Metal tube radiator hoses

[parsonsj]

I know, not the most interesting thing ...

I've just about got this car finished, and it's time to get my real radiator hoses. In order to get my car running before moving to Florida, I cut a couple of corners for some prototype hoses. My upper hose is a universal convoluted black rubber hose, and looks like I stole it from a school bus. The lower hose is a wacky collection of 3 pieces of rubber hose, some leftover ss header tube, and chunk of 4130. If I ever get in a fight, it would make an awesome weapon.

Anyway, I thought some bent aluminum (polished and anodized, of course) or ss tube would be a big improvement. Anybody know of a source for that? Or even a place that could bend some aluminum tube ...

jp

[Matt@RFR]

You'll want to use aluminum tube for its conductivity properties over stainless, and Ron Davis sells 90º bends and Burns sells U bends, 90's and 45's. Both are 6061.

[parsonsj]

Ron Davis sells 90º bendsExcellent! Thanks Matt. I'd sent an email off to Tim Crosby at RD, but perhaps he's not there anymore. I'll give 'em a call.

Of course, this means I have to get my TIG welder fired up ... it's been sitting lifeless here in Florida. I got some wiring to do.

jp

[porschev8]

Yep... still here.

[parsonsj]

Excellent. I'll call you guys today.

jp

[Matt@RFR]

Nice try John, but you can't get rid of Tim that easily...I've tried, :)

[SicMonte]

do they make these type of coolant "pipes" already made? I cant tig weld for anything and id love to have a set on my car.

[Matt@RFR]

Not that I'm aware of. Armed with knowing what CLR (center line radius) the bends you want to use are, you could bend up a piece of TIG filler in the shape you need and have someone local make one or two up for you.

[parsonsj]

So I talked to Tim today, and the aluminum bends are on the way.

Thanks for all the help guys.

jp

[rob07002]

John how do you plan to connect them to the rad and intake?

Love the article on your car in this months PHR....

[parsonsj]

Hi Rob,

Thanks! Any thoughts on my color choice? I was a little nervous about that ... but the boys at Road Killer Kustoms did a fantastic job on the sheetmetal and paint.

Connections will be via short pieces of rubber hose on either end.

jp

[rob07002]

Of course I'm partial to blue :cool:

just a thought but have you thought of buying striaght aluminum tubbing and have a muffler shop make the bends?

[Matt@RFR]

Of course I'm partial to blue :cool:

just a thought but have you thought of buying striaght aluminum tubbing and have a muffler shop make the bends? It doesn't quite work that way.

[rob07002]

It doesn't quite work that way.

Is that because of pressure rating or because its not mandrell bent?

http://www.onlinemetals.com/merchant.cfm?step=2&id=71

buy a lenght of tube and one could even use a pipe bender to make the bends. No?

Please elaborate...

[parsonsj]

No worries, Rob. I'm sure Matt is off working on the rest of the answer: the "why not"? part ...

One thing that's obvious to me (since can see how the part needs to bend) is that the bends are too close together for a bending machine (mandrel or otherwise) to do the whole thing. I'd have to cut and weld the resulting part anyway, so why not start with mandrel bent pieces and build it that way.

I'll bet the other thing Matt was alluding to is that 6061 aluminum work-hardens, so it gets more and more difficult to work with as you go. Heat treatment is needed to bring the alloy back to it's "full soft" condition. That sort of thing is beyond most muffler shops.

jp

[rob07002]

Makes sense, I didn't realize you need such tight bends.

I also forgot about the mailiableness (is that a word) of the aluminum, but still think you could do yourself with a pipe bender and torch if your design was simpler.

Hey I learned something today... time for a drink!

[SicMonte]

hey john...why did you move to florida from maryland??? kinda sucks b/c I wanted to come to your plae and check out the car.

[parsonsj]

Sic,

My wife was transferred down here. Since we work for the same company they agreed to let me keep my current job and do it from the house.

So here we are.

jp

[Matt@RFR]

Rob, just get the idea out of your head! I've tried it and it doesn't work.

6061 needs to be annealed to T0 (full soft) before bending, 775ºF for three hours, then cool at a rate of 50ºF per hour until you reach 500ºF, the cool the rest of the way in still air.

