Welding Tips and Tricks

Is it possible to weld stainless to mild steel?

Seems I may need some stainless electrodes, of some type of 306 flavor or similar. I'm not sure I've seen that, but vaguely remember seeing some stainless electrodes at my LWS.

I need to weld 4 nuts to some angle iron, so bought 2 sets of 4 nuts in chrome and stainless. I'm currently soaking the chrome nuts in vinegar to remove the chrome, but thought I would post and ask about the stainless nuts and see what the consensus is on using 7018?

I've seen some controversial threads in a quick search, where some old timers insist it must be done with 306 or 306L, but others saying they have welded stainless to mild steel and it's held up fine...

This is a VERY low stress application, it is basically holding a nut to a welding table to screw the caster bolt into...I'm pretty sure solder would work or even jb-weld, but let's say someone was wanting to weld a stainless nut to angle, would you guys even worry about that?

I mean I'm probably more anal than many folks for even soaking the chrome nuts to remove the chrome, I see people welding chrome nuts to steel on the web, just as I do folks welding with no gloves or arm protection...so, with all that said, not looking for a fight, just a discussion about stick welding and what some of you folks that know more than me have to say about it.

Alan

You can use standard TIG rod or 7018. Both mild steel fillers will rust where the stainless won’t. The stainless nut will also melt at a much lower temp than the steel you’re welding to, so be mindful. You could also get a stainless stick rod and have a go.

309 is for dissimilar metals. SS to carbon.

Edit
You can get different kinds of flux on 309. It’s a designation after the numbers 309. It dictates position of the weld. I’d recommend the one for all positions, but the most common one I’ve seen stocked is for flat work.

double post...

aland wrote:

Poland308 wrote:309 is for dissimilar metals. SS to carbon.

Edit
You can get different kinds of flux on 309. It’s a designation after the numbers 309. It dictates position of the weld. I’d recommend the one for all positions, but the most common one I’ve seen stocked is for flat work.

Indeed you are correct Josh, they list that 309 and 309L as "Joining stainless steel to mild or low alloy steel". and it looks like the 309/309L are the only ones recommended for that.

I will pick some of those electrodes up, I see that Lincoln makes some of those in Excalibur. It's expensive, so I will see what they have in small packs, don't need 10 lbs. of electrodes for this application. In fact, the guy at my LWS was trying to talk me into using tig for it.

I was at the LWS store today getting some 7018 electrodes, I wanted a tube of Excalibur 3/32". Somehow I let him talk me into buying a 5# plastic tube which he said was the exact same electrode. However, after I got home and looked closely at the container, it's Jet-LH, so even though it's E7018, it has slightly different amps/temps than Excalibur but more importantly it's made in Mexico. Excalibur is made in the U.S.A. (from USA and imported materials). I can't do nothing about the materials, but the price was the same per pound, and I would rather have the sealed metal tube for the same price...so they will get the Jet-LH back tomorrow in trade for some Excalibur and I'll look for that 309/309L electrodes, maybe I can get a pound of that.

Alan

I wouldn't make a Mars Mission out of it, if you have to stick weld it, just weld it on there with some 601X.

Regardless of how you weld it, and what you use, it's probably going to:
a) rust, either due to "alloying" between the A36 and SS, or due to carbide precipitation in the SS due to the heat, and possibly
b) shrink and/or move so much that you need to cut it off and try again.

Don't over-complicate it. Put something in the hole (alum foil, mud, whatever) to protect threads from spatter, weld it on (HOT and FAST to limit distortion) and paint it afterwards to protect against rust. No need for $$$$$ Unobtainium electrodes...they won't help much, anyway.

Lightning wrote:I wouldn't make a Mars Mission out of it, if you have to stick weld it, just weld it on there with some 601X.

Well, that's why I was originally asking. Does seem that 309/309L is the correct electrode for that, touche to Josh for providing the right answer. I know I can just weld it on there with any 'ol rod I have, and can weld the chrome nuts that are soaking in the garage, should be clean of chrome by now.

Thanks for your thoughts.

aland wrote:

Lightning wrote:I wouldn't make a Mars Mission out of it, if you have to stick weld it, just weld it on there with some 601X.

Well, that's why I was originally asking. Does seem that 309/309L is the correct electrode for that, touche to Josh for providing the right answer. I know I can just weld it on there with any 'ol rod I have, and can weld the chrome nuts that are soaking in the garage, should be clean of chrome by now.

