TIG Welding Machines (what am I looking for?)

So, I'm thinking of building a Milholland Double Eagle for my first plane. The fuselage is 4130 steel tubing and the original was made using a gas welder. I want to go TIG because it seems to be better in many respects, just harder to do.

Now comes the question; what machine would work best for me and grow with me as I move up to more complicated aircraft like Sonerai or the like?

I saw where Aircraft Spruce has one (the Invertec V155-S) that is small and affordable but I'm worried that it won't grow with me. I surely can't afford to spend $3k on this but I also down want to throw away $1.5k either!

Has anyone used this machine or simular power machines and how does this scale when I start building the more complex and larger aircraft?

Thanks for your time,

SNZ

Sub, check out the Miller Diversion 165/180 machines. They use pulse technology, make quality welds and are very easy to use. I rented one this past summer for a couple jobs and I liked it better than my old Syncrowave machine I had years ago. I plan on buying one if enough work piles up.
Street price for a 165 is ~$1400 and if you decide you don't need it you can sell it and get your money back because being a name brand it holds it's value very well. Don't waste your money on off-name brands, cause you will be disappointed and you can't get rid of it without taking a beating on price.

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Originally Posted by martymayes

Don't waste your money on off-name brands, cause you will be disappointed and you can't get rid of it without taking a beating on price.

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Buy Miller, Lincoln, or Hobart. You can get parts & service in most decent sized towns, they all make good products & the companies will be around for along time. Millwright & pipefitting firms are always watching for used models of those 3 brands so you can get a decent price if you want to sell it. The off name brands may work OK, but like Marty says, you cant sell them easily because people assume you are getting rid of it because you didn't like it.

I totally agree with Martymayes - the little Miller machines will handle anything you need to do with Chromemoly and they are a very good value and hold their resale. You do not need anything more for aircraft materials. The bigger and more expensive machines can handle thicker plate, but you will never need to weld something better than 3/8 inch thick.

When you look at the Miller Diversion models, you can weld aluminum with the more expensive one, for like another $200 give or take. This is a nice feature to have. And...the Diversion models run on either 110 or 220 so if you don't have 220 installed, you don't need to go through the expense of that. The only thing is when you run it on 110 if you are welding something really thick and welding continuously, it will blow a 20 amp breaker consistently. But for aircraft thickness materials, you will be fine. More complex aircraft doesn't necessarily mean much more heavier tubing and plate and you will be fine with the little Miller machines. I have used them and their big brother counterparts in many welding classes under the supervision of an instructor who was a welder in the Air Force for a career, and now welds aircraft parts as his second career and he owns nothing but Miller and in many sizes including the Diversion series.

And another thing, if you can gas weld, you can most certainly TIG weld. You have more control with TIG. When you are welding up clusters, it can be tough to have the space to get in there with the torch, where-as it would be easier with gas. But there are pencil thin torches that you can use for when space is limited.

i have one of these:
http://www.millerwelds.com/pdf/spec_sheets/AD1-2.pdf
It does every thing I need, stick, tig alu/steel.

try to find one used for around $500.00

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Originally Posted by subnoize

So, I'm thinking of building a Milholland Double Eagle for my first plane. The fuselage is 4130 steel tubing and the original was made using a gas welder. I want to go TIG because it seems to be better in many respects, just harder to do.

Now comes the question; what machine would work best for me and grow with me as I move up to more complicated aircraft like Sonerai or the like?

I saw where Aircraft Spruce has one (the Invertec V155-S) that is small and affordable but I'm worried that it won't grow with me. I surely can't afford to spend $3k on this but I also down want to throw away $1.5k either!

Has anyone used this machine or simular power machines and how does this scale when I start building the more complex and larger aircraft?

Thanks for your time,

SNZ

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Dumb question, why do you feel that Tig is "better" for you? I assume you already have a torch setup? If not I would invest in one along with the Tig machine as you will likely want one for tempering critical weldments and the like.

