Once the new fittings are attached and the heatercore has had a bath and another leak test, it should be ready for a nice paintjob. I normally add a couple of primer coats, a couple of color coats and then a couple of clear coats to greatly improve a heatercore’s appearance. If given the option, Duplicolor primer, paint and clear coat is what I use if it is available in the color I need. Getting a primer, a color coat and a clear coat from the same manufacturer is a fairly simple method for making sure you will not have incompatibility issues between the finish coats and Duplicolor paints are easy enough to find.
Before beginning the painting process, attaching the brass barbs to the core is a good idea. Attaching the barbs before painting keeps paint off the threads of the fittings and out of the inside of the heatercore.
Once the brass barbs are screwed into place, mask them off and make sure the ends of the barbs have a layer of tape over them to keep the paint on the outside of the heatercore. After masking everything, a couple of thin layers of primer should be sprayed onto the heatercore.
Do not spray paint or primer directly into the fins of the core as this can hinder its cooling performance. Instead, lightly dust the top edges of the fins from a fairly low angle while the sides of the heatercore are being coated. By just dusting the tops of the fins, the paint should go no deeper than about 1/8″ and it will not hurt the heatercore’s cooling abilities.
As can be seen in the picture, the heatercore was elevated off the bench a few inches which really helps get paint in the ridges on the sides of the heatercore. I discovered that a 4″ wide Tupperware type bowl that is about 3″ tall makes a very nice platform to set the heatercore on while painting it. Once again, make sure the significant other is elsewhere when you sneak into the kitchen cabinets and abscond with the ill-gotten Tupperware booty for your heatercore project.
After letting the primer dry per can instructions, two or three color coats can be added in the same manner. Always spray thin coats and let each coat dry before adding another coat to prevent paint drips, runs or nasty finish sagging. Once the color is nice and rich, add a couple of clear coats to bring up the shine and add some depth to the finish.
After letting the final finish coats dry overnight, carefully remove the masking tape and then remove the brass barbed fittings. Either wrap some Teflon tape around the threads on the brass fittings or add some of the pipe joint compound to the threads, screw them back into the fittings and tighten them down securely. The entire painting process is fairly simple, takes only a little bit of time and greatly improves the heatercore’s visual appeal.
To really get the most out of a heat exchanger, a fan shroud is required. Of course, a standard 120mm fan can be bolted directly onto the Chevette heatercore but the same heatercore with a good shroud will gain a performance boost of 35-40% which is well worth the cost of the shroud. While there are numerous ways to construct a shroud for a heatercore like the ’86 Chevette core, the easiest and most cost effective route is to buy one pre-made as there are several shrouds for this heatercore that are very inexpensive. An example of a good commercial shroud for the Chevette core is the Coolingworks Coolshroud. Check out the Coolshroud
While heatercores may require some modifications before being hooked into a watercooling loop and they are by no means beautiful right out of the box, a little time and effort can turn them into very effective and nice looking heat exchangers. Even after adding in the cost of the necessary parts or supplies needed to give a heatercore a solid transformation, they are still much less expensive than almost any other option and they will perform just as well if not better while still leaving extra money in your pocket.