309/309L is no more "correct" for your application than 601X (just more expensive), for the reasons I stated. It's still going to rust, unless you paint it because it's going to alloy with the A36 and because the heat will cause carbide precipitation.

BTW, no need to remove the chrome on the nut. You can weld right through it and it will dissolve in your weld deposit (which will have about 25% chrome in it, anyway, if you use 309).

Lightning wrote:309/309L is no more "correct" for your application than 601X (just more expensive), for the reasons I stated. It's still going to rust, unless you paint it because it's going to alloy with the A36 and because the heat will cause carbide precipitation.

BTW, no need to remove the chrome on the nut. You can weld right through it and it will dissolve in your weld deposit (which will have about 25% chrome in it, anyway, if you use 309).

Lightning,

Just got back from the LWS, boy oh boy, I learned a lesson...I just hadn't realized that stainless fumes are not good for us either, cause I've seen people welding on stainless quite a bit, but usually with tig.

My LWS pointed out that using stainless is merely trading bad plating fumes for bad stainless fumes, and because the metals are different, as you are pointing out, there could be problems between the two.

My LWS gave me these Harris Super MissionWeld electrodes, I think they must sell them to NASA, but he said they will weld anything together. He also mentioned they are very pricey, but he gave me a couple 3/32" and a couple 1/8" electrodes. He said it is some type of 312, but that it will weld any type of different metals together. Anyone heard of these?

BTW Lightning, my LWS also laughed and said it was no big deal to weld up a few nuts for an application like mine, not like all 4 would fail at the same time even if it did fail, but I'm sure any way will work fine. I was mainly wanting to understand that if you did have dissimilar metals, and in this case was stainless/mild what would be the correct choice. The reason I asked is that I did google first and a thread came up on WeldingWeb where someone said they used 7018 to weld up some stainless and mild and even though not recommended he had done it several times and no leaks for over 10 years...

I think this has taught me mostly that it could be good to have some inexpensive exhaust system to pull the fumes away, or in the worst case I will just use a small fan to blow the fumes away from me.

Alan

PS I apologize for my anal retentiveness, it probably matters little, I just like to understand those things...

aland wrote:PS I apologize for my anal retentiveness, it probably matters little, I just like to understand those things...

No trouble...hexavalent chromium should cure it.

P.S. That SuperMissileWeld is some exotic, expensive and effective stuff. I sure as he¡¡ wouldn't waste it for your little "welded nut" project.

aland wrote: I think this has taught me mostly that it could be good to have some inexpensive exhaust system to pull the fumes away, or in the worst case I will just use a small fan to blow the fumes away from me.

Alan

Yeah, ventilation is a very good idea regardless of what you're welding. Aside from the chromium, there are other additives like manganese that can cause some serious problems down the road. Even using a regular box fan to draw the smoke/fumes out will help.

ps. Apologies for my abrasive introduction. That was a bad reaction and unnecessary. You don't have to worry about that happening again.

PeteM wrote:Yeah, ventilation is a very good idea regardless of what you're welding. Aside from the chromium, there are other additives like manganese that can cause some serious problems down the road. Even using a regular box fan to draw the smoke/fumes out will help.

Indeed, I will be fixing that problem in the future, and using a box fan in the meantime.

PeteM wrote:ps. Apologies for my abrasive introduction. That was a bad reaction and unnecessary. You don't have to worry about that happening again.

No worries, I have thick skin. I'm certain you have a lot more welding experience than me, and I will be the first to admit, the project that has sparked my interest in welding is a critical one. I do plan to take it on, but not until I feel comfortable with it. I purchased a piece of plate to use, but can always opt to have someone weld it for me should I not feel comfortable. In the meantime I'm doing some smaller projects that are not as critical/dangerous, some of them tig, but I've been practicing my stick and feeling a lot more comfortable with 7018 and 6011, just not comfortable enough to take on the hitch just yet.

This is a very non-critical application, a nut to hold a caster on the bottom of a piece of angle under a simple welding table. Just trying to understand the metals and fumes...about 15 years ago I started blacksmithing, and used to hang out on AnvilFire, where Jim "Paw-Paw" Wilson, a great blacksmith, used to help folks, publish articles, and in general promoted the art of blacksmithing...I only knew him for a couple years...but he was taken victim of fume fever...a sad day indeed when he passed, mainly as he knew better...$#!T happens to the best of us...I would encourage anyone who is not very familiar with fume fever to read this, it does talk about welding hazards on that page, so very pertinent to welding.