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Originally Posted by Aaron Novak

Dumb question, why do you feel that Tig is "better" for you? I assume you already have a torch setup? If not I would invest in one along with the Tig machine as you will likely want one for tempering critical weldments and the like.

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Errr, I own nothing right now or I wouldn't be asking questions. What I had read is gas heat the surrounding material which is bad in things like aircraft and race cars. For bending tube I was going to get a set of small brazers but was going to skip gas otherwise. This is really a money issue, otherwise I wouldn't be building a Double Eagle but I still want to get what technological advances I can for the money. After all, I wnt to fly my kids around in this thing safely, right?


snz

I own a nice little Lincoln mig & I can borrow a Lincoln Pipeliner whenever I need it, I do 90% of my welding with a torch. The only time recently that I felt something would be better being tig welded was when I needed a fairly heavy pipe fitting welded to the bottom of a fairly thin walled fuel tank.

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Originally Posted by subnoize

Errr, I own nothing right now or I wouldn't be asking questions. What I had read is gas heat the surrounding material which is bad in things like aircraft and race cars. For bending tube I was going to get a set of small brazers but was going to skip gas otherwise. This is really a money issue, otherwise I wouldn't be building a Double Eagle but I still want to get what technological advances I can for the money. After all, I wnt to fly my kids around in this thing safely, right?


snz

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Ok it sounds like you might not have too much information on this subject so let me help you out a bit. The material you are working on was developed in the mid 1920's and fabricated using both arc (stick) and o/f (gas) welding in aircraft structures until about 1960 when Tig slowly started to take their place due to better economy for production ( no post weld cleaning operations needed etc. ). 4130 is what is called a low-alloy steel, and due to the levels of chromium and other elements, it is heat treatable and can attain very high hardness ( with low ductility ) even though it has a lower carbon content. This comes from the fact that the material uses a martensitic base structure vs a pearlite based structure. Ok enough of the technical parts, what does this mean to you? What it means is that that 4130 likes to be cooled down slowly from welding temperature, or what we call a "cooling rate". Cool it too quickly and the base material next to the weld with have a VERY low fatigue life. This is a common result of the Tig process due to the localized heat input and cool shielding gas. Choice of filler rod has no affect upon this. This "hardness" can be altered with what we call a PWHT or post weld heat treat, and can be as simple as a localized tempering/stress relief with a torch using a proper method. Also with this due to the materials somewhat sensitive nature, larger fillets that flow smoothly are much better for fatigue. Larger HAZ (heat affected zone) bears no impact upon joint strength or fatigue life....none. The same strength calculations are used for both a properly performed Tig weld, and a Gas weld since both have areas next to the weld that are annealed. So in the end, provided you use the right process (process meaning fitup to pwht), either process will give you the same(ish) mechanical properties. Gas welding tends to be much more forgiving of process variation, and naturally forms correct size and shape fillets, Tig tends to allow the user to make undersize and incorrectly size fillets, and can cause serious problems in the base metal that need to be dealt with after welding.

Subnoize,

We are here to learn from each other so don't be afraid to ask questions.

To comment on your most recent post, in gas welding the heat affected area will be greater than in TIG, and this is a good thing as there is a school of thought that says becaue the heat in TIG welding is so concentrated, that it results in stress in the welded joint that should be relieved with gas heat after every cluster on the aircraft has been finish welded. This is an un-going debate with some saying TIG is better, others saying Gas is better.

If you want to get a set-up for minimum dollars that will do the job, then I would get a gas set-up with a couple different size tips, and lease a pair of tanks. It will do anything you need to do aircraft-wise. If you go with TIG, you will pay more for a set-up, and still have to rent a tank for Argo.

If you plan non welding gas tanks, etc. Some guys can weld aluminum with gas but I don't have a clue how to do that. Aluminum takes more skill to weld with TIG also. Chrome-moly welds up really nice with either gas or TIG.

