It is well known among both painters and professionals that epoxy primer is ideal wherever a high level of corrosion protection is required for metal components. It is used, among other applications, to protect steel structures, fences, and most importantly, car body parts.
How does epoxy primer protect against corrosion?
Once cured, the epoxy primer forms a highly durable and chemically resistant coating on the surface, which provides a physical barrier protection that limits the penetration of water and oxygen – two key factors which cause corrosion.
The epoxy resin contained in the primers protects up to twice as effectively as acrylic resin, thanks to its very high degree of crosslinking. Adhesion promoters added to the epoxy primer are also of great importance, which ensure very good adhesion of the primer to a wide variety of demanding substrates such as steel, galvanised steel, laminates, aluminium, old paintwork (as an insulator).
BOLL offers two types of epoxy primer for various applications and methods of application:
1. Two-component epoxy primer 1:1 – for application with a paint spray gun. The primer should be mixed in advance with the hardener and, depending on the version of use, with epoxy thinner.
2. One-component epoxy primer spray – for spot repairs as well as quick and easy application to so-called ‘bare metal spots’.
Which primer should you choose?
BOLL epoxy primer 1:1 is an ideal solution for insulation of polyester putty, which is why painters very often apply it under the putty - to increase anti-corrosion protection and adhesion, as well as on the putty (before application of acrylic primer) to close (insulate) its absorption. For repairs without putty, the epoxy primer can be applied directly on the metal surface. This protects the substrate against rust and eliminates minor irregularities in the car body. Then, we apply a base coat (i.e. color), followed by a layer of clear coat.
An overview of the repair system using polyester putty and epoxy primer is presented in the image below:
Epoxy primer 1:1 can be used in three versions: filling, filling-and-insulating, and wet-on-wet. The choice of application version depends on the amount of thinner added (proportions provided in the table).
Advantages of BOLL epoxy primer
BOLL 1:1 epoxy primer is one of the few available on the market that has passed corrosion resistance tests for the C4M class at an external accredited laboratory. Meeting the requirements assigned to C4M class, as described in the PN-EN ISO 12944-6:2018-03 standard, means that BOLL epoxy primer 1:1 provides high and long-lasting corrosion resistance, even in industrial and coastal areas with medium salinity, chemical plants, swimming pools, or shipyards.
Meeting the requirements of C4M class provides painters with a guarantee that BOLL epoxy primer 1:1 will provide effective corrosion protection to any repaired car body part for many years to come. It is worth noting that the tests for determining the corrosion class are very stringent. Samples of material containing BOLL epoxy primer 1:1 had to undergo several hundred hours of testing in accordance with international ISO quality standards:
- in the corrosion chamber, which tests the resistance of materials to a brine solution as a cause of corrosion,
- in a humidity chamber which is kept at a constant temperature, in which the resistance of the samples to condensation is tested
The next stage of testing involved a visual assessment of the changes resulting from the exposure of the sample to the conditions in the chambers. After the tests were completed, adhesion was also measured.
Advantages of BOLL epoxy primer in the spray version
Epoxy primer spray is a one-component product, and it is precisely this fact that gives it a number of advantages and benefits for users:
- it is ready for use without the need for mixing
- it provides an incredibly fast application process
- it does not generate waste (product waste) and does not require cleaning of the spray gun.
Due to the aforementioned properties, painters primarily use single-component epoxy primer on so-called "burn-throughs," meaning areas sanded down to bare metal during the sanding process. These typically occur when sanding the edges of parts that were previously coated with the cataphoresis process or epoxy primer applied with a paint spray gun.
A very important advantage of BOLL epoxy primer spray is the short curing time. With the application of a single layer of primer, the next step - applying base coat - can begin after only 15 minutes.
The use of a epoxy primer in spray form gives a painter the assurance of effective corrosion protection and can save a bodyshop additional costs associated with customer complaints. Time savings are also significant: covering burn-throughs does not require preparing a new mix of two-component primer.
This product is a popular choice for people with no paint experience who want to carry out minor repairs on their own. Thanks to its convenient spray form, it does not require a spray gun, making it an ideal solution for amateurs. Other products such as a base coat (prepared in the mixing shop by the colorist) and a one-component clear lacquer are also available in the spray form, which significantly simplifies the process of completing a comprehensive paint repair.
For spot repairs, the application of several coats of primer is recommended. The evaporation time between coats is between 5-10 minutes, while the curing time takes 1 hour. The product is available in four colors: white, grey, black and olive, which is fully compatible with 7033 RAL – the most common color of cataphoresis.
In summary, epoxy primer in spray form:
- facilitates quick and effective insulation of surface abrasions that occur during preparation of the element for painting,
- is perfect for quick spot repairs,
- thanks to special epoxy resins, it is ideal for use directly on to sheet metal, aluminium, galvanised steel and old paintwork,
- offers excellent adhesion to surfaces, as well as outstanding anti-corrosion and insulating properties.
- ensures significantly reduced drying time – only about 15 minutes at 20 degrees (after applying one coat).
BOLL epoxy primers provide extremely effective, laboratory-confirmed, barrier anti-corrosion protection.
You can find BOLL products in over six thousand independent retailers, automotive wholesalers and online shops. Go ahead and make a purchase!