R.I.P. Paw-Paw, you will be long missed...

http://www.anvilfire.com/iForge/tutor.p ... fety3/demo

These little nuts are nothing like that. Just good to be aware, don't breath the crap, it's not good for you. I'm certain I could weld this in my shop and be done with it and go on with life...but that doesn't mean it's right. I *WILL* be getting better fume extraction, no question.

Alan

Hex chrome vapors do require more than just a fan to get rid of. The fab shop at the place I work has to use special monitoring equipmen to monitor levels. Even with the shop doors open and fans running the levels can be high. You need special point of use vac systems to capture the vapor plume off the weld. If your concerned about such things.

309 is formulated specifically for low carbon to SS joints. It will maintain the corrosion resistance while keeping your joint from becoming brittle. For your application it may not be necessary, but it is the correct way. 312 is expensive but not uncommon. However it is formulated for other purposes. Simply reading the info from the manufacturer web site will no doubt remove personal opinions and empower you with facts.
http://weldingwire.com/Images/Interior/ ... ry/312.pdf
http://weldingwire.com/Images/Interior/ ... ry/312.pdf

Lightning wrote:P.S. That SuperMissileWeld is some exotic, expensive and effective stuff. I sure as he¡¡ wouldn't waste it for your little "welded nut" project.

Almost missed your post, but I won't be using it for this...I am going to use mild steel after the plating is removed.

I honestly don't know what I will use it for, since stick welding stainless is not going to be something I do regularly, I was actually thinking about using the stainless to avoid the plate fumes...given there is no gain, mild steel is the way to go. If I understood my LWS correctly, even when tig welding you need to be aware of indifferent metals as they have different heat temps...(i.e., stainless and mild have different melting points). That said, I do use tool steels occasionally, but would probably use tig for that in the future. You still need to understand differences as fusion will take place at different temps, so starting on the stainless side of the weld with tig and moving to the A36 might be desirable, I'm not sure...just talking out the side of my arse...but I can see that would be an issue for tig as well.

Poland308 wrote:http://weldingwire.com/Images/Interior/ ... ry/312.pdf

Yes, thank you for that link:

"312 is a good choice for welding carbon steels to stainless, tool steels and other difficult to weld steels."

Would probably work but not perfect for this application as A36 is a low carbon steel. Stainless to O1 would probably be a better match for 312 I would think.

That may be useful in the future. I do work with tool steels quite often, but try to pick ones that will weld, like 8620 when welding is a possibility. I have made some stuff like axles for bearings to ride on that would be welded to mild steel, and in that case will use 1018 as it welds. In the past I would take the axles and mild steel to a local fab shop and get them to weld it for me, but trying to learn that so I don't need to job that type of stuff out anymore, since I have a small welder now. Even so, I think tig would suit welding dissimilar metals more than stick.

Alan

When welding on nuts for whatever purpose I only use what I think they call flair nuts. The ones with the built in washer flange on the bottom. Even a 1/4in has enough of a flange to get a secure weld without chancing blowing into the threads. Screw a bolt just thru the nut to protect the treads.

homeboy wrote:When welding on nuts for whatever purpose I only use what I think they call flair nuts. The ones with the built in washer flange on the bottom. Even a 1/4in has enough of a flange to get a secure weld without chancing blowing into the threads. Screw a bolt just thru the nut to protect the treads.

If I may, never screw a stainless bolt into a stainless nut and weld the nut. The heat will fuse the bolt to the nut permanently, even if you weld the flange. If you coat the bolt with AntiSieze you stand a chance to get it out, but use an oxide or zinc bolt for better results.

Actually all I ever use is mild steel. I never worked with stainless other than some plasma cutting. From following the threads

cj737 wrote:

homeboy wrote:When welding on nuts for whatever purpose I only use what I think they call flair nuts. The ones with the built in washer flange on the bottom. Even a 1/4in has enough of a flange to get a secure weld without chancing blowing into the threads. Screw a bolt just thru the nut to protect the treads.

If I may, never screw a stainless bolt into a stainless nut and weld the nut. The heat will fuse the bolt to the nut permanently, even if you weld the flange. If you coat the bolt with AntiSieze you stand a chance to get it out, but use an oxide or zinc bolt for better results.

