Old Timers Guide to Repairing Honeycomb Radiators Lost to The Ages???

[leomara]

As the story goes there are ways to repair the leaks in honeycomb radiators, however, the old timers who knew how to do this are all gone and that skill has been lost to the ages.  Perhaps it is a tedious labor intensive job that no one today wants to be bothered with when they can sell a re-core job for thousands of dollars.  Seriously, someone out there knows how to do this, please respond. 

[Rusty_OToole]

I suspect that 100 years ago they just soldered them but today the metal is so old and deteriorated there is nothing left to solder.

[dibarlaw]

Yes, I recall from about 50 years ago a friend had a radiator from a late 1920s Chevrolet Harrison core repaired by a local shop. That shop had been in business for over 40 years at that time and the fellow doing the work was over 60 at the time. Putting into perspective the NEED for repairs was somewhat constant even in the cars of the period (1960s-1970s). My 1969 Buick LeSaber having had a radiator repair as well as a heater core repair as a 4 year old used car. Having had 2 honeycombs replaced in my 1925 Buicks with modern style cores I can identify. My go-to guy did not want to fool with possible honeycomb repair and recomended a re-core. With modern plastic units etc. there simply is not a volume of work for a radiator shop to exist and be profitable. My go-to radiator man here in Chambersburg continued for about 5 years past selling his business by working at a tractor repair facility.

He has now retired. The closest shop to even consider working on a regular modern core radiator is now over an hour away and he is also making retirement noises.

 When I moved to Chambersburg 38 years ago we had 4 radiator shops to choose from.

 To add to Rusty's comment. So true! The aged and corroded brass can only be resurected so many times by cleaning.  Heat and cooling cycles and age also cause the brass to inbrittle and fail. These units were probably expected to be in service for around 5 years, not for 100 years. My 2 cars are now approaching their centennial in 2 more years. The original honeycombs were in them for around 50 years at least.

Edited February 19, 2023 by dibarlaw
Added content (see edit history)

[Shipping reccomendations]

The last Cord I restored had a honeycomb radiator that couldn’t be repaired. I had a new honeycomb radiator core made in Great Britain to the tune of $2200. It was perfect but expensive. I then had to solder on the top and bottom tanks.

[leomara]

Good points, however the radiators I'm speaking about have come out of low milage cars, one has 11,500 miles on it and the other has 24,000 miles.  No one has been driving these cars for 100 years.  However, I do understand the concept of metal becoming deteriorated over the years even if it has not been used.  Some of the rumors I've heard talk about finding the offending "combs" and filling them with something to isolate them from the rest of the core.

[jp1gt]

I have 2 radiators and hopefully one is good. Do they have much problem with plugging up? Maybe turn them upsidedown and flush them out?

[Mark Shaw]

Gentlemen:  Please keep in mind that not everyone in this hobby is a trophy hunter.  Those of us who enjoy our mostly un-restored "Driver Cars", appreciate and preserve the bumps and bruises our cars have endured over the years.  Unlike "Show Car" owners, we are not afraid to drive these cars for fear of getting them scratched or rock chipped due to many miles of driving on beautiful un-paved back roads; just as they were driven back in the days when they were new.  

 

I am financially capable of restoring my cars to pristine condition, but I choose not to.  I like them as Driver Cars because I feel free to drive them and enjoy them as they were meant to be driven.   Last year I repaired two leaks in my 1908 Model F Buick radiator.  One was in the bottom tank mount and the other in the lower section of the "Bottle Cap" core.  It was a rather involved process that required much preparation of the metal to take solder, but it worked well and is still holding up nicely.  I have since driven it on two tours with no need to add coolant.  With a bit if research and watching a few YouTube videos, you can do it too.

[Bloo]

On 2/19/2023 at 12:14 PM, leomara said:

Seriously, someone out there knows how to do this, please respond. 

Apparently not, considering the direction this thread is going 😜.

 

23 hours ago, leomara said:

Good points, however the radiators I'm speaking about have come out of low milage cars, one has 11,500 miles on it and the other has 24,000 miles. 

The sad truth is they are probably junk. That wouldn't stop me from trying to repair though. People used straight water for coolant then, and usually not even distilled. The passages in a honeycomb radiator are tiny. The small flakes of rust plug things up quickly. Mineral deposits from the water do too. There is no practical way to clean them out other than backflush. Better than nothing, but it doesn't do much. If the cores ever froze, there will be too much damage.

 

23 hours ago, leomara said:

Some of the rumors I've heard talk about finding the offending "combs" and filling them with something to isolate them from the rest of the core.

