Bionic Balls

I just feel bitter because if I go out on my mountain bike I have to spend about an hour cleaning the thing before I can put it away. Lucky git

I think I'm probably going to mostly repeat what others have said but the more the merrier..right? I'm not a welder, nor can I likely weld much better than you! I am a welding engineer which means I have to think about all of the problems associated with joining two pieces of metal and decide which is the best way to go about it. Welding itself is a true skill and there is an entire spectrum of people out there working as "welders". I work in the power generation industry and along with other process industries (including oil and gas), there is a real need for highly skilled welders. Many of the best welders in the UK are well into their 50's and did an apprenticeship with a large fabrication company that gave them experience of the different processes, metals, equipment etc etc.. If you can get yourself an apprenticeship and stick with it then you will almost certainly have found a solid career choice, particularly if you're willing to travel around with one of the larger companies (like Doosan or Alstom). Becoming a MIG/MAG welder in a fabrication shop is a start and you're unlikely to be away from home too much but in most cases I expect it is far less "glamorous" (if that's the right word!).. As others have said, it is hard work- don't doubt that. Days long, working environments noisy and working positions might be uncomfortable but if you do a consistently good job you can get anywhere. To actually answer your questions- - yes it is repetitive (particularly if you're starting out) - yes you'll need to be awake (!) - working environments as above - it should be sustainable, particularly if you're willing to move around a bit (there is a shortage of good welders and it's getting shorter) - there's always new joints, materials, processes to learn and there are more formal qualifications should you wish to pursue them so there's potential to progress there Good luck! Adam

It may be tricky but that doesn't mean it's OK not to get fusion all the way through! It looked like you had to give it a reet decent twist before any "tick" so if there is a crack, it must be pretty small..i.e. it's unlikely to completely fall apart just yet. Why not just ride it until it's gotten a bit worse- you might be able to find it then and prove it is a warranty problem..? Adam

Swindon high street is pedestrianised.

Some photos of Al welded on DC- http://weldingweb.com/showthread.php?51165-Anybody-here-good-with-DCEN-Alum-Tig-welding Does indeed need to be clean..a decent scrape on the bevel prep with a rasp and not hanging about is apparently the secret! Al in general is prone to porosity so a fueltank might not be the best thing to start with.. AC would probably be a better bet (on another set by the sounds of it) but might be worth a go for tacking?? No promises! Get the stainless plate..no-one wants a rusty bench Adam

Agree with the least possible approach- too much and the turbulence draws air in. Start low and if you're seeing too much oxidation or porosity (that's what springs to mind anyhow) then turn it up a bit..make sure there's not a draft where you're working either! I'm a metallurgist/welding engineer so I really should know this by all accounts! Adam

Pre-gas is a few seconds or so to purge the line before the arc strikes and post-gas is again a matter of seconds just to keep the hot weld and electrode shielded from the air till they've cooled down a bit. Slope up is there to help reduce thermal shock on the electrode and give you a bit more life- it just means the arc grows stronger gradually. Perhaps 3-5s or so? Slope out is again to reduce thermal shock but it also gives you a chance to fill the crater at the end of the pool in before the arc goes out (as the arc dies out the crater gets smaller and smaller). Just have a play about and you'll learn alot I'm sure! As you and f**kme have already said, stick with DCEN.. Sometimes Al is welded DCEN but it's definitely not common- you can even weld DCEP but that's probably even less common! Yeah just give it a clean and try it! Nothing to lose.. I see you have a 1.6mm electrode and came up with 65A on thin sheet- sounds perfectly reasonable to me. Don't get hung up on the leftward/rightward welding thing but usually with tig (for a righthander) it's torch in righthand, filler in left and move from right to left.. ooo and gas flow rate..something like 4-7litres/min would be typical(ish). Enjoy! Adam

I'd suggest any brand ER316LSi filler will be fine- go for 2.4mm diameter. Electrode wise look for ceriated or lanthanated (keep away from the thoriated if you're working at home- radioactive dust probably isn't something you're geared up for) and again 2.4mm diameter. Try and grind the tip on "axially" if that makes sense- more like whittling a stick than a pencil sharpener.. Before faffing about with backpurges see if you can manage a fillet like f**me's second photo above. Last thing I'd say is look at trying some MMA electrodes- you may find it easier anyway, won't need to worry about the backpurge and probably just need to get a new electrode holder to plug into your TIG set. Might not be a machine mart job but you'll want specific electrodes designed for rooting- the Metrode range at http://netlite.com.my/home/wp-content/uploads/2011/11/A91_A97.pdf should give you an insight into what's available (there's even a cored TIG wire on there that doesn't need a backpurge). Practise! Adam

Never actually seen any braze welding but I think it'd be difficult to match the strength of a matching (welded) filler, unless you re-design the actual joint using lugs etc.. Bronze age vs. iron age...?!

Not as far as I know..! Any particular reason why you think that? Which process to use is more a question of the geometry and size of the thing here- the materials can be welded by most processes, with similar final properties. Adam

Agree with recycling an old frame- definitely the best way in my opinion. Don't worry about purging tubes, but do make sure you clean up the bore as best you can. Also wouldn't worry about heat treatment, CrMo or otherwise. Expect there's a bit too much specialist equipment involved there anyway! Without sounding like too much of a twat, I get the feeling you're not really getting into the "engineering" of a frame here. You mentioned what diameter to use for the tubes which was a start. Look into which tubes are in compression or tension, different ways the frame might break that you need to design against (yielding, buckling, fatigue), advantages of different materials, ways of joining tubes together, effect of different shapes of tube (moment of inertia?) etc.. Good luck- there's a lot of effort gone into frame design! Adam

Family Biker- on steel frames I can't think of many occasions when it'd need heat treating, though I don't claim to know all of the different steel types used on bikes nowadays (some materials always need it!). Generally speaking it'll improve the toughness (which I'd expect to be good enough anyway) and reduce the risk of any unexpected distortion (linked to residual stresses)- a frame needs to be nice 'n straight after all. I'm sure there's other good reasons that crop up too. Aluminium is a completely different story.. f**me- the word "stainless" is just too vague! I'm still intrigued as to whether a 304/316 frame will be any good..will at least look good that's for sure. Adam

Yeah err..not really. Wasn't getting at you- sounded like you had it all planned out! I like other bike stuff too but I'm actually a metallurgist so it got me thinking Adam

Why would you consider heat treating a lighter frame, unless you'd changed the material? Adam

Reynolds..good choice! I take it you work with CrMo steels too? Geeky question but do Reynolds recommend consumables to use on their tubing? Good luck! Adam

Wrong way around f**me.. Needs beefing! (but yes the Chromium content is higher..the strength isn't)

Did I read this right in that you're planning to make frames out of 304/316? Don't think I've ever heard of that before... I can't help but think it's going to be much more expensive than you have in mind and won't be of much benefit- will have to beef the tubes up to get the strength.. Interested to hear how it goes though! Adam

Wahey Swindon is back on the map! Shame my computer can't handle youtube without skipping.. it's that old.. Top stuff

But they could be cast..? No-one would be any the wiser without chopping them up (or at least a bit off)! Adam

Swindon.. bangin'. Get a ride organised! I'm in Middleleaze.

waaaaa?? top job Ben

Enjoyed watching that very much. Top job

alcohol ay...? So that's the secret..

That was awesome Ben.. looking really effortless

awesome riding Dan! Stacks at the end showing some effort going in! Swish. Adam