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Hello all. I am an artist that makes stainless steel sculptures. on my recent work, I have been welding together 304 stainless round tubing (.065 wall) for my main structure. This is the first time I have welded round tube and had quite a few issues with making a beautiful bead all around the 90 degree tubing intersection. My setup: -Millermatic 135 MIG, 308L ss solid wire, 98% argon 2%CO2 gas-all tubing is 304 stainless with 0.065" wall thickness-All 3" tubing is standing vertical during welding and I have to stand on scaffolding to access the top welds.My process:-I bored a 1" diameter hole in the face of a 3" tube.-I inserted a 1" OD tube into the hole for a 90 degree joint. (this is to allow wires to pass through the joint easily)-Then, I would clamp everything level and straight and tack weld 6 spots around the joint, alternating sides and checking level.-Then I would stitch the welds together around the joint.-Spatter is kept of the main structure with anti-spatter spray.The problems:-The welds have good penetration and no burnthrough, but they do not look that great. I'm sure this is mainly a factor because of my limited experience welding two pipes together at a 90 degree angle. More, extensive practice will help I'm sure. -The biggest problem is that the client now would like all the welds to "look great." Like they came off a robot or something. They mentioned hoping the welds would look like that of a bicycle frame, where the beads are perfectly laid over each other and consistent. (I know it is humanly possible, but I am NOT an expert welder) -I found that I had to keep the amperage down to prevent the tubing from overheating and warping.Pictures:The above picture is of a straight butt weld in the corner of a 1 square .065 tube to the 3 round tube. I cut the 1 tube to a radius to fit the round tube. I show this for reference to how the welds look normally. The color is taken off easily with a wire brushThis picture shows the 1 tube welded in the 3 tube. It is very ugly and shows how much a novice I am at welding fishmouth welds at weird angles.Another image of the Ugly weldsNow, I tried to grind and sand the welds, but they look worse.. and when I electropolish it all, the grinding marks will show up even more possibly.I tried to TIG the surfaces on a test-piece to smooth out the MIG bead. To get the metal to flow enough, the base metals were overheated and sagged and warped. I cannot have this happening.Side-view of the warped base metal form over-heating.So, what do I do? I have been practicing more and found that if I grind down the original welds slightly, then gloss over them with the TIG, I can get a decent looking weld with less distortion. Lots of steps.Keep in mind, this is not a huge load bearing structural member and they are mainly concerned with how it looks.Any recommendations? I cant grind it out and re-weld cause it would mess up the surfaces of the base metal. What can I do to remove the heat better when surfacing the welds with a TIG?Some of the welds are hard to get to, so I need to make a solution quick. I appreciate all your help and comments. Please dont tear into me too bad for my poor welds, I am still learning and generally, I only weld square tubing and solid rods together.Have a good day.Eddie
Reply:You say "sculpture" ? Seems to me since you already have a Tig that you should just put the Mig on the shelf for now. On some scrap try practicing with a 1/16th or .040 tungsten, straight argon. Just try fusing (no filler) at first to get the hang of it. Then, once you're use to the angles you have to deal with add filler and practice some more. Tig is really the way to get that smooth fluid look your customer wants. I've not seen anyone that could make a Mig weld as smooth and purty as a nice Tig weld.Practice, Practice and let us know if it's working for you.Anything worth doing is worth doing RIGHT
Reply:The bottom two pictures didn't appear to have enough shielding gas coverage.
