wood skills vs aluminum skills

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lurker

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i'm fairly handy with wood, have built some plain and simple furniture and a kayak or two of wood and have a couple of nice tools, nothing really fancy, table saw, router, drills, sanders, that sort of thing. but after starting a couple of fuselages, i see that wood is very sensitive to the quality of the glued joints, which i don't really know about until i put them under load, at which point they fail somewhere, usually catastrophically. this is why i don't talk much about building airplanes lately.
i wonder if aluminum tube and gusset would be more appropriate for an ultralight? i've never done much with aluminum tube, but am competent with a hacksaw (or a powered equivalent), drill press and pop rivet gun. would it be difficult to pick up the necessary skills to consistently bend and join tube? what about special tools?
 

pwood66889

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see that wood is very sensitive to the quality of the glued joints, which i don't really know about until i put them under load, at which point they fail somewhere, usually catastrophically.

One thing my A&P training channeled my mind towards was inspect ability. Glued things do not lend them selves to such; the event that lead to our "Friends" (isn't that what the "F" stands for in FAA?) powers was the death of Knute Rockne. This was caused by (story I was told) not inspecting where the covered, wooden empanage had "dry" rot, which as you know is not due to being kept dry!
Thus, riveted metal construction, as you are considering, allows easy and fast look at each rivet as set. Pulled blind ones take less skill, which is quicker found, over "bucked" ones - quieter also!
Since you mention pop rivet gun, I'm taking you to mean not hand squeezing each and every one! You may wish to acquire (or at least the use of) a tube bender. Oh, yeah - drill bits; lots of drill bits... :)
 

TFF

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To me it's all about the same skill wise. It's boredom you have to fight. Wood and 4130 are entertaining to me and rivets put me to sleep. My point is pick one you enjoy. It's the only way to finish. Casein glue is what got Rockne. His plane was held together with Elmers that got wet. We have come a little farther now. A lot of the wood planes at the Smithsonian are original unrestored.
 

wiloows5050

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I had a machinist friend over to work with me. He got 6 aluminum parts made in 3 hrs (on a Bridgeport) which I though was amazing. I only got 22 wood parts completed in the same time frame, all depends on you skill set. The aluminum parts would have taken me all day and maybe the next.
 

BBerson

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A truss tends to collapse in compression at once no matter the material when beyond design load.
Not so much total collapse with steel tube, from looking at wrecks.
 

wsimpso1

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i'm fairly handy with wood, have built some plain and simple furniture and a kayak or two of wood and have a couple of nice tools, nothing really fancy, table saw, router, drills, sanders, that sort of thing. but after starting a couple of fuselages, i see that wood is very sensitive to the quality of the glued joints, which i don't really know about until i put them under load, at which point they fail somewhere, usually catastrophically. this is why i don't talk much about building airplanes lately.
First off, there is nothing inherently wrong with wood. Many many successful airplanes out there in wood.

Second, you should select a build medium that you can communicate in. If you do not love working in it, it is folly to embark upon an airplane build in it. It sounds like you like working wood. Going to metal might be a mistake for you...

If you are finding catastrophic failures in wood joints you have built, I gotta ask: What kind of failures? What were the materials? Good epoxy and sanded wood should fail in the wood. If it failed in the glue line, something seriously wrong there. Use a proven design, stick to the plans, sanded wood, and good epoxy will make a fine airplane. Lots of threads on the topic. Run down to the bottom of this thread for a few starters. I like and recommend West System. There are other excellent epoxies. There are some systems I would not repair the trim on a bird house with.

Billski
 

pilot103

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Sometimes you don't know until you play with a material. I love wood working, love sawdust and the smell. So a wood airplane sounded like a natural for me. I ordered the vertical starter kit for a mini max. And while I love wood I found I hated epoxy, I never finished that simple piece. Next I considered steel tube, I am a certified aerospace welder after all. So I ordered a sample 4130 kit from A.S. after making a few joints it was too much like going to work. So while I had zero aluminum experience I ordered the tail kit for an RV6. I loved working with it I had a couple A&P friends look over my shoulder as I got started, I took to it pretty quick. So fool around with what ever you chose and make sure you like it and are comfortable with it.
 

