Brush-on primer

[John_Corey]

Hi all,

After removing rust with sandpaper and with a wire wheel, which rust converter gives the best results? Should I use a zinc spray before using a brush-on primer? And which brush-on primer is the best? Should it be self-etching primer? How about a marine primer?

The rust spots that I am fixing are in hidden areas. While those repairs do not have to look good, I want them to be as long-lasting as possible.

Thanks in advance!

Cheers,
-J

 

[mechtech2]

Old fashioned naval jelly [phosphoric acid] works very well to eliminate surface rust, and rust in the pores of the metal.
Gob it on, let sit, and wash with plain water.
Repeat as necessary.
Then prime and paint.
There are rust converting sauces, but they are not suitable for fine automotive finishes. Only hidden areas.

 

[John_Corey]

Hi mechtech2,

Thank you for your response.

After the treatment with naval jelly, and subsequent washing and drying, which type primer should I use? Does a primer contain zinc make any sense? Should I use a self-etching primer, or maybe some other kind of primer? I really prefer a brush-on paint over spray paint.

Cheers,
-J

 

[Carbon]

POR-15 is good if you want to not have to remove all of the rust.

 

[mechtech2]

I am not a paint expert, although I have done just about everything paint wise. New products are developing, and you already seem to know about your choices.
1/2 hour on the internet will get you primer specifics.
Zinc rich primer is an old staple, it has much merit.
Make sure it is compatible with your final top coat paint.

 

[JT1]

Urethane primer works very well on bare metal, better than zinc primer IMO.

 

[John_Corey]

Hi Carbon,

I took a look at their Website. I may get Metal-Ready, the 4oz can of Por-15 Rust Preventive Paint and a pint, which is the smallest size, of Sterling Silver.

Cheers,
-J

Originally Posted By: Carbon
POR-15 is good if you want to not have to remove all of the rust.

 

[mechtech2]

4 ounces won't cover a lot. [But POR15 is a very good product.]

Auto parts stores have spray cans of special anti rust primers for about $10. I would also consider them.

 

[John_Corey]

Hi mechtech2,

I am sure 4 ounces will suffice for painting two quarter size rust spots!

I don't want to use thin spray paint. The two rusty areas are right under the lower edge of the rear window where the water runs off under the trunk lid.

Cheers,
-J

Originally Posted By: mechtech2
4 ounces won't cover a lot. [But POR15 is a very good product.]

Auto parts stores have spray cans of special anti rust primers for about $10. I would also consider them.

 

[mechtech2]

It's good that you are taking care of this early.
Some people wait until there are two football sized rust holes!

 

[John_Corey]

Hi mechtech2,

I am beating myself up over not preventing those rust spots from happening in the first place. I should have applied Krown or a similar product in rust-prone areas as a preventive measure from the beginning.

Cheers,
-J

Originally Posted By: mechtech2
It's good that you are taking care of this early.
Some people wait until there are two football sized rust holes!

 

[andyd]

Originally Posted By: mechtech2
It's good that you are taking care of this early.
Some people wait until there are two football sized rust holes!
Yah , but by procrastinating , I get to improve my tin knockin

 

[mechtech2]

Just one more thing..
If you are going to do it, DO IT!
Don't be hesitant and afraid to get all the rust off. Dig deep and get the edges.
This is the #1 amateur mistake. Not diving in and really fixing it. Just tick tac top patching.

 

[severach]

I find that all rust can be removed with a large enough wire brush. There isn't much that can stand up to the 10,000 RPM angle grinder brush.