I have a big problem with heating aluminum with an oxy/fuel torch because it loads the aluminum with carbon, possibly making it extremely crack prone. Although for something non-structural I guess it'd be ok. I wouldn't do it though.

6061 will actually naturally age back to T4 (dunno how long it takes), but to get it back to T6, heat to 320-350ºF for 18 hours then air cool.

Also, Rob, I hope you're using "pipe bender" incorrectly. There's a huge difference between pipe and tube benders. A pipe bender will wrinkle the inside of the bend something awfull, which is the last thing you want in a cooling system. Exhaust shop benders will do the same thing.

[SicMonte]

just wow..amazing. how in the heck do you learn all this stuff??? im completelly amazed by your knowlegde...and im being 100% serious.

[Matt@RFR]

You may have noticed how I tell everybody to search before they ask questions (and then get jumped on for it), well I search before I give answers. Most of the stuff I write here is off the top of my head, but a lot of the finer details (like the post above) is curteousy of the internet. For example, search for "annealing 6061" and on the first page is this (http://www.suppliersonline.com/propertypages/6061.asp) gem. I'm not a metalurgist, and there's no way I could remember all the details to annealing every single metal I work with. I just remember enough of some topics to know that I need to search the internet or consult one of the many books I own on metals and metal working to get the specifics. All good machinists own books about machining. All good engineers own books about engineering.

Thanks though. :)

[SicMonte]

good point. My dad and I have a small machine shop in our garage (south bend lathe, bridgeport mill, etc.) and we have alot of books about machining. The best one I got was from the 40's...all the old school knowledge and everything...awesome book.

Matt...what do you do for a living? just curious

[parsonsj]

there's no way I could remember all the details to annealing every single metal I work withI knew you were doing research ... I was serious when I said you were working on why. As for me, I wanted to do that research, but I couldn't remember the word "annealing", as much as I racked my brain, so I couldn't get any traction with google.

These things happen at my age. :)

jp

[andrewb70]

Hey John,

For that ultra clean look, you might want to look into some stainless T-bolt clamps for the short rubber sections. Are you planning on bead rolling the tube? That would probably be a good idea for better sealing.

Andrew

[parsonsj]

you might want to look into some stainless T-bolt clamps for the short rubber sectionsGood idea. Any thoughts on the best source for those?
Are you planning on bead rolling the tube?Yes: Tim Crosby at Ron Davis said they would do it for me if I send them the tube when it's done.

jp

[SicMonte]

i cant wait to see this car when its done.

[CraigMorrison]

https://static1.pt-content.com/images/pt/2006/08/enginecompvi-1.jpg

Used stainless exhaust tubing, cut to fit and welded up like a header tube ( then sanded the welds and polished the tube) and then used short pieces of rubber hose on either end. This was done on both the top and bottom tubes. 7500 miles in three years and no problems what so ever.

[rob07002]

Rob, just get the idea out of your head! I've tried it and it doesn't work.

6061 needs to be annealed to T0 (full soft) before bending, 775ºF for three hours, then cool at a rate of 50ºF per hour until you reach 500ºF, the cool the rest of the way in still air.

I have a big problem with heating aluminum with an oxy/fuel torch because it loads the aluminum with carbon, possibly making it extremely crack prone. Although for something non-structural I guess it'd be ok. I wouldn't do it though.

6061 will actually naturally age back to T4 (dunno how long it takes), but to get it back to T6, heat to 320-350ºF for 18 hours then air cool.

Also, Rob, I hope you're using "pipe bender" incorrectly. There's a huge difference between pipe and tube benders. A pipe bender will wrinkle the inside of the bend something awfull, which is the last thing you want in a cooling system. Exhaust shop benders will do the same thing.


All I can say is WOW! I had no idea and stand corrected. To me it sounded like a simple idea.

I know pipe benders are not the preferred tool but can get the job done. I didn't think they made tube benders big enough to handle that diameter. ie, tube bender for brake lines, pipe bender for exhaust and roll bars.

Maybe I'm getting them mixed up?

good info to know for sure, thanks Matt..

John please disregard anything I say in the future:hammer:

[andrewb70]

Good idea. Any thoughts on the best source for those?
jp

Any online turbo dealer should have them. I think a local well supplied truck (semi) shop should carry them as well.