Armilite

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The Plane you pick and its Plans will dictate the Material you use! Cutting Aluminium or Steel Tubing isn't really much different from cutting & drilling Wood. It's using the right Power Tool and Blade/Drill for the Job at hand. Most Part 103 Tube & Fabaric Ultralights use 6061 Aluminium Tubing with Bolts and Connectors. Probably the simplest to use No Welding is needed on most. You can use a Table Saw with the right Blade and Cut most metals. Metal Chop Saws are cheap also. So if you don't know how to Weld Steel Tubing which is usually Tig Welded, that rules out metal Tube Airframes. There aren't many Welded Aluminium Tube Airframes which are also usually Tig Welded. So once again if you can't Tig Weld Aluminium, that rules out them Airframes. You can take about an 8 week welding course at most trade Schools, usually 2-3 days a week and learn how to weld, and today there is some cheap Combo Mig/Tig/Stick Welders out there starting around $850. Harbor Freight has a nice one called a Vulcan 210.

It's usually easier and cheaper to buy a used airplane and make any repairs, and just upgrade it! Saves you a lot of Time and Money also.
 

Little Scrapper

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Do the thing you're not skilled at. Do the things that scare you.

That's where growth comes from.

Everyone here knows my experiences with welding and metal fabrication. That's my comfort zone, that's where all my skill set is, decades worth.

So here I am working on a wood MiniMax. Totally out of depth. Sawdust in my hair, no real complete tools, fumbling around clueless, pieces laying around the garage, total chaos.

I love it. Why? Well, growth. Growth feels good. Asking others for help feels good. Learning to appreciate others working in wood feels good. Expanding your depth feels good. It's like being a kid again and learning for the first time. Seriously, how often does that happen in life? Not often.

Learning something new gives new meaning to your life, it adds a whole new dimension. It's exciting.

Thousands and thousands in metal working tools and I don't miss it one single bit. Working with a new material has been a game changer for reducing stress and giving me something to look forward to.

So, in my opinion, do the thing you hate because odds are you hate it because of fear. Imagine the man you'll be after your done. Solve the wood issue, don't run from it because mentally that's a paved road to hell.

Mike
 

pwood66889

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Use a proven design, stick to the plans, sanded wood, and good epoxy will make a fine airplane. Lots of threads on the topic.
Billski
Didn't comment on this when I first saw it, Billski, but had read somewhere (Roger Mann? Banty plans??) that sanded wood was to be avoided because the saw dust got into the pores and caught the glue leaving a weak joint.
 

TFF

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Sanded wood. Zen and the Art of Airplane Building would have no sanded wood. Scraping joints with glass, hand coped splices, razor plane shaped bevels. Power tools? We dont need no stinking power tools. I think modern glues, availability of just about any power tool much less really nice power tools, and the absence of little wood monks makes sanding wood joints a forgotten problem. I doubt there is many people who know how to do it the old fashioned way. Wood surfaces to be glued should be cleaned. Spruce is so benign, but some woods can be sappy and should to be cleaned with acetone and let evaporate before glueing. Epoxy can practically glue just about anything, it makes average builders build better.
 

Tiger Tim

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When I work with wood it’s a warm and lovely experience as I carefully hand fettle each stick and block to the perfect shape for fitting. It’s a very visceral and relaxing experience. When I work with aluminum I get blood on everything.

I know that means I need to do more metal work but it’s hard to want to, you know?
 

pwood66889

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Sanded wood. Zen and the Art of Airplane Building would have no sanded wood. Scraping joints with glass, hand coped splices, razor plane shaped bevels. Power tools? We don't need no stinking power tools.
Just moving stuff, and found out where I got that non-Zen information. Per Mike Mike Kimbrel's Banty plans: Wood glue joint surfaces (faces) must be clean and dry, free from oil, and preferrably freshly machined, for sound gluing. Page 8 also notes: Never glue broken wood together. Glue faces must be machined. Also, do not sand glue faces. Broken wood, or sanded soft wood will not hold together reliably with glue. See dat? `Taint always the voices in my head, TFF...

So speaking of ... does HBA have a plans library? I might make some donations...
 

TFF

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I'm saying what you read is the zen way. I'm just saying Kung Fu is a tv show not Marshall Arts. What you have read is the right way, just the impossible way at the same time. I probably could make one out of a hundred joints that would be good enough to that standard. If you are a true wood artist and have apprenticed under Sam Maloof, have at it. The rest are going to cheat.
 

mcrae0104

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Ten points for TFF, for knowing the Stelio Frati of furniture makers.
 
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