How to paint a heater core?

[DarkenReaper57]

Hey, I want to paint my 77' Bonneville heater core after I sweat some barbs on. Anyway, how should I go about this?

I'm reading that its best to sand it down with 400 grit sand paper, spray on some paint, let it dry, then add on two clear coats (this was posted by weapon on another forum)

Now, what type of paint should I use that is effective, black, reasonable glossy, and cheap? I dont want the result to be bland (my heater core, shroud, and fans will be externally mounted on the top of my case, so I want it to look attractive). Also, what type of spray should I buy for a clear coat?

If someone could just write out a quick to-buy list and a short guide I will be extremely grateful.

 

[weapon--]

I'm reading that its best to sand it down with 400 grit sand paper, spray on some paint, let it dry, then add on two clear coats (this was posted by weapon on another forum)

well, I think I said:

core painting -
1. scrub down the sides, the top tank and the bottom tank with cast aluminum wheel cleaner (bascially acid) and a brass brush - rinse it off with lots of water and let it dry.
2. lightly rough the sides and tanks with 400 grit wet/dry paper, once again, rinse with lots of water and dry off with lint free paper towels or terry cloth.
3. 2 mist coats of Duplicolor adhesion promoter as per can instructions.
4. 2 coats of Duplicolor Hi-Build sandable primer, lightly sand between coats with 400 grit wet - if you sand thru the primer and hit metal, add another primer coat.
5. 2 coats Duplicolor Primer Sealer
6. 2-4 coats of Duplicolor Enamel paint
7. 2 coats Duplicolor clearcoat.

let dry for about 5 days minimum if you go with the above painting scheme.

how to speed up the process.
1. steps 1-4 as above.
2. skip step 5 from above.
3. 2 coats of Duplicolor Truck and Van paint in whatever color you like.
4. 2 clear coats.

bake in oven at 125 deg F for 1-2 days.

both methods require a little more than sanding and spraying on some paint.

anyway, if you go with Duplicolor, their enamel paints have one helluva shine to them - especially the black enamel. fair warning: if you use several coats of it, the enamel paint can take days (if not weeks) to dry and harden.

the Duplicolor truck & van paint can also look really good but you have to lay on several clearcoats to add depth to the finish.

autozone, o'reilly's or advance auto carry all of the Duplicolor products I mentioned as well as the 3M wet/dry, etc.

 

[vbbartlett]

on the subject of painting, does painting the heater core have any effect on the performance of the heater core? I would think that if you painted it, especially the fins that it would act as almost an insulator...?

 

[M4d-K10wN]

Yeah, paint isn't a very good heat conductor, I would leave it unpainted to have better performance. One of the ways to get it looking pretty and not lose any performanace is plate it with some metal. Nickel, silver, etc. Obviously, silver would be best in this case

 

[weapon--]

on the subject of painting, does painting the heater core have any effect on the performance of the heater core? I would think that if you painted it, especially the fins that it would act as almost an insulator...?

Painting the tanks and the sides of the core has zero measurable effect on the cooling ability of a heatercore. As for the fins, hold the can at a bit of an angle to the side of the core so that the spray just covers the very outer surface of the fins. If done correctly, the paint will go no more than 1/16" - 1/8" down into the fins.

pic of core with fin edges painted:

Painting doesn't hurt the performance of the heatercore because it isn't insulating any of the areas where heat exchange takes place. I have a core dissected in the garage, I will take some pics of it and show exactly where the cooling takes place. Would you believe there are fins inside the fins?

 

[DarkenReaper57]

Thanks again

 

[M4d-K10wN]

Silver-plate it, I says.

 

[DarkenReaper57]

Ok, I put on a couple coats of black "Color Cast General Purpose Enamel" paint.

Now, how long should I wait until applying a clear coat? Fortunately, this clear coat drys to the touch in 20 mins (does that mean I can start setting up my system in an hour or so after?

I wanna speed things up as I painted the enamel 24 hrs ago, and I'm anxious to start setting everything up .

BTW, what material is the easiest and cheapest to make a shround out of: plexi or sheet metal? I am leaning towards the latter, because I think it will be more fun and will look better, however, I dont know whether or not my father has tin snips (lol). What else can make clean cuts on sheet metal?

Thanks.