Hi there - have really enjoyed the videos on the site, and it finally got me to be able to TIG alloy - I've only ever done mild and stainless before (not very well either!!) - most of the stuff I do is with a MIG. Anyway, after watching a few vids, I taught myself to TIG alloy the other day, and now I can get a nice row of nickels with various size filler rods etc - and I think I now know what to look for to get achieve a good (looking) weld - however, my problem is this:
I've been practising on a nice new bit of 2.5mm alloy plate, cleaning it with a stainless brush where necessary and always wiping it down first with acetone. My welds form nicely (well, I'm pleased for only about an hour of practise) - but after I've finished they look "dirty" like the alloy was uncleaned when I started. How can I get my welds nice and shiny like in Jody's vids? I have a pic I took with my manky old phone if anyone wants to see that....
anyway, thanks in advance and I look forward to spending some hours on here
90 percent sure the alloy your referring to is aluminum(which is usually just abbreviated, aluminum)
What kind of machine are you using?
If your getting a decent looking bead than that sounds like your electrode is balled nicely.
If your cleaning everything with a S/S brush(one that has NEVER been used for anything BUT aluminum), and wiping it down with some sort of alcohol/acetone or what have you, the next step would be to make sure your tungsten is not contaminated, and once again, should have never welded anything except aluminum with that piece of tungsten. Also, your gloves should have never touched anything except aluminum(dont use your mild steel gloves to weld aluminum).
After that check your arc balance. I'd start around 60/40(this depends on your machine, and you normally adjust the amount of cleaning (EP) you want. So when your adjusting it, you'll only see one number. Start around 35-40 percent and go from there).
Be sure you clean your filler metal the exact same way you clean your plate. Brillo or some steel wool works good for cleaning off heavy stuff, then wipe it down with the alcohol as well. Try not to set it on anything dirty/not aluminum.
When I first started tig'n, lets see I think that was last night... LOL.. well anyway, cleaning is often taken to unnessecary extremes. Here's the deal, the surface needs to be oil free so Acetone is a good choice for that. On clean new metal you just gonna hit it with a stainless steel wire brush after and go. If you're using something like Alprep to strip the mill slag off then there shouldn't be any oil on it and face it, if you've got the slag off (shiny stuff) then where's the need for wire brushing. If the Al is old an nasty then yeah, you gotta go to some extremes to try and get the slime and corrosion of it but as much as you try you probably won't and you'll still spit and spatter. If you're using a scotch brite pad on a die grinder like I do then wipe it down with Acetone first or you're just going to push the surace oils deeper into the metal. You don't need to wipe it down afteward, just hit it with some clean air or a clean rag and weld. Some of my best welds, I think the count is two now, happend with just basic surface prep. Probably because I wasn't all tuckered out from all the unnecesscary cleaning.
However, to get to the point of the problem of the hazy looking welds. Speed it up or add a little more flow to your gas or turn the heat down a tad or don't be so stingy with the filler rod. Try one at a time until you find what works. It's your machine and your technique and there's no one out there the same. Just keep playing with those four things and pretty soon it will just happen.
Here's the deal, once you find the sweet spot for you and your machine, you'll know from that day on what a good sounding and good looking arc is and how to get there repeatedly on any metal you choose.
Highly skilled at turning expensive pieces of metal into useless but recyclable crap..
thanks for the replies everyone! yes, when I say alloy I mean aluminium.
Had some guys drop into the workshop yesterday to look at the racecar I'm doing (they are ally welders by trade) and they mentioned the same things - gas flow, clean the rods etc. Also, the gloves is a good point - I've had them forever and they're pretty grubby! I've been thinking about it, and as the beads seem contaminated by a black "soot" I suspect it is just impurities in either the base material, filler rod or tungsten - tho the tungsten is a new one sharpened to a moderate point.
The machine is a chinese brand one, tho they have a good rep here in NZ, but I can't remember the name of it right now sorry I'll keep trying different settings and make sure my work is as clean as can be!
I'll keep trying different settings and make sure my work is as clean as can be!