Forming/Shaping fuel and brake lines.

[Wicked Stick]

Just wondering if there's any tips or tricks from the collective minds here at RivetBangers about easy ways to shape/form/bend fuel and brake lines and get it right the first time. Particularly the lines that run from the selectors to the tanks, and the selector to the FI pump. There are some tight spaces and awkward bends that take place in an 8 for those runs. I'm sure running the lines around the landing gear weldments in a 7 is equally difficult, so let me know what worked for you guys too.

I was thinking about using coat hanger wire to bend into a simulated shape/routing inside the aircraft and then remove it and try to copy that over to the fuel lines on the bench.

Or, should I simply measure and bend via trial an error with the actual fuel line ?

[Brantel]

Most everyone recommends the bent wire method.

I did pretty well on my 7, hardest ones were the vent lines.

[cjensen]

...let me know what worked for you guys too.

I gave it a shot, and decided I sucked at it. This works MUCH better...



SS braided line is easier to make the bends...

[Wicked Stick]

...let me know what worked for you guys too.

I gave it a shot, and decided I sucked at it. This works MUCH better...



SS braided line is easier to make the bends...

Chad, I did this for my brake lines. I will do the vent lines out of aluminum tubing, and want to keep the fuel lines aluminum too.

The braided lines are easier. What size did you use for your fuel lines ?
The picture makes them look smaller than the aluminum tubing. I would be concerned if you have a smaller "inner" diameter braided hose than what the fuel line would be in aluminum. Also, would using braided hose require a shorter life span/change out versus aluminum tubing ? How many years do they recommend for rubber hose fuel lines (even though they are stainless braided on the outside) ?

[cjensen]

What size did you use for your fuel lines ?

They are -6 lines. I don't know what the ID of the AL tube is, but they matched up when I checked them against one another.

Also, would using braided hose require a shorter life span/change out versus aluminum tubing ?

I think this is a bit of an unknown, but this is racing quality stuff, and SS braided line of this quality is approved for use on certified airplanes as well, it just doesn't get used because of cost. Even if it does require a change out sooner, the ease of doing so is worth it to me.

How many years do they recommend for rubber hose fuel lines (even though they are stainless braided on the outside) ?

No recommendation given...

[aparchment]

Not that it matters, but I agree with Chad.

The Bonaco lines are very nice quality, and the time savings associated with installing them rather than dealing with the intricate bending of the aluminum tubing had me sold. Even if they have a lower service life I would rather replace the braided hoses than deal with the tubing.

Some folks may prefer that sort of retro technical look you get from a nicely done aluminum tube install (kind of like looking up into the gear well of a P51) but I prefer the clean modern look of the braided tubing.

Some of the guys on here, like Brantel, have done masterful jobs of installing their tubing. It really adds to the craftsmanship of the airplane, and I am sure pride of ownership. I am truly impressed with that level of detail. My goal, however, is a fast, functional plane with as many modcons and time saving tricks as I can afford. I won't win any Grand Prizes for craftsmanship because of this, but I will enjoy flying my plane just as much as anyone I suspect.

Cheers guys!

[weezbad]

get some extra and practice..it bends easily...but you will need some practice...if i ever have to repair, i will likely go with braided stuff. at times i estimated how much i needed and cut off that many loops. i then unrolled it as i went. a long straight piece is a pain to work with.

[Brantel]

The fuel lines from Bonaco are Teflon inside. Everything has a life but most agree that Teflon hoses will last a long, long, long time.

[cjensen]

Teflon!! That's the word I TOTALLY blanked on last night! Yes, they are Teflon lined...thanks Brian...

[jim_geo]

This is the little write up that's on my web site. The web site is way under construction with mostly unfinished stuff on it so please don't judge me to harshly. Frankly there isn't much there other than this write up which probably needs some more editing to make it a little more clear. So anyway, I'm not sure how much help it will be with an 8 but here it is.

http://www.rvforge7.com/pg3.htm

[Dan A]

WS, No, It's not easy to make the bends for the 8 fuel lines. I have a tubing bender for 3/8 tubing and used that and it worked pretty well. Just a lot of trial and error. -- Sometimes heavy on the error!! I don't have any pictures of mine or I would send them. I guess I should have taken some. The only thing else I can say is - You side by side builders have it easy when it comes to the fuel lines!

Good luck!
Dan N742DA

[jim_geo]

If I had it easy then I feel really sorry for you guys building 8's.

[Sully]

I do pretty good on locating the bends but has anyone got a good way to get the tube nice and straight after you unroll it. Some guys lines look like they are straight as an arrow between the bends which make them look great, but I can't seem to get them that way.

[Brantel]

I do pretty good on locating the bends but has anyone got a good way to get the tube nice and straight after you unroll it. Some guys lines look like they are straight as an arrow between the bends which make them look great, but I can't seem to get them that way.

I unroll it on my kitchen counter top and take the palm of my hand and smack it about a million times working the humps out while rolling it. Works ok for me....

[BrickPilot]

I do pretty good on locating the bends but has anyone got a good way to get the tube nice and straight after you unroll it. Some guys lines look like they are straight as an arrow between the bends which make them look great, but I can't seem to get them that way.

One of the tricks from the Bearhawkers group is to clamp one end in a vise, and then hog down on the other end with a pair of visegrips. Smack the visegrips with a hammer, and you have a nice straighht piece. Cut off the ends, and you're good to go.