PDA

View Full Version : TIG Welding a Fuselage-Insight needed



Charlie Becker
08-09-2011, 08:45 AM
I've started the finish welding on my fuselage. Here is my setup:
Lincoln Precision TIG 185
Set at 48 amps
20 CFH on the flow meter
1/16 2% thoriated tungsten
1/16 welding rod (ER80
7 seconds postflow
I'm generally using a gas lens.

Any tips or tricks for TIG welding the clusters, especially the acute angles.

If you want to see my project, it is a super cub clone: www.facebook.com/piratecub (http://www.facebook.com/piratecub%20)

Aaron Novak
08-09-2011, 02:23 PM
For the tight corners you may need to break the 1D tungsten stickout rule of thumb and go more like 1.5D. Gas lens is a good idea, if you are going to push more stickout you may want to go to a 3/32 tunsten to help cooling and decrease the flowrate to prevent pulling it atmospheric air. Shut all the doors, dont breathe too hard and remember to always weld with the grain ( i.e. if it was a 90 deg tee you weld from the tee section to the lap section in 4 segments). Dont shortchange the size of the reinforcement and avoid convex welds and dont start and stop 15 times per weld, stray arc scars are great places for crack initiation. I (and every welding engineer and metalurgist I work with ) would temper the critical weldments as well ( engine mount, landing gear, wing and strut attach ). Oh and a blunter ( I know its not a real word) grind angle on the tungsten can help prevent arc wander. Have Fun!!
-Aaron

-P.S. if you get into some heavier areas and need a REAL tig welder you can use my Dynasty300 :).......(Sorry.....I had to...)

Chad Jensen
08-09-2011, 02:57 PM
Excellent info for those of us that are new to (TIG) welding...thanks!

jacktextor
08-12-2011, 05:35 AM
Charlie, this is the best site for welding tips Iv'e seen...
http://www.weldingtipsandtricks.com/index.html

Chad Jensen
08-12-2011, 07:38 AM
Cool website Jack!:cool:

Aaron Novak
08-12-2011, 11:50 AM
Word of caution, many of those online welding sites are copy and pasted bits and pieces from some highly questionable sources. There are sources of data that are many times biased, uneducated or unexperienced. From my experiences working in engineering, typically they are as follows.

1-Welding Equipment Suppliers. Remember they survive by selling equipment, many times the testing is biased or non-existent.
2-Authors. Especially those that never worked in engineering, but like to give hard and fast advise on every aspect of welding ( many times highly opinionated ) or very wild and broad claims.
3-Welding consultants. Remember , they dont have to deal with the aftermath of their suggestions.

So who can you trust?? Usually the best source of information is an independent person, not connected with any company that makes a profit by welding equipment sales, that has or is working in a current engineering field. It helps if this person or source is also a hobbyist in the same areas you need advise in. Why? Because they tend to highly educate themselves on the particular subject and have access to information you will NEVER find on google. Engineering texts are a great source of information, however pay attenting to many of the AWS texts as they are not as unbiased as you may think, check the authors. The ASM handbooks are a great start, as are the plethora of doccuments available in the nasa archives.

AllenR
08-13-2011, 09:30 PM
20 CFH on the argon seems kind of high. You'll waste a lot of gas. I used 12-15 CFH for my whole Skybolt fuselage and aluminum fuel and smoke tanks. Don't be afraid to pull out that tungsten as far as you need to reach into the acute corners. If you're not getting enough argon around the weld, it won't even weld- just a bunch of sparks. Use a gas lens ALWAYS. Turn off the fans. Be sure you see the filler melt into the surrounding material as you run your bead. Everything else sounds perfect. I have the same setup, I love it.

