The preservation of automotive patina is a growing topic in the automotive enthusiast community. For years the accepted standard of restoration has been to bring a car back to new, or better than new, condition and frequently, with an eye to originality. However, lurking in the background there has always been an appreciation for well-worn but maintained examples of a given marque. I first appreciated these “survivor” cars in the Bentley community. The “Bentley Boys”, as they are known, are world famous for driving the heck out of priceless specimens with great admiration for the worn in but original cars.
What is more contentious in the automotive community is the preservation of neglected but original cars. To many, these are just rust buckets, fodder for a restoration project. But it seems an increasing number of automotive enthusiasts are appreciating the neglected, rusty “patina” as form of art almost. In some cases, the elements can wear a car’s finish and look to a point where the car gains an honesty of aged exposure, like the car is wearing it’s life story in its faded patina. I will admit, it seems to be more popular with less collectible cars and there is still a strong desire by many to restore these cars to their like-new former glory.
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All this newfound appreciation for patinated cars has given rise in discussion forums about how to best protect and preserve the existing patina, essentially trying to freeze the current state of decrepitude. And this is the topic of this article. Star Motors recently acquired one, gorgeous to my eyes, 1961 International Travelall featuring plenty of “patina”. In this case, the vehicle is on the hairy edge of what even the most diehard patina appreciators would consider acceptable. And with the finish so far gone, how can we best freeze the “look” while preventing further corrosion?
Before this novice patina preserver is about to tackle this pro-level preservation project, I needed to perform a test with the products available and get some practice. So enter Star Motors’ 1966 Mercedes 200D. I acquired this car, along with a parts car last Fall. I am a total sucker for these old finbacks and even though the condition is barn find rough, the body is remarkably rust free for one of these old Benzes. It will provide the perfect, low-risk testbed for the testing I had in mind.
There are many professional level products for preservation of patina and many folks just choose to clearcoat the whole car. But there is also a whole group of everyday, off-the-shelf products that people, over time, have come to discover work pretty well for preserving patina on our rusty classics. Based on my research I wanted to test out a few of these products to see for myself, so I headed off to the local hardware store. Don’t forget to pick up some heavy duty rubber gloves, I STRONGLY recommend wearing gloves when handling these chemicals!
Just like waxing your every day whip there is prep work to be done prior to the Simonize step. For prepping, my research revealed two products I wanted to test, Bar Keepers Friend and CLR. Bar Keepers Friend (BKF) is a slightly abrasive powder whose active ingredient is primarily oxalic acid. I have used it many times scrubbing pots and pans and washing down our porcelain sink. Because is has been both a powerful cleaning agent yet somehow mild compared to rest of the world of powdered cleaners I have used it seemed like a good candidate. CLR (Calcium, Lime, Rust), whose primary active ingredients are also acids, is relatively new to me. I vaguely remember using it to remove rust stains from a toilet years ago but otherwise have little experience with the product. What intrigued me about CLR was the claims (and picture evidence) that it cleaned up rust while pulling a stronger color out of the existing paint.
I started with a general washing of the trunk with mild soap followed by an application of CLR. While I speculated that the proper order would probably be the Bar Keeper’s Friend followed by the CLR, I was really excited to see the effects of just the CLR. So that’s where I started. I mixed up the CLR in the recommended 4:1 water to product ratio and put it in a squirt bottle. I used a blue Scotch Brite scrubby pad to apply the CLR by wetting the finish then scrubbing vigorously. It felt crazy, I would never even think of using a Scotch Bright pad to clean a car, but in retrospect I will consider using a slightly more aggressive green pad in the future.
