Better Paint Performance, Simpler Pre-treatment
EPS offers outstanding paint performance – both paint adhesion and corrosion resistance.
Testing was performed by accredited testing labs to determine the curing, adhesion, corrosion resistance (salt spray exposure testing) and gasoline/oil resistance of EPS. In every test, the EPS samples exceeded the automotive OEM’s acceptance criteria.
Some of the OEM Supply Chains Using EPS
“Eco Pickled steel is safer for our workers and the environment. It offers a cleaner surface for paint adhesion which minimizes the use of degreasing agents used in paint preparation. That impacts the environment in a positive way.”
Yarder Manufacturing Company
Custom Sheet Metal Fabricator
What's Your Paint Pre-treatment ?
If you don’t have a pre-treatment wash to remove HRPO’s oil, you won’t even use acid pickled strip. You’ll use hot roll black and clean it as best as you can before painting. If you do use HRPO, you (or your painting partner) will typically have a 5 to 7 stage phosphate wash/rinse system. Expensive, but necessary.
But EPS steel ordered dry (no oil) will reduce the time and expense of your pre-treatment. With no oil to strip off :
- you can ‘lean out’ paint pre-treatment – eliminate a stage or reduce the chemical concentration – with no loss of corrosion protection
- you can reduce the temperature of the pretreat bath
- you’ll change pre-treatment wash solutions less often
- there’ll be no more residual oil to pollute a paint bath
EPS Paint Performance Explained
The EPS surface is clean – oil and contaminant free – which certainly helps paint performance. But the secret to EPS’ superior paint adhesion is its ‘optimized’ surface texture.
The EPS surface is typically ‘rougher’ than acid pickled steel, as measured by Ra value. It also has a more ‘jagged’ profile of sharper peaks and valleys that holds on to paint better than the acid pickled profile. But does this jagged profile yield a rougher final paint finish?
It does not, because the amplitude of peaks and valleys are less overall, they deviate little from the average, and their pattern is very uniform. ➤ This EPS characteristic, termed low Rz, promotes a smoother, more uniform paint appearance.
Photo of EPS surface at 200X magnification, taken with a scanning electron microscope (click image to enlarge)