Copper coating on mild steel filler rods.

[Steved]

Hi there.

TIG welding is supposed to be the cleanest welding out there. When welding mild steel the filler rod has a copper coating on it. What happens to this copper? Does it evaporate or become impregnated in the weld pool? Should you sand this off before you use the filler rod?

Thanks,

Steve

[arcdawg]

maybe its just a habbit but i sand down my filler rod....sometimes i will even use accitone to make sure all the impurites are off the filler rod.....

i also clip off the end of the filler rod when i start back up......

do a test on aluminum.....one rod that hasnt been cleaned and one that has

you will see a diffrence in the weld pool while you are welding...

dawg

[dyn88]

you should always wipe your al rod before use as good welding practice. I have only heard of removing the copper caoting when welding chromemoly. Ill be interested to see the answers to this question

[arcdawg]

from what i understand the copper coating (mig & tig) is to keep the filler material from rusting........... while in storage

i have always gotten better results when EVERYTHING IS CLEAN EVEN GLOVES....on the real fancy stuff

but i am no filler metal engineer

dawg

[Alex]

With the cost of copper what it is today, I can't imagine that the coating is more than a few microns thick. IMHO, it doesn't affect the weld.

Weld on,
Alex

[72boss]

copper coating

I do not use any copper coated rod or wire. Copper produces toxic fumes and is to be avoided if possile. The copper coating is used by the producers as a lubricant in the manufacrturing process, not for a rust deterrant in later storage.

And, yes the copper contaminates the weld to the extent that the copper remains behind in the weld after welding, it does not evaporate.

[Steved]

So, remove the copper (if that is what it is) from the mild steel filler rods before welding?

Can you purchase non coated mild steel filler rods?

Thanks!

Steve

[dyn88]

yes you can purchase uncoated rod.I think this question is awsome and I love some of the replies.

[HAWK]

As 72BOSS mentioned the Cu is a lubricant which aids the manufacturer in drawing the wire to diameter. Personally I despise Cu coated wire for MIG or TIG. I do use the Cu coated TIG filler since the uncoated is tough to find locally. However, when I am done cleaning the filler the Cu is no longer a visible villain. I refuse to use Cu coated MIG wire unless it is an absolute matter of use it or don't do the job! From what I have seen the Cu floats around and is trapped near the weld surface in most situations.

[BCarlucci]

I use Harris Welco's 1200 tig rod, it's a none coated tig rod and i've always used since starting to tig weld in my fathers shop, the only prob, is if it sits to long in the shop it rusts. Unless you have a heating fridge, well that's what i call it, that's where i store all my rod and tig rod. Still trying to convince the little lady to let me buy a digital camera so i can show you guys my setup.

BC

[wrench3047]

Just today I was in the weld shop at work and the door was open on the MM251. I seen a spool of copper coated wire. I asked about it and he let me play with it. After I was done I lifted my hood and watched the coating sizzle of the rest of the wire sticking out I thought it was cool. Our welder said it mostly vaporizes.

[revpol]

30yrs of tigging under x-ray conditions the only time I ever removed the coating off of 70s wire was when I thought it may have been contaminated with rust. Then I just threw it away. Never have I had a problem with the coating, but I always had a good quality rod from a major filler rod company. You could possibly contaminate the rod or weld with sanding dust If you don't use a cleaner of some sort after you sand the coating off. I've never heard of that either but I suppose it could happen. Stainless,certainium,inconel, stuff like that comes uncoated. Although some s.s. wire has a flux coating. revpol

[HAWK]

revpol,


Good point. I always use acetone for a final wipe after sanding (with Scotch-Brite not sand paper) and before welding. I also Scotch-Brite my rods in the outdoors. That keeps the dust from collecting inside the shop.

[BCarlucci]

Hawk,

Always have to have a clean shop right? I know when it comes to mine i hate it when my floors are dirty and there's dust all over the place.

BC

[klsm54]

This is one of those areas that HAWK and I have pretty much agreed to disagree... .....While I am certain that there is nothing wrong with bare, un-coated, rod and wire, I have yet to be shown the downside of coppercoated rod and wire. There is literally millions of pounds of coppercoated filler metals used every day in this country, much of it on extremely critical welds, with no ill effects.

While un-coated mig wire is readily available, bare tig filler, in any normal alloy would be a special order item. W-1200, while able to be used as a tig filler, is designed as a gas rod and lacks the mechanical properties of an ER70S-2 wire. The occaisional high alloy tig filler comes in a bare wire, but even the 80's and 90's and 4130 and such comes with a copper coating.

Now, I am not arguing that it IS a method to help in the manufacture of the wire, the drawing process, but if it was a detriment to the weld deposit, or the operator, I would expect the AWS to be specifying many more rods and wire without it. As far as a danger to operators, as with any welding, precautions should always be taken so that you are not directly inhaling the fumes.

If you want to strip your rods and buy bare when available, I am sure that it will work just fine, but I will always believe that it is not something that is needed to make quality welds....