Follow a Part From the Start: Chrome Plated Brass Grille Surround

February 2, 2015 by Josh - No Comments

If you have studied or read much about automotive history, you may be familiar with a period or automobiles referenced to as the Brass Era.  Back before nickel and chrome plating were used as the accepted finish on automobiles, brass was the number one choice by carriage houses, coach builder, and auto manufactures.  Whether it was polished brass or brass plating, it was the finish of choice for trim adorning new horseless carriages during this time.

Although the brass era of automotive manufacturing was long over by the late 1920’s, a few manufactures still chose to produce a number of their car parts in brass and have them plated in nickel or chrome.  In fact, many European cars (most notably Jaguar) feature trim and various other parts manufactured in brass up into the 1970’s.  American automotive manufactures on the other hand had pretty much eliminated the use of brass by the 1940’s and moved to using steel and die-cast to form parts out of that would require plating.  This decision was based mostly on what was most cost effective versus what was going to plate the best and last the longest.  Of all the metals that you can chrome or nickel plate, brass is by far the superior metal of choice.

However, there are pro’s and con’s to everything and stamped/formed brass parts all seem to have the same con…they crack and split easy.  While this is not necessarily a problem with solid brass parts, we see our fair share of formed brass parts and the majority of them have cracks or splits.  This tends to happen since brass is more brittle than steel.  This is especially prevalent on items like headlight rings and grille surrounds, mostly because these items are flexed and stressed more than other trim items.  Have no fear though, should you discover that some of your car parts are made of brass and cracking, we can fix them!

While the majority of the parts that come through our doors here at Advanced Plating are pot metal and deteriorated steel, we also repair cracked brass parts as well.  In this edition of Follow a Part From the Start you will see from start to finish all that is involved in repairing and re-plating a part that is made of brass and is unfortunately cracked.  Our subject at hand for this edition will be a grille surround for a 1929-30 Chevrolet.  Take a look and see how we solve this splitting issue.  Enjoy!

brass grille repair

Here is the grille surround in raw brass after it has been electro-stripped of its existing plating.

brass grille chrome

Typical of vintage parts made from thin brass, the grille surround has cracked and split. This crack is located around a couple of rivets on the lower side that attaches the steel brace to the surround.

brass grille repair

Before any repairs are made, the surface of the grille is highlighted with a hard backed grinder. This allows the polisher to identify low spots and high spots, as well as any other imperfections.

brass grille repair

The low spots that were revealed by the highlight polish are then tapped out with a hammer.

brass grille repair

When the polisher has achieved the desired level of straightness with the surface for the first round of plating, he will then proceed to make repairs. Here the polisher uses lead solder to fill and repair the cracks.

brass grille repair

With the repairs made to the cracks and sanded down smooth, the polisher now uses an air file on the flat sides to ensure a wave free finish.

brass grille repair

Once the sides of the grille were air filed flat, the whole grille was sanded to uniform finish and readied for plating.

Successful plating relies a lot on excellent racking. Here the grille surround is racked upside down from the brace. This way any marks left from racking will be in areas unseen after assembly and hanging upside will also minimize the chance of any particles landing on the face of the surround during plating.

brass grille repair

Any part that is plated must first go through a caustic cleaning bath, which will remove any unwanted oils or compounds from polishing.

brass grille repair

In order to promote thorough adhesion, the grille surround is first placed in the cyanide copper tank for few minutes, or what is called “strike” of plating.

brass grille repair

Only a couple of minutes later the grille has a strike of cyanide copper on it.

brass grille repair

Now that the surround has a cyanide copper strike on it, it is moved to the acid copper plating tank for an extended period of time. The buildup from the acid copper is comparable to a high build primer. This will allow the polisher to air file and hard block the flats to wave free finish.

brass grille repair

Once the grille surround had spent the appropriate amount of time in the acid copper, it was returned to the polisher for air filing and hard blocking. After it had been sanded as much as possible, it was sent to the plating line for another round of acid copper.

brass grille repair

Upon its return from acid copper plating, the polisher looks it over and determines where it can be polished out for chrome or if it needs another round of acid copper. This time the polisher has decided it can be polished out for chrome.

brass grille repair

Since the grille surround is ready for chrome, the polisher has used a DA to sand smooth the surround and is now buffing it out to a bright finish, which will make it ready for chrome plating.

brass grille repair

Here is the grille surround after the polisher has buffed it out bright. If there were any imperfections in the surround, they would show up at this time.

brass grille repair

The grille surround is now racked up and ready for chrome plating. When racking this time, there are “cheaters” attached to the racks to draw plating away from areas of high current where buildup would be substantial.

brass grille repair

Per the norm, the grille surround is cleaned in a caustic cleaner before being placed in the nickel tank, ensuring that any residual buffing compound is thoroughly removed.

brass grille repair

After being cleaned and rinsed, the grille is now placed in the nickel tank for the appropriate amount of time.

brass grille repair

Once the right amount of time had passed, the grille surround was removed from the nickel tank and moved to the chrome plating tank.

brass grille repair

After the required amount of time and amps have been used for chrome plating, the grille surround is removed from the chrome plating tank.

brass grille repair

Almost like magic, a thorough rinse removes the orange residue from plating to reveal an beautiful finish. Now it is off to inspection.

brass grille repair

The finished product is beautiful and is ready to be shipped to the customer.

brass grille repair

All that hard work has paid off as the reflections show that the sides and faces of the surround are wave free. The desired results have been achieved.