Author Topic: Bending tank tubing (copper) (Read 3339 times)

Phil Goldberg · « **on:** July 09, 2015, 04:10:54 PM »

I just received my uniflow tank for the ringmaster. The uniflow tube and the pick up tube are coming out of the front of the tank and not leaving me room enough for the engine. Therefore I want to bend the tubing in a U shape away from the engine. Is there a best way to bend copper tubing. My plan was to insert a copper or brass rod, bend the tubing then remove the rod. If I bend to far it might be too hard to pull out the rod. Possible I should cut the tube shorter, and then solder an extension on bending away from the engine. Thanks. Phil

Juan Carlos Pesce · « **Reply #1 on:** July 09, 2015, 04:31:39 PM »

1) heating the tube

2) use K&S tubing bender

Phil Goldberg · « **Reply #2 on:** July 09, 2015, 04:35:18 PM »

Thanks, who would have thought. Are those dense springs in various circumferences?

Juan Carlos Pesce · « **Reply #3 on:** July 09, 2015, 05:20:05 PM »

Yes Sir

frank mccune · « **Reply #4 on:** July 09, 2015, 06:32:17 PM »

Hi Phil:

I too use a K&S tubing bender and it works very well.

I have also use a 3/8" bolt with two nuts on it. Put one nut on the bolt and place the tubing at a right angle to the bolt where you wish to make the bend. Run another nut on the bolt on the other side of the tubing. Tighten the nuts against the tubing, and make your bend. I also anneal the tubing by heating it with a propane torch until red and then plunging it into water. This will soften the tubing a bit more. I have never had a failure bending tubing this way. On larger tubing, I have had great luck with various sizes of Vee pulleys.

Good luck,

Frank McCune

Alan Hansen · « **Reply #5 on:** July 09, 2015, 09:48:36 PM »

Hi, I use whipper snipper / weed whacker nylon cord that fits inside the copper tube after bending it pulls out fine.

Cheers

Phil Goldberg · « **Reply #6 on:** July 09, 2015, 11:30:44 PM »

The weed wacker cord sounds good since in my application I do not want to add much heat as the tank is already put together and I do not want to melt the existing solders.

john e. holliday · « **Reply #7 on:** July 10, 2015, 10:33:56 AM »

Myself, even though it is a lot of work, pull the back plate, remove offending tubing, then bend new tubes to put in the tanks. That way I can get uni-flo where I want and make sure no crud in tank. Then put back the back plate and seal it all up. Don't for get to pressure check when done. Some how I always wind up with a pin hole some where.

Phil Goldberg · « **Reply #8 on:** July 10, 2015, 04:21:17 PM »

Decided to use the tank as is on my BiPlane to replace the standard vent tank. With the standard vent the OS LA .46 was leaning out in the middle of the flight. Used the Uniflow today and had much better engine runs today with consistent RPMs throughout the flight.

John Leidle · « **Reply #9 on:** July 10, 2015, 05:00:03 PM »

Phil, I picked up a tubing bender at Harbor Freight last week it wont bent sharp but it bends with out kinks or wrinkles best one I've ever used by for $ 8.88 American,,
John

John Rist · « **Reply #10 on:** July 10, 2015, 08:29:45 PM »

Quote from: John Leidle on July 10, 2015, 05:00:03 PM

Phil, I picked up a tubing bender at Harbor Freight last week it wont bent sharp but it bends with out kinks or wrinkles best one I've ever used by for $ 8.88 American,,
John

Is this the one? http://www.harborfreight.com/1-8-eighth-inch-to-1-4-quarter-inch-tube-bender-94571.html

John Leidle · « **Reply #11 on:** July 10, 2015, 08:58:40 PM »

Yes it is John, I bent pipe for a living for 35 years & I know a quality bend,
John

Motorman · « **Reply #12 on:** July 10, 2015, 09:31:46 PM »

You've got to do it like flight of the phoenix, fill it with sand.

MM

Robert Zambelli · « **Reply #13 on:** July 11, 2015, 08:36:37 AM »

I found this neat little gadget at a swap meet.
It's perfect for bending 1/8 inch tubing.
Might be made by Harry Higley.

IMPORTANT: when bending any metal tubing, anneal it first.

Bob Z.

Bill Johnson · « **Reply #14 on:** July 11, 2015, 09:01:22 AM »

Quote from: Robert Zambelli on July 11, 2015, 08:36:37 AM

I found this neat little gadget at a swap meet.
It's perfect for bending 1/8 inch tubing.
Might be made by Harry Higley.

IMPORTANT: when bending any metal tubing, anneal it first.

Bob Z.

Bob, that's pretty easy to make. Can you measure the diameter of the groove? That's probably about the minimum bend radius I'll ever need.

Robert Zambelli · « **Reply #15 on:** July 11, 2015, 09:51:21 AM »

Sure, Bill - no problem.

The groove diameter is .380 x .127 wide.

Bob Z.

Bill Johnson · « **Reply #16 on:** July 11, 2015, 10:44:25 AM »

Thanks, Bob. That's tighter then I would have guessed so it's great information. I should be able to knock one out of either brass or aluminum 1/2" hex stock if I'm careful. You have to have 1/2 of the tubing in the groove minimum so it'll be close. 5/8" stock or bigger would work better but I don't have a lathe, just a drill press with a 1/2" chuck.

Robert Zambelli · « **Reply #17 on:** July 11, 2015, 12:04:23 PM »

Bill - you could make it from plastic - Nylon or Delrin.

Bob Z.

frank mccune · « **Reply #18 on:** July 11, 2015, 05:05:45 PM »

Hi Robert Z. et. al:

That Harry Higley item is the same thing as I mentioned in my above post! Mine was made from a 3/8" bolt and two hex nuts.

Good luck,

Frank

eric rule · « **Reply #19 on:** July 11, 2015, 05:11:17 PM »

This is why we use only annealed copper tubes in our GRW fuel tanks.

john e. holliday · « **Reply #20 on:** July 11, 2015, 05:32:38 PM »

I have the unit like Robert Z. shows and have had it for at least 40 years, works great. Then I bought the Higley tubing benders, yes there was two piece set. Tower Hobbies has the one that bends 1/8 and 3/32 tubing. That is the one I use most. It is order #lxl781 Harry Hiogley Biso Bender at $5.39. Well worth the money.

Geoff Goodworth · « **Reply #21 on:** July 11, 2015, 05:47:24 PM »

Another solution would be to use a Profile Uniflow (HF style) from RSM. All the plumbing is on the side.

Bill Johnson · « **Reply #22 on:** July 11, 2015, 07:06:59 PM »

Quote from: Ty Marcucci on July 11, 2015, 12:13:40 PM

Or Bill, you could just stop by the house and borrow any of the four different tubing benders I have. Just saying.

I should just move in to your garage. It would make my life so much easier.

Unfortunately, Krystal would be ....