Reply:Hi Eddie, I think it's cool that you make sculptures. I'm not sure how to fix what's in place with TIG over top, that makes me nervous. I would practice running some beads on scrap ss. If you adujust your heat and speed you should be able to make very pretty beads using the full circle or half moon pattern. Try welding around a piece of sq. tubbing on a flat metal surface. If you can't get it to look great you can always pulse it. I'm not trying to insult you but does this make sense. I like to use sq. and round tubing and when the metal gets to hot or I make holes pulsing always fixes it. Hope this helps.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:Thanks for the responses. I typically use MIG welding because I often weld in very strange positions making quick tack welds. Some of the welds are all at full arms reach as I stretch within the sculpture. see here:Each side is 5 feet long.I only recently purchased the TIG, so I am still practicing with that. Since making the horrible MIG fishmouth welds, I have gotten better at TIG and might be able to do better at that weld in the future. However, whats done is done and It seems I have to fix it as best I can. I will try upping the flow rate of the argon on the TIG to touch up the welds. I'm sure there are impurities on the original MIG welds that are getting into the TIG arc as well. Perhaps I will try to clean the MIG bead better before trying to smooth it with the TIG.Eddie
Reply:Laura,You are not insulting me at all. I actually figured the replies would be harsher... but I am still waiting. What do you mean by pulsing? Do you mean, weld a small amount, let it cool a bit, then weld another small amount? Or, is this something I have to do with my welder set-up. I have a Miller MaxStar 150 stick/TIG(DC) welder with a footpedal, 1/16th tungston, 100% argon.All the welds end up looking chrome plated after electropolishing, so the color is not important to me right now, its the warping and consistency of bead. anyway, thanks for the reponse.Eddie
Reply:WOW, looks like you make some awesome things. Do you then sell them to Children's Museum's or something? I never thought of going this route. Is this what you do for a living? How cool. When I refer to pulsing I mean with the MIG. It's basically like zapping it, you squeeze the trigger then move in the direction you want the bead to go either vertical, around or overhead and just zap it again and again trying to keep the same consitency thru the entire bead. I can't even imagine making many things other then robust or heavy duty items with stick. I'm good with stick but rather use another method. I'd also second the TIG comment. They can look perfect if you get the technique right. Some guys are soooo good at this. My welding teacher taught me, your bead should like a stack of dimes that was knocked over. Regardless what method you are doing stick, MIG, TIG. Should lay in a perfect line, he can actually weld like that.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:HokieEd here is a paste of a link to one of ZTFAB's projects with Stainless Steel. He's about the best out there when it comes to welding but this should give you an idea of what you can accomplish with TIG.....someday.I think you probably want to focus on TIG to get the good looking welds.http://www.weldingweb.com/vbb/showthread...ighlight=ztfabMichaelMillermatic 25115" Rockwell Drill Press10" Logan Lathe5hp - 2-stage 80 Gallon CompressorHome Made Sand / Soda Blaster
Reply:Pink, are you talking about "trigger welding" ? Did they teach you that in school ? As my screen name implies, I'm a little older but in my book that's not an acceptable welding practice. It might work for non critical very light load stuff, but it's nothing more than glorified tacking. PULSE welding is an electronic function of a pulse welding machine. I suppose that as long as you're only making pretties it wouldn't hurt anything but it is a bad habit to get into.Anything worth doing is worth doing RIGHT
Reply:Olddad, Yes that's what I meant, "trigger welding" my instructor didn't teach me that some of the senior guys did. I try to only ever use that method if I'm burning holes in the metal or it's super thin stuff. Keep in mind I'm down here in the "dirty dirty" deep southern Ga. and I went to school with a bunch of country boyz who grew up on farms. Sadly I didn't learn much book work or the "whys". Just mainly "on the job" stuff and "watch me, then do it" type things. However, I did learn a lot. When I took blueprint I & II he told me to draw a picture then build it. You use the same quote my instructor does.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:Eddie, What is electropolishing? What tool is it, how can I get my hands on one? Also olddad has lots of expertise. The pix on my profile is a work table my husband wanted so he can plane wood. Done with sq tube and angle iron.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:HokieEd,If you want to stick with mig, maybe try straight argon as the shielding gas. The CO2 in your current mix adds carbon and a little heat. This might allow you to slow down a tad more and control the size and shape of the bead. I assume that you are using .030" wire, and that should be fine. good luck,cricman
Reply:Stainless wire brush those MIG welds as much as possible.Remember, stainless steel requires LESS amperage than mild steel does, as it does a far worse job of dissipating heat, so don't expect to crank the heat in there and have it wet out. If you HAVE to drywash over the MIG welds, it wouldn't hurt to take some very thin stainless wire and add some along the way. This may help some with the appearance and impurities, and help minimize chances of cracking.
Reply:Eddie, I would suggest using the mig to tack the parts together, and then use the tig welder with the same filler wire from the mig machine for some nice small welds. Look to use around 60 amps to do the job. The mig welds on SS always look dirty, or like there is not enough gas coverage. It's the nature of the weld. Use 100% argon to do the tig work. Clean any black soot from the mig weld with a scotchbrite pad and acetone to get rid of the black without marring up the metal too much. Hope this helps. Paul. PS, awesome sculpture!!!And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Wow, great comments everyone. Thanks. So, I guess I am on the right track with what I am doing now. Working on learning TIG better, and tacking MIG and welding TIG. Again, I just need practice. As far as the welds that I have to "purdy" up, I plan on using a dremel tool to smooth out the high spots on the welds, then going over it again with the TIG. I have been practicing with the TIG this evening and was able to keep the parts from getting too hot. I'll report back on weather or not this worked. I will also try putting in a little bit of filler wire as Rojo suggests. Aslo, next time I try more extensive welds with the MIG, I will try 100% argon.I'll post next about the electropolishing for Laura, and Supe. I DONT clean off any welds until the final polishing step. And laura, yes, I do this full time. The sculptures go in childrens museums, retail locations, doctors offices, etc.