Andrew

[SicMonte]

I have those coolflex hoses...anything wrong with them?

[parsonsj]

cut to fit and welded up like a header tube ( then sanded the welds and polished the tube) and then used short pieces of rubber hose on either end.Nicely done! The only thing is I'd prefer aluminum to minimize oxidation issues with my aluminum block and heads.

Now tell the truth: there's some body filler on it, isn't there? Or at least high build primer in order to get those smooth as glass joints ... Beautiful work. :twothumbs

jp

[parsonsj]

Any online turbo dealer should have themOK, thanks. I know where to go now ...

jp

[Matt@RFR]

Matt...what do you do for a living? just curious I do all our mechanical design and FEA (SolidWorks), manual machining (mainly for prototyping and fixturing), all the welding, fixture design and I work with all the vendors we use to make our proprietary parts (flat laser, tube laser, CNC press brake, CNC mill and lathe). Our vendors like the fact that I know how to run the machines they use because I can communicate with them on a level where there's no guess work or interpretation on their part, and the parts I design require no modification to be efficiently made on their machines.


I know pipe benders are not the preferred tool but can get the job done. I didn't think they made tube benders big enough to handle that diameter. ie, tube bender for brake lines, pipe bender for exhaust and roll bars. All "Pipe" benders will wrinkle the inside of the bend, and the bend cross section will be oval.

Being familar with brake/fuel line "tube" benders is essentially enough to understand how the bigger tube benders work. They use much more accurate dies to keep the tube close to round and to not wrinkle the inside of the bend. Any approved bar, cage or chassis you see was bent with a "tube" bender because any wrinkling of the tube wall is unacceptable in any rule book I've ever seen. The only downside to tube benders is they all have a minimum wall thickness they can bend before even they wrinkle the inside of the bend.

For thin wall tube ("thin" is dependant on and relative to OD for this discussion) the tube needs to be bent on a mandrel bender. Same overall concept as a standard tube bender, but they use a flexible mandrel that slips inside the tube in the area of the bend to keep the walls from collapsing or wrinkling. This is how all exhaust U bends (etc.) are made, and is mostly why they're so expensive. CNC mandrel benders can range from $50k to 200k and up. Die sets alone are in the $4k-8k range, and a different die set is needed not only for different OD's, but for each wall thickness AND for different CLR's. It gets expensive quite quickly.

[rob07002]

Matt, thanks for clearing that up (seriously) I was always getting the two confused and didn't really know the pros and cons of each.

[Matt@RFR]

John, I missed the question about rolling a bead in the end of your tube. I hate to take money away from Ron Davis but you can simply run a weld around the circumference of the end of the tube. All it is is a stop to keep the hose clamp and hose from coming off the tube. The hose seals just fine on plain tube.

[parsonsj]

you can simply run a weld around the circumference of the end of the tubeCool, sounds good; I understand what you mean. Thanks! The bends are here ... so I'll have to do some practicing. I haven't made a TIG weld in months.

jp

[andrewb70]

John, I missed the question about rolling a bead in the end of your tube. I hate to take money away from Ron Davis but you can simply run a weld around the circumference of the end of the tube. All it is is a stop to keep the hose clamp and hose from coming off the tube. The hose seals just fine on plain tube.

Excellent tip Matt!

Andrew

[porschev8]

just wow..amazing. how in the heck do you learn all this stuff??? im completelly amazed by your knowlegde...and im being 100% serious.


Matt..... possessor of superhuman capabilities. :hail: You are my Hero.

[Matt@RFR]

It's a little early to be hittin' the sauce isn't it?

[porschev8]

It's a little early to be hittin' the sauce isn't it?

Nope. It's after 10:00 am! :Alchy:

[Matt@RFR]

I have nothing funny to say, so here's a bannanna doing a dance just for you.

:bananna2:

[porschev8]

I have nothing funny to say, so here's a bannanna doing a dance just for you.



That's okay Matt. We love you for your mind...

[Matt@RFR]

Does that mean you don't find me physically attractive anymore?

YOU CHEATING WHORE!

:)

[MuscleRodz]

John, I have hand beaders for tubing from WWII era if you want to borrow one and roll them yourself.

Mike

[parsonsj]

Mike,

I appreciate that. I'll drop you a PM.

jp