gpw rad resto

[Bill M]

Regarding GPW F marked radiators, my lower tube is too far into the bottom tank and I need to pull it out so the drain cock can unscrew. I plan to gently heat it so the tube can be moved out and resolder the tube to complete the task. Is this as easy as it seems?
cheers
Bill.

[Jerry Hudgens]

To clean your radiator I suggest a product called ChemPrime. Its basically phosphoric acid with other chemicals. It says on the jug label that its useful for cleaning radiators.

I use it on a lot of things and I find its a little more easier to use/handle than muratic acid. I use it to clean up copper and brass items. It will eat rust away and it will take away tarnish on copper and brass but it doesn't harm the copper and brass.

Jerry HUdgens
42 GPW

[Lew Ladwig]

Jerry,
Where have you bought this stuff? As to redoing the tube it is as easy as it sounds. Just be sure the new area is super clean and use lots of flux. It's just like doing a copper water line joint. I would position so that extra solder does not flow into the tank.
Lew

[Bill M]

Thanks Lew, I'II be watching this post with interest to see what information comes out of late GPW radiators.
cheers
Bill.

[Ralph]

Lew,only the top tank need be removed for rodding.The debris loosened is easily flushed out the bottom hose casting when you are finished.When removing the tank(after unsweatng the side braces from same) set the radiator on its side so that the solder will more easily fall away as it melts.Put the heat source,(we used natural gas pushed by air) on the seam only and use a stiff acid brush to get that solder out as soon as it will melt.Put a wood-handled wire brush into the top hose casting,handle end first,to gently wiggle the tank -only- after 75% of the solder is removed,it will speed the process somewhat.After it is off,you really need a stiff piece sf stainless long enough to go all the way through and still hold onto.It of course shoud be less width than the tube.Try to get one from a rad shop,and watch for smirks...it helps if you can hook water to the bottom casting to have a flow through the tubes while rodding.A lighter radiator grade flux is better than Muratic for this job.Too much Muratic on an older radiator can finish it.The radiator shop acid tanks are greatly diluted....before reinstalling the tank,wire-wheel it in the area that goes down into the core.When soldering the tank in.set the radiator in its natual upright position of course.Watch the heat;it is thin brass.Good Luck

[Jerry Hudgens]

Lew,

Sorry for the late reply. My e-mail has been down as ususal.

I buy ChemPrime from a local building supply company here. Its made by AL-Con Chemical Company, New Orleans LA 70182. It says on the label: "Coolers, pipe lines, radiators, tanks, etc. are filled with ChemPrime from 1 to 10 hours and then flushed with water." I don't think it would hurt to allow the stuff to work on your radiator for longer than 10 hours since it does not attack copper or brass. If a steel part is left long enough in the solution (over 24 hours), it will etch the good metal, but it primarily just eats rust.

Its basically Phosphoric acid with inhibitors and other chemicals. I find that it works better than Ospho and I use it for a lot of different things. I use it to remove rust on parts by soaking. I use it to clean brass and copper parts, and occasionaly I use it as a mild pickle prior to zinc plating. Finally I use it as a painting prep on clean metal before priming. If you use it for painting prep, apply it to your part and then dry it with a clean cloth. Don't let it air dry on the part. After you dry it with the cloth, prime immediately.

Try it, you will like it.

Jerry Hudgens
42 GPW

[Lew Ladwig]

Thanks Jerry,
I'll give it a go on the radiator and report back.
Lew

[Tanker Dawson]

I'll suggest you check your chemistry on the material that basically turns iron oxide into iron phosphate.

After all you're not trying to preserve any iron deposits inside the radiator and you also need to remove calcium.

In my first post I suggest a DILUTE solution of the Muratic acid.

A simple test on the inside of the removed upper tank will give you a base line.

The use of a rod sized to the radiator cooling tubes is also most important to removing scale build up.

You need the chemical and the physical actions to do the job correctly.

[lt.luke]

One note about the "GPW F" marked radiators that no one on this thread has mentioned yet. The cooling fins on the front edges of the core are cut at a 45 degree angle. It's very obvious, I just don't know if it applies to your 1945 GPW.

I believe it is true that less things were "F" marked later in production, but I hadn't heard of a non "Ford" radiator. is there any way you could post some photos along with this thread please? I'm interested in saving my original radiator, and I'm not sure the guy at the local radiator shop thinks it's really possible.

One question, are you planning on taking it to a local shop for a pressure test when you complete the project?

[Lew Ladwig]

I think I will pressure test it at home. I can simulate about 7lbs and have it in a tub of water and look for bubbles. I plan to cap the hose tubes by using old hoses and plugs and to run a new cap. I hope to get to the hardware store today to get a piano wire to rod it out. I need some more acid to clean with also. I plan on experimenting to see what mix works best.

Lew

[Lew Ladwig]

OK, I tried the phosphoric acid type solution today and it did not do much. I tried muratic acid and it worked fair. Once it had been in muratic a little acetone cut into the paint real well. So far I have only soaked the top tank. I am now in the process of redoing the outlet pipe. I took the pipe out (unsoldered it). The tank has a large crack ajacent to the pipe hole. I am currently making a copper bandaid to go on the inside of the tank to fish plate the crack. I rodded the tubes out using a long strip of aluminum cut to just under the 5/8" width of the tubes. I did this since a rod bent around any obstructions. I did push a bunch of junk out. I also found a few tubes that were full of oily tar stuff. I rinsed the rad core inside the tubes with acetone. I also removed the splash plate inside the top tank to be able to clean behind it and make more room for fixing the outlet pipe.
I'll keep you posted.
Lew

[Tanker Dawson]

You'll want to keep water flowing in the tubes as you rod them, this as a lubricant as well as a way to flush out gunk.

If you hit a hard spot then use a smaller rod.

The rods come in different sizes and are ment to be used in stages.

Sounds like you're getting the job done, and yes I've had to patch tanks with a copper strip before so now just hope the tank is not too brittle.

Moving right along.

[Lew Ladwig]

Got the outlet pipe repaired. I used a good tinning flux and the solder flowed nice and built up where I wanted it for extra strength.
Tanker, I had the hose going when I rodded it. The strip metal worked great. It really pushed all the gunk out. If it's not too cold tommorrow I will try to dip the core in acid and give it a good rinse. I'll probably rod it once more to be sure I got it clean.
It will take some good polishing to get all the metal bright so I can solder the tank back on.
Lew

[Jerry Hudgens]

If you soak the copper/brass in the Phosphoric acid solution it will work on the tarnish so that when you polish the copper/brass it will come clean and shine. I have had good results using the Phosphoric acid solution to remove rust and tarnish off brass and copper. I generally let it soak a few hours.

Jerry Hudgens
42 GPW

[Chuck Lutz]

I wonder if that oily tar-like gunk in there was our old friend, "Bar's Leak" that a PO had used?