Preforming a Rubber Fuel Line

[Uncle Phil]

Has anybody figured out or know of a way to 'preform' a rubber fuel line?
I need an 'S' shaped one for a particular project and when I try to bend it, it collapses in the bends.

 

[W0QNX]

Copper holds fuel too.? rubber to copper back to rubber via splices?

 

[newtonhubcap]

Would try to use as thin a wall of fuel one can find. Using a stiff(ridged) wire bend it to shape. Insert it inside the fuel line and then place in warm (slight boil) water and let it heat soak for about 5 minutes, then pull it out and place into cold water to set the shape. I with poly line you can a pre-formed pipe and heat gun and do the same. Thin wall fuel line work best with this.

 

[Uncle Phil]

I'm thinking now about metal line - there is stainless steel and aluminum fuel line as well as copper.
I'd just have to have a small pipe bender so I didn't kink it in the bends.

 

[naedlaen]

Uncle Phil,

I have read that a spring inside the rubber hose will keep the rubber hose from kinking in the curve. The trick is finding the correct size spring.

Good luck,

Neal

 

[motornut]

I have read that a spring inside the rubber hose will keep the rubber hose from kinking in the curve. The trick is finding the correct size spring.

Your spring inside is really good, I have also used springs on the outside too. What is , like you say finding the right size is necessary. I am a spring freak and keep springs all the time.

 

[wizel]

This is called an anti-kink spring in Germany.
The fuel hose goes in there and then you bend the spring into the desired shape.
holm from germany

 

[Al st1100]

Has anybody figured out or know of a way to 'preform' a rubber fuel line?
I need an 'S' shaped one for a particular project and when I try to bend it, it collapses in the bends.

 

[Larry Fine]

You might be able to make it with two elbows.

 

[dduelin]

Uncle Phil,

I have read that a spring inside the rubber hose will keep the rubber hose from kinking in the curve. The trick is finding the correct size spring.

Good luck,

Neal

Yes, like a stent in an artery.

 

[Uncle Phil]

The heat gun he said was from Harbor Freight.
And looks they also sell the 'tube benders'.
We'll give that a whirl and see how it goes.

 

[Gus1300]

I'm thinking now about metal line - there is stainless steel and aluminum fuel line as well as copper.
I'd just have to have a small pipe bender so I didn't kink it in the bends.

Fill it with sand or other suitable small grain medium, cap the ends, bend away then empty and flush it out. It won't collapse on the filler. The line's physical characteristics will determine min bend radius.

 

[Al st1100]

The heat gun he said was from Harbor Freight.
And looks they also sell the 'tube benders'.
We'll give that a whirl and see how it goes.

never tried it but it can't be that difficult. Maybe you can bend a slightly smaller steel line to the curve you need then slip the hose over it and heat it . |Then let it cool without holding it.

 

[Uncle Phil]

never tried it but it can't be that difficult. Maybe you can bend a slightly smaller steel line to the curve you need then slip the hose over it and heat it . |Then let it cool without holding it.

I think the key is figuring out the 'right' amount of heat without weakening the hose.

 

[Al st1100]

I think the key is figuring out the 'right' amount of heat without weakening the hose.

it's an adventure!

 

[Larry Fine]

Is someone who makes these for a living a
, eh?

 

[ST1100Y]

I think the key is figuring out the 'right' amount of heat without weakening the hose.

Well, while I can see the need (looking myself for a solution as many pre-shaped ST1100 hoses are unavailable by now), I'm not fully convinced...
After all have the hoses/lines already been vulcanized (the sulfur molecules bond/replace rubber-chains at 120~160°C/250~320°F), which is why they always want to pop back into that circular shape of the spool they've been stored/delivered on...
Not sure if this bond can so easily be broken and reshaped again, or at what temperature range... (imagine your tires would loose the molecular bond...)

a) I see that Honda pre-curved hoses mostly made of their two-color/layer material (grey out-/black inside), so maybe those lines actually support heat-forming?

b) to ensure a more precise and evenly heat (ideal temperature TBA), I'll use a stove and build a jig (like wiring the thing in the intended bend/shape onto a metal grille)...

c) for larger diameters the mentioned Unicoil adapters seem really safe...

I do see an imminent need for items like the ST's carb bowl drains (connecting to the 4-way T)... hence looking for a reliable solution myself...

 

[Uncle Phil]

I figure I'll give the 'heat treatment' a whirl and see how it works.
At the worst, I melt a short section of hose!

 

[motornut]

There are tubing benders that you can make a stainless elbow with then put a first stage of a flare to make the rubber hose seal. Before installing to prevent a chance of shorting wires line the out side with shrink tube. I have also spiral cut a rubber hose to keep it from rubbing but that eats room. Looking at the type of curve you could also take the time at a wrecking yard to find an automotive application. That looks like a common bend I have seen under hoods.
Depending on the application I have used shrink tube as a way to put tension on vacuum line ends too, it frees up the room clamps take.

 

[Uncle Phil]

I know I can bend metal line to fit what I want or make elbows as junctions, etc. for this application.
But now I'm interested if I can actually preform rubber hose with the right amount of heat and not damage it.
If that is the case, then that will come in handy in a lot of applications on the ST1100.
Instead of 'hunting and searching' for the correctly bent hoses, you could just get right type and diameter in straight or rolls and form it to what you need.
That should work with gas lines, vacuum lines, water hoses ....