Do you know how long it takes to paint the Statue of Liberty? Any guess as to how many gallons of paint are required to paint the iconic statue that has welcomed millions to the shores of America? Is it painted with brushes, sprayers, rollers? How often is the Statue of Liberty painted? Do you know already? Care to wager a guess? The answers are as follows….

No time at all…zero…none of the above…and never.

That’s right, the outside of the Statue of Liberty isn’t painted at all! It’s coated in a layer of copper that’s a little less than 1/8th of an inch thick. Cleaned on occasion? Absolutely. Painted? Never.

The Statue of Liberty may not be painted on the outside, but paint crews have done extensive restoration on the inside.
Image source: Wikimedia Commons

However, the interior of the Statue of Liberty is an entirely different matter. The painting of the Statue of Liberty is quite instructive for professional painters eager to learn about surface preparation techniques on massive metal and steel structures. The interior has always been painted and over time has accumulated a staggering number of coats intended to protect the structure from damage and preserve its industrial strength.

When the Statue was completely restored in 1984, the interior revealed seven layers of paint on the inside of the metal framing and two tar-based top coats. The very top layer of paint was originally a vinyl coating in a green color that would be removed and replaced with a color similar to that of a copper penny. Interestingly, the numerous layers of paint, substrate variations, and different degradation levels beneath meant that paint crews had to try a variety of paint removal methods just to strip the paint at all. Different parts of the interior had been well-protected by the coating while others showed damage and corrosion that compromised the strength of the Statue. The team painting the Statue of Liberty used chemicals, scrapers, and heat with varying degrees of success throughout the interior of the Statue in an effort to remove toxic paint and apply the new protective coating. In some places they were able to remove most of the paint layers, while in other places they left the paint completely intact. Working on a structure as large and as old as the Statue of Liberty meant that the paint on the interior would be of varied strength and integrity throughout. And even though the end goal was to have the inside shine like a new penny, the more pressing matter was making sure the metal and steel within the structure were kept clear of future corrosion and damage.

Just like the crew working on the Statue, painters working on industrial structures like oil rigs or metal art sculptures are called in not just to maintain or improve the atheistic and appearance of the structure but also to offer coatings that protect the substrate’s structural integrity. And whether working on a national monument or a set of mailboxes, the steps required to prepare the surface and protect it over time are largely the same.

1. Prefabrication Primer.  Use prefabrication primer to offer a quick protective coating before the real work begins. Shortly after sandblasting the substrate or stripping previous coatings, apply a primer to curb any short term damage or corrosion that might occur on the surface. Like other types of primer, the idea behind prefabrication primer is to create a layer between the substrate and the upcoming coating that will adhere together completely.
2. Intermediate Coating.  Think of your intermediate coating as adding a “skin” to the structure as a way to protect against the physical wear and tear of wind, sand, and naturally occurring minerals like salt. Take advantage of coating additives like glass or fiberglass flakes to increase tensile strength and decrease the permeability of environmental moisture. On many structures you will want to use more than a single layer of intermediate coating to buildup protection on the substrate.
3. Stripe Coating.  Stripe coating is a supplemental paint layer that addresses the parts of a metal structure most vulnerable to corrosion, degradation, and eventual structural weakness. If a part of the structure is more likely to be weakened over time, apply stripe coating. Stripe coating most often addresses welds, joints, screws, and nuts where penetration by moisture or standard wear and tear typically occur. The stripe coating provides an additional physical and chemical layer of protection to the steel material underneath.
4. Top Coating.  When adding this final protective layer, take care that your top coating is of sufficient hardness for the environment. Yes, the top coat gives the structure its final color and sheen, but that won’t matter much if it wears off quickly. If possible, apply the top coat with a sprayer to ensure a thick and uniform coating.

From oil rigs out in the ocean to gym equipment at the local park, professional painters must keep in mind that their service quite often has little to do with appearance but a lot to do with protecting the steel substrate from damage. Exterior paint work is never just about making something look good. It’s also about making sure something is around for years to come in the first place. Whether working on a national monument like the Statue of Liberty or the local water tank, surface preparation and protective coating for industrial structures is much different than painting an office building or set of kitchen cabinets. Click here to learn more about preparing and protecting exterior surfaces with paint and coatings!