. If you hang to much metal inside the gap, it could disqualify your weld. While welding you are not necessarily pushing the rod hard into the gap but just touching the surface making sure not to leave undercut. Most of the time the metal on the inside will take care of itself. Moving to fast can leave not enough metal at times too. Practice will help you overcome these obstacles. It is just part of welding.
Rod angle and heat coupled with travel speed will either make or break your welding experience.
Once you learn the characteristics between these 3 critical components coupled with either uphill or downhill you will see a difference in your ability to weld, and the appearance of your weld.
While welding downhill it is best to keep the rod in the center of the weld piece. There is really not a need to move the rod from side to side. This is what I refer to as the dragging affect mentioned earlier. At some times there will be a need to move from side to side to allow the slag metal to pass around the good weld puddle. In this case gravity is helping remove that unwanted metal build up. While going uphill, the tendancy will be to move the rod either side to side or in a U pattern. Sweeping from side to side going up and back down into the puddle as it freezes. Now I am not talking about some super exaggerated movement here.
One more thing before I go is this: Welding is a multi-tasking process. While the hand is moving in a direction accross the weld piece it is also moving closer into the weld piece because the burning rod keeps getting shorter the entire time you are welding. To learn to sequence these movements while keeping the proper angle is the trick of making killer looking and proper welds.
Welding is a smooth fluent motion. It is best to make yourself as comfortable as you can while welding. I very rarely weld with one hand because I find myself not as steady.
Experiment with these techniques and you will have success. Until next time, keep your eyes behind the welders lens
Thanks from the author!
The Welders Lens Weblog 