Thanks everyone for their responses. Firstly, I intend to weld more than 4130, the double eagle is to stop the bleeding ($140/hr to rent LSA) so I can spend my money on what I truly want, a vastly more complex aircraft. The usage of TIG isn't in question, the starter machine is. I was looking at the Lincoln Electric Invertec V155-S which Lincoln points very specifically to the small aircraft builder like myself. Now, am I getting myself a machine that is going to take the load I present to it when building aircraft or is it a cheap machine that will not provide me with good welds? Will it grow with me or become an expensive toy? I don't have the money to throw away. If I buy this its something I want to live with for 15 or 20 years and MANY airplanes, right?

Sub, perhaps you can try out oxy/acetylene welding as well as TIG welding before you invest any money and decide which one fits your needs the best.

I stand by my earlier selection if you decide to buy a TIG machine. You won't outgrow it.

If I were building a steel tube fuselage airplane, I'd gas weld it but that's just me.

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Originally Posted by subnoize

Thanks everyone for their responses. Firstly, I intend to weld more than 4130, the double eagle is to stop the bleeding ($140/hr to rent LSA) so I can spend my money on what I truly want, a vastly more complex aircraft. The usage of TIG isn't in question, the starter machine is. I was looking at the Lincoln Electric Invertec V155-S which Lincoln points very specifically to the small aircraft builder like myself. Now, am I getting myself a machine that is going to take the load I present to it when building aircraft or is it a cheap machine that will not provide me with good welds? Will it grow with me or become an expensive toy? I don't have the money to throw away. If I buy this its something I want to live with for 15 or 20 years and MANY airplanes, right?

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Sub,
The point some of us are trying to make to you is that if you are going to be looking at your budget so closely, be sure that you include some method of performing PWHT should you choose the Tig method. The machine itself really bares little on the finished weld, afterall its just a DC power supply and just as quality of a job can be had with either a $10K Tig machine, or a series of batteries. Although one comes in a shiny blue or red box box and tends to impress the uneducated. Since I prefer Miller over Lincoln (lincolns little tigs are italian) lets look at some realistic pricing. Keep in mind that you will probably want a fingertip control, so be sure to figure that in.

Miller Diversion 180 $1800
Mid Grade Auto Dark Helmet $150
Argon Cyl $125
Total $2075
*Note this does not include a way to perform PWHT

Now what does a Gas setup cost?
Handle $110
3 tips $65
Hose $15
Regs $87
Goggles $20
Tanks $250
Total about $550 (Add $80 for aluminum welding)

So in short, if you want to equip your shop for safe Tig welding, figure on about $2500. Also please bear in mind that this is coming from someone that Tig welds regularly in their field of work, owns two of the best inverter machines for their home shop. So I will be blunt, I think its foolish and naive to jump into Tig for homebuilding without first having mastered, and having a shop equipped with, a good O/A setup. As a side note I am curious why you are set on the Tig process?



P.S. As far as lifespan of the machine, 15-20 years is probably pushing it for inverters. Honestly they can and do fail, and when they do repairs are easily in the $700-1200 range or more if the boards are even in production anymore. People do have them last longer, and others die sooner. Lack of use will kill them faster than heavy use. On the flip side my oldest welding torch is from 1909 and still going strong.

Hmmm, ok this is what I was looking for when I first posed the question!

I'm not sold on a brand or even a process, I have goals and now I better understand how to achieve them. To be honest, welding is something I really don't want to learn but I'm hobbled by not knowing it. It severely limits my choice of aircraft designs and tasks I can accomplish myself in my own shop. I can rent a gas torch and bottles for about $60 a week on the high end and as you pointed out Aaron, to buy it isn't all that much money. In the end I may just do what the designer did and go gas, it sounds easier.

Here is the fun part, if I pick up that little Lincoln from Aircraft Spruce AND a gas set up I'm just about at $2,100.00. If I drive down to Peachtree City, GA I can knock it down to about $2,000.

