Soldering copper radiator

[Napalm00]

Just reaching out and see if anybody has ever done this. It feels almost kind of like a lost art.

I initially JB welded my original 1964 copper radiator in our dart and it wound up leaking after a couple 110 degree days.

Just finished soldering it after stripping the entire top cap and it looks amazing compared to the jb. Sometimes the old way is the best way ?

 

[michael67]

I soldered the radiator cap rim where it meets the radiator top on my old CJ8. Done in-place and no leaks. Anything that involves melting metal is a good thing.

 

[MountainD]

I did it with my 68 firebird. They wanted two weeks so I gave it a go. Works for years till I sold it. Super easy… just need to be clean, fluxed and solder follows heat! The plastic aluminum radiators are the worst ever. Aluminum is good but frankly they’d all be copper if it wasn’t so damn expensive. One of the better thermo transfer metals out there

 

[erover82]

Aluminum is good but frankly they’d all be copper if it wasn’t so damn expensive. One of the better thermo transfer metals out there

I'm not so sure. As much as I like to hate plastic parts, plastic/aluminum radiators have proven highly reliable in nearly every modern automobile. Specifically regarding the Defender aluminum radiators, ZG has said they've seen very few issues last time I inquired. Thermal conductivity isn't the only factor in cooling capacity. Aluminum's strength allows them to be built such that they actually have better cooling capacity in the same form factor. However, reparability is definitely a brass radiator's strength.

An Aluminum or Copper Radiator for Your Car - Car Craft Magazine

Learn how to plan what cooling system to put in your car with the choices of an Aluminum Radiator vs. a Copper Radiator in Car Craft Magazine.

www.motortrend.com

 

[evilfij]

We are going to test that aluminium is as good as copper theory.

 

[michael67]

I recently switched over to an Allisport aluminum radiator on my 110, and it definitely keeps it cooler here in Texas during the summer than the custom copper radiator I had. I would not have bought the Allisport if it had plastic ends. My '08 Lotus had an aluminum radiator with plastic ends and they gave out suddenly after about five years of use, very typical of the Elise/Exige family; I replaced it with a one piece aluminum.

On the other hand, I have a '96 Ford Powerstroke that has an aluminum radiator with plastic caps and about 250,000 miles - I haven't heard of any problems with those.

 

[MountainD]

I'm not so sure. As much as I like to hate plastic parts, plastic/aluminum radiators have proven highly reliable in nearly every modern automobile. Specifically regarding the Defender aluminum radiators, ZG has said they've seen very few issues last time I inquired. Thermal conductivity isn't the only factor in cooling capacity. Aluminum's strength allows them to be built such that they actually have better cooling capacity in the same form factor. However, reparability is definitely a brass radiator's strength.

An Aluminum or Copper Radiator for Your Car - Car Craft Magazine

Learn how to plan what cooling system to put in your car with the choices of an Aluminum Radiator vs. a Copper Radiator in Car Craft Magazine.

www.motortrend.com

If you are getting your information from an article that is quoting an aluminum radiator company that says aluminum is better then you really need to check your sources. While studying engineering (including thermodynamics) and working on designs for co-gen plant studies at UCLA (which was subsequently built in 1994 and still operating) tells a vastly different story. If you delve just a little bit deeper into the science of it all (starting with the metals which has a thermal conductivity advantage over 2:1 in favor of copper), then you will find out that the copper radiator efficiencies can be way higher than aluminum. The bottleneck is one of the heat transfer from the tubes to the fins--the cheap mass produced (common) way is attaching tubes to fins with solder and it is the solder joint that has abysmal thermal conductivity. THAT is the method that aluminum radiator companies will compare to--but make no mistake, aluminum is used do to cost not efficiencies. There are several construction methods that are better than using soldered fin/tubes such as brazing and different types of welding such as laser welding. One method is Cuprobraze which results in W/m values of that technology is 377W/m for Cu Fin style compared to 222 for Al Fin or 160 for Al Tube.

My 2000 Disco II had plastic end caps. I replaced mine 3 times under warranty for leaking so I have a negative impression. If they have come a long way, then great. What I was told when it leaked out of warranty was they were not only unserviceable, but that they are considered disposable items now. Again, decisions based on cost, not on best. I am sure they have come a long way on durability--I won't use one if I have a choice.

