> Hammerite is a common hammertone paint. I think you used
> wrinkle finish, similar to that which used to be common on electronic panels.
I'm pretty sure that Hammerite does make a crinkle-finish paint.
If not, I discovered how to do crinkle-finish without the special
paint, as part of my continuing study on How To Ruin Paint.
> > I put the hammertone paint over bare metal. By bare, I
> > mean I did prep the metal for cleanliness and I gave it an acid
> > wash first, but no primer. I did not prime the bare metal
> > because I didn't know how a primer might affect the crinkle
> > action. I ended up with a great finish, but now I wonder about
> > the long term stability of the finish.
If you did use Hammerite brand paint, you're basically stuck with
it. That stuff is supposed to be virtually indestructible -- rust
proof, abrasion resistant, even dent resistant to some extent (hence
the name). I'm going to Hammerite the inside of Kim's Radio Flyer
wagon (her Christmas present) as soon as I see the first indications
of scratches or rust. That should protect it from having tools,
rocks, hunks of dirt and even kids tossed into it from time to time.
According to the package directions, you need to let the Hammerite
cure for 6 weeks, after which time it's a rust-proof, chip-resistant
seal that will protect the metal against most ugliness. I want to
do all the underhood sheet metal stuff (air cleaners, valve cover,
heater, brake box cover, etc.) in Hammerite. When I have the 18GK
apart, I'll do the cam covers, timing cover, and oil pan too.
> Many people use lacquer-type primer surfacer before paint. I would not
> worry about omitting this. In most people's hands, I doubt it does much
> for adhesion of the finish paint.
Ah, but in the hands of a Trained Paint-Ruining Master, even ordinary
primer can turn smooth-finish semi-gloss black into crinkle finish! Just
take a look at the front cross-member of my MGB sometime! :-)
> It sure does very little, if anything,
> to protect the metal. Metal primed with lacquer type primer surfacer will
> rust almost as fast as bare metal.
One interesting feature is that primers typically use a hygroscopic
filler (often gypsum) to make them take up the color coat more readily.
This is good if you prime, let it cure, flat it out and do the color
coat immediately. But it can be very bad if you prime, let it cure,
and then drive around in the rain for a long time. The filler will
absorb moisture and hold it right against the metal, which is just
exactly what you want if your goal is to turn your car into a piece
of iron-oxide lacework in the shortest possible time.
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