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Any advice for cleaning out a radiator

JohnC

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I have a Harrison radiator that seemed to work OK ages ago when the car ran. Rather than throw in a aluminum radiator, thought I'd try to clean up and paint mine and see if it keep her cool (350 with AC).
Radiator is obviously out of car. Trying to get rid of scale and sediment/deposits etc. My thought is pour a gallon if vinegar, cap it and flip it around for a couple of days, then flush. Other thought would be CLR.
Any reason why these would hurt the radiator? Anyone got another magic elixir to clean a radiator?

I don't think we really have many radiator shops in this area. I don't think it's cost effective to re-core or boil out a radiator in this area.

Thanks
 

kmakar

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Last one I did on the cheap was to lay the radiator down with the ports up (cap on), poured vinegar in and filled it and let it sit for 24 hours.

Poured out the vinegar, mixed a light solution of baking soda to neutralize the vinegar, poured that in and let is sit another 24 hours, then poured that out and rinsed it.

Came out surprisingly well.
 

JohnC

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Thanks. Vinegar seems obvious but I hadn’t thought about baking soda to neutralize. I was just planning to flush.

Thanks for the link.
I bought some Eastwood radiator paint too to make her pretty afterwards.
 

77cruiser

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I clean a tractor radiator a couple years ago with CLR, it worked great. I neutralized with Purple Power.
 

Nashville Cat

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Is a watered down muriatic acid too strong to clean one ?
I like this idea : use a kerosene bullet heater to boil the cleaning solution

 
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Pete 67

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Thanks. Vinegar seems obvious but I hadn’t thought about baking soda to neutralize. I was just planning to flush.

Thanks for the link.
I bought some Eastwood radiator paint too to make her pretty afterwards.

John,

In the future, save yourself some cash & skip the Eastwood overpriced spray cans. They just repackage other brands for the most part.

For radiator paint, I buy Krylon or Rustoleum gloss black in Lacquer. Usually around $5 a can at Lowes or HD.

Other paints that Eastwood advertises like cast gray or cast aluminum are available locally as well for way less $. If you want more info, I can post it.
 

JohnC

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Thanks. I had always thought the radiator paint was a lower solids paint so you don’t get the paint on too thick where it might prevent heat transfer.
Yeah, if you’ve got recommendations for hardware store equivalents I’d love to hear them.
Maybe I’m wrong but I avoid gloss black. Too shiny. For under hood stuff my goto was alway Krylon “semi-flat.” I always thought that looked the most correct
 

Pete 67

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Thanks. I had always thought the radiator paint was a lower solids paint so you don’t get the paint on too thick where it might prevent heat transfer.
Yeah, if you’ve got recommendations for hardware store equivalents I’d love to hear them.
Maybe I’m wrong but I avoid gloss black. Too shiny. For under hood stuff my goto was alway Krylon “semi-flat.” I always thought that looked the most correct
Lacquer is what you want for a radiator as it goes on very thin...no heat transfer issues. Gloss black is factory correct for a radiator. in '67 if you're going that route. Heater boxes are also gloss black as are the wiper motors for '66-67. No need to use lacquer on them however.

For other underhood items like inner fenders or air cleaners, pulleys, brackets, Rustoleum Professional Semi Gloss black is the ticket sprayed over epoxy primer. Used to be available in quarts at Lowes for about $9. I just checked...thanks to supply chain issues & the price of oil, it doubled to $16, but it's out of stock nationwide everywhere. :rolleyes:

Home Depot sells it in gallons, but it also doubled in price...at $72. I bought a gallon for $30 2 years ago. Sigh....


Regardless of price, it's the perfect shade of black & you can spray it on heavier if you want your sheen glossier or drier if you want them flatter. You can thin it with acetone & even add hardener to it. I used it for my firewall & floorpans under the car as well. Reduces with acetone. I usually mix it 1:1.

Even this stuff doubled in price since I bought it.. But you only need about an ounce of hardener per pint so it goes a long way.


Eastwood cast aluminum is the same paint as Krylon Dull Aluminum

Seymour Cast Blast & Stainless Steel paint are great for small parts & can be found for about $12 a can online. Again these have doubled in price, but still cheaper & better quality than Eastwood.
 
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SSuperDave

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I was always told that painting the tanks is ok, but not the finned area. I put an aluminum radiator in my Caprice last year and did the top and bottom tanks with catalysed enamel, and left the fins natural, and have had no issues with it. Between the a/c condenser and the shroud, the fins are not visible.
 
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