FWIW, my LS and soon my Cummins radiators are all aluminum. Only because that is what is considered the best option of affordable custom radiators for me although I did reach out to folks using copper brazed technology. Copper pricing is through the roof so it just didn't make sense economically.

 

[Napalm00]

Good news is that the rad has held with me driving it hard in 97 degree heat. Now the question is will it make it from San Jose to Las Vegas when it's 115

 

[MountainD]

It’s not the heat, just the pressure. I’d do a pressure leak down test after soldering. Copper is good to 600 degrees+. I tested my at 24psi for 24 hours after soldering. Never leaked from there. I did it prior to installation.

 

[Napalm00]

The higher the heat the higher the pressure . It originally blew this crack open on 110° day here

 

[michael67]

Perhaps check your coolant tank cap then? The cap should keep the pressure within a fixed limit.

 

[Napalm00]

its a 13lb cap just when it would get hot enough and the pressure high enough it would split the seam on the tank, why it was resoldered . its working fine now, took it to the cars and coffee today . a looong while back I fitted an overflow as well, prior it would just puke it on the ground as mopar intended

rad is original and ~57 years old so it has seen some days that for sure.

 

[MountainD]

its a 13lb cap just when it would get hot enough and the pressure high enough it would split the seam on the tank, why it was resoldered . its working fine now, took it to the cars and coffee today . a looong while back I fitted an overflow as well, prior it would just puke it on the ground as mopar intended

rad is original and ~57 years old so it has seen some days that for sure.

pic, pretty please! I love those jeeps!

 

[jymmiejamz]

I have replaced an astonishing number of aluminum radiators for leaks over the years. The plastic ones seem to leak the worst, and many times have catastrophic leaks. Copper and all aluminum radiators leak too, but they usually just seep slowly

 

[Napalm00]

I kind of wish I had a video of when this radiator popped its leak. It was kind of almost like a movie trope. Steam was billowing out from underneath the hood when I pulled up to a stoplight thankfully near my destination. I pop the hood and a stream of steam and coolant sprayed into the air about 4 ft high

I felt totally ridiculous

 

[MountainD]

I kind of wish I had a video of when this radiator popped its leak. It was kind of almost like a movie trope. Steam was billowing out from underneath the hood when I pulled up to a stoplight thankfully near my destination. I pop the hood and a stream of steam and coolant sprayed into the air about 4 ft high

I felt totally ridiculous

Getting breakdowns when your a car guy that works on cars sucks. Period.

 

[RBBailey]

I have a couple of cracks in the top of the Series radiator that I used an aluminum brazing stick from Harbor Freight on a few years back. I had just spent $300 to have the thing recored and cleaned up, and 100 miles later it leaks again, and I just got pissed and didn't feel like pulling it out and driving two hours to the shop to have it done AGAIN.... so I put that stuff on, and it worked.

Four years later it is leaking again, so I am trying again with some proper copper solder and such, but I'm not having as much luck. Two holes plugged, but one still seeps.

I once had the engine in my 1972 Volvo (my first car) pop loose from the mounts on a hard stop. The engine flew into the radiator with the armor plated Swede fan spinning. It was just after dark, and the fireworks show was spectacular. A perfect arch of welding sparks flew out from under the hood for a good five or six seconds. Lots of dying cat noises. Lots of steam, and water all over the place, and then smoke and a fire. I got out and put the fire out, and the whole time my girlfriend just sat there straight-face like she had instantly decided to just roll with it. Kind of wish I still had that car.

 

[evilfij]

I have replaced an astonishing number of aluminum radiators for leaks over the years. The plastic ones seem to leak the worst, and many times have catastrophic leaks. Copper and all aluminum radiators leak too, but they usually just seep slowly

Is there a DII with an original radiator left.

The main issue I have with the copper/brass ones is that they are staggeringly expensive. ~$1000. I can put 4-5 plastic ones in for that. I don’t mind the all aluminium ones, but I am not aware of any of those for NAS defenders, RRC, D1. I just went with the nissen (sic) plastic and aluminium one Zach at RN had for the LWB and now she does not budge the needle. Looking at the old rad, she seems to have had a tiny leak under pressure only in a corner.

 

[RBBailey]

I’m with you on that. I have not had overheat issues, but if they develop, or if the leaks get worse, I’m just going to one of the RN versions, even if I have to replace it in five years… which I probably won’t.