I may buy both, and have the best of both worlds, right? Check it out for yourself;

http://www.aircraftspruce.com/catalo...clickkey=13604
http://www.aircraftspruce.com/catalo...clickkey=12326

(I am aware I'm missing the gas regulators and bottles for both but I'm looking to get the major equipment first)

Lastly, I'm sure when I enroll into an EAA welding class the specifics of what I'm doing with the equipment will be properly explained. Like building the actual aircraft, I wont be learning to weld in a vacuum!

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Originally Posted by subnoize

I can rent a gas torch and bottles for about $60 a week on the high end

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Yikes, that is high. My tank rental is $36 per year for each tank. I probably don't have more than $250 in my torch, tips, & regulators (but then I bought most of it back in the early 90s)

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Originally Posted by subnoize

To be honest, welding is something I really don't want to learn but I'm hobbled by not knowing it.
Lastly, I'm sure when I enroll into an EAA welding class the specifics of what I'm doing with the equipment will be properly explained. Like building the actual aircraft, I wont be learning to weld in a vacuum!

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This is an attitude that you would be wise to work on changing. Welding is a very practice and focus intensive skill to learn, much more so than painting, riveting, covering and the like. Having the mindset of "having" to learn something to get to a goal will just lead to frustration. The EAA classes give you the fundamentals, however when you leave them you wont be ready to start welding up a flight structure, it will take many hours of practice for this. The technical aspects of welding and fuselage construction are covered in EAA welding manual very well, and also covered in the new FAA A&P handbooks. Those would be my first two "go to" sources. I encourage you to go through with this though, it is a very rewarding skill to have learned and something you can be very proud of. On the equipment you have listed, both are probably your last choice. The 155 is a lift arc only, and you really (REALLY) should have hi-frequency start. The Henrob is more suited for sheet metal work, and is an awkward, clumsy torch for tubing clusters. I would go with the Smith Airline (Aw1A) handle, tips, and such from Aircraft Spruce for a gas setup. For the Tig, a DC only machine is pretty pointless as it have less capability than a simple torch ( cant weld aluminum with a DC tig, but you can with a torch ). So If you are going to spend the money, and AC/DC machine with high frequency start would be your best bet.

I just wanted to say "Thanks!" for this thread. I didn't start following it until just a few days ago because a) my plane is finished and b) I normally don't have anything to weld, but c) welding is a skill that I've always kinda wanted to learn back in the bucket list category of things.

The contributions to this thread from Aaron and others have been clear, concise, and loaded with excellent newbie guidance that doesn't have a single syllable of condescention. VERY good information. Thanks again;......

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Originally Posted by Mike Switzer

Yikes, that is high. My tank rental is $36 per year for each tank. I probably don't have more than $250 in my torch, tips, & regulators (but then I bought most of it back in the early 90s)

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Well, that was on the high end and I called the place and was like Mr. Noob himself so I was fully aware they were trying to take me for all they could. I think I will probably go with the little Lincoln TIG and a gas torch and start taking EAA classes. That way I can practice until I get good enough to complete the task (build the Double Eagle), which ever way is the best. Since I will have both I can then make a better choice about how to proceed based on my own skill level.

snz

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Originally Posted by Aaron Novak

Having the mindset of "having" to learn something to get to a goal will just lead to frustration

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With all due respect but if that was true I would not be where I am today, professionally that is. I sweat for 99% of what I do so I can get to the 1% I really enjoy. I believe they call that "Life" if I'm not mistaken.

Sub,
I would agree more with you on this if I didnt help teach more than a couple people these skills. I say this because what you will find is that the act of welding is more of an art than a science. I think you will see what I mean when you get to it. Good Luck!!

