Flaring 1/2" copper tube

[scrapdaddy]

Hi Guys,

I'm thinking about using 1/2 copper tubing for my rear heater in a Land Cruiser. How could I put a bubble flare? in the end, so the heater hose doesn't blow off? I want to run a hard line under the vehicle, instead of rubber hose.

Thanks in advance!

Ron

 

[tcianci]

Sounds like you don't have a flaring tool large enough for 1/2 inch material. Otherwise, you could just utilize the double flare adapter to create a little upset on the end of the tube to retain the hose. I have made an upset out of a ring of 12 or 14 gauge copper wire soft soldered to the tube near the end, works perfectly and you always have the right size!

 

[csp]

Get the ring from a compression fitting and solder/braze it on to the outside of the copper.

 

[matt_i]

Copper is a bad idea for a vehicle line.

Reason: as it flexes, it work hardens. When it work hardens, then it cracks.

If its a coolant, run a heater hose. For protection, encase it in the appropriate size split black conduit...avoiding the exhaust system heat. The split conduit is wonderous at preventing chafing.

There is no sense in putting a bubble flare in a piece of tubing if you don't have the mating flared socket to receive it...if its a SAE 45 deg flare or a JIC 37 degree flare, there are tools and dies for those, but you need the mating flare nut and flare fitting to make it work. A bubble flare is a special system invented by automotive manufacturing to give a higher incidence of leak-free tube connections....and it uses steel-based tubing...

If you are talking about rolling a "hose retention bead" it can be done on a lathe with special roll tooling. Alternatively it could also be made with a pair of pliers and special dies. The fast and easy way I have made them before is to take a piece of .035" mig welding wire, wrap it in a circle around the tube end and then either soft-solder or silver-braze (56% silver) the wire to the tube. It creates a small area of larger OD that retains the hose clamp and doesn't cut the hose ID the same way as a single flare.

 

[scrapdaddy]

Thanks Guys,

The reason I was thinking copper line instead of hose, is the line will run @ 3 feet under the vehicle and I am afraid of snagging or cutting the hose. This is a four wheel drive and we'll be back road camping, so I want it sound. So, you think copper would crack from flexing. What about soft copper tubing? Good idea on soldering wire on the end.

 

[akdiesel]

Just get some .035 wall stainless tubing. It's not that much more and use the compression fittings and then back to an npt fitting if needed. Very similar to flare.
You shod be able to get a slight bend radius. Just just do it around a 2" or larger pipe for a guide.

 

[dynahoe]

can you run it inside under the rocker trim and carpet out of harms way? Or use pex

 

[94yj]

i would go with stainless tubing as that is what the vehicles with rear ac and heater use look for a older suburban with rear heat or ac and grab those lines

 

[AndyCBR]

Thanks Guys,

The reason I was thinking copper line instead of hose, is the line will run @ 3 feet under the vehicle and I am afraid of snagging or cutting the hose. This is a four wheel drive and we'll be back road camping, so I want it sound. So, you think copper would crack from flexing. What about soft copper tubing? Good idea on soldering wire on the end.

Soft copper is annealed but it does work harden over time.

Once the soft copper tubing is put in service it will eventually lose some of its malleability.

I've encountered older soft copper installations and the pipe is much more stiff years later.

 

[chris142]

I usually run a bead of solder around it instead of a flare.

 

[kbs2244]

I put rear heaters in 2 different vans.
I used regular heater hose from the engine compartment to just in front of the left rear wheel well.

I used lots of wire ties, with pieces of paint stirring sticks as stress protectors, to fit the hose up in the corner between the frame and the bottom of the floor.
The frame was as good as protection as you could ask for.
(If you run the hot water through the heater the hose becomes very flexible and easy to fit in tight spots. I had to trim the ends of the hose after snuggling up the droops.)

I just double hose clamped the hose to the short pieces of ½ in copper I used as splices.
I never had any leaks.

