Duh! yeah was being a bit dense there! got me grinning now tho (and feeling a bit of a high horsed fool). Must be the pmt (now you all know I'm one of the Chosen Ones I can say these things)..that of course stands for pre-mig-turmoil.
btw - do you want to expand on "you can weld 10mm with the 180, it just depends what you are joining it to and how you are going to join it " what are my joining options? (and don't say 'welding' I already got that)
grinding down the edges to a Vee shape where the join is will make the metal thinner therefore easier to weld, this is a common practise especially in pipe welding, like others said you are not going to need complete penetration to make a strong enough weld, as you are not doing structural welding. are you planning on welding 10mm to 10mm? or are u intending to weld smaller things onto 10mm? honestly I think you would be capable enough with 180amp welder, maybe less depending how creative you can be.
pre mig turmoil lol
arc welding would be a cheaper alternative, but personally I dont like it, I find it messy, fiddly and tiring.
thanks - that's very helpful. I'll be doing both on this particular project...10-10mm and 10-2mm (I shall have fun with that I'm sure). I do already have a good arc welder (I said it was an AC but might be DC..I dunno..whichever, it's the one that's easiest (and priciest) and less likely to stick...hmmm maybe that's why they're called stick welders!!) but yes it can be messy and tricky to control for tiny welds - which I often want to do. I guess I can use it for the big stuff if necessary. It's been a while since I've done any welding (too busy doing moulding and resin casting for clients) and I could do with going on a refresher course, although the forum tutorials are very helpful. The PMT continues but I see light at the end of the tunnel (hope it's not an oncoming train)
Coming back to Weldequip's suggestion of TIG instead of MIG. That's not a bad idea.
TIG welds can look cosmetically better than MIG welds. Problem with MIG is the wire carries the current and has to feed in all the time. That tends to cause a bit of weld build up. TIG on the other hand uses a tungston to transmit the arc, and you can feed in as much or as little wire as you like. So you could get a much flatter weld with TIG.
Another advantage of TIG (if you chose wisely) is very low minimum amps making really thin metal possible to weld. Better for detail work.
A disadvantage of TIG is it takes a whole lot longer to learn. I've had a couple of afternoons on it and still struggling even after having read the instructions. I'll get there, but it's not a pick up and play device - there's skill (and co-ordination) to develop. The accuracy required means you need to be in a comfortable position when welding or have a lot of skill. They tend to be more expensive too, especially if you go for an AC TIG that can weld aluminium.
Does sound like a useful tool for a sculptor who already has an arc welder.
Don't forget there's loads of work you can do with brazing. Sorry miggies, but theres more than one way to skin a cat, or stick two together... If you want to do very fine work brazing can be the biz, especially for joining dissimilar materials (but not ally).
Also, on this working on 10mm steel business. You don't need a big welder. You do on MIG just what you do with MMA, which is build up the weld with multiple runs. Like Haze says, you need to prep the steel appropriately, especially with butt welds, but in fact ALL butt welds should have a degree of prep - even the thinnest materials should have a small root gap left to avoid buckling and to ensure penetration. The thicker the material, the more prep - usually grinding to a vee. A Fillet weld though will usually not need prep.
Frankly, if you're making sculptures that only need to hold themselves together, just squirt some snot at it and concentrate on the art!
For a bit of inspiration on techniques, and some fancy sculpture, take a peek at this guys' work:-
And Ratty, re the pmt reports, I get enough of that plumbing nonsense from Womens Hour, and the Missus, so if you wouldn't mind... (even if you are talking migs)
Welding more slowly on the 10mm will certainly help, and leaving a small gap between the butt joints will help a great deal in getting more surface area welded
It's not a matter of surface area. It's about getting full penetration of the weld throughout the joint, and then the joint remaining stable on cooling. Also, welding "more slowly" implies that the welding is been done too fast! More slowly than what, Alex?