Charlie Becker
08-24-2011, 09:27 PM
Ok, here are a few photos of what I've welded so far.
355356357358

Aaron Novak
08-25-2011, 07:10 AM
Hey Charlie,
What I am seeing is fairly inconsistent penetration, inconsistent fillet size, marginal shielding and some lack of heat control. The weld fillet is generally the size you should be aiming for. I also see some undercutting in areas, some spots where you touched the tungsten to the weld pool. ( remember if you "snag" a tungsten you need to grind out the area where it touched, imbedded tips of tungsten can be crack initiation points ). I know you really dont want to hear this, but I think seriously doing some helmet time with flat stock will help you. Butt, Tee and lap welds perfected in flat stock will make an easier transition to clusters. Is what you did unsafe? I dont know, If I was the instructor looking over your shoulder I would have had you do a lot more practice parts and sectioned them so you can see how your terchnique influences the weld quality beyond external "looks". If you would like someone to look over your shoulder I can run up the hangar sometime, let me know.
-Aaron

AllenR
08-26-2011, 09:41 AM
Whoa, way too harsh. Charlie is too nice a guy so he probably won't reply but I will. First of all, are the welds perfect? No. Do they need to be as perfect as the TIG welds on P&W turbine blades. No. Are they more than serviceable for an experimental. Yes. My only issue with the welds is that you're using a little too much heat (move along faster) and the bead needs a little more filler rod. Otherwise they are OK. If a builder insists on perfection on his airplane, he will never finish.

Practice never hurts, but it will take 500 hrs. practice before you approach a stage of perfection that's just not needed. So finish weld small parts like rudder pedals, etc, so that if you're not happy with the weld, you can easily and cheaply build another. On the fuselage, you will start finish welding at the tail and move your way forward so by the time you get to the high stress areas north of the pilot station you will be pretty damn good.

Forum members should refrain from super critical posts since they do nothing more than shut people down from sharing. If you have a real concern, private message the person. Certainly, if you live in the same town just call them up. Just my $.02.

Jeff Point
08-26-2011, 10:42 AM
Allen, I gotta respectfully disagree with you. I thought Aaron's comments were spot on. Based on the tone I suspect that they know each other. I respect Charlie for putting his rookie efforts up here for all to see and he did invite the criticism. His welds aren't terrible but they could use some improvement, he was looking for insight and Aaron offered it, along with an offer to help him get better.

As a tech counselor I've had to tell people (rarely) that their workmanship is not good and the parts they made are not airworthy. It ain't easy telling someone that their baby is ugly but sometimes it needs to be done. Building an airplane requires, among other things, thick skin sometimes.

Aaron Novak
08-26-2011, 11:05 AM
Allen,
No harshness meant at all. Purely technical. When you are dealing with something of an engineering nature, sometimes you need to leave emotion out of it. Think of it as a student/teacher relationship. Notice I never said the welds were unsafe, thats for Charlie to judge, I just pointed out areas of improvement. It takes a lot of guts to post images of your own workmanship in a public forum, and it also takes guts to post honest thoughts on it. Unfortunately what gets difficult is that there are more people watching this than just Charlie, and many people will look to this to judge their own workmanship and so keeping responses private is not really fair to them. I see this as excellent potential for a learning experience not only for Charlie, but for others as well. Nothing I mentioned was for asthetics, and in all they will probably be just fine. Another thing to realize, and this is something that I tell students of mine, is that the only reason I will be a little "hard" on you, is that I want you to be safe, nothing more, nothing less. This is supossed to be fun afterall! :)

steveinindy
08-26-2011, 12:40 PM
Aaron, once I start getting my aircraft built, you're invited to come down and critique the heck out of it at each of my "So what did I muck up this time around?" parties that I plan to host in the hangar. Beer, food and magnifying glasses will be provided. That is exactly what I want to hear from folks. 'Good enough' is not good enough in my book. That goes for the rest of you as well. Come out when I post the notices and let me hear it.


