Comb-Overs ‘N’ Cover-Ups

Tech

InTheGarageMedia.com

BY “Rotten” Rodney Bauman

Photography by THE AUTHOR

Comb-Overs 'n' Cover-Ups title typography

Restoring a Good, Used Radiator

ust about a month ago, while sorting out a coolant recovery system for our ongoing ’55 Chevy second-series build, we painted up some pieces—and they turned out real nice. Ordinarily that’s a good thing, but we were hoping to illustrate clever ways to fix minor imperfections, too. This time around it looks as though we’ll have our chance to do that.

With a little help from nearby Reynolds Radiator we’re wrapping up the truck’s cooling system. When we first received the job, it came with a functioning used radiator. It wasn’t much to look at, but at the time it seemed to fit in with its surroundings just fine. Now that those surroundings are shiny like-new, the radiator needs a little attention.

Just to catch us up, the truck’s OE-type used radiator has already been flushed, pressure-tested, and pronounced healthy to run. Our radiator guru, Howard Lilly, offered to paint it with a waterborne coating, but we opted to pass on that. Then sure enough, back at our own shop, we began to notice a number of cosmetic hiccups, like a dented top tank and mangled copper fins.

For straighter rows of fins (like most A/C condensers) a fin comb could be handy. Through Summit we’ve seen four types available. The trouble is here we’re not working with straighter rows of fins. We’ll be on our own to test and determine which of our sharp, pointy instruments are best suited to restoring the convoluted type of fins this radiator came with.

Sometimes radiators are beyond repair, so we teamed up with Classic Performance Products and Duralast to go a step further by creating a neat little instructional video on installing a brand-new radiator. Visit DuralastParts.com to find the radiator application for your classic truck.

To properly repair this radiator’s top tank, it should be removed, metal-finished, and then soldered back into place. Considering the amount of attention that other parts still need, that doesn’t seem like a good use of time. For situations such as these, cheating comes to mind.

If you’ve been with us you may have noticed that we keep polyester body fillers on hand at all times. Through the years such fillers have come a long way, but would a 1/8-inch (or so) smear hold up to cooling system temperatures? Since we know the same fillers would hold up under black exterior topcoats, even in the blistering summer sun, we’d hazard a guess that ours will hold up well right here.

What our good, used radiator needs now is a good old-fashioned cosmetic restoration. For that we’ll use whatever’s in stock along with the Evercoat fillers that we routinely order through Summit. As a timesaving measure we’ll try out a convenient Dupli-Color aerosol Filler Primer, which coincidentally (like most of the materials we’ll use here) comes from Summit as well.

Toward the end of our story we’ll load up a ’gun for a spray application of our favored high-temp coating. If things go our way, we’ll have the minor imperfections we’ve been hoping for.

1. Straight from the radiator shop, we could go ahead and paint this thing. The top tank, however, is beginning to bug yours truly.

2. Here’s a closer look. It looks pretty lumpy now. Just imagine how lumpy it’ll look in semigloss black.

3. Backing up a bit or two, let’s begin again by blowing bits of crusty crud from the radiator’s core.

Treating this like any other part to be painted, grease ’n’ wax remover comes into play. With clean disposable toweling it’s dried off before solvent can evaporate.

4. Treating this like any other part to be painted, grease ’n’ wax remover comes into play. With clean disposable toweling it’s dried off before solvent can evaporate.

For filler to adhere paint must be removed and brass below must be abraded. For this we’ll use 3M Scotch-Brite discs on Harbor Freight’s angle die grinders.

5. For filler to adhere paint must be removed and brass below must be abraded. For this we’ll use 3M Scotch-Brite discs on Harbor Freight’s angle die grinders.

6. We’ve seen these steps before, but probably not on a radiator, right? Overprepared brass we’re smearing stock-viscosity Rage Gold.

7. A proper-dimension flexible sanding block should fit the bill here. Like we would for body panels, we’ll begin with 40-grit, switch to 80, and then 120.

8. In a few places undercut edges could transition a little smoother. For this bit of fine-tune feathering we’re using Metal Glaze 416.

Used as a blending putty, Metal Glaze sands very easily, so we’re able to do this without much effect on the previous smear. This tank is now ready to prime.

9. Used as a blending putty, Metal Glaze sands very easily, so we’re able to do this without much effect on the previous smear. This tank is now ready to prime.

So what about the radiator’s core? Fins are bent and some are even torn. There’s no specific-purpose tool for this bit of repair, but we can try some things we have.

10. So what about the radiator’s core? Fins are bent and some are even torn. There’s no specific-purpose tool for this bit of repair, but we can try some things we have.

11. A small pick tool is helpful to get things started. Sandwiched between screwdriver blades the fins straighten right out.

Now we can spot-prime the tank as necessary. Let’s also try skipping the ’gun-cleaning step. With aerosol Dupli-Color Filler Primer we’re thinking we might save some time.

12. Now we can spot-prime the tank as necessary. Let’s also try skipping the ’gun-cleaning step. With aerosol Dupli-Color Filler Primer we’re thinking we might save some time.

So it’ll tolerate expansion, we’ve gone light with only two wet coats of filler primer. For the pinholes we can see, we’re using good old-fashioned 3M spot putty.

13. So it’ll tolerate expansion, we’ve gone light with only two wet coats of filler primer. For the pinholes we can see, we’re using good old-fashioned 3M spot putty.

Let’s consider this prepped at 320-grit. The small chunk of red Scotch-Brite pad is a close equivalent to 320, so for deeper reach we’ll use it in crevices.

14. Let’s consider this prepped at 320-grit. The small chunk of red Scotch-Brite pad is a close equivalent to 320, so for deeper reach we’ll use it in crevices.

Back where we started we’ll finally be painting this thing. We’ll be using a type of high-temp coating that ordinarily requires engine heat to cure.

15. Back where we started we’ll finally be painting this thing. We’ll be using a type of high-temp coating that ordinarily requires engine heat to cure.

In this instance a nice paintjob won’t require an expensive ’gun. From Harbor Freight this HVLP was under $10. This would be a good time to exit to fresh air.

16. In this instance a nice paintjob won’t require an expensive ’gun. From Harbor Freight this HVLP was under $10. This would be a good time to exit to fresh air.

By this time we’ve applied two wet coats of our high-temp coating. We’ll need to handle the radiator, so we’re attempting to force-dry the fresh finish.

17. By this time we’ve applied two wet coats of our high-temp coating. We’ll need to handle the radiator, so we’re attempting to force-dry the fresh finish.

Right about now this is feeling like a win. The restored radiator is installed, but what’s this? Somebody’s missed a pinhole! Now, finally, we get to fix a minor imperfection.

18. Right about now this is feeling like a win. The restored radiator is installed, but what’s this? Somebody’s missed a pinhole! Now, finally, we get to fix a minor imperfection.

A rummage through our sticker stash has rendered a solution. Up to our fairly high standards, the top tank is finished but what about the radiator’s core?

19. A rummage through our sticker stash has rendered a solution. Up to our fairly high standards, the top tank is finished but what about the radiator’s core?

20. Remember a little earlier, when we were straightening fins? That turned out pretty good! If it hadn’t, we’d have been ready—with another solution.

Harbor Freight Tools
(800) 423-2567
harborfreight.com

Summit Racing Equipment
(800) 230-3030
summitracing.com

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