welding cor-ten

[ironman]

Hi, I want to work in cor-ten and have been advised to use ER80S-Ni1 mig wire. Does anyone have a source for this wire, .030 ga. in 10-11 lb. spools? OR is there another low alloy wire that is good for cor-ten? Thanks Jeff

[sculptorsam]

I use Lincolnweld LA-75. It comes in .035 in 30 lb. readi-reels. It might be available in other sizes as well though. Call your local welding supply shop and they should be able to order it. I use a two part shielding gas though three part would probably be better. There is some more info around here somewhere on welding with Cor-ten. When I get some more time perhaps I can dig something up for you.

Sam

[ironman]

Hi Sculptorsam, thanks for the info. I already knew about Lincolns super-arc LA-75 but just assumed that a 30 lb. ready roll wouldn't fit my Millermatic-150. I do have enough clearance for a 12" diam. roll with standard 2" center hole so maybe I could use it if it'll fit. I looked in the Miller literature for info on max. spool size but couldn't find anything. I do have the local welding supply co looking and have checked Hobarts web site. I have been told by Hobart that ER80S-Ni1, .030, 10 lb. spools might be hard to come by. So if it fits, I may have no choice but to use the LA-75 in .035 ga. Thanks again, Jeff

[sculptorsam]

I use a Miller 185 myself. Your clearance sounds about the right size, not being able to check my welder half way across the country at the moment.

[julian]

Hello,

I was told in my welding store that it is OK to weld Cor-ten (I use 606 type 4) with standard welding wire (NOT the stuff with 1% Nickel, ER80S-Ni1 / LA-75) as long as it is single pass welds. The argument was, that this is sufficiently thin for the alloys to mix which makes the weld as corrosion resistant as the rest of the steel. The guy who said that is considered a real expert, and he even claimed that all the water tanks in Portland, OR are welded like this. For multi pass, the special wire is required. I have no reason not to trust him, but I would like to hear other opinions, because of the scary stories that Cor-ten sculptures fall apart, after their welds in mild steel rust out.

thanks,
Julian

[sculptorsam]

For me, it's always better safe than sorry. I use the appropriate wire because of the type of work I do (I often fill large gaps, "sculpt" the works with large amounts of wire, etc.) and to avoid any problems down the line. I do believe the alloys will mix a fair bit, but even still, it will be diluted by the wire.

Often times, the needs of industry are different from that of sculpture. It's possible they use Cor-ten for the water tanks because of its abrasion resistance and higher tensile strength. I'm sure they paint the tanks somehow if they are in constant contact with water, since that will continue to degrade Cor-ten. In which case, they may use standard wire because there is minimal loss of strength with a cheaper consumable. If you're using literally tons of wire, minor cost savings are very important. In addition, materials are chosen for the expected life of an object. They may expect to replace the tanks every 20 years (wild guess) whereas I expect my sculpture to last 100 at least with minimal care.

Just some thoughts.

[julian]

Hi Sam,

thanks for your reply. Your water-tank arguments make a lot of sense.

I noticed what I bought as Cor-ten was A606 type 4, whereas a friend swears, his A588 is Cor-ten. So what is Cor-ten then? Is there a website where the differences are cataloged? And more importantly: Is there a website where it says exactly which wire is best for which alloy, i.e. which wire is closest in composition (of the significant elements) to the composition of a given steel?

thanks,
julian

[sculptorsam]

Sorry for the delayed response, Julian...

Check out this site: http://www.centralsteelservice.com/

I ordered some 1/2" A588 rod from them a while back. You can ask them for a more specific answer to your question, but I was told once that the numbers were more for reference to the form (sheet, plate, rod, angles) than their properties. I don't believe that to be entirely true, but I have welded A588, A606 and A242 together with the same LA75 wire and have had no problems and an even colored/textured rust. Hope this helps.

[julian]

thanks for that link, probably the alloys (A588 and A606) are almost the same...

While doing research for my cor-ten welding I learned someting from Hobart (1-800-532-2618 or Ivanmitchell@Hobartbrothers.com) and a friend (http://www.devinlaurencefield.com/) that struck me. You and others here seem to be using LA-75 for Cor-ten. I was told the Nickel in there makes the alloy only match cor-ten's mechanical properties, but NOT the corrosion resistance. The following wires need to be used for that and color match:
Esab Dual Shield 8100w (AWS classification E81T1-W2 or E81T1-W2M) and what I believe is pretty much the same from Trimark, called TM 811w (AWS E81T1-W2-H8) is the right stuff. Both are .045 flux core wires specifically for A588. (and A606 probably...)

And that is my problem right there: as a garage welder with a 135 Millerbaby and 115 volts, it looks like I cannot do this properly.

[sculptorsam]

Thanks for the info, but I'm in a similar boat with my mid-sized welder. There's so much conflicting info out there about Weathering steel it makes it difficult to decipher. Back when I was first researching what to use, the engineers at Lincoln told me that LA75 was the proper stuff to use, I believe for both mechanical and a color match. The first batch of wire I got from a semi-local bridge-building company that specialized in weathered Cor-ten pedestrian walkways, etc. If the wire properties were good enough for them, it should be good enough for my sculpture.

[phuzman]

What about stick welding electrodes? Is there a special type for Corten? I have a mig welder, but for some reason I love stick.

[oddist]

Curiosity about Corten and welding lead me to do some searching.

MatWeb (http://www.matweb.com/index.asp?ckck=1) is a real good material resource.

Looks like A588 (http://www.matweb.com/search/GetKeyword.asp) is plate and A606 (http://www.matweb.com/search/GetKeyword.asp) is sheet and coil.

Both are HSLA (High-strength low-alloy) steels used for their higher strength and atmospheric corrosion resistance.

Good stick welding electrode for Corten is PRIMA-8018 (W) (http://www.varunelectrodes.com/stic.php3?bcode=b002) to resist atmospheric corrosion.

[dblcorona]

Just about all stick manufactures make E8018 electrodes. Lincoln is probably one of the easiest to find.