Welding rods get no respect. Out in the field I've seen guys throwing 50lb. rod cans from the truck onto the ground, torching cans open diagonally, beating the wrong end open with a chipping hammer and every other conceivable tool, and leaving open rod cans out in the open.
Let's look at what's wrong with each…
First and foremost, ALWAYS open the “right" end of the can. Some cans and boxes even say “open other end", or “don't open this end", or “the other end moron!. " (last one made up by me. ) The reason you need to open the right end is because you can damage the flux coating. You want to open it on the side where the rod is bare for the stinger, or electrode holder. There's a lot less chance of damaging the flux that way. 7018 is very prone to flux damage while 6010 is a lot tougher.
Most guys out in the field aren't gonna’ be thinking about the welding rods inside the can as they toss them from the truck to the ground. When the cans get manhandled the flux gets jarred loose on the welding rods inside. It's bad enough when the flux gets chipped off the end of the rod, flux chipped from the middle and you can pretty much kiss that rod goodbye. It's worse, if you don't realize it's chipped because right in the middle of a good weld you'll suddenly be welding with no flux. No flux equals no shielding from the atmosphere, and that equals a garbage weld.
You can use a lot of different ways to open rod cans out in the field if you are careful. I've even used the P38 C ration can opener I had in the army. If you use an oxygen/acetylene torch you need to be real careful not to burn the flux on the rods inside.
You can open a rod can with a chipping hammer, but it's not advisable. You gotta’ be sure and hit it just right, at the edge of the can. You should hit the edge with the hammer follow-through swinging away from the can, not striking down into the can at the top. (I'm sure the electrode manufacturers are cringing when they read this!)
Of course the best way is whatever the can is designed for, some of them open like a sardine can, but a lot of times it doesn't work so you gotta’ improvise.
Leaving open cans out allows moisture to get into the flux. Moisture in the flux can cause porosity, or worm holes in the weld. Rods should be stored in a proper oven or unheated container if they don't need the moisture protection. 7018 needs an oven, while 6010 doesn't need the heat, but still needs to be kept protected.
Martin Rice is a writer for RodOvens.com, where you can purchase electrode, flux, mig and tig rod ovens . At RodOvens.com, better welds are our business. Our objective is to make rod ovens affordable for welders by selling directly online, and avoiding cost-doubling and cost-tripling distribution methods that are common in the welding industry.