Need an Aluminum Expert

[TJay 1041]

Looking for spar Material for our birds and looking at Online metals they have a

2.5" OD X 0.065" 6061-T6 Bare Seamless Aluminum Tube And they also have a

Drawn Aluminum Bare Tube 6061 T6

What is the difference. By the price they must be really different.

[Avid Bart 39]

I am also looking for tubing to extend my spars. From what I have found, the tubing is available as extruded or drawn. Both types are extruded, but the drawn is pulled through a die which increases the strength and makes the tubing more uniform and straight. I will be going with the drawn tubing for my extensions.

[nlappos 413]

Yes, drawn is stronger and has tighter tolerances. Drawn tubing can be 20% stronger.

 Here is a good discussion:  http://www.kamkiu.com/down/seamless_and_drawn_tube_information.pdf

[TJay 1041]

Thanks for the help.  I always see Seamless stamped on spars but nothing else. The other thing I don't understand is through aircraft spruce the tubing is 10 bucks a foot and online metals its 4 bucks a foot quite a difference there.  I better keep researching on this.

Edited 24 Feb 2019 by TJay

[1avidflyer 1983]

I got a quote from Just aircraft for 13' 6" spars a couple of years ago at $130 each. Probably the same material as the ACS stuff at $10 per ft.  If I was just looking to extend the wings, I doubt it would matter which type tube was used, but would for sure want the better material for a full length spar.  Maybe some  one has a set of uncovered wings and can look at their spars.  There probably are factory numbers on the spars saying what they are.  JImChuk

[sioux201 84]

 I have two  Lengths of  heavy hauler wing spars,70.5" & 40" 

[Buckchop 479]

I have the bluefox wings in shop on stands doing all the stiffners like Tjay and some other have done, plus other fun stuff like...... Replacing all 5 trailing edge rib tails  Ill look today and c if i can read anything or get a good pic 

[Buckchop 479]

Here is what is printed on the spar of my bluefox wing #0038 

[Avid Bart 39]

You guys made me curious what the markings on the spars mean. Some of the markings on my spars are not legible. I tried piecing as much of the writing together and here is what I came up with:

ALCOA 6061-T6 WW-T-700/6 AMS-4082 ASTM-B210

 

The 6061-T6 is the alloy and temper

WW-T-700/6, AMS-4082, and ASTM-B210 are standards that cover aluminum drawn seamless tubing

 

I agree with Jim that the extruded tubing would probably be fine, but the factory used drawn seamless tubing and the cost difference is not that significant. I wouldn't take the chance on the cheaper tubing.

 

 

Edited 25 Feb 2019 by cr125r847

[TJay 1041]

Kitfox says on there webpage that they do use Drawn spars. Good to know.  Now to find 13'6" length is next to impossible.

[Avid Bart 39]

I found a source for 2.5" diameter 0.083" wall tubing and they would be happy to sell you 13' 6" lengths. Unfortunately, they charge $4,432 for an 8' length 

https://www.twmetals.com/catalog.html?cid=tube-aluminum&id=44887-8

 

I was thinking maybe they have the decimal in the wrong place, but all of their prices are that high. They cater to the aerospace industry, so maybe that's the going rate for their customers.

[1avidflyer 1983]

I'm sure Kitfox or Just aircraft will sell you the spars that you need.  A few years ago, Just aircraft quoted me $130 each. Shipping would be expensive though.  JImChuk

[1avidflyer 1983]

When I talked to Just aircraft about the spars, I also talked with them about the aluminum stiffener they use.  The guy I was talking to said they could install the stiffener into the aluminum spar if I wanted and that would help on shipping and such plus get it in where it needs to be.  If my memory is right, they wanted 40 for the stiffener at the time.   I think those prices have gone up since then though.  JImChuk

[japowell 4]

I contacted Avid aircraft about a set of flapperons a couple of weeks ago.  He said they could ship both flapperons thru Fastenal for a flat rate of $150. That might be an option for the spars. Jim

[Torch 18]

I'm glad they sell 'em but I find it interesting that Just Aircraft will sell spar blanks and stiffeners.  

[Turbo 162]

Extruded tube is seamless.  Buckchop's spars are extruded.  Drawn tubing has much finer surface finish.

[Cloud Dancer 69]

If you have any machinist friends you may check and see if they can have an extra piece shipped with their next order. The last machine shop I worked at was Energy Manufacturing. We used mostly steel seamless tubing and chrome plated rod in various sizes. We did use some aluminum and the same vendor could get it all. Much of the metal such as the chrome bar stock is color coded on the end with spray paint. You needed a metals chart from the vendor to identify the metal bars material hardness and tolerances. Once someone cuts a piece off the bar you either paint the new bar end to identify it or your left with mystery metal down the road that ends up being sold for scrap. If I needed a piece for a home project I just had my supervisor order it with the next order and had them take it out of my check. We ordered most of our stuff in 10', 12', or 24' lengths. Usually it's cheaper in the long lengths but not always.

[NorthIdahoAvidflyer 374]

I guess I'm lucky to have one of the best metal stores around right here. We also have an aluminum foundry (Kaiser) here in town also. I can get that material in 20 foot lengths for way cheaper than any place I'd previously priced. The problem for everyone else is shipping it. 

[TJay 1041]

Thanks  I checked with my local guys and they said by the time they would arrive they would be so beat up you wouldn't be able to use them ha. I'll  get something figured out I don't really need anything till next year.

[Torch 18]

Almost worth building your own narrow but rugged crate and shipping it to the supplier. I have used Fastenal several times on shipments with good results and very reasonable rates. 

[Buckchop 479]

How about askin ur shipper to put the spar tubing into a piece of 3" ABS sewerpipe, glue some ends on the ABS, wrap/tape the two sticks together and send them it that to protect them, cheap and everyone has a Lowes' or Home Depot. 

[1avidflyer 1983]

If I was going to buy some from Just aircraft, I would ask them what they do for shipping.  Probably not the first time they've sent them out, and so should know what's worked in the past.  JImChuk

[Cloud Dancer 69]

If you end up with any extra material from an old or new spar you might want to save a piece of it to pick up WiFi out in your hanger or shed. How? Link here on building a quality antenna. https://www.youtube.com/watch?v=1veNvAxWHyM&t=132s  The tube size he uses is about the same as our spars and most of us have access to a piece of brazing wire. Simple build. I have not tried it but I've built other designs of his. He's pretty sharp on simple antenna builds.