I'm confused old chap. You should be welding at the correct speed for the current and feed. If you want more heat, turn the current up. You will penetrate 10mm with a 150amp welder, but only a bit of it. If you don't prep the butt and leave a root you wont penetrate too well at 200 amps! You're looking to lay down a 10mm bead, if in one pass, so you need a welder that is capable. Otherwise you go for multiple passes.
The slower you weld, the more time the metal in any given area has to turn molten, if you move on too quick, the metal will not continue to heat and therefore wont turn molten in as big an area and will penetrate less.
Like a soldering iron, you can have a 100 Watt iron and a 15 Watt iron, they are both the same temperature, however when you touch the 100 Watt to the work it gets the work up to temperature much quicker than the 15 Watt.
So you can understand all I was trying to say is that to get the best out of what the guy has (150 amp) you would do best going slow on very thick sections as the metal will absorb the heat away from the weld at a rate the lower power unit cant keep supplying the same as a more powerful one.
If you had a 6mm thick bar, holding the torch in the same position it would eventually burn through, the longer the bar the longer it would take because there is more area for heat to dissipate.
Sorry Alex, not annoyed at all, didn't mean to give that impression. It's just the way I argue...
My issue with what you are saying about speed is that, as I say, speed relates to current and feed. For instance, taking your example of 6mm bar, holding the torch in the same position will burn through only if the current is high enough. Otherwise, if the current is low, you will just build up a big lump of weld which will get bigger and bigger. The job will gain heat, but not enough to blow through. Even in a small piece of bar, it will radiate enough heat not to melt.
So if you have a limited current available, you should travel at a speed which will give a well proportioned weld with good penetration. If you turn the feed rate down that may improve matters, but you are limited to how far you can go. Don't forget that steel is a poor conductor of heat. The weld heat does not dissipate quickly, whatever the power of the welder.
It's not an issue, unlike soldering, as irons effectively have a mass which holds, if you will, a volume of heat, thus a 100w iron has more heat to give away, and the ability to replenish itself. Yer little iron shoots its bolt quickly. The point of an iron is that it has to inject heat quickly into copper, which does transmit the heat away quickly.
You are quite right to suggest not welding too fast. That will give a poor weld that is narrow with no pen , but a slow travel may simply put in a high weld, even if you keep the feed as low as you can without balling at the tip. As a compromise I could suggest a weave. That will keep the height down but still keep heat in the job.
Sorry again Alex, no offense intended!!
I hope you're paying attention Ratty!!
Arn't you near the old William Morris place in Chipping? Visited there when I was learning cabinet making in Thame, many moons ago..
Malcolm - thanks for clear informative reply, and Simon and Alex, I'm digesting all of this and thinking carefully.."A disadvantage of TIG is it takes a whole lot longer to learn." that's my big bugbear! If I was welding exclusively and every day, I'm sure I'd get to grips with it but the welding can be erratic as I also bolt, screw,tap, bind...etc (using mixed materials as I do, the method depends on the materials - and in between I'm moulding in silicone, casting in resin, articulating skeletons.. and doing lots of other welding unfriendly stuff). I am still in a quandary as I like the idea of being able to weld small and neat but don't want to have to spend days learning only to not use the thing for weeks then have to learn all over again! Oh decisions decisions. Of course if/when I get into it more fully the chances are it will allow me to expand on the way I work, so again...want to make sure I get the right machine and not one I'll want to upgrade in a few months. I think I will try and find a friendly welder who will show me the basics of both mig and tig so I can at least see what I'm dealing with. I've also been looking into local short courses. As I'm busy with clients work at the moment I'm not in a great rush to buy and will keep researching till I work it out.
Thanks to all of you for taking the time to give advice, although, Simon, with respect.."just squirt some snot at it and concentrate on the art!"...that's not my style mate! I can't do bodge and I hate to see sculpture by 'artists' who have no craft ability. The way things are put together is very important to my work, it's part of the integrity of the sculpture and very much a part of the way I am creative - problem solving. I love the way things 'fix' which is why I often chose to bolt - when I can - rather than weld as I like the physical appearance of functional connectors. I'll be getting my own website up and running before too long so I'll be show some clearer pictures of details and you'll see what I mean. Meanwhile....back to research! yawn... and no more plumbing talk I promise.
