Okay, new discussion: welding

Discussion in 'Tube and Fabric' started by Medic9204, Sep 24, 2005.

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Which way to weld 4130 steel?

61 vote(s)
39.1%

14 vote(s)
9.0%

80 vote(s)
51.3%

1 vote(s)
0.6%

61 vote(s)
39.1%

14 vote(s)
9.0%

80 vote(s)
51.3%
8. Other

1 vote(s)
0.6%
1. Sep 24, 2005

Medic9204

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Okay, I'm about to learn how to weld but need suggestion and ideas of which method to go with.

I'm welding 4130 tubing and sheet steel for the fuselage.

What's best? gas, tig, mig, arc, something else?

ALL opinions are welcome, and I'd appreciate reasonings.

Thanks!

Last edited: Sep 24, 2005
2. Sep 24, 2005

dustind

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There are some good discussions on this forum as well as www.canardaviationforum.dmt.net

I do not know so all I could suggest is searching this forum and google.

3. Sep 25, 2005

BD5builder

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IMO for something like a tube and fabric fuselage, i would go with TIG. But thats just my opinion from what little welding experience i was required to get with all the different versions. If ya check out the AC43.13 online it gives a pretty good description of welding techniques and preparation.

4. Jan 6, 2006

jetblackaircraft

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The BEST method for your application is TIG. The easiest to learn is MIG. MIG welding your frame might work out alright, but like I said, the BEST method is TIG.

5. Jan 7, 2006

Spinnetti

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Well, 'Best' means different things to different people. bad welding by any process is dangerous, and good welding of the wrong process or wrong rod for the material is still dangerous.

I've seen many folks say that gas is the best to learn as you can easily transition to tig, which I think makes the most beautiful, and most controlled welds.

Pretty much all steel planes were welded with gas until tig (Heliarc) came along. You can get excellent results with gas, and its cheap to get a welding setup. There is some debate between gas and tig about the larger heat affected zone using gas welding vs. the lack of 'normalization' from tig welding for 4130. Check out the miller welding site for more info. (I'm no expert but did weld professionally for a few years).

I weld gas, mig and tig. I'm best at mig (from many years practice), like tig the best (still learning), and usually just use gas for cutting off stuff and heating things up.

6. Jan 7, 2006

jumpinjan

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I'm pretty much convinced that TIG is safe and no normallizing is required because we are using a thin wall tubing. Some preheating might be needed if working in cold shop conditions. Lincoln has a small amperage TIG (185) and it has a better range (5-185) than the Miller (10-180). I'm going to buy the Lincoln and I very happy with my MIG 185 that I had for 5 years now. Read this about rod specifications:
http://www.lincolnelectric.com/knowledge/articles/content/chrome-moly.asp

7. Jan 9, 2006

wally

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If I could afford it, I would buy a TIG machine. It makes welding aluminum a breeze. A nice machine will set you back close to a $1000 or more What I have is a cheapie oxyacetylene torch from harbor freight$100. I had to purchase the bottles from the local distributer ($250) but refills are then cheap. It will do the 4130 welding you need to build most any homebuilt airplane part. And it is really not hard to learn either. You can use MIG to build the trailer to haul the plane to the airport but I would NOT use it for building the airplane itself. 4130 alloy steel that is normally used does not like MIG. You can buy aluminum gas tanks already made for several airplane designs or form the metal and then have the local shop TIG weld it. Wally Last edited: Jan 9, 2006 8. Jan 9, 2006 CAB CAB Well-Known Member Joined: Nov 27, 2004 Messages: 128 Likes Received: 0 Location: Colorado 9. Jan 23, 2006 Orion L. Vick Orion L. Vick Guest Got a question. I am new to building so please no snickers, What is the best way to attach formers to a welded frame when using aluminum for the outer skin? 10. Jan 23, 2006 Craig Craig Well-Known Member Joined: Jan 30, 2003 Messages: 543 Likes Received: 0 Location: Jupiter, Florida Tabs and formers Orion Vick - I welded small tabs with 3/16" holes to the tubes in the places where I wanted them, then bolted or welded "L" shaped pieces to rivet the aluminum skin to. The ones around the cockpit look like partial bulkheads, which indeed they are. I also used the tabs for things like the skin, floors, instrument panel, stringers, turtleback, etc. Some of my aluminum skin was drilled on 1" centers for brads, and the aluminum nailed to the stringers. Small holes - about #70, as I recall. The stringers (1/4" x 1" spruce, gives the fuselage it's curvey shape) are bolted to the tabs. To hold the tabs in place while welding, I used a stiff piece of about 1/4" dia. copper wire, with a clamp on each end. Put one clamp close to the place where you want the tab, they tab in the other clamp, and bend so that the tab is where you want it. For floors, instrument panel, cowling pieces, etc, I slipped a "U" Tinnerman nut over the hole in the tab to take a #6, 8, or 10 Type "B" sheet metal screw, depending on what I was fastening on. Hope that this helps. 11. Feb 19, 2007 jany77 jany77 Well-Known Member Joined: Jul 5, 2005 Messages: 390 Likes Received: 12 Location: california 12. Feb 19, 2007 wally wally Well-Known Member Joined: Apr 1, 2004 Messages: 926 Likes Received: 14 Location: southwest TN. If you are building a steel tube fuselage like the Baby Great Lakes, buy the oxyacetylene torch kit - also from Harbor freight.$100. I bought one a couple of years ago and it works just fine. There will be a lot of times you need to heat and bend metal and you cannot do that with just a MIG machine. And MIG isn't really the right way to weld 4130 steel. It works beautifully on mild steel, some types of stainless and some aluminum but don't use it for 4130.