Before buying anything, I suggest you go to your local community college and take both the gas and TIG classes. Not only will it make you a better welder but will network you with folks that are in the know and use the equipment.
I did that before buying my Miller synchro wave TIG, took my aircraft cert exam as well as became a competent ox-acetylene welder. Also, like any other skill, practice and then practice some more before welding anything that your life depends on.

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Originally Posted by gisnar

Before buying anything, I suggest you go to your local community college and take both the gas and TIG classes. Not only will it make you a better welder but will network you with folks that are in the know and use the equipment.
I did that before buying my Miller synchro wave TIG, took my aircraft cert exam as well as became a competent ox-acetylene welder. Also, like any other skill, practice and then practice some more before welding anything that your life depends on.

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This is a great idea. BUT, the number of community colleges or technical schools teaching those classes is in a steep decline. The last time I checked here NW of Atlanta, there wasn't anything available within about 40 miles, which is sad given the fact that there are 2 technical schools and two engineering schools within about 15 miles.

Go to your local welding or fabrication shop, they are probably starving in this economy and ask if they will teach you to do TIG and GAS.

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Originally Posted by Tom Downey

Go to your local welding or fabrication shop, they are probably starving in this economy and ask if they will teach you to do TIG and GAS.

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Tough part of that is finding one who's people are proficient in welding fairly light gauge material, especially in Gas. Plus I see a lot of bad techniques used by most "welding shops" in respect to aviation welding. Maybe a call to the EAA will lead to a connection in your area ?? Afterall you do pay this organization for help in this manner.

Aaron,

What do you think about this kit from Aircraft Spruce?

http://www.aircraftspruce.com/catalo...gentecKA50.php

What would the pros and cons of such a setup?

Here are more pocket sized setups;

http://www.amazon.com/Victor-0384-09...pr_product_top
http://www.amazon.com/Hobart-770500-...lene+torch+kit


snz

PS. lots of good things said about the Henrob package so I'm weight that as well...

Sub,
None you have listed are what are considered "aircraft" type torches, meaning small handles, front valves, and "A" size fittings on the torch. Here is a link to a Uniweld setup that I use and have suggested to many students. Made right here in the USA and of good quality.
http://www.amazon.com/Uniweld-Centur...weld+torch+kit

This setup comes with small cylinders, however should you get into a big project, larger ones can be bought/leased and the torch set transfered to them. Setting up a high quality homebuilders shop does not have to be expensive, if you add a flare reduction lens to this price you can now weld aluminum with excellent results.

Oh and on the Henrob....save your money as you will find it awkward for tubing welding. I own one along with over 50 mainly aircraft size torches...so I do have something to compare it to :) Its a nice torch, but does nothing that a normal good quality design wont. The claims of fuel savings when welding are all BS.

Aaron, the setup doesn't include tanks as noted in the product features header below. That doesn't mater to me as most places switch out bottles on you from what I hear. What does bother me are the bottles suppose to come with this setup and the third party seller just trying to cheat me?

Uniweld's site has different products listed than the Amazon search. Is the Amazon affiliated seller just selling older stuff?

snz

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Originally Posted by subnoize

Aaron, the setup doesn't include tanks as noted in the product features header below. That doesn't mater to me as most places switch out bottles on you from what I hear. What does bother me are the bottles suppose to come with this setup and the third party seller just trying to cheat me?

Uniweld's site has different products listed than the Amazon search. Is the Amazon affiliated seller just selling older stuff?

snz

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Sub, the Uniweld page says the KLC100P comes without (w/o) tanks. It is the fourth one listed in the table under the specifications tab, but NOT the one shown or talked about on the other tabs.

http://www.uniweld.com/index.php/pro...g,-and-brazing

Jim
Also interested in learning gas welding.

I bought a set of Victor torches, gauges, and regulators from a pawn shop for 100 bucks.

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Originally Posted by Jim Hann

Sub, the Uniweld page says the KLC100P comes without (w/o) tanks. It is the fourth one listed in the table under the specifications tab, but NOT the one shown or talked about on the other tabs.

