Metal Paint/Finish

[Bjorn]

Hello all. Recently I was asked to make railing panels for a deck. I usually do indoor small things, and give them a wire brushed lacquered or hot oil dip finish. Since the railings are to go outside in all weather and variety of storms we get in Kansas, I figure I need to paint the metal, but the customer doesn't want the plane color of black paint, and neither do I. So I was wondering if there are any clear paints for metal that will stand up to outdoor conditions. Thanks to all the happy smiths of the world!

-Bjorn

[mike-hr]

I've been using Sherwin-Williams OPEX clear metal laquer for around 5 years, haven't had any comebacks. I live in high desert type climate with snowy winters and lots of UV when it's not snowing, don't think I'd trust it on the coast.

[Bjorn]

Hmmm... Do you have to paint it on? or can I possibly put it in an automotive spray gun?

-Bjorn

[mike-hr]

I use a touch-up spray gun in the shop, paint brush in the field.

[Candidquality]

Any idea on the actual life span. I know that any coating that's used now is going to wear off. The old lead based paints were great for wear, just a bit unfriendly to the environment. Do you instruct your customers that they will need some upkeep? do you do that work yourself? How much of your design takes into account the fact that you don't want a place for water to gather, or do you worry about that?

[Glenn]

If you use automotive paints, I would imagine that they would last as long as they would on a car. Scratches would have to be touched up of course.

[jeremy k]

I use automotive Epoxy primer w/ catalyst and Acrylic Enamel w/ catalyst. I've been using automotive paints on my hand railings for almost 20 years. You get the durability and the capability to color match existing colors and or trim on the house for accents etc. Now the paint can be made in small spray cans for touch up that you can give to the owner for later use. I also try to keep a record of the paint formulas from the automotive paint supplier of each job I do for future use/additional metalwork they may want the same color. All my metal work gets sandblasted before painting. - JK

[HWooldridge]

There are several things you can do but in all cases, I suggest you sandblast the work before applying the finish. Scale has a tendency to loosen and pop off from normal thermal changes in the weather.

1. I often cold blue pieces, then clear coat with satin urethane. This works well outside and will last several years if it's not scratched. It has no "cover effect" and completely shows the nature of the forged surface. I use this process exclusively for interior work but it looks great on external stuff if you take the time to do it. I use "Varithane" brand urethane in the rattle can.
2. I sometimes will spray a piece with the cheapest black paint on the market (Home Depot sells their house brand for $.99 a can). Let sit a few seconds and then wipe off the excess. A few layers of this will color nicely. Apply the clear coat and you get a similar look to #1 above with slightly more cover. If the customer wants, I also will provide metallic patinas to enhance the highlights.
3. You can sand blast, wire brush the whole thing and use the torch to color it from a brown to a nice peacock blue. After it cools, apply clear coat.
4. You can flash rust the work after sand blast. Obviously, it will be a shade of brown but that color can range to almost black if the reaction is pushed. You can make a very nice mottled surface or have the entire thing close to the same color. Instructions to do this can be found here in the archives as I was the one who asked how to do it and received several responses. The peroxide/salt/vinegar mix coarsely sprayed and followed by bleach works quite well - but you need to apply heat in the form of a torch or something else. About 200-300 degrees is right to have it sizzle.
5. Sherwin Williams will make any color you want and their house brand of synthetic enamel is very durable but slow to dry. However, if you can apply it under the right conditions (either bake or let air dry for a few days), it will be quite tough and resistant to damage.

Use your imagination - basic black is fine but there are many options available these days.

[mike-hr]

I'm very up front with customers in regards to the longevity of laquer. I guarantee the finish for 5 years, and tell them it will probably need work after 7 or so. It's real easy to sand down, and brush on a new coat. I've had problems with painted railings, specifically Sherwin's Polane catalyzed, in shades of gray. The black does fine, but the gray crashes from UV in 3 years or less. For painted stuff I now use Sherwin's Sher-Kem. We'll need another 3-4 years to see how it's working..

I got to experimenting a few years ago, trying to duplicate the look of wire-wheeled steel in paint, I got a real good look by mixing half black with half chrome fleck metallic.

[Frosty]

MIxing a little graphite with black paint will give a nice "steel" finish as well.

Frosty