No off road use, just normal family use in north Illinois.
I sold both vans after 5 and 7 years with the heaters still installed and no damage or obvious wear to the hoses.

I found it best to route the hoses so the heaters were in parallel, not series. The drivers area is smaller and when you turn down the heat up front you do not get enough hot water to the back for the larger rear area. I also used a simple on/off switch to control the fan. Again, because the larger area, there was no need for a multi speed fan,

 

[c39er]

I use this on 1/2" copper and stainless. Works fine.....

 

[Dagny]

nothing is needed on the pipe slide the hose on tighten clamp it won't leak there is not much pressure in it.

 

[scrapdaddy]

C39er,

I have the same Mastercool kit. Didn't know it has 1/2" dies! Now I'm set. Made all my fuel and brake lines with it.

Thanks everyone, great suggestions.

 

[c39er]

I used my mastercool to double flare a 1/2" AC line on a 60 Crown Imperial a couple months ago. No cracking or issues at all.

 

[matt_i]

nothing is needed on the pipe slide the hose on tighten clamp it won't leak there is not much pressure in it.

I disagree. If you go wide open throttle with a closed thermostat you can see 75psi in the system. The heater circuit will have some restriction likely which creates a pressure drop, but using that advice is a problem waiting to happen. It may not leak the first day you assemble it, but who wants a complete blowout at a random time with all the coolant dumped out on the side of the road and your Eng Temp gage pegged in the red....

Use Occam's Razor: if automotive manufacturing companies worldwide could go with straight bibs and no retention beads they would have done so from the dawn of time to save on cost.

 

[kbs2244]

Sorry matt, but I disagree.

The auto co.s use the bumps in the tubes because they can spec it at no added cost from the heater supplier.
Then they can use a single, bend to tighten, clamp on the assembly line for speed and cost saving.
Neither is available to the home mechanic.

When I used the copper pipe as splice pieces I went 2 inches into the hose and double screw clamped each end. Screws 180 degrees apart and aimed opposite each other.
2 hoses and 2 slices each for 4 splices and 16 clamps per install.
Any OEM production engineer that signed off on such a procedure would be fired within a week.

I put well over 150K miles on each of those installs and never had a leak.

(In retrospect, there were the bumps in the tube attached to the heater core.
And I single clamped them. That makes it 18 clamps per install.)

 

[scrapdaddy]

I'd rather use some sort of bead or flare, instead of double clamps. I've been reading about corrugated stainless steel tubing that's bendable, used for solar collector systems. You can cut to any length and use their fittings. That would solve all my issues.

Here's a link...http://solar-trac.com/about.html

 

[tcianci]

While copper will work harden, it only will under conditions where it is allowed to flex. A properly fastened and isolated copper line shouldn't be a problem and since the OP is asking about providing a bead so that the rubber hose cannot slip off, he is providing isolation from the work hardening vibration by virtue of the rubber hose. A stainless line is subject to work hardening as well and depending on the grade of stainless, maybe more so than copper. The mention of stainless lines in factory applications is referring to a formed, anchored line.

The corrugated, bendable stainless that was mentioned is designed and specified for a solar application, and would never see any vibration as such. In this application, work hardening is not a concern. What would be a concern is making reliable connections to the corrugated pipe. I may be wrong, but I think this pipe is similar to a product we use in gas fitting called Trac Pipe. It is a corrugated, or more correctly, convoluted plastic coated pipe designed for gas applications and as such, has specially designed termination fittings that allow for a leak proof seal between the convoluted pipe and other connections.

For a 3 foot piece of pipe, properly attached to the vehicle chassis and isolated by rubber ******* at the terminations, a piece of plain old copper tubing will do just fine.

And Matt, it would be interesting to hear you explain how the pressure in an automotive cooling system, which is regulated by a pressure relief device, either on the radiator cap itself or on the coolant tank, can get to 75 PSI. Thermostat open or closed.

 

[scrapdaddy]

Good input! Thank's