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I stand corrected!

Thanks everyone! I think I will buy gas if I do build this Double Eagle. Truthfully, when you do the costs and time it will take, the Double Eagle takes about the same amount of time as a Sonex, costs more in tools and doesn't give you 1/10th the airplane. I might as well just forget the welding thing and go the route I wanted to in the first place and except it will take me five years to finish.

I would much rather end up with a Waiex for the pain, right? :D


snz

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Originally Posted by Aaron Novak

Sub,
None you have listed are what are considered "aircraft" type torches, meaning small handles, front valves, and "A" size fittings on the torch. Here is a link to a Uniweld setup that I use and have suggested to many students. Made right here in the USA and of good quality.
http://www.amazon.com/Uniweld-Centur...weld+torch+kit

This setup comes with small cylinders, however should you get into a big project, larger ones can be bought/leased and the torch set transfered to them.

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I just ordered and am looking forward to receiving a KCL100 Centurian set - that P/N is less tanks and cart. I've been searching and researching welding sets for awhile now and your post - along with the fact that they are made in the USA - finally made my mind up. I also looked at the slightly more expensive Patriot set but could find no difference other than a shinier regulator - with the same flow rates and one extra welding tip. Uniweld's site is a little tedious to navigate and doesn't contain a whole lot of information to compare their products or explain why one is better than another for certain jobs.

I have a question about backflash arrestors. I grew up and still live in farming and ranching country and just about every other pickup has a set of tanks in the bed which are used by folks from 8 to 80 years old. I have never seen a backflash arrestor and never heard of an incident because of the lack of them. So, to the point.

• How important are they?
• I see that there are regulator end and torch end types. Is one better than the other, or do you need both?
• The price! I found it ranged from less than $20 to over $100! WTH - I wouldn't expect that much spread unless I compared SnapOn tools to Harbor Freight stuff. Uniweld's were among the most expensive. If one really should have them, what properties should one look for and expect to pay? I guess the first part of that question is not so important as no ad or even uniweld's site gives any performance data on them, some didn't even mention what size connection they had.

Thanks for any light you might be able to shed on this subject.

Steve

Don't know if I have any business thinking about building an airplane at my age but the small torch will sure knock out a lot of those artsy, craftsy things my spouse wants constructed.

My welding shop guy told me I didn't want backflash arrestors. I don't recall why but he explained it to me at the time, and he could have made more money if he had sold them to me.

My torch (Victor 100) does have built in check valves.

That would be interesting to know if it ever comes back to you. I might bring the subject up when I get my tanks. I didn't buy the torch locally because their gas welding stock leans heavily towards heavy cutting sets and is all made in China.

Thanks for the reply.

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Originally Posted by Mike Switzer

My welding shop guy told me I didn't want backflash arrestors. I don't recall why but he explained it to me at the time, and he could have made more money if he had sold them to me.

My torch (Victor 100) does have built in check valves.

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I will ask next time I am in there if I remember. Ernie passed away shortly after that but his son is running the shop.

Typically arrestors are not used on small torches due to the low pressures and small volume of gasses contained in the hoses. Check valves usually require some ammount of pressure to open, and that pressure is often times higher than what the torch is running at, so they either wont open, or "squeal" and pulsate like crazy. In all honesty a flashback on a small torch is a non-event. Ive had it happen 20 or 30 times. Just shut off the valves, wait for the handle to cool a bit and get then re-light. Use the tool smartly, respect it, and you will be fine.

Quick comment,When a young chap I worked on the mines here in Aussie and we used to repair the aluminium parts of the underground rock drills with the oxy.These were the actual piston body parts and you had to use a stainless wire brush only so as not impart any ferrous impurities in to aluminium.WE used a one eighth aluminium rod and learned the melting point and when to remove the flame.It's solid one moment and liquid the next.It can be done ,it just needs judicious use of the flame. Cheers ross