Tig torch angle advice please

[Doormandean]

Hi people,

So I'm welding up some parts on the inside of a tunnel underneath a motorcycle petrol tank, and at one end I have I have an area of overlapping. I've had a t**t of a time trying to figure out the best way to do it (especially in an area I can't fit the torch into properly), so I thought I'd polish off some IT skills and make a quick drawing and ask you're opinion!!!

Which angle should i have the torch?

Having a sod of a time, either I'm getting clumping on one part of the steel, or just blowing through eventually while waiting for the pool to get nice fluid.Is there a 'troubleshooting guide' on here anywhere as well? I would love to know when the gas is too high/low, heat too high/low etc etc. I'm kind of muddling through at the moment with what looks right, and it's getting varying results!
Thanks one and all

 

[Doormandean]

by the way, it's around 16 gauge at approx 1.6mm thick

 

[chevy2]

The top sketch is closest to the torch angle you need but a bit more upright at around 60degrees? whereas your sketch is around 40,
Aim to keep more heat on the lower piece as it'll handle more heat and not burn an edge away,
Try building the weldpool when adding filler rod each time while keeping the torch more towards the lower piece and move the pool to the upper edge joining the two and then back to the lower panel to add filler before moving it back up to the upper edge each time.

 

[Doormandean]

Brilliant, thanks!

What kind of flow rate would you suggest for the gas?

 

[Lawnmowerboy]

4 to 6 lpm depending on gas lens or ceramic and size.

 

[chevy2]

Yeah as above, on the lower size with a gas lens

 

[chevy2]

To add, if you're not already,
1.6mm red tungsten sharpened to a fine point with 1mm A15 filler rods will work well.

 

[Wallace]

Just in case you did not know, Tig filler rods are not the same as gas filler rods.

 

[Doormandean]

Thanks again! Really appreciate the help.

I had the gas flowing at 10, and it seemed to be a bit on the angry side, but then lowering it felt like it wasn't moving the pool around very much. Think I'll try it on 6 again tonight and see what's happening.

Chevy, that's the sizes I'm using at the moment I think (definitely on the tungsten)

Wallace, yep, tig filler rods all the way.

Really kind of you chaps to take the time to give some advice to a newbie. I'd love to do a night course to help me understand things better, but it's not a possibility at the moment unfortunately. It took a fair while to get a good handle on the set-up of the mig, now being back at square one with tig is both interesting and frustrating as I don't look at a weld and think 'Yep more/less gas needed and hotter/cooler' etc. I am a determined bugger, so will get there in the end!!

 

[Lawnmowerboy]

You don't need the gas moving the pool round. How clean is the material

 

[Doormandean]

ah, therein lies a problem and lack on knowledge on my part then, I thought the gas would move it about a bit!

Generally pretty clean

 

[Lawnmowerboy]

Clean as in no paint rust oil grease dust etc?

 

[chevy2]

You can get away with quite low gas flow rates,
using a gas lens doing downhand bench welding with minimal tungsten stick out i've gone down around 3lpm,
so long as theres no porosity/air pockets in the weldpool then you have good gas shielding,
slighty more gas flow is needed when welding overhead as argon is heavier than air and so needs a higher flow rate for adequate coverage,

Already said is your material clean enough?
with tig everything should be very clean, ie no scale if so clean it off,
dirty material with often give you a lazy weldpool so that when you move the torch forward the weldpool has a delay in catching up.

 

[norlander]

assume you have similar kit to me and have no footpedal, if the puddle is playing hard to start, try dipping the filler rod in anyway,- I've found this bridges the joint and starts the puddle off.