Do they need to be as perfect as the TIG welds on P&W turbine blades

Hmmm...I wish I could get that level of accuracy. Then again, I just flat out need to learn to weld at all first!

uavmx
08-26-2011, 03:18 PM
I think Aaron's comments were appropriate constructive criticism...as the OP wanted! Airplanes are made to try and kill you....having advice like that on your workmanship may just save your life. Myself and ANYONE should welcome that criticism when building an aircraft, it might just save your LIFE.

As an A&P and IA, I see plenty of airplanes that I would not get into, people tend to push their luck a little more then I would personally. Keeping people safe, learning methods, PERFECTING methods are what this forum is for. Otherwise just don't post images of your work and you will never have to worry about having your feelings hurt :-)

Eric Page
08-26-2011, 05:48 PM
Do they need to be as perfect as the TIG welds on P&W turbine blades?

Hmmm...I wish I could get that level of accuracy.

Steve, ain't happenin' till you get a CNC robotic TIG welder at the end of your arm...

Great thread guys; just what EAA is all about!

Neil
08-26-2011, 08:58 PM
I try not to get into welding threads too much simply because a lot of what is out there is opinion and not all opinions are correct. You can find someone willing to argue with anyone.

I suspect Charlie has no intent of becoming a commercial welder of aircraft and he really has a lot of guts to put pictures of his work up for others to judge. I do a good bit of aircraft welding and none of what I have done has ever failed but there are people better at it than me. I do find Aarons comments accurate though.

Among the recommendations I would make would be to get with a good welder, ask for guidance and practice some more. You are getting there but you have not yet mastered the clean, even weld. If you aren't using RG 70 wire you might give some a try. The other thing that I do is to reserve the TIG welding for parts that I can jig up and weld on the table. This way you can brace up and control the Tig torch well enough to prevent making a career out of re grinding the tungsten and the weld that the tungsten stuck to. I prefer to use a Gas (O/A) torch (RG 45 wire) to weld the fuselage as it is too dificult for me to work around the tubing, inside and out, with a big clunky helmet and trying to control the heat with a foot control. For me the gas torch is more forgiving of my unsteady hands when there is no place to brace up on for control. Proper Gas welding technique will leave a weld that looks as good as an average Tig weld. When I built me Sonerai back in 83 every one thought it was Tig welded but it was all O/A with a Harris torch I bought at a pawn shop.

Just my thoughts.

AllenR
08-26-2011, 11:27 PM
I don't want to make a big deal about this and I'm sure that Charlie can handle the criticism. My point is that other builders on the forum may see that and say "boy, I'm never going to put myself out there like Charlie did". In all my builds, I've welcomed the tech counselors into my shop and told them to be brutally honest as I'm sure you have as well. But on a public forum, I think we need to exhibit a critical tone that is more like coaching than cold criticism. My background is education and we always practiced the rule: "tell the kid 2 things he's doing right before you hit him with what he's doing wrong, and always give a solution to help improve his skill". That keeps them learning and motivated. I've been on other builder forums and if the criticism of a picture was harsh, you wouldn't see another picture posted by anyone for 6 months.

Maybe I'm getting too sensitive in my old age.

uavmx
08-27-2011, 04:27 AM
Maybe I'm getting too sensitive in my old age.

Yeah, I think you're just reading into it too much. Again, if you don't want honest, true opinions, don't put up a thread, don't put up pictures. Go ahead and risk your safety. I commend Charlie on posting his welds, and he should adhere to the advice given....its for his own interest and safety, not for anyone else's.

Neil
08-27-2011, 07:26 AM
Couple of things I didn't mention, I like the 3/32 tungsten and I find the 3/32 wire easier to use than 1/16 in some areas so I keep both on hand. Also the cleaner the tubing and wire, the cleaner the weld will be. Having dirty wire and parts will shorten the life of the gas lens quite a bit. Wiping the wire and the parts with acetone or lacquer thinner helps a lot. The smaller the nozzle the better because the tungsten doesn't need to stick out so far and when the tungsten is short you don't stick it so often. Generally you look a little too hot so you might want to bring the amps down a little. That will let you slow down and have more control. Grinding the tungsten parallel with its length instead of with the circumference helps keep ark wander to a minimum. Don't grind the tungsten with a dirty wheel or belt or it will drive you nuts trying to figure out what is going on.

