(And finishing other DIY Projects.)
Now that you’ve invested all that time and effort into building an incredible trailer, how should you finish it? Of course, you don’t want it to rust, and you want it to last. So, here are some suggestions for trailer frame painting and finishing. In fact, we’ll cover the finishing of trailers in general.
Prepare For The Finish
Before you start painting, it’s essential to prepare the frame properly. While it may seem fine at first glance, those unsightly welds will become very noticeable once painted. Here are the areas you should focus on:
Welds: The first step in preparation is to clean up around the welds. Remove any splatter and grind down any unattractive welds. A majority of the residue can be scraped off using a flat screwdriver or a piece of flat-edged steel. For the remaining residue, a grinder can be used.
Oil and Mill Finish: New raw steel often has a rust inhibitor coating. This coating needs to be removed using soap and water. This step will also get rid of any incidental grease or oil.
Rust: Most projects will have some rust on a few pieces. Ensure that all rust is completely gone before painting by using sandpaper, sand blasting, or other applicable methods.
Surface Prep: The key to a great paint job is to start with a clean and slightly roughened surface. Sandblasting is highly recommended for trailer frame painting, although using sandpaper meticulously can also achieve the desired effect. Both methods require time and attention to detail.
Final Preparation: If possible, hang the frame for painting. If hanging is not feasible, place the frame on a few points of contact. Before painting, thoroughly clean the frame with soap and water, and ensure that it is completely dry.
Options For Trailer Frame Painting
“Painting” is a broad term for finishing. While you can certainly paint your trailer frame in the traditional sense, another option to consider is powder coating. But which option is the right one for you?
The goal of finishing the frame is to protect the metal. Paint and powder coat both achieve this, but in different ways. Paint is a liquid that dries in place, while powder coating involves a dust of plastic that electrostatically adheres to the metal and is baked in an oven to create a protective layer.
It’s important to note that there are variations within each method. Powder coat can be made more durable and weather resistant with a zinc primer, and not all paints are equal. For instance, a two-part epoxy primer provides more longevity and toughness compared to a rattle-can.
Some argue that powder coating lasts longer than paint, but personal experience has led me to believe otherwise. In my opinion, powder coating has become my top recommendation for trailer frame painting due to its convenience and durability. However, about 25 years ago, I discovered the effectiveness of two-part epoxy primers, which completely changed the game. When applied correctly, epoxy primers are incredibly durable, allowing you to paint your frame in any color you desire.
If you’re looking for a long-lasting finish, I recommend skipping the rattle-can option. While Rustoleum or other brand spray paints may provide a nice look initially, they are not as durable and will likely require a refresh in a couple of years. Trust me, it’s better to do it right the first time. The two options mentioned above are superior choices.
Recommendation – Powder Coating
Personally, I now prefer powder coating for my trailer frames. I even include a special zinc primer to provide enhanced weather protection. This option, in my opinion, provides the best overall result. However, keep in mind that powder coating cannot be done at home. You will need to take your frame to a specialized facility equipped with the necessary coating equipment and a large oven for baking. Additionally, powder coating can be quite expensive. While there are many color options available, paint offers a wider range of choices if you have specific preferences.
For me, the most convenient approach is to take the frame to a professional for the final preparation and completion of the job. If budget allows, this is my top recommendation.
Recommendation – Trailer Frame Painting
Another option I highly recommend is painting with a two-part epoxy based primer. This type of primer consists of a base primer and an activator. When combined, they chemically react to create a hardened and durable surface.
I first discovered this method approximately 25 years ago and used it on a trailer frame that has withstood the harsh conditions of the Bonneville Salt Flats. The salt flats are known for their corrosive environment, but the epoxy primer protected the frame from rusting. Although the application process for painting is more do-it-yourself friendly, it does require some effort. You can achieve satisfactory results by creating a makeshift paint booth in your garage. However, if you prefer, professional painting services are also available.
More Info On Epoxy Primers:
The epoxy primers I recommend are specifically designed for “Bare Metal Applications.” You will need both the primer and the hardener, mixed in the correct proportions. It’s important to make small batches as the mixture solidifies over time.
While researching various epoxy primer brands, I came across Cromax 2580CR. However, the price of $363 for a gallon of primer plus $294 for the hardener seems outrageously expensive to me. Another option is Medallion’s epoxy primer, priced at $26.10 per quart plus $10.50 for the hardener (note that this is a quart price, and gallons are also available). I cannot vouch for the quality in comparison to Cromax, but the store owner claims it is an excellent product.
In the past, I had success with the PPG DP-40 two-part epoxy primer, although it may no longer be available. The newer DPLF line is reported to be slightly more challenging to work with, particularly when sanding it for a perfect top coat. However, for most trailer frame painting, perfection is not necessary.
While exploring different options, I stumbled upon a spray can of epoxy primer from Spray Max. This unique can, which requires activation from the bottom, eliminates the need for sprayer clean-up. Although I cannot vouch for its quality, it appears to be incredibly convenient for smaller projects. However, please note that priming an entire trailer frame would require multiple cans.
One Last Tip:
Regarding disposable paint sprayers, when using epoxy primers, I recommend a disposable aerosol sprayer. This type of sprayer consists of an aerosol top that attaches to a glass bottle filled with paint or primer. It effectively turns any paint or primer into a spray can.
While the sprayer in the image is of good quality, similar options may be available at local retailers such as Walmart or Harbor Freight. However, I cannot personally confirm their availability as I do not frequently shop at those stores.
To me, this method is an excellent way to apply spray paint or primer. It offers convenience and eliminates the need for sprayer clean-up. Check if your chosen primer requires thinning before spraying. These aerosol sprayers tend to work better with thicker paints. It’s always important to double-check before diving into your trailer frame painting project.
Good luck with your trailer frame painting! (Or any other DIY project you’re working on.) We hope the tips provided above are helpful. If we have missed anything, please feel free to leave a comment.