That's how it was done, except it was to isolate the outside. In fact, I've done it when I was a teenager, but I don't remember how. I have also repaired some cracks in the middle of tube and fin cores when the radiator shop said it was impossible. Looking back on that, I think a lot of dumb luck was involved. By the way, you would fill a cell like that when the brass was cracked out in the middle of the cell. That's kind of a "worst case" repair. On a honeycomb radiator, the soldering is all on the front and back face of the core. Any solder problems would be fixed right there on the face. The information I had on how to fix these either came from Dykes, or from the giant stack of late 1938-41ish Mechanix Illustrated, Popular Mechanics and Popular Science my dad still had laying around from those days.

 

Ok, so if you are going to plug a cell, something has to go in the hole. The solder on the outside of the core is the only thing that keeps the core from falling on the floor in a pile of parts, so you can't get it too hot. That is the biggest danger. The solder probably isn't going to bridge a whole cell by itself. Solder follows the heat, so if you heated it from the backside enough to fill the whole cell, both ends of the tube would be hot enough to melt solder and I think the core would fall apart. Oddly I think this is how it was done, and probably how I did it, but I can't imagine how. Filling it with copper wire won't work. It would not only be thicker than the brass, but it's way too good of a heatsink. An approach that sounds like it would work, just thinking about it now, would be to take a brass tube that would fit inside the cell, bend over a tab on each end of the tube to cover the hole, stick it in the cell, and solder each end separately.

 

If I remember correctly, the old radiator shops used an oxyacetylene torch, or maybe an oxypropane torch and lots of liquid killed acid flux. Killed acid flux is a small miracle. I believe they used a slightly carburizing flame to avoid oxidizing the solder. In any event it was a hot torch. Keep it moving! If I were doing it, I would run with the flame turned down to keep the flame speed kind of low and less aggressive. I think the old axiom of electronic soldering applies here: "Get in, get done, and GET OUT". The idea is to get the work hot enough to melt solder, and it HAS to be hot enough to melt solder by itself, and get done before the heat has a chance to spread very far. Spreading heat is your enemy. Any time you are in doubt, stop and cool the whole radiator *all the way down* before having another go. I would definitely want a water hose handy to cool things down quickly if I stopped in the middle of a repair. You might need your final repair to cool naturally though. Don't tell yourself "I'm almost done, just a little more....." When in doubt stop. As long as the core hasn't fallen apart you can always have one more try.

 

Recently, working on a tank leak on my 36 Pontiac radiator with a Harrison strip core (GM called that honeycomb, even though it isn't quite. It is still soldered on the core face like honeycomb). I used a piece of copper sheet to shield the front of the core, the idea being it might keep that solder on the face too cool to melt. I guess it helped.

 

I'd start with Dyke's. Have fun.

 

Edited February 20, 2023 by Bloo (see edit history)

[60ch]

5 hours ago, Bloo said:

Apparently not, considering the direction this thread is going 😜.

 

The sad truth is they are probably junk. That wouldn't stop me from trying to repair though. People used straight water for coolant then, and usually not even distilled. The passages in a honeycomb radiator are tiny. The small flakes of rust plug things up quickly. Mineral deposits from the water do too. There is no practical way to clean them out other than backflush. Better than nothing, but it doesn't do much. If the cores ever froze, there will be too much damage.

 

That's how it was done, except it was to isolate the outside. In fact, I've done it when I was a teenager, but I don't remember how. I have also repaired some cracks in the middle of tube and fin cores when the radiator shop said it was impossible. Looking back on that, I think a lot of dumb luck was involved. By the way, you would fill a cell like that when the brass was cracked out in the middle of the cell. That's kind of a "worst case" repair. On a honeycomb radiator, the soldering is all on the front and back face of the core. Any solder problems would be fixed right there on the face. The information I had on how to fix these either came from Dykes, or from the giant stack of late 1938-41ish Mechanix Illustrated, Popular Mechanics and Popular Science my dad still had laying around from those days.

 

Ok, so if you are going to plug a cell, something has to go in the hole. The solder on the outside of the core is the only thing that keeps the core from falling on the floor in a pile of parts, so you can't get it too hot. That is the biggest danger. The solder probably isn't going to bridge a whole cell by itself. Solder follows the heat, so if you heated it from the backside enough to fill the whole cell, both ends of the tube would be hot enough to melt solder and I think the core would fall apart. Oddly I think this is how it was done, and probably how I did it, but I can't imagine how. Filling it with copper wire won't work. It would not only be thicker than the brass, but it's way too good of a heatsink. An approach that sounds like it would work, just thinking about it now, would be to take a brass tube that would fit inside the cell, bend over a tab on each end of the tube to cover the hole, stick it in the cell, and solder each end separately.