If you are into bifocals like me you may need to buy some readers at the drug store that give the correct focus for your arm length to the weld. These days I don't see as well and shake a bit more and it shows in my welds.

Hey Al, hows the Skybolt coming? Haven't seen you on the BIPLANEFORUM in a while.

steveinindy
08-27-2011, 08:55 AM
LOL Man to have the budget for one of those. Still, I'm going to be anal retentive about the quality of welding on my aircraft.

AllenR
08-27-2011, 04:19 PM
Hey Neil:
The Skybolt is on its gear but in my hangar in N. Fla while I live in S. Fla. Still trying to sell my house in S. Fla so I only get to the hangar once a month for a couple of days. This has been going on for the past 5 years. When I'm up there I work on it, when I'm down south I work on my RV9A which is closer to completion. I don't recommend working on 2 planes at the same time to anyone.:rollseyes: On top of that, from 2006-2008, I worked at a shop and restored 2 Stearmans and a Great Lakes. My RV is almost ready for paint.

chintonmd
08-27-2011, 09:47 PM
It would be nice if Aaron or someone else would take Charlie's pictures and mark them up to show where the problems are. I can see that they are a little bit rough but they look about like mine. I know what really good pro welds look like, especially when done on stainless tubing and pipe. They're really pretty, almost like someone put them on with caulking gun. But what I'd like to see is what an acceptable aircraft weld looks like even if it is not a near-perfect professional weld.It would also be nice to review the sequence for the welds in a cluster so that distortion in minimized.

Aaron Novak
08-27-2011, 10:51 PM
It would be nice if Aaron or someone else would take Charlie's pictures and mark them up to show where the problems are. I can see that they are a little bit rough but they look about like mine. I know what really good pro welds look like, especially when done on stainless tubing and pipe. They're really pretty, almost like someone put them on with caulking gun. But what I'd like to see is what an acceptable aircraft weld looks like even if it is not a near-perfect professional weld.It would also be nice to review the sequence for the welds in a cluster so that distortion in minimized.

Actually I had hoped to do exactly that and mark up the pictures, unfortunately photoshop was not working for me and I was running out of time ( as usual ). However this might be a good lead in to homebuilt aircraft welding 201 webinar type deal.......who would be interested?

AllenR
08-27-2011, 11:26 PM
Webinar sounds good to me.

Jeff Point
08-28-2011, 12:35 AM
+1 on the webinar.

Frank Giger
08-28-2011, 04:08 AM
...including how to grind stuff down for a "do over."

Not that I could do one jot better, mind you - I think the statute of limitations on welding skills has long passed for me! Happily, my plane is all tube and gusset for that very reason.

I don't know about tons and tons of practice being needed. When I was learning to weld a looonnnnggg time ago the Ag teacher had me run beads down some flat stock in straight lines about four inches apart. When I could make a decent bead that way it got a lot easier for angles as curves, since I knew not only what right looked like, but what it felt like to make it.

Neil
08-28-2011, 08:49 AM
I think you should do it Aaron. I can always learn more, and welcome the opportunity to do so.