I am I am!! all these posts arriving while I'm typing protracted responses in between eating! I am following the arguments though - interesting stuff about welding v soldering, steel v copper..never knew/thought about the heat dissipation thing, v interesting..
"Arn't you near the old William Morris place in Chipping? Visited there when I was learning cabinet making in Thame, many moons ago.."
actually no, that's just the gallery who sell some of my work, I'm miles away in windswept Norfolk. My mother has some nice William Morris wallpaper tho.
Now I'm sure there is a way of dropping in short quotes so they are in those natty blue boxes and without having to copy and paste but I still haven't worked it out. I tried hitting 'multi-quote' but nothing happens. It's all or nothing. Never mind, maybe it's a mac thing. Have to get some sleep, my head is reeling so please may I be excused, my brain is full.
just before I collapse...please tell me more about brazing Simon..I have oxy acet cutter which I think has a brazing torch I've never tried...or are there other ways? .....and maybe I could gas weld - if I learned how - which would be fine if I didn't have wood/leather/plastic in the vicinity - then maybe a mig could fill in the gap? oh ouch. too many welders too little time to learn how they all work. anyone out there know how to clone? I need another me (or two..or three)
brazing will be useful for some materials, but I would definately recommend mig for your main use, its clean and relatively hassle free, tig i think would be a pita for you, gas welding too.
LOL. I'm glad you liked the snot comment!!
I had a mate who moved to Oz a few years back, who ended up doing creations for the Sydney Olympics opening ceremony. His stuff was brill, very mutoid scrap robotic etc. Couldn't weld for toffee though. It was a style very popular with artistic crusty types a few years back. We made some dubious mutoid vehicles which went to Glasto, and other stuff for street theatre performances, and the welding was seldom up to much. (except mine, of course!)
Brazing:- Bottles, torch, tub of brazing flux, rods. Heat rod a bit, dip in flux, heat work, apply rod, melt braze into joint, voila. Like soldering but hotter and stronger. Fantastic for fine work and MUCH neater than welding. Look at www.coolshelves.com - same bloke with the artinsteel site. Good pics of what you can do with brazing. (not trying to plug him, just illustrative). With practice, you can braze copper, but you really should have low melting point rod. I've done it with standard brazing rod but it took me a while to get the technique to not blow through the copper (which has a lower melting point than brass)
And yes, you can gas weld with that lot too, but you would use a finer nozzle for more concentrated heat. No flux required.
Mig is really useful as it's the easiest way of welding. It makes tacking up work a doddle, and you can pour on weld with a minimum of experience. It is a terribly forgiving medium. Mwah.
But really, have a bash at brazing. Looks good too polished up, little bits of shiney brass all over the place.
yes, I think mig is the way I'll have to go, (forgiving medium...sounds good to me) tig sounds great in theory but I can see now that Malcolm's enthusiasm is a cleverly disguised plot. I found your post 'tig - how hard can it be' - obviously not too easy! you just want me to get good then tell you how to do it! also...followed a link to the miller site which is VERY useful and the thing no-one mentioned is that you not only need a co-ordinating foot but TWO hands...I don't have enough hands as it is! (although Manfrotto magic arms are a pretty close substitute).
I've found a 2 day welding course which covers gas, mig & arc (not tig sadly) so I'm going to do that to get some basics and a refresher and when I clear some of my backlogged clients work I shall have a bash at brazing and gas welding. I've done a fair bit of soldering so reckon I could get to grips with brazing. All else failing I've always got the snot route!
one other thing..just spoken to a friend in London who uses both tig and mig and he thought mig was not so good at filling in awkward gaps, although he admitted his gear was pretty ancient and things might have changed..have they? is he right? wrong?
btw..Haze..wot's 'pita' mean`?
same principles apply for modern mig as with the old, like we said your not making a race car chassis or structural beam welding so using unconventional techniques when mig welding should keep you satisfied,