Reply:Eddie, Please do, I'd love you pick your brain, I want to be an artist as well. Not really they way you are, but I'm very creative. So when you have time. Let me know.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:So, here are some pictures to show you my results with electropolishing. Keep in mind, it may cost $300 to $600 to do really large projects like these, so cost may be a factor. I started out by hand polishing using an old arc welder, a hand-made cathod/anode and a citric acid solution. Connect the part to ground, then rub the part with the electrified, acidic cathode/anode(I forget the order). Anyway, it looks MUCH better to have someone else do it than by going at it by hand.I posted BIG pics so you can see the details.This is a sculpture in California at SUN microsystems. 6' long, 4' deep, 5' high.This image shows some details inside the case. I design and fabricate everything. Where necessary, I contract out jobs such as the "ball hooks" and have them made based on my CAD drawings. (waterjet cut aluminum) Other parts I machine on my mill or make with hand tools.This close-up shows how good the electropolishing is. It is the reverse of chroming... where you TAKE OFF a small amount of surface metal to leave the part smoother. What you see is pure, clean stainless steel and it will stay like this forever, as long as you dont go rubbing carbon steel all over it. All track is hand-bent. I have strong thumbs now! :-)Can you see all those tack welds? maybe over a thousand. and many of those welds are made with my other hand holdin gtrack in place. So, MIG is the best option for me at this time. I hope you enjoyed all these pics. Good luck with all your projects everyeone and be sure to check back as I will update on the weld cleaning tomorrow evening. Have a good day-Eddie
Reply:Laura, All you gotta do is find a niche market and do things nobody else has done before. Use the internet to your advantage and away you go! I'd love to keep talking about all this too. I always try to encourage people to develop new ideas and go for it.
Reply:Originally Posted by pinklilly11 Also olddad has lots of expertise.
Reply:Did you study an art program or an engineering program? I never really thought about who created these projects but my 3 year would LOVE one. I'm a little confused on the electropolishing thing. It's not a tool like the hand dremel with tiny little discs and wheel? Are you actually rubbing that solution on the metal? Are those ss rods to begin with. I see all the tacs and absolutley MIG is the only way that makes sense.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:I studied Mechanical Engineering, and am very creative by nature. Electropolishing is an electro-chemical process that uses current and an acid solution to remove surface imperfections. The acid acts as a pickling agent, removing oxidation and color from the welds while the current removes metal to smooth the surface. Doing it by hand involves rubbing an electrode wrapped in fiberglass and dipped in acid, along the surface of the welds. This will remove the discoloration from the welds, but is not perfect. To get it perfect, you have to dip the entire stainless steel piece in a bath of the acid solution and electrify it. Make the stainless part the Cathode, and drop in anodes around it. The surface metal of the stainless part moves from the cathode to the anode, trying to reach equilibrium. You don't have to electify the part long to see results. Leave it in there too long and you begin to loose material.. say .0002 to .0006 inches for instance.Just google "electropolishing stainless steel" for much more information than whats on the top of my head.All the rods are 304 stainless, 3/16" or 1/8" round bars.Eddie
Reply:I knew you were an engineer, brillant. Dumb me thought I could buy a polishing tool for that finished look.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:Olddad, You may be just another guy on the board, but I have been around here long enough to read your posts, and You definitely know your stuff. no need to be humble around here, besides no one else is........ hehehe HokieED, Only thing I can recommend is practice and more practice. I also agree with rojo and oldad. Go with the tig, use a 1/16th tungsten with pure argon and mig wire for a filler to get a small bead. Its just gonna take more practice....... Pinklilly, Where in south GA are you and what school are you attending? I am in SW GA right on the GA/AL line. One thing about those farm boys. We tend to think we know more than we really do. I used to help teach the metals labs at ABAC when I was over there, and if there was a girl in the class I could have her out weld any guy in the class simply because she didn't already think she new everything.Very interesting projects you have there, EddieI'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Originally Posted by Hammack_WeldingOlddad, You may be just another guy on the board, but I have been around here long enough to read your posts, and You definitely know your stuff. no need to be humble around here, besides no one else is........ hehehe HokieED, Only thing I can recommend is practice and more practice. I also agree with rojo and oldad. Go with the tig, use a 1/16th tungsten with pure argon and mig wire for a filler to get a small bead. Its just gonna take more practice....... Pinklilly, Where in south GA are you and what school are you attending? I am in SW GA right on the GA/AL line. One thing about those farm boys. We tend to think we know more than we really do. I used to help teach the metals labs at ABAC when I was over there, and if there was a girl in the class I could have her out weld any guy in the class simply because she didn't already think she new everything.Very interesting projects you have there, Eddie