Sirota
08-29-2011, 09:17 PM
I'd LOVE a webinar on welding

Aircamperace
09-05-2011, 07:15 PM
I would definitively like to see more articles about Tig welding in Sport Aviation magazine. I've found some good info on the Miller site; http://www.millerwelds.com/resources/articles/Best-Practices-for-GTA-Welding-of-4130-Chrome-Moly-Tubing.
(http://www.millerwelds.com/resources/articles/Best-Practices-for-GTA-Welding-of-4130-Chrome-Moly-Tubing)I would also enjoy reading the TIG welding procedures and inspection criteria used by a tube and fabric aircraft manufacturer such as American Champion. Everything that I've read seems to be in agreement concerning joint preparation but there's very little about what is good enough, what is acceptable and factors such as penetration. Thanks for sharing Charlie and getting the conversation started.

steveinindy
09-05-2011, 07:17 PM
Likewise, as a very novice welder, I would love to have that information as well. :)

Aaron Novak
09-06-2011, 08:38 AM
Hey Guys,
Havent forgotten about you, I have just been out of town. I am currently putting together an article on this subject, from both engineering and practical perspectives. One thing I would like to point out, is that a vast majority of the articles on the internet about weldiung 4130 with tig are written with the intention of selling a welding process, and typically by automovie motorsports persons ( this is important ). They also tend to have little or no engineering test data behind them. Tensile testing is whats mostly talked about since its cheap and easy to perform, however in most cases pointless. A correctly designed weldment in our tubing sizes will never fail in the weld, even with the weakest welding filler ( RG-45 ), it will always fail in the HAZ reguardless of welding process and with similiar strengths. Whats this mean, the correctly designed joint in 3/4" .035 welded with RG-45 and a torch will have the same strength as if it were welded with ER120S series and a the gtaw process. Go up to 3/8 plate and things change a bit, and high strength fillers and electric welding have an advantage. So since strangth is not the issue....what is? Fatigue. Look back at incident reports and some 98% appear to be all fatigue failures. So the auto racing industrys products (cars) tend to use heavier material, typically have a very low useful life, and so they tend to use Gtaw, high strength fillers with little or no reguard for fatigue as they typically destroy a vehicle before the fatigue life of a weldment is surpassed. This is why one should be very careful is chising where to get information from. The auto racing world, while using the same alloys, has a completely different set of operating and lifecycle conditions than aviation. So what about fatigue, well thats the article I am writing.......

Jon Johnson
11-14-2011, 08:40 PM
First off, you are much braver than I posting pictures! I am not a professional welder, but I weld all my own boat, house, car and plane projects.
The first photo shows pits on the left side. Might have touched the tungsten. These may cause stress cracks. I have had weld results like yours and have had them crack as soon as they cool!
The second photo shows a pit where you might have shut off while the pool was molten. Can you taper off on the peddle until the pool hardens? It also shows some discoloration. Do you have your machine set up for post gas flow? Keep the torch on the weld after you stop. Gotta protect the weld until it has cooled enough.
The third photo looks a little ugly. Where you covering up a gap or hole? I like to fit things up with no gaps. Much easier to weld that way.
The fourth photo looks pretty good. Make sure you carry the weld on the quadrant past the end of the weld on the next finished quadrant. Just don't need to add filler on the overlap.
Great suggestions in the other replies, so I won't repeat them.
Here are a couple of more. I like to rest the cup on one or both tubes to keep it steady otherwise my poor hand to eye would make a real mess.
Polish the weld sites and clean all oil and fingerprints. Us a new wire brush or wheel and don't use it for anything else (contamination).
Can you set your machine for pulse? I find it does better for thin materials. I like a faster pulse, around 200 per second.
Do you have a really good helmet? I started with a cheap auto-dark and it kept flashing me when I was welding hard to reach places. Not enough sensors. I bought a nice Miller helmet and love it. Make sure to set the dark so you can see well.
I don't know if your welds are safe or not. But you are pretty close to doing a very nice job. It should not take you long to get results you are proud of. If it was my plane, I would weld all the cut-offs together for practice. Maybe build some deck furniture or something out of it. TIG welding really is a lot of fun, so the practice should be enjoyable.

highflyer
11-16-2011, 01:28 AM
I am just a bit curious. Why do we want to do all this TIG welding on 4130 anyway? It welds very nicely with gas which is easier to use than TIG. You need the gas anyway to normalize the area after you are done so you don't crack next to the weld next week. :-) A couple of gas bottles on a "lifetime" lease and a good Smith torch with a fair selection of tips is relatively inexpensive and does a beautiful job on clusters, etc. Gas also works well for aluminum welding for fairings and stuff after we bump them out on a sack and stake with a hammer.