Actually all I ever work with is mild steel. I do know from following the threads that if I ever decide to try stainless that I got a lot of " learnin" to do. Thanks for the advice.

cj737 wrote:

homeboy wrote:If I may, never screw a stainless bolt into a stainless nut and weld the nut. The heat will fuse the bolt to the nut permanently, even if you weld the flange. If you coat the bolt with AntiSieze you stand a chance to get it out, but use an oxide or zinc bolt for better results.

cj,

I don't work with stainless too much either, I was only thinking that I would be ok welding stainless, but as it turns out the fumes don't seem any better.

The casters don't have stainless bolts, they have zinc I'm almost certain.

I took a fan in the garage and will just use it to blow the fumes, grind the chrome off and weld these nuts on there. It's not a big deal. I welded the cross bars with the holes on earlier, but got summoned away for dinner.

I could just jb-weld these nuts on also, they only need to hold the caster in. Am I allowed to mention jb-weld on a welding forum?

Alan

JB Weld -- AAARRRRGGGGGHHHHH !!!!

homeboy wrote:Actually all I ever use is mild steel. I never worked with stainless other than some plasma cutting. From following the threads

cj737 wrote:

homeboy wrote:When welding on nuts for whatever purpose I only use what I think they call flair nuts. The ones with the built in washer flange on the bottom. Even a 1/4in has enough of a flange to get a secure weld without chancing blowing into the threads. Screw a bolt just thru the nut to protect the treads.

If I may, never screw a stainless bolt into a stainless nut and weld the nut. The heat will fuse the bolt to the nut permanently, even if you weld the flange. If you coat the bolt with AntiSieze you stand a chance to get it out, but use an oxide or zinc bolt for better results.

Actually all I ever work with is mild steel. I do know from following the threads that if I ever decide to try stainless that I got a lot of " learnin" to do. Thanks for the advice.

The best “learnin’“ I’ve ever received in welding and fabricating left the worst scars Just trying to help someone avoid costly medical bills...

homeboy wrote:JB Weld -- AAARRRRGGGGGHHHHH !!!!

Whoa, watch it...I love that $#!T...it's one of the best to repair cast iron...and I hate to admit but i have jb-welded nuts on for almost the same application, different project....I've used it to get me out of a pinch before...it works. On broken cast iron parts I have used blue painters tape to build a small dam around the area I want to fix, pour the jb-weld in, then machine or file after it's dry.

aland wrote:

homeboy wrote:JB Weld -- AAARRRRGGGGGHHHHH !!!!

Whoa, watch it...I love that $#!T...it's one of the best to repair cast iron...and I hate to admit but i have jb-welded nuts on for almost the same application, different project....I've used it to get me out of a pinch before...it works. On broken cast iron parts I have used blue painters tape to build a small dam around the area I want to fix, pour the jb-weld in, then machine or file after it's dry.

Just kidding. I have heard it's a good product also.

homeboy wrote:

aland wrote:Just kidding. I have heard it's a good product also.

The reason I even mentioned I possibly shouldn't mention it on a welding forum is that it is kind of a controversial topic, but it is pretty darn useful and I know a lot of XLNT machinists that use it.

It is really good to be used as a filler, like in a porous situation where you want to paint a machine, as an example. If you let it firm up just a bit you can use it like bondo to smooth out the cast iron.

Alan

Without a doubt JB weld or any specialty epoxy definitely have a place. Theres always more than one way to skin a cat. Sometimes it’s the most practical, economical, or efficient solution. I’ve used a product from 3m that’s called liquid metal for repairing small screw holes that needed filled and retapped. When disassembly or heat from welding wasn’t an efficient option.

Lightning wrote:P.S. That SuperMissileWeld is some exotic, expensive and effective stuff. I sure as he¡¡ wouldn't waste it for your little "welded nut" project.

Lightning...I'm gonna use it. I'm kind of curious now. I was going to use 7018 today, but before I went out to the garage I got inclined to google for the super missleweld. This link to video Wyatt Swaim did a few years ago talks about it. This is good information on the subject, but it got me to thinking I just try one of those electrodes.

Honestly, I could get more if I wanted and can even get them at my LWS. He was nice enough to give me a few, I should just use them. The interesting part is how the chromium carbides build up on the backside. I think tig will be the choice for similar welding in the future, so I might as well burn one and use a fan to blow that chromium off to the neighbors house...

I will probably have the other 3 electrodes in my canister 10 years from now...

Oh, this video is doing tig, but mentions and talks about the super missleweld. Wyatt also implies some of the dangers in using it, I'll just use a fan. I'll let you know how it goes.