Low hydrogen electrode coatings are typically brittle. I threw in the comment about trimming a rod being a bad practice due simply to the risk of coating fracture.
Even a zip disc trim job leaves micro cracks in the coating which when the electrode is struck can break off causing arc wonder, gas shielding instability, and a greater risk of porosity on arc starts.
Ok...that and because from a control aspect,the arc doesn't stabilize as quickly. And a shorter electrode length also reduces a natural heat sink effect in the electrode core wire and coating so from a practical reasoning, the weld pool heats quicker faster...
Manufactures go to great length to ensure quick reliable arc starts. Some even tip coating the electrode with metalic powders to improve this effect. While trimming a rod to a shorter length can be acomplished, as can tacking three together to get length, it's just not a "good" practice.
"Good" welding practice suggests you strike your arc ahead slightly of the start point. Lifting the electrode or elevating the rod slightly after striking to stabilize the arc is high voltage low amps.This flaring is not as noticeable on the inverter power sources as compared to a transformer rectifier power source, thats the volt amp curve thing again.
Welding is like sex, get it hot before you proceed.
Flaring the arc after striking is much like foreplay, not much is happening but it heats things up.
As voltage flares in this few fractional seconds in time the material and the rod heat up, causing the coating to melt, releasing it's gas formers, improving electricial conductivity and the path for electron flow. Tightening the arc to reduce voltage /gaining the amperage to get the electrode to start melting and before depositing much metal the operator then falls back down into the start point all within a fraction of a second or two to start the weld.
Welding over the arc strike start point remelts the area, cleaning any deposit while annealing the arc strike into nothingness if done right.
Not done right or fumbling of the arc due to broken or cracked coating leads to splatter lumps, porosity, slag inclusions. Sure, higher currents burn that out but around the post of welding a 4" pipe with 1/8" 11018 or similar it may not be the best approach.
In another world, it's a leaky pipe. Todays world it's a law suit and litigation.
Any stumbling of the arc in doing critical welds is a risk not worth taking.
If you have to do it, your going to do it because your a do-er, the job needs to get done, then do it.
But do it with knowledge of the risks, and do your best to minimize them.
Thats a mistake in practice if you don't.
Do it with the knowledge of the process, and use them to your advantage.
Thats a mistake in education and understanding if you don't.
Now having said that, I was taught to weld before I was taught to think why? Thinking wasn't a job, doing was a job. I'm a do-er. Don't think about it, just do it.
Never gave much thought to why?
A big concern for my generation is we were taught to just do it. No fear. My generation teaches your generation.
Do this, do that.
Scary when you think about it. Not thinking...or of the consequences. And of not actually doing.
So like ugly not being a weld fault other than inexperience and opinion, the mistake is not in the do, it's a mistake in the why do it.
I hope this answers a bit of the why I thought trimming a rod a mistake.
On that fast finish, with an inverter, the Happy button aids in preventing the stubbing action of a trimmed rod, or a used rod stub, thats a bonus.
But if one is welding too high in amperage due to a difficultly in controlling arc length, well... then stuffing the short rod in the puddle things will cause things to get hot quite quickly and control is soon lost as the rod heat up, the weld pool grows hot and liquid, your brain is processing side to side paint the fence up and down and remembering to breath as you think your loosing control, deep in trouble and questioning do I pull out or keep going...
And that how babies are made.
Does that make any sense?
Uhhhhhhh, nobody shortens a rod on the front end.
They clip the electrode holder end.
The factory formed working end remains unchanged. Only the overall length is modified.
And, uuuuugh, trying to give lessons on human reproduction via the interwebs, as if only you understand that process, is ....just....plain....silly.
Look at all the rugrats running around over the last few thousand years : )
J
on edit: did you really think that welders were cutting off the factory end to shorten the rod?????? Really??????
Have you "ever been" a welder under harsh specs? Good grief man, that post just drips with "I've never welded anything but I'm a INSPECTOR condensation" as I like to call it. Drip, drip, drip.
Condensation, arrogance, primidonna inspector, who doesn't understand the trade they are inspecting, call it what you want. This superiority attitude hurts the trade and cost's magnum $$$$ to owners (and end users, needlessly).
If you work with idiot welders, then it is what it is, you picked your workplace.
Go on now, tell us how you're a nuke primadonna done it all hand.
My goodness. lack of understanding runnin' amuck here.
No offense to the real inspectors that I respect who inspect to the standards in effect per the job, right or wrong. Lot's and lot's of offense to the ill informed "power drunk" many (MANY) idiots running around trying to impose their stupid little opinions and trying to tell a welder how to shorten a rod : ).
The inspection world is in pretty poor shape right now in my experience, and really needs to clean up their house.
We'll see a lot of replies noting junk welders, so be it, run them off (withing the confines of the standards in effect), that helps me quite a bit and means work for me. But the stupid inspectors really need to be weeded out. Samo samo with the stupid welders, in my opinion only.