Eric Marsh
11-16-2011, 07:47 AM
That fourth picture looks pretty good. I do notice a bit of a gap where the piece in the upper right hand corner of the photo is fit. How are you doing your pipe fitting? The reason I ask is that it's a skill I would like to develop and so far my results have been poor.

Chad Jensen
11-16-2011, 08:29 AM
I am just a bit curious. Why do we want to do all this TIG welding on 4130 anyway? It welds very nicely with gas which is easier to use than TIG. You need the gas anyway to normalize the area after you are done so you don't crack next to the weld next week. :-) A couple of gas bottles on a "lifetime" lease and a good Smith torch with a fair selection of tips is relatively inexpensive and does a beautiful job on clusters, etc. Gas also works well for aluminum welding for fairings and stuff after we bump them out on a sack and stake with a hammer.
This is a matter of personal preference here, and I would argue (well, not argue but mention) that TIG is easier. I've done both, and much prefer TIG over gas. Most people do not normalize after TIG welding unless they are in a cold shop where it will cool rapidly.

Gas is cheaper by a huge margin, and it does a fine job. It just comes down to preference I suppose. :)

Mike Switzer
11-16-2011, 09:38 AM
Besides the equipment being expensive, you will need a fairly good sized dedicated 220v circuit, so make sure the electric service to your shop can handle it before buying the equipment.

Chad Jensen
11-16-2011, 09:42 AM
Besides the equipment being expensive, you will need a fairly good sized dedicated 220v circuit, so make sure the electric service to your shop can handle it before buying the equipment.
Excellent point Mike...

Jim Hann
11-16-2011, 09:47 AM
Besides the equipment being expensive, you will need a fairly good sized dedicated 220v circuit, so make sure the electric service to your shop can handle it before buying the equipment.


Excellent point Mike...

Okay, that answers it for me for now. Not economically feasible to upgrade my house wiring/service for 220V to the garage. If/when we move I know what will be on my list!!!

Mike Switzer
11-16-2011, 10:12 AM
My buddies tig requires a 40 amp 220v circuit - some of them need 60 amps. There are still a lot of older houses around that only have 60 amp service to the house. I've got 400 amp service, one 200 amp box for the office/apartment, another 200 amp box in the shop, but if I need something tig welded it is still easier to just haul it to my buddies shop & have him do it.

Tom Downey
11-16-2011, 10:38 AM
I have a ATA in welding tech. with certification for nukie boiler plate and pipe in all positions, and own a Miller Econo TIG setup in my garage running off the dryer style plug on a home 50 amp service. I see nothing wrong with the welds pictured here that practice in how far to move the puddle, and how much rod to add to each dip. wouldn't cure. practice, practice.practice makes perfect.

As far as gas over TIG, makes no matter, use what you are good at.

this is the unit I have they can be bought for way less than a grand used
http://www.gts-welco.com/gts-welco.aspx?pcid=340&ptid=1

Aaron Novak
11-17-2011, 08:41 AM
Most people do not normalize after TIG welding unless they are in a cold shop where it will cool rapidly.

:)

Chad,
I wouldnt say that. Looks like this might be a good topic to bring to the chapter meeting....if you guys are interested in Metalurgy and Phase Transformation 101 :)

Chad Jensen
11-17-2011, 08:53 AM
Chad,
I wouldnt say that. Looks like this might be a good topic to bring to the chapter meeting....if you guys are interested in Metalurgy and Phase Transformation 101 :)
We talked about it at the last meeting...your dad was involved, and there seemed to be two schools of thought...;):)

Jeff Point
11-17-2011, 08:59 AM
We talked about it at the last meeting...your dad was involved, and there seemed to be two schools of thought...;):)

I smell a webinar coming on!