Reply:Really awesome work.Yea, I know where Valdosta is, been there many times, and have a couple good friends living down there. You will be fine. 99% of this stuff is not going to be taught. The more you do the more you will learn. Everyday you will learn something new, and as long as you look at it that way I have no doubt you will be an expert yourself before too long.........I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Hey Eddie, Any luck with welding today?Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:I have seen the pics...I know what your process is...With a tig and the way you fit everything...Fusing it would work with no problem...Then you'd see results......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Hello all. The "fix" went well today as far as appearances go. When I polish up the display, the welds will be pretty smooth looking. I ended up just smoothing out the sloppy MIG beads with the TIG as best as I could. Where necessary, I filled in the spaces using MIG wire for filler. It doesn't look like I knocked over a stack of dimes, but it will do. Actually, it looks more like someone smoothed it over with their thumb around the joint. horrible! The problems, as expected, were due to heating up the base stainless steel tubes. Like the profile view of the weld I showed in the first post, all of the colums warped inward some. I had to actually cut of track and supports connected to the horizontal supports, and re-weld then on once the TIG process was complete. It was a big pain having to re-level and realign everything. However, I cannot imagine trying to do all that once all the track was welded around the main frame. Another problem was that as the base metal warped inward, it caused the joint to become flat. like pressing your thumb into a spot in a cardboard tube. When that isolated spot became flatter, it lost the rigidity usually found in a cylinders walls. So, now the horizontal supports flex form side to side easier. Oh well. Good thing it's not a jungle gym.I'm going to continue to practice my TIG process welding in anticipation of future frame assemblies. The biggest problem I am dealing with is how to handle warping in the base metal as it is heated up. Currently, I fit everything perfectly and clamp the heck out of it all. I suppose the best thing to do is to learn to weld with lower heat and smaller beads. I know it is just something a welder has to work around, but is anyone has any tips, fire away.I look forward to posting more welding adventures. Have a good day-Eddie
Reply:ZAP... What do you mean by fusing it? Is that just doing TIG without a filler material?
Reply:Hi EddieI have just made a stainless ladder and rails for a cabin bed using 32mm 16swg for the runners and 25mm 18swg for the treads. If you can get a good fit then you can run the joint without any filler.Sorry about the focus on the photos but you should be able to see what we mean.Nice work by the way.Regards from sunny Cornwall__________________www.iancarey.co.uk
Reply:sonamar!! Thats what I want my welds to look like. Did you do any hand sanding or anything to smooth them over? it appears you polished them. What settings did you use? My fittings were slightly loose. What did you use to bore the holes for the rungs? Thanks for sharing
Reply:Eddie,re "fusing" Yes, fusing when TIG welding refers to welding the two workpieces together and not adding filler metal to the weld joint. You use the pinpoint arc from the TIG and melt the seam between the pieces. Done. Since you aren't adding extra filler metal, there is no build-up of a weld bead. That might be what you are looking for looks-wise in your sculptures.Since fusing is using the existing material from the workpieces to fill in the 'gap' between them, you need the gap to be really-really-really small. You need a tight fit between the parts to fuse them properly. If you have any appreciable gap between the parts, when you go to fuse them you end up with a sunken crater filling the former gap.If you are fishmouthing one tube to butt against the other, then you don't need to drill or make a hole in the tube. If you drill or otherwise make a hole in the big tube, then you don't need to fishmouth the other (in your case) smaller tube. Do one or the other, not both. Drill hole in big tube and insert smaller tube into hole and weld the joint. Or fishmouth smaller tube and butt against bigger tube and weld the joint. Since you said you are running wires through the inside of the tubes, you need to drill (or otherwise make) a hole in the big tube and then just slightly insert the small tube into the hole. Then weld the joint. Done.Practice, practice, and practice some more. If you are trying for appearance welds and speed of production is not a main driver, then TIG is probably the way to go. And-or make sure you add just enough filler (MIG or TIG) so that you have a slightly 'proud' weld bead (convex weld bead) so that you can go back and grind/sand/machine it all smooth as desired.Oh, and if you tried tigging right over the MIG