Welding undercutting

   / Welding undercutting #1  

Eric_Phillips

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Rochester, NY
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FarmTrac 270DTC
I am in the process of building some forks for my FEL. I am getting some undercutting when I weld the pieces together. Is this a technique thing or do I have it set too hot. I am using AC stick.
 
   / Welding undercutting #2  
a little hot is my guess, it may be some rod choice (type and size of rod diameter) , and technique,

prepare the metal correctly and depending on the rod of choice, use the proper heat and weld proper speed and weave,

most of the time I find that when your using a rod that is not "hot" deep penetrating, one has the tendency to up the amps to get penetration of the weld, but depending on the rod and the speed of welding of the bead one can undercut the steel being welded,

some rods I think have more of a tendency to undercut than others, as well,
not really the rod but the way the rod is used.

moving to fast and not letting it fill properly is another possibility,

I know we (I) get lazy and some times turn up the heat when in a hurry to by pass the proper beveling of the area to be welded,

multiple passes are fine, one does not need to build the weld up in one pass.

some times the angle in which the rod is held can contribute as well,

if the metal is extremely cold may not benefit as well as the weld may cool faster than desired,

it has been a long time since I used straight AC, but I know I have done enough under cutting, in my day when starting out, and I can do it on DC as well, :)
 
   / Welding undercutting #3  
Rod type and heat.

6010 & 6011 are deep penetrating

6013 & 7018 are low penetrating

A good inbetween rod is the 7014. High tensile strength, super easy to weld, and medium penetration.

The 7014 is my favorite rod. :)

On my Miller Wildcat I run the 1/8" 7014 at 140 amps. The 3/32" works well at 90 amps.
 
   / Welding undercutting
  • Thread Starter
#4  
Thanks for the help. I have to admit I have no idea what the rod was I was using. I got the welder when my wife's uncle passed away and he had some rod laying around. It was in an opened package but with no identification on it and the rod itself had nothing stamped on it. That is all used up now and I do have some 6013 I bought. I will try going over the top with that to see if it helps.
 
   / Welding undercutting #5  
Thanks for the help. I have to admit I have no idea what the rod was I was using. I got the welder when my wife's uncle passed away and he had some rod laying around. It was in an opened package but with no identification on it and the rod itself had nothing stamped on it. That is all used up now and I do have some 6013 I bought. I will try going over the top with that to see if it helps.


Never use old and/or damp rods. Always keep the rods in a cool dry place, preferably in a sealed rod box/canister. The red or blue rod "tubes" are about $15.

The flux coating will wick up moisture and not weld correctly.
 
   / Welding undercutting #6  
Me I use an old fridge to store my rods in and in the event of them being damp I place them in the oven at about 50 deg C to dry,or if I am in a hurry just stick the rod for 10-15 sec or until the steam disappears.


Stock

ps have being nosing around for a while
 
   / Welding undercutting #7  
The Lincoln rep used to tell us that the low hydrogen rods are the ones that tend to have problems with moisture. Regular rod isn't as touchy and weld ok once they get dry, they are just a little harder to use when dripping wet....
 
   / Welding undercutting #8  
....
A good inbetween rod is the 7014. High tensile strength, super easy to weld, and medium penetration.

The 7014 is my favorite rod. :)

On my Miller Wildcat I run the 1/8" 7014 at 140 amps. The 3/32" works well at 90 amps.

I'm no welder, but I have done a fair amt of welding. 7014 is my favorite also.
 
   / Welding undercutting #9  
I prefer the 6010 (6011 for AC) and 7018 myself. The 7014 are easy to run, but seem to be a bit on the brittle side. 7018 are much more ductile, but they do require a bit more skill to run. BTY, undercutting is more technique than amperage, with the correct technique, a proper weld can be made even if the amperage is a little too high. Proper setting of machine, right rod for the situation and a skilled user will make a beautiful weld. I have seen ugly welds that function just as well as pretty ones though, after all on the farm, we are not required to meet any specification or Code except our own personal requirements.
 
   / Welding undercutting #10  
Never use old and/or damp rods. Always keep the rods in a cool dry place, preferably in a sealed rod box/canister. The red or blue rod "tubes" are about $15.

The flux coating will wick up moisture and not weld correctly.

Horriable Fright has tubed Rod Holders (Orange) with a sealing gasket for $5.99.
 
 
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