Chad Jensen
11-17-2011, 08:59 AM
You smell right! That doesn't sound good...how 'bout, You have a nose for these things! ;)

Mike Switzer
11-17-2011, 09:30 AM
there seemed to be two schools of thought...;):)

When I read the book I got at the Sportair gas welding workshop, I noticed there were at least 2 schools of thought on most everything :)

Jeff Point
11-17-2011, 11:55 AM
Reminds me about the old joke- there are two schools of thought on how to make consistently good landings. Unfortunately, neither of them work.

Hangar10
11-17-2011, 01:14 PM
When I read the book I got at the Sportair gas welding workshop, I noticed there were at least 2 schools of thought on most everything :)

I am finding that to be true as well. I read through Richard Finch's "Welder's Handbook" as well as EAA's "Aircraft Welding Techniques" and watched the DVD prior to getting into much welding. This summer when I went to Gas Welding 101 at Oshkosh, I remember saying to myself, "that is exactly opposite of what the book says." Not that either is wrong, but it sure doesn't help the new guy figure out what is the best way. :)

I'll just keep on trying... eventually I'll figure out which technique I like best by which one produces the best results.

Jon Johnson
11-17-2011, 04:31 PM
Chad, I agree with you. I find TIG much easier than burning gas (I used gas on my champ rebuild). And if you get a nice tight weld, you don't heat it up too much. No normalizing. My welder is a Miller 200DL. It runs on any voltage, 110V, 220 single phase, 220 three phase, 440, etc. It is the size of a medium suitcase and has a suitcase handle. The argon bottle is much heavier, but I have lugged it around and used it with sticks. You only get around 100 amps with 110V, but that is more than enough for cars and planes. You would need a dryer hookup to do aluminum. I have 220 three phase at my shop. I find that I can get may face much closer to the work with a TIG. That allows me to see what I am doing better. I cost me around $2000 (plus bottle and accessories) and payed for itself building stuff for my boat.

SoCal Ken
11-17-2011, 05:27 PM
Allen gives some good advice on several fronts & in many respects. I'm a bit OCD, so I have been "wasting" some good 4130 plate & tubing doing practice with my new TIG unit & checking my weld quality, but fully understand that not everyone is as OCD as I am. I've decided to follow his advice about starting with smaller, less critical areas as I get ready to start my WagAero Super Sport Trainer (Cub clone). Thanks for the sound & very thoughtful suggestion re: starting at the tail & moving forward on the fuselage! It was a good $.02 worth you gave.

Aaron Novak
11-18-2011, 11:09 AM
We talked about it at the last meeting...your dad was involved, and there seemed to be two schools of thought...;):)

Always at least 2. Thats why I think bringing some test data is in order. Nothing like SEM (scanning electron microscope) images of test welds to dispel the old (young) wives tales. No opinions, no sales pitches, no guessing. Just science and data.....should be fun. One of the things I have learned in life is the thing that usually seperates schools of thought, is knowledge of the subject.

Chad Jensen
11-18-2011, 11:12 AM
That would be very cool Aaron! I'd love to see that!

Aaron Novak
11-18-2011, 11:24 AM
Alright then we can plan on it. I think you guys will find it interesting.

Tom Downey
11-19-2011, 12:26 AM
Nothing like SEM (scanning electron microscope) images of test welds to dispel the old (young) wives tales. No opinions, no sales pitches, no guessing. Just science and data.....should be fun.

I wonder how many home builders have that stuff. :)

jimtho
11-29-2011, 04:15 PM
I agree with Allen. Whe
n I built my Flut-R-Bug, I was advised by other experienced builders to start with the tail section. By the time I reached the fire wall, my welds were really good. Everyone knows the tail section air loads are lighter.