welds without brushing them and cleaning them first, you'll probably have crud on the surface of the existing MIG welds which will make your TIG on the top look like crap. Sort of frosty and grainy, just like what happened to you. Clean it first before welding.Ian from Cornwall,Nice work, very clean looking. You camera seems to have focused on the plaid blanket/sheet instead of the metal ladder, or you were a little too close for it to focus on the ladder. Next pics try the "Macro" setting on your camera (if it has one), or move back a little bit and make sure the camera focuses on what you want it to. Oh, and put a coin in the close-up pics to give a sense of scale. Put a pence in the pic, as it were.Laura,Eddie gave you a quick description of electro-polishing. As he said, it is sort of the reverse of electro-plating in that it is using electricity and an electrolyte (the acid) to smooth out the workpiece. Because of the way electricity works, it will hit the points and ridges and sharp points on the work first and tend to smooth them out first. Thus making the workpiece smoother and polished-looking.Also, "trigger welding" is just a bunch of cold tack welds all jammed together. Which is not good welding, even if it can give you something that looks like a stack-o-dimes. Anytime you have a discontinuity, you have made a weak spot. And a whole bunch of cold tacks is just a big string of weak spots. Smoothly welded and flowing beads that fused properly into the base metal is what a good weld is supposed to be. TIG welding gets that stack-o-dimes look when properly welding because of the 'heat with arc from torch-dip filler into weld puddle-move-repeat' action.Last edited by MoonRise; 07-23-2007 at 03:06 PM.
Reply:Originally Posted by HokieEdsonamar!! Thats what I want my welds to look like. Did you do any hand sanding or anything to smooth them over? it appears you polished them. What settings did you use? My fittings were slightly loose. What did you use to bore the holes for the rungs? Thanks for sharing
Reply:That is some sharp work there sonamor !!Anything worth doing is worth doing RIGHT
Reply:Moonrise, I recently made and eisel to hold a large wooden frame my husband built and I mosaiced it with glass. Once it's grouted it'll be too heavy for a wall, hence the eisel. It's just over 60 inches high, about 28 inches between the 3 legs, I used conduit. I tacked it all together then welded it. Because it's stationary there are some places where I had to do overhead (the suppport bars in between the poles) when I was trying to run beads I was burning up the metal plus I didn't completely sand all the paint off so it was burning up (lesson learned). I had to "pulse it" as I call it to weld it at the akward places. Once it was finished my beads looked mostly the same between running the flat beads and the pulsed ones. What do you do if it's a really hard spot to weld and you're burning it up besides turning the heat and wire speed down? This is the only other thing I know to do. I really like the electropolishing look and idea. Although it makes me nervous about the electricity. I need to see someone who knows what they're doing do it, I'll probably hurt myself.What is the difference between fish mouthing and scalloping the ends? I think I did the same thing with my above mentioned project to the support conduit bars but I was told it was something else. It was the same concept, to avoid any gap when joining the two pieces for a nice fit. Coping the ends I think.Last edited by pinklilly11; 07-23-2007 at 06:12 PM.Laura MM 180Chop SawDewalt grinderhelpful husband
Reply:Laura,Fishmouthing or scalloping the ends of one piece to fit against another piece or coping the one piece to fit against the other piece all mean pretty much the same thing.Fishmouthing usually applies to round parts (pipe, tube, bar) because after you make the cut-out, the piece often looks like a fish mouth wide open.If the chosen welder settings are burning through the metal, lower the heat (on MIG that means slowing down the wire speed) and/or increasing your travel speed.You can't weld paint, or rust, or dirt, or oil, etc. But seriously, you can't weld paint, or rust, or dirt, or oil, etc. You weld metal. So do the prep work to make sure you have METAL where you are going to weld. Some welding processes can -tolerate- certain amounts of not-metal (SMAW aka stick welding), some can tolerate almost 0% non-metal (TIG is that way), but you always get better results if you have clean metal to weld.Besides, burning paint stinks! (been there, done that)
Reply:Moonrise,Nice use of smileys!
Reply:Thanks for the advice, I did sand down the conduit to remove the paint I tried to sand it all the way off and I wanted to use the sanding disc on the grinder but another student said to use fine sand paper and was rushing me along. So that's what I did, lesson learned on that project. Sometimes I lack the confidence so I don't trust my better judgement and the guys I went to school with, well the crowd I finished with are great welders but kinda lazy and country so a little paint burning to them was no big deal. I thought I was gonna pass out from the smell. With all my questions you must feel like I feel at the end of the day after answering all my 3 year olds questions.Thanks for teaching me.Laura MM 180Chop SawDewalt grinderhelpful husband |
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发表于 2021-9-1 00:08:46