 

If I remember correctly, the old radiator shops used an oxyacetylene torch, or maybe an oxypropane torch and lots of liquid killed acid flux. Killed acid flux is a small miracle. I believe they used a slightly carburizing flame to avoid oxidizing the solder. In any event it was a hot torch. Keep it moving! If I were doing it, I would run with the flame turned down to keep the flame speed kind of low and less aggressive. I think the old axiom of electronic soldering applies here: "Get in, get done, and GET OUT". The idea is to get the work hot enough to melt solder, and it HAS to be hot enough to melt solder by itself, and get done before the heat has a chance to spread very far. Spreading heat is your enemy. Any time you are in doubt, stop and cool the whole radiator *all the way down* before having another go. I would definitely want a water hose handy to cool things down quickly if I stopped in the middle of a repair. You might need your final repair to cool naturally though. Don't tell yourself "I'm almost done, just a little more....." When in doubt stop. As long as the core hasn't fallen apart you can always have one more try.

 

Recently, working on a tank leak on my 36 Pontiac radiator with a Harrison strip core (GM called that honeycomb, even though it isn't quite. It is still soldered on the core face like honeycomb). I used a piece of copper sheet to shield the front of the core, the idea being it might keep that solder on the face too cool to melt. I guess it helped.

 

I'd start with Dyke's. Have fun.

 

Bloo, Great tips for soldering. Thanks much.

Terry

[Oldtech]

Old radiator guys can do amazing things with a torch and not turn the thing into a puddle on the floor, but I'm not that guy. I have repaired or helped repair some old radiators with my father, who always used an iron. I think he had some kind of iron beat into a long thin end to get between the tubes. Everything depends on where the leak is. We are fortunate to have a very skilled local rad shop guy, but, as usual, he is talking retirement. 

[studeboy]

Well you want old time. here is what the 1923 Dykes manual says.

 

[leomara]

Hey studeboy, great information, however I would think this type of work would only be done by someone very versed in soldering techniques, not an amateur like myself.  Hope springs eternal. 

[dodge28]

I am an Old Rad guy, now retired. I will be 87  9th. March. The process of making Honey comb rad is more complicated than straight fins. Honey Comb is more efficient heating, the reason it was widely used in heaters up to the 60's. Most of the leaks are internal, from one strip to the next, caused mostly by using incorrect antifreeze. If you have the chance to open one look through a strip  towards  the sunlight and you will hundreds of tiny holes.

It is possible to get an oversize copper core in decent shape and cut it to size and use the old plate and tank to make a replacement.. The best preservative for old tanks is automatic transmission fluid. Fill the inside and spray the outside.

[R Walling]

 I have been saving a honey comb radiator out of my 38 Buick for some time now. Several times I was going to scrap it but something always stopes me .

 I was going to sell it  and I tested it. The core is good but the top brass is cracked in several places.

 It makes a nice ornament though.

[Mark Shaw]

2 hours ago, R Walling said:

The core is good but the top brass is cracked in several places.

 It makes a nice ornament though.

Roger,

     I encourage you to sell the core to someone who has good top & bottom tanks. 

IMO, wall hangers should never be usable parts.

[Ben Bruce aka First Born]

2 hours ago, R Walling said:

 I have been saving a honey comb radiator out of my 38 Buick for some time now. Several times I was going to scrap it but something always stopes me .

 I was going to sell it  and I tested it. The core is good but the top brass is cracked in several places.

 It makes a nice ornament though.

 

 WOW. Surprised '38 Buick had a "honey comb" radiator.

 

  Ben  

[DFeeney]

I have never regretted having a pre war  radiator re-cored once the bill is paid.   They always run much cooler as the original radiator had lost its efficiency.   Think Spring  

[hidden_hunter]

There is a guy in Queensland that also makes them using the original tooling 

[dodge28]

In my days it was possible to buy new cores and then cut to size and install your old plate and tanks. May be we should look around.

Harry near Toronto Can.

[drhach]

Go to the last page of this thread. He's about to embark on a project to make one from scratch. 

 

 

[JayinPA]

The honeycomb style radiators were used on several WWI aircraft, including the Fokker DVII.  On that plane the radiator is so prominent that any replica that does not use this style radiator is at a disadvantage.

The old machinery used to make the honeycomb is very ingenious and one machine was restored and used to build new radiators for a collector/museum in New Zealand.  I heard that the folks that made $$ from The Hobbit and Lord of the Rings movies have a little industry there that focuses on bringing back the original technology and parts.

A google search should turn them up.  

[Wascator]

There was an excellent Youtube video showing such radiators being made, I think in Australia, for antique cars. They are repairable and replaceable; like everything else, $$$. 
I had a Pierce-Arrow radiator recored modern, for a driver;  could have bought a new honeycomb core for $5000. Some will slice off the front of an old honeycomb and place it over the modern core to hide it. 
Found it: Vintage Honeycomb Radiator Company 

 

Edited July 16 by Wascator
Add info (see edit history)

[hidden_hunter]

On 7/16/2024 at 11:54 AM, Wascator said:

I think in Australia, for antique cars.

Yeah he's just near Brisbane airport from memory