I never cut them on the front end I cut them more on the back end to shorten it. I don't want to screw up the factory end.
LMAO! There we go, clarity.
Now I understand that. You understand that... And if everyone does it we can start a trend to getting manufactures to make rods shorter :)
Human nature being what it is, someone somewhere will not get that and I sure didn't do anything to explain it better than you have and I thank you for the clarity in correction.
" on edit: did you really think that welders were cutting off the factory end to shorten the rod?????? Really??????
Have you "ever been" a welder under harsh specs? Good grief man, that post just drips with "I've never welded anything but I'm a INSPECTOR condensation" as I like to call it. Drip, drip, drip.
Condensation, arrogance, primidonna inspector, who doesn't understand the trade they are inspecting, call it what you want. This superiority attitude hurts the trade and cost's magnum $$$$ to owners (and end users, needlessly).
If you work with idiot welders, then it is what it is, you picked your workplace.
Go on now, tell us how you're a nuke primadonna done it all hand.
My goodness. lack of understanding runnin' amuck here."
This reaks of internet bully behaviour. Well, good luck with that.
"No offense to the real inspectors that I respect who inspect to the standards in effect per the job, right or wrong. Lot's and lot's of offense to the ill informed "power drunk" many (MANY) idiots running around trying to impose their stupid little opinions and trying to tell a welder how to shorten a rod : )."
The offense is welders who fail to share what they have learned in a mannor thats of benefit to others learning the trade. The offense is failing to improve ones hand skills, understanding of process and application knowledge. The offense is your tone and quite frankly your rudeness.
"The inspection world is in pretty poor shape right now in my experience, and really needs to clean up their house."
I'm not an inspector. I'm a welder, retired an educator. Some pass with high marks, some pass with low marks. Doctors call it practicing.
"We'll see a lot of replies noting junk welders, so be it, run them off (withing the confines of the standards in effect), that helps me quite a bit and means work for me. But the stupid inspectors really need to be weeded out. Samo samo with the stupid welders, in my opinion only."
Well, I'm aware of where you stand with your opinion. I don't think I'm a junk welder but if thats your opinion so be it. I think however if you had a pointer past the trimming of the rod to assist with the problem we would all endure reading it, in my opinion only.
Ok figure out how to run these rods, now spent sometime yesterday and have learned i had to change my technique up a little and as i run this rod i do like counter clock wise little circles and it helps to really spread the metal. i've had to move quite a bit faster to lay down a more narrower bead but it seems to really work for me and i've gotten it to look pretty good while i have heard that it won't look that good, few times i had to stop and make sure i was welding with a 11018 and not a 7018 rod. Thanks for the tips.
Chris
GOOD....
Chris it matters not what you hear, what matters is what you apply and it WORKS for you. A good welder can tell when the metal being applied is working good. So if it you got it going on and it is visually defect free....by all means continue and go test. Do it!
Thanks tommy as i told you yesterday no need to test for that place now since i landed the refinery job, Just gonna have to see what happens and all about the per diem. Never worked refinery before so gonna give it at try per diem or no per diem it's another stepping stone.
By Chris2626 
Date 06-24-2014 19:47
Edited 06-24-2014 19:50
You're a freaking trip
No I agree with ya cutting the rod does crack the flux and yes I have had issues when i light up it all wanted to break off. I thought this test was a 4 inch piece of pipe on a 6G and that was it and i can do that but it turned out this test was a 6GR and this company just had a booth to kinda ween out the guys who couldn't make it they said when they would send me to the company that did the real test it was a box they basically put over the pipe so it is very restricted. So I said to the guy let me go buy some of these 11018 rods practice a week and i'll be back and go take the real deal. He said to me if you practice a week you could probably make the test, the guy was gonna send me over to take the test but I knew i wasn't gonna make it so if I could practice a week Id rather do that because if I blew the test I'd have to wait 30 days, it's at a shipyard which I'm not to fond of the shipyard but it was a good stepping stone to learn to weld some exotic metals and thats what I wanted to try for. If it doesn't happen well off to the next one it's as simple as that.
Funny thing is I hate to even say this i have three certs on pipe, all x-ray but made me realize those 3 certs don't mean sh*t when it came to welding with this rod it was completely different for me.
Thanks for all the tips going to cut some pipe and practice.
By lo-hi 
Date 06-24-2014 20:37
Edited 06-24-2014 20:51
Plasma I think your posts are awesome and to the point. The mashed potato explanation was a big help. One time I was making supper and grabbed the carton of o j instead of milk, instantly I invented citrus potatoes. To shed some light on the rod cutting, I only use the stub with the factory end, the other piece goes in the stub bucket or to someone for home projects. I was also taught to weld and not to think. That was somebody else's job. The sex analogy is correct, hotter and cleaner makes doing a good job easier. Although everything you've said makes sense to me, I am not so sure about everybody else. Perley
Rather than cutting rods I set back a few that didn't get burnt all the way . They are much better for restrike than cut rods
