What's the Difference Between Paint and Coatings?

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In my 40 years of working with steel , I've found that when you accidentally spill paint on something it tends to stick forever, opposed to purposely trying to paint it.

This retired paint chemist says thanks for explaining this in a way that people not in the industry could understand. Ever thought about getting your "rustomatic" an ASTM approval? The current tests are in sealed boxes, for reasons you have yourself discovered. Again, thanks for highlighting this little-known, but important, field. Take care.

1:10 "High performance coatings systems for corrosion protection" sounds like something a bucket of paint would write on its resume.

As someone who has served on Submarines, poor surface prep is 95% of why paint fails, particularly when the surface has flash rust or someone didn't feather the edges of the old paint, giving the paint a seam. The Navy manual for paint and preservation gives a detailed rundown on how to paint, down to how you should dip the brush in the paint.

I was a paint and coatings chemist for nearly 40 years. Grady nailed it in this video - no errors that I noticed. By the way, the collapsed bridge at 3:02 was the Fern Hollow Bridge in Pittsburgh, where I lived and worked. But no, I didn't paint the thing.

So this is the episode on watching paint dry

I’m a chief officer on an oceangoing container ship, I always tell my guys surface prep is of upmost importance. We use coroseal and 2 part epoxy, but if it’s not prepped right it won’t last long in the very unforgiving environment. I’ll definitely use this to teach my guys of this! Thank you!

My parents wanted me to paint the handrail on the outdoor staircase. I really worked it over. First steelbrushed to remove paint and rust, then a primer and a coating of black ship paint. It was still in a good shape 22 years later when my mother sold the house.

Grady, I spent my career as a naval architect and marine engineer working for tanker operators. We had full-time corrosion engineers that monitored the ships and studied the changes in coatings. I remember them testing coatings in distilled water rather than salt water. It turns out that distilled water is harder on coatings than salt water. We used pure epoxy paints for potable and fresh water tanks. In general, if coatings did well in distilled water they would work well with crude oil or salt water. Surface preparation is everything when it comes to coating performance. In coating ships we started in most cases with a near white, SA2.5 finish. Coatings, whenever possible, were applied in a dehumidifed atmosphere. We used not only our own corrosion engineer to oversee the coatings, but inspectors from the coating manufacturers. We hired the manufacturers paint inspectors and had them report directly to us to remove pressure from the shipyard. As for primers we used weldable primers such as Nippe Ceramo, as well as zinc chromate and inorganic zinc, depending on location. In cargo tanks we used two coats of epoxy paint the first coat wss applied directly to the prepared surface. Coats were of contrasting colors to make seeing holidays easier. It should also be mentioned sharp edges are the bane of effective coating. Paint flows away from sharp corners leaving the surface exposed and a place for corrosion to start. On old bridges or ships with riveted construction there's an inherent problem of corrosion between plates of steel. When surface preparation is done you can't blast between the plates. Bob

Painting your home is often about protection as well. Bare drywall and wood are highly permeable surfaces that aren't resistant to water and generally should be painted for protection as well as looks. This is doubly so for outdoor paint.

As a pipeline corrosion tech, I am loving this series. It is always tough to relay the importance of surface prep or the correct coating with management that just want to do it cheap.. For us, we call coatings for underground structures and paint for above ground. The CP video was awesome for a visual of 70% of my job. When we deal with hundreds of pound of anode material to protect 10-15 miles of pipeline, people have a hard time understanding how chuncks of metal and current protect metal. It is truly fascinating to see!

I worked at a shipyard on the great lakes in the 1970's. The ore carriers (or lakers) had little rust on them because of good upkeep. We occasionally got to work on ocean vessels that had rust everywhere. I asked one of the mates why they didn't keep the rust down, he stated it was cheaper to build a new ship in 10 years then to constantly fight the rust. Didn't make sense to me.

The Forth Rail Bridge really was painted continuously for decades, until a new, longