radiator reservoir paint type?

[rmmchl]

I am tired of trying to keep my  polished brass radiator resevoir looking anything but polished!----------I am going back to the original paint. I glass beaded it today, and I am going to paint it black again. I thought about using semi gloss BBQ grill paint by rustoleum. Any other suggestions?

[Raymond]

Start with scuffing up that beautiful finish with a Scotchbrite pad to give the paint a key and use a self-etching primer.  Then use satin black top coat for authenticity or gloss black if you like shiny.  I do.  I like engine enamel, but as these tanks won't get over 240 degrees, Rustoleum should be fine. 

[scoot]

I have a related question - does the PRIMER need to be high-temperature?  Or can it just be the same self-etching primer that I used to paint other metal objects...

[thelews]

I like Duplicolor low gloss black engine enamel (high temp) for many things.  Great paint.  I'd prime it first.  Duplicolor makes a high temp primer too.

[graphic66]

This the best I have found  http://www.eastwood.com/paints/detail-paints/eastwood-radiator-black-paint.html   It looks perfect and holds up well.

[rmmchl]

I ordered the eastwood radiator spray paint today-$14.99 free shipping today also---It does not need primed. It's brass-------------no primer needed . The paint is especially formualted for high heat copper and brass.

[wwheeler]

If you want to stay with the brass finish, you could always spray the polished brass with a high temp engine clear. Rust-o-leum makes one and works well. The brass should stay in good shape under the clear. As another option, you could powder coat the brass tank with clear as well. That would be a much more durable finish. They also have a satin black powder coat color as well. That seems to match the MB black pretty well.

[hkollan]

Powdercoating this tank will sometimes cause the solderings to fail, depending on the temperature used in the oven baking process.

[wwheeler]

Powder coating requires a maximum of 400* F. Usually you can away with 370*F and clear is less at around 350* to 360*F. What kind of weld is used on the tank, solder or brazing?

[graphic66]

It is soldered.

[wwheeler]

Yes, a soldered joint could be a problem. The melting point is pretty close to the powder coat curing temp. Probably wisest to stay away from powder coat. Good thought Hans!

[DavidBrough]

I had mine powder coated and it fell apart at the first attempt so I had it re soldered and with the knowledge that was delicate the powder coater took special care and succeeded the second time.

[mdsalemi]

I posted about this last year.

A quality powder coat job will entail a pre-bake process that is done at a higher temperature than the actual curing.  The powder coater that I use does this on most materials.  If you don't do it, impurities in the surface of the metal can come back later and either bubble up during the actual cure, or later and caused bubbles and adhesion issues.

What I did with my tank was have it stripped and tested for powder coat.  The tank's solder  joints began to flow.  More importantly, perforations appeared in the tank itself, around some of the fittings.  Remember it is not just a tank, but a tank with a fitting on the bottom, a cap fitting on top, and an overflow fitting on the cap fitting.  More complex once you stop and think about it.

So, the tank was "damaged" or more likely, defects revealed in the pre-bake.  I took it to a specialty radiator shop and inquired about brazing.  Can't do it, they said--the brazing (silver solder) temperature is too hot, and with the thin brass of the tank, it is likely that it would warp.  They have to heat the substrate to glowing in order to properly braze.  Brazing temperatures are above 800 degrees F, or 450 degree C.  That's OK for piping, not for thin-wall brass.  Possible they said, but if the tank is ruined...

Well, not wanting any more trouble, I had them solder up the perforations, re-solder all the joints, and pressure test it.  I took it to my local shop, and they put a nice coat of semi-gloss black paint on it and it is now fine.  A set of new clamps and the assembly looks great!

[graphic66]

And another thing about the "pancake" style tank. It was the source of a very annoying rattle in my car. It sounded like it was coming from the right hand fresh air vent in the dash. It was actually the bottom bracket on the tank that had become unsoldered. Easy fix, tough diagnosis. So if you have a rattle, maybe check that. It might be like the heater cores on these cars. I think all of them have come apart at the mount, they don't rattle or cause any problems to my knowledge though.

[ja17]

Since these tanks are brass, they are soldered together. The melting point and strength of solder depends on the Tin and lead content of the solder. It can vary. Powder coating could be a risk.

Most paints will withstand at least 300 degree temperatures (same applies to primers). If you get your engine coolant that hot, the paint will be the least of your worries ! So use a good grade paint. The high temperature paints will work fine,  but are normally used on  the  very hot areas like the exhaust manifolds etc.

Two stage professional paints (urethanes etc.) with a catalyst are harder, more chemical resistant and will last the longest and hardest to apply!

[rmmchl]

the eastwood brand radiator paint did very well. The only drawback was it is supposed to be satin black. It looks very flat. It is not satin. It still looks very good

[DaveB]

Hello rmmchl,

The factory paint on this part was fairly flat, at least on the NOS 'pancake' (like that term!) type at the bottom of this post:

http://www.sl113.org/forums/index.php?topic=14372.msg98784#msg98784

I would describe it as halfway between flat and satin. In fact it's a terrible paint job with runs all over, but it is the genuine factory finish.

[rmmchl]

thanks daveb--makes me feel better about the flatness of it, knowing they cam from the factory that way