Heater Core, paint or no paint?

[Iconic]

Hi All !
This is the first thread I have started in many years. That is because this forum is awesome and has so much info available.
But, I could not find that anyone has asked this question before.
I pulled my heater core and had it re-cored.
The guy that repaired it gave it to me unpainted. I inquired why and he stated that the paint would smell in my car. Well, I've done this same job on my previous Pagoda, and it was painted and I believe that is normal. The heat should make any smell go away quickly, so I am not worried about that unless one of you experts tells me he is correct ......
But, then I got to thinking, what if I paint the brackets, plate, and end tanks, and leave the copper core with no paint.
I was thinking more heat might come off of it if there was no paint. 
What do you think???
No paint at all?
Paint the whole thing?
Or, paint all but the copper core??
For sure I am polishing the inlet and outlet that come out of the firewall and putting a little high temp clear for cosmetics under the hood.
Thanks for your time,
Mark

[Jonny B]

Mark,

Glad to see a post!

I looked in the tech manual, and it shows a heater core, new from MB, painted all black. Then just below it it shows a heater core being repaired and it is unpainted showing the metal. Your choice, I would guess that painting will diminish the heat transfer  bit, and your could block the air pathway with some paint, but probably minor. Boils down to your choice as no one is going to see it anyway.

The end plates of the core would be black and they extend out the firewall. Are you going to polish them to brass? Or keep it with shiny black paint? Again, your choice as very little of the metal shows between the hose connection and the grommet to the firewall.

Will be curious to see what you hear from others.

[Iconic]

Thanks Jonny,
As far as the inlet and outlet pipes, I was going to polish the brass and clear coat it. That is what I have done before.
I believe in the old original pictures I have seen, there is a little brass showing between the firewall grommet and the connected heater hose.
I'm going for that look.
Are you stating that you believe those pipes should be shiny black?
As far as the rest of the heater core that you do not see when installed, we are in complete agreement and I also would like to hear what others have to say.
Thanks !
Mark

[BobH]

Hello, these are how the new ones are finished:

https://www.authenticclassics.com/Mercedes-New-Heat-Exchanger-Core-230SL-250SL-280SL-p/auth-009299.htm

https://www.niemoeller.de/en/w113/w113/B044/830/d83187-heater-core-reproduction

[Iconic]

Thanks Bob,
That is helpful.
I know I'm hijacking my own thread, but I've inquired at both of those vendors whether their cores are aluminum or copper.
I was just curious and it would be good to document that here. So, once they respond, I'll put the answer here.
Maybe the answer to a question that no one else was asking. 
I have a good idea how I will be painting my core....
I'll report back when done.
Mark

[BobH]

No problem, please post here what you find out and i'll add it to the Technical Manual for others to see

[Jonny B]

Mark,

Hard to be completely certain with my 280 SL, as there is very little showing, and I don't think it has been touched (given the state of the grommets).

My guess is that by leaving them as brass it would make for a better sealing surface?