vmirv8bldr

vmirv8bldr

Well Known Member
I'm working on the fuels lines for my -8, the tubing that came in the finish kit box was fine, except that I didn't have nearly enough since I kept screwing it up. I ordered an additional 12' roll from Vans, and it got here quickly. So I went out to the shop, measured, cut, bent, and then got ready to flare the end. I placed the nut on the tubing, then attempted to place the collar on. It won't fit. The tubing seems to be slightly oval shaped, and not quite round. I thought maybe it was just this spot and had become warped or something. Nope, whole roll. I also tried sanding a bit in case the tubing cutter put a slight bur on it. That didn't help either.

Anyone else have this problem?

I assume I need to get some more Al tubing. Has anyone found any at a local place? I didn't see any at HD or Lowes.

Thanks,
 
I had a similar issue recently with the supply of 3/8" tubing that came with my AFP pump install kit. Luckily I had a big coil on hand that I was able to use to get the job done. Maybe they got a bad batch?

Anyway, I don't think you're likely to find any at the local builder's store - you'll probably have to mail-order it unless you're within driving distance of a place like Spruce.

cheers,
mcb
 
Remove oval....

If it was coiled too tightly, it might have made the tubing slightly oval like you mention.

Can you gently squeeze the end few inches back into a circular shape??

gil A
 
5052 tubing is available from Wicks in straight sections, uncoiled. Much nicer to work with than the coiled stuff. I helped a friend make all new lines in the gearwells of a P-51 and that's what was used. Polished it all too, looks awesome.
 
Worked out ok

I could get the collars started, but they were hard to slide, so I used a nut portion to help push it down enough to put the Parker Rolo-flare tool on it. After flaring, it slid nicely back into place.

I'm now officially finished making fuel and brake lines! God only knows how I'm going to tighten them all on the valve though! One at a time I guess.

Thanks,
Bart
 
Just a recommendation for 1st-time builders like myself: If you screw up your supply of Van's-supplied tubing trying to install your fuel lines or whatever (like I did), buy a bunch if you have to re-order. It's $.045 cents/ft for 1/4" OD, $0.69/ft for 3/8" OD (at Aircraft Spruce) with a 20 percent discount for a 50-foot roll. Where ever you buy it, buy more that you think you need. That's pretty cheap insurance to have plenty of tubing without having to re-order again and waiting for it to arrive. Hope this help.
 
Agreed

Van's sent 8' of the 3/8" stuff. I ordered an additional 12' and ended up with about 1 foot left.

I did a full dual fuel return, so ordered extra 1/4" anyway, I got the longest piece Vans has and have plenty of 1/4" left over.

I don't care how careful you are, you're going to kink at least on piece. Furthermore, you're going to have one bent just perfect, I mean BEAUTIFUL, and after you flare it you'll realize that you forgot the AN collar and nut. Nothing provokes more foul language than that.

Do the long pieces first, if you screw them up, the scrap can still be used for shorter pieces.
 
Many ways to go wrong !

Bart,

How about: you got your "perfectly" bent tube, with the nut and collar on, yep, you double checked :) and make the flare. Very proud of this masterpiece you try to screw the nut on the coupling, but somehow it wil not go on....... until you notice you got the collar on the wrong way around :eek:.
 
Point of no return

Yeah, I started making it a habit to make that one final check after clamping the tube in the flaring tool. I did this because on one of the flares I made, I noticed the lack of the collar and nut just as the flare started...flaring.

.0000000001 seconds too late.
 
I'm back to working on the #$%^&* fuel tubing right now, after having made one of each of the mistakes you guys just outlined. :mad:

Where were ya in August when I really needed ya?? ;)
 
One thing that I did after a couple of tries is to go from the fuel selector to the fuselage side down in the corner with one piece of tubing. I then put an AN821 elbow and then run from there out the fuselage and into the wing fitting. This makes a clean easy installation that is really easy to put in and service. Don
 
I ran into this problem of oval tubing and took a block of aluminum about 2 inches by 3 inches and cut it in half lengthwise, then clamped it together and drilled a lengthwise hole in it the size of the tubing. Then, whenever I had an end that was too tight for the fittings, I put the tube end in the aluminum block, put the block in the vise and squeezed it into shape. It always worked.

Jeremy Constant
 
The tubing does not appear to be mil-spec

The Vans coiled tubing I received appears to be commecial air conditioning tubing:eek: If you measure it after straightening it is not truly round due to deformation.

I don't even use it. I use the wwt-700/4, 5052 condition-0

Straight 6 foot sticks so you don't have to make it straight before you bend it again.

Tighter tolerances on OD. and ID. and typically marked on 1/4" and above.

It works great for flaring and bending with the correct tools.

For what you are trying to do with it it is not that expensive, especially in the 1/4 and 3/8th sizes.

For Tubing info see

http://www.gen-aircraft-hardware.com/images/pdf/tubing+info.pdf

If you would like purchase go to

http://www.gen-aircraft-hardware.co...+Aluminum -> Tubing&menuID=263~264~264&id=265

Have fun!
 
Updated

I checked prices on the 1/4" and the 3/8" aluminum tubing and dropped them down a little as they had crept up with my inceased costs.

Hope this helps.
 
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