Printable View
Just curious if flux core welding has any place in welding 4130?
It seems to me to be a good fit between Gas and TIG...
Greater deposit rates than both gas or TIG and less heat input than gas.
And initial cash outlay is far less than either.
I have easily welded steels down to 0.03125".
Any thoughts???
Jim, I have welded 4130 with MIG and flux core wire. Nothing on an airplane but various parts of the kids go-kart, jigs, fixtures, etc. Like you, .032" or 1/32 is the thinnest base metal as I have done. With a little practice, I would definitely consider welding a steel tube fuselage. Many years ago a friend welded a fuselage with MIG but I think he used hard wire. He never completed the project so I can't tell you how it turned out.Quote:
Originally Posted by Jim Hardin
From what I understand American Champion welds their fuselages with migs - not sure what kind of wire they are using. I read somewhere that some of the heavy equipment manufacturers switched to flux core due to increases in gas costs.
They have been doing it for many, many years but they use hardwire was the last 411 I had.Quote:
Originally Posted by Mike Switzer
I thought that's what I would do when I bought my MIG machines several yrs ago, but it came with a spool of flux wire and ever since that is all I have ever used.
I guess we need some Welding 101 here (I have been doing arc welding for many, many years)
Oxy/Acetylene:Flame is heat source for welding process.
Filler Metal is added manually by hand.
Shielding Gas is the CO2 produced by the flame.
TIG = Tungsten Inert Gas:Utilizes the arc between the base metal and a tungsten electrode as the heat source.
Filler Metal is added manually by hand.
Shielding Gas is used.
(similar to Oxy/Acetylene but arc is heat source and gas is added)
MIG = Metal Inert Gas:Filler Metal provides arc heat for welding process.Flux Core:
Filler Metal is on spool with auto feed.
Shielding Gas is used.Filler Metal provides arc heat for welding process.So while Flux Core may appear to be like MIG, the processes are distinctly different.
Filler Metal is on spool with auto feed.
Filler Metal is hollow and filled with welding flux which burns and the gasses produced act as the shielding gas.
(flux may include other chemicals & metals to form an alloy as base metal and welding wire mix)
Of course then there is the wire/flux selection to match the qualitites of 4130... ;)
I, like you Jim have been welding for some time. As for Flux core on 4130 for aircraft, my biggest concern would be the amount of slag left in the weld itself. I have welded 4130 on Late Model Stock car roll cages, it worked quite well as long as I kept sufficient heat to properly "burn-out" the impurities. To be on the safe side I would weld a test piece and spend the extra money to have it x-rayed. Weld-Test will do a single shot for about $50.00. Just one person's opinion.
First of all, I should have acknowledged and thanked all those who have responded, and those that will...
I am gathering that no one has really done it with aircraft and wondering if there was any specific reasons. I will have to explore some other resources about this and will post back any findings!
Quote:
Originally Posted by Jim Hardin
Jim,
Lots of reasons NOT to:
1-Oxide and slag inclusion(fatigue failure)
2-Impossible to create uniform penetration and fillet shape (fatigue issues)
3-Rapid cooling rate after welding will induce poor base metal microstructure (fatigue issues)
4-Messy process creates lots of spatter and possible arc scars (fatigue issues)
5-Slag removal can be difficult and may create poor paint adhesion.(corrosion)
So in short, if there was ever a process that was NOT suitable for 4130 aircraft welding, FCAW would be it. The ONLY reason mig was ever used in production was for cost reduction, never an engineering advantage. Gas and tig using proper welding process are going to be the best way for you to go.
BTW Jim.....every technology has been investigated at some point or another. Keep the FCAW for welding manure covered agricultural stuff :)
Thanks for the posting!
I was also in touch with a CWE (Certified Welding Engineer) and he made a similar case against FCAW along with the addition of too great penetration, producing burn thorough.
You may also be interested to know that FCAW is approved and used in Pipeline and Bridge construction.
I was never certified on it, but oddly enough, taught many of our welders how to use it before they were tested :eek:
The early Glastar fuselage cage were MIG welded and I'm pretty sure they used the inert gas process. I understand there were some weld failures and the MIG welding was discontinued and TIG replaced that method. There are no subsequent weld failures of which I am aware.
As previously mentioned the MIG units are excellent for farm use, building fences BBQ pits and wood racks, not airplanes.
While some of the light plane manufacturers do use MIG, I would be very hesitant to use anything other than TIG or O/A.