Airframe Welding

rkirk77 · Fri Dec 26, 2014 7:17 pm

Hi Guys,

Totally new to tube welding and gave it a shot a week ago.. and it didn't turn out too good, lol.

I am using 35 amps and a 3/32 tip and I am totally lost.. so any advise would be welcome.

TRACKRANGER · Fri Dec 26, 2014 7:26 pm

Hi rkirk77

You are probably holding too long an arc length, and going way too slow.

Reduce your amperage slightly, hold a much tighter arc and see if that heads you in a better direction.

I would find time to practice on something a little less challenging than thin-wall tube. Try some 16 or 20 gauge sheet and practice some fillet or butt joints on that first, Try some different settings on the machine until you are comfortable with that, then take the next steps.

Trev

Oscar · Fri Dec 26, 2014 8:05 pm

what else have you practiced on? (tubing is the #1 worst thing to start tig welding on, even for practice!) My advice is hidden in my question, BTW.

Please list what machine you are using, and the settings you have tried with it. From here on out, you will get bombarded with questions, so just disclose EVERYTHING up front and save everyone sometime if you would like to get good, concise advise.

WerkSpace · Fri Dec 26, 2014 8:13 pm

Yes, lower your amps and shorten the arc length.
I learned to weld by filling in holes on sheet metal.

If you have some scrap tube, try adding weld to the ends.
See if you can build up the end of the tube and close it off.

If you mess up, just cut the end of the tube off and try again.
It's all about learning heat control.

Fri Dec 26, 2014 8:21 pm

That looks like 4130 tube,

say, 1/2" X .035 wall, or maybe .049.

The heat-affected zone makes me agree with Trev, you're putting in too much heat. The blow-outs confirm this.

What filler are you using? Do you have a foot pedal or other remote control? Thin tube is much easier to TIG weld when you have complete control over the welding current.

Questions, questions...

Steve S

rkirk77 · Fri Dec 26, 2014 8:27 pm

Oh crap.. sorry guys.. lol

I am practising on 4130 tube that is 1" OD / 0.035 wall thickness

Everlast PowerARC 160 STH (I took the 2T switch off and am learning to use the pedal).

Fri Dec 26, 2014 8:35 pm

rkirk77 wrote:Oh crap.. sorry guys.. lol

I am practising on 4130 tube that is 1" OD / 0.035 wall thickness

Everlast PowerARC 160 STH (I took the 2T switch off and am learning to use the pedal).

That's a big plank with big-arse nail holes, then, if that's 1"... That's why I thought it 1/2".

I'm tickled I got the thickness from the picture.

Steve S

WerkSpace · Fri Dec 26, 2014 8:47 pm

Check out this video, it has some decent pointers.
https://www.youtube.com/watch?v=1nLsrcscoOA

Oscar · Fri Dec 26, 2014 9:53 pm

Oh and ditch the 3/32" tungsten until you really get good. Pro's can work with it much easier, but I'd bet you will be able to do much better with a 0.040" or 1/16" tungsten sharpened to a point with a long taper.

Something like this would work much better (after you practice on normal flat plate that is----you can forget doing aircraft/airframe welding anytime soon

) That is a 1/16" tungsten, and a 0.5mm "arc length", for reference.

rkirk77 · Fri Dec 26, 2014 10:23 pm

Ok.. thanks oscar!

What type of tungsten are you using and how long is that taper?

PS, i am using electrode negative..

rkirk77 · Fri Dec 26, 2014 10:33 pm

Here is the tungsten I have been using..

Oscar · Sat Dec 27, 2014 12:25 am

rkirk77 wrote:Ok.. thanks oscar!

What type of tungsten are you using and how long is that taper?

PS, i am using electrode negative..

I use 1.5%La/2%La/Quad-Mix interchangeably for everything (not that I do much other than plain ol' steel, but all of those work great for the few times I decide to make something out of aluminum). Yes, you are supposed to use DC Electrode Negative for all steel tig welding, lol.

For the taper, glance at the un-sharpened portion of the tungsten itself. It is 1/16" in diameter (1.6mm). Then glance over at the tapered point. Then glance back at the rod. Then back. You'll get it.

The E3 would work just fine, it's just operator-error at this point. TIG welding small round tubing for aircraft frames is not something that you pick up over a couple weekends. More like 5-10 years of day-in/day-out tig welding. You must crawl before you can walk. Start practicing on 1/16" - 1/8" flat steel, just running beads without using filler or anything. Then you move on to adding filler. Then you move on to doing butt-joints. Etc, Etc, Etc. If you can' do basic joints in flat-steel practice parts, you won't get anywhere fast doing thin-wall small-diameter tubing.

motox · Sat Dec 27, 2014 10:31 pm

rkirk77
take what Oscar to heart
start with simple welds on a flat surface
till you can do it without thinking.
then try laps, butts and then up hill.
same thing till you can do it without
thinking. by then you will know how to
grind your tungsten, set your machine
and even weld.
it takes time and practice just be ok
stay at it.
craig

rkirk77 · Sun Dec 28, 2014 9:56 pm

I took no offence to any of it.. I am going to the scrap yard tomorrow and i an going to burn, burn, burn!

Thank you all for your help!

doneinone · Mon Dec 29, 2014 12:22 am

What kind of airplane are you building? I ask because I saw the fuselage drawings.

rkirk77 · Mon Dec 29, 2014 12:50 am

It's a Pietenpol Air Camper.. very easy and fun to build!

aeroplain · Mon Dec 29, 2014 2:03 am

I thought the Piet was all wood.? Didn't know they were made Rag-N-Tube.

rkirk77 · Mon Dec 29, 2014 9:11 am

Yup, the tube airframe was designed by another builder back in the 60's. The tube fuse is about 30-40 lbs lighter than the wood one!

jwright650 · Mon Dec 29, 2014 11:11 am

rkirk77 wrote:I took no offence to any of it.. I am going to the scrap yard tomorrow and i an going to burn, burn, burn!

Thank you all for your help!

If you don't have any flats handy, you can still practice running stringers longways on the tube....just practice forming a puddle and moving the puddle along longitudinally along the pipe.... get that down and then start adding filler

jwright650 · Mon Dec 29, 2014 12:22 pm

(don't laugh) Here is a pic of my first ever Tig weld...I'm not sure of the wall thickness of this tubing, but it was thinner than the paperclip I used as filler. Been awhile so I don't remember the machine settings. I opened the box when the welder was delivered that day and this was the first time ever using this machine. I didn't have any filler, so I straightened a paperclip and used that.

Superiorwelding · Mon Dec 29, 2014 12:34 pm

John,
What I want to know is, what wire classification does a paper clip fall under?

-Jonathan

jwright650 · Mon Dec 29, 2014 12:56 pm

Superiorwelding wrote:John,
What I want to know is, what wire classification does a paper clip fall under?
-Jonathan

I'm not sure.....The paperwork on it flew away in the wind when I took the paperclip off

Jason_alex · Tue Dec 30, 2014 1:55 am

LOL I have never seen anyone use a paper clip for filler......

Tue Dec 30, 2014 3:07 am

Piston rings work unreal for cast iron tig because they have very high nickel content.

jwright650 · Tue Dec 30, 2014 8:53 am

Jason_alex wrote:LOL I have never seen anyone use a paper clip for filler......

LOL...now you have