Plan on buying your oxygen and acetylene tanks from a local gas distribuitor. Expect to pay another $250 or$300. Refills are cheap after that. An oxyacetylene rig will last many, many years when taken care of. And once you have it, handier than a shirt pocket.
Good luck,
Wally

13. Feb 20, 2007

Midniteoyl

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Ahh... buy both a TIG and Oxy setup...but not from HF. TIG the 4130.

14. Feb 20, 2007

AlRice

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For a TIG, you want to go with a big name like Miller or Lincoln for reliability and service. I doubt if the HF TIG will last through the whole fuselage before burning out. Also, if you plan to weld aluminum, the inverter type TIGs won't do it, you need DC- output for steel and AC output for aluminum. You can usually find used Millers and Lincolns on Ebay.

Recommend you either try out TIG and O/A at Sun N Fun or Oshkosh or take a Sportair workshop. You get to burn up all kinds of metal and get all your questions answered at the same time.

Last edited: Feb 20, 2007
15. Feb 21, 2007

Peter V

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Well, a cheap inverter won't, but if you want to spend $there are 250 amp inverter TIGs that are great for aluminium. You just wont find them for under$2000. :dis:

16. Sep 2, 2007

Mike Armstrong

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One of the reasons I went to Osh this year was to settle, in my mind, the question of Gas vs TIG for welding 4130. Several lectures and hours of practice welding later, I decided on Gas. I could have flipped a coin early on however after attending Budd Davissons long lecture in which he described in detail the pro's and cons of both technigues and his preference for the age old, tried and true Gas, my mind was finaly made up. My last couple of days there I concentrated on Gas welding steel tube at the workshops with old timer and younger experts showing me the ropes. By the end of the week I felt pretty comfortable that I could continue to practice on my own at home. I ordered Kent Whites 4130 Deluxe Kit #3 as soon as I got back. His equipement and videos are excellent, I recommend them (as many others at Osh recommended his kit to me).

I agree that both techniques work well for 4130, but I'm also glad to finaly have the question of which to use settled in my own mind.

Mike

Last edited: Sep 2, 2007
17. Dec 29, 2007

planecrazzzy

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I'll keep this simple....If you TIG , you need to aneal the area with a torch...

"NEW GUYS" ....might as well weld with Oxy/acet.

That also TEACHES you how to TIG...:ban:

OK , I'm done...
Gotta Fly...
Mike & "Jaz"
http://finance.groups.yahoo.com/group/mikepierzina/
( ASME CODE & State(s) Certs- MIG,TIG,STICK,Sub Arc, Pulse,Dual Shield,Metal Core )

Last edited: Nov 22, 2009
18. Dec 30, 2007

Mike Armstrong

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Thanks Mike.

19. Dec 30, 2007

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I havent read all of the posts --but this topic has been discussed many times over the years. I weld with all -- I prefer MIG -- many say it cant be used on Aircraft--Tell that to American Champion Aircraft --they used it exclusively for years to build their airframes

20. Dec 30, 2007

planecrazzzy

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Kolb aircraft also use MIG....

But "I" had to re work the whole frame due to the "Cold lap" starts....

At the time "I" did the repairs....I didn't have my TIG yet....

So I used my MIG ( SP100 ) but before each weld....

I'd grab my craftsman instant start propane torch....and sweat the tubes

that prevented cold lap starts.....

Some of the other guys with Kolbs , had gotten the frames "powder coated"

and later , because of cold laps..Rust would leak down....

That's bad....with flexing...the weld can only fail.

They say...Weld what yer BEST with...
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Gotta Fly...
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