I wasn’t super impressed with the outcome of the CLR on its own. To be fair, there was not a tremendous amount of rust to reveal the cleaning power. Close observation reveals a significant reduction in oxidation but I feel that the Scotch Brite may have been the larger contributor here. I did notice a somewhat darker shade of the blue being revealed but not nearly as much as I expected. Overall, I think I will keep CLR in the regimen because of the color change. I was also very happy that the effect was mild. The last thing I want to is be overly aggressive on the Travelall’s delicate patina. I think I need to experiment a bit with dwell times. For this experiment, I worked in small sections with about 5 minutes of dwell before rinsing. On to the Bar Keepers Friend…
I used the same cleaning method with the BKF. Wet the surface, powder with BKF, Blue Scotch Brite scrubbing the paste like BKF and water mixture, about 5 minutes of dwell, then rinse while rubbing residue off with my hand. Overall, I was very happy with the BKF. It did a great job of removing oxidation while being mild enough to control the effect and level of removal. Beware, the rinse water leaves a white residue when dry. If this is an issue you may want to be careful about where you perform the application. Ultimately, for the prep of the rest of the car, I blue scrubbied with the BKF, rinsed, then followed with the CLR. I was pretty happy with the result of this technique.
Three products drew my interest for mission protect and preserve. Zep High Traffic Floor Wax, Boiled Linseed Oil (BLO), and Flood Penetrol. I have had some experience with BLO from some botched furniture restorations of the past. Seems it was popular in the 80’s to use BLO mixed with paint thinner to wash/restore furniture. It looks great for a few years but over time the wash marks are revealed essentially ruining the furniture’s finish. Based on this experience I was very wary of the BLO, especially its effects over time, but it has a religious following amongst the rusty faithful. I have zero experience with the Penetrol, it is a flow aid for oil-based paint application. It looked very easy to use with a dramatic result. Lastly, the floor wax made a lot of sense to me, after all, I’ve been waxing cars my entire life. I have used floor wax for protecting floors and find it easy to use and durable with a low sheen finish. This low sheen is important to me because shiny rust looks stupid, in my opinion.
All three products were simple to use and easy to apply. I used a cloth rag and applied sparingly! For all of these products it seems that a little goes a long way and using too much can cause problems. From my research, I was prepared for the floor wax to require three coats to come up to snuff, the other two products require only one application. So how am I judging the products, what are the criteria?
- Durability – How long does it protect? How does it hold up? Negative effects over time?
- Appearance – How does it look? Is it too shiny? Which one provides the best balance between protection and authentic look?
- Finish – Is the finish smooth? Rough? Tacky? Does it bead water?
For the first criteria, we will have to wait and see. The 200D has been moved outside and I intend to take a time series to see how things hold up.
For the second, all three products did what I would consider a good job. I was surprised by the Flood Penetrol, the old paint sucked this stuff up and looked really good. Also, the BLO which I was prepared to dislike, worked really well. The floor wax, after only one coat did not measure up to the other two for look. After three coats, I was happy.
And for the third criteria, I liked the floor wax the best. The finish feels durable and frankly like a waxed surface. The water seems to sheet of the wax while beading off the other two. The wax surface dried first and with little residue. Initially, I did not like the Flood Pentrol’s finish, it was tacky and seemed to hold dirt. After a day though, it has dried out and feels pretty solid. But I like the BLO better. It also, initially has a slightly tacky feel, but it solidifed quickly and while it held dirt more than the wax not like the Penetrol.
So far, I have decided to move forward with a larger test area of the Floor Wax and BLO.
I believe this next picture shows the major difference between these two products, the BLO like the Penetrol is oily going on and soaks into the finish. The wax on the other hand does not soak in as much as it coats. Notice the tape line down the center of the hood where you can see the BLO bleeding along the tape line where the floor wax has a neat clean cut line. I’m not sure which is better but I suspect the floor wax may be the ultimate winner for me. Time will tell.
So in summary so far:
Prep – I think the BKF followed by the CLR will be a go to prep strategy moving forward. It was easy to control the amount of oxidation removal and I do believe the CLR helps to pull the color out of the underlying paint. The blue Scotch Brite did nothing to harm the surfaces I was working with and I am tempted to up the game with a green pad in the future.
Preserve and Protect-
| Flood Penetrol | BLO | Floor Wax | |
| Pros | Easy Application Great Color Seems Durable | Easy Application Great Color Seems Durable Wide Following | Easy Application Seems Durable More Familiar |
| Cons | Tacky For a While More Unknown | Tacky For a While | Three Coat Coverage |
I will give the products some time outside and report back in a while. Thanks for reading!
Here are links to a few of the articles that got me going:
https://www.hotrod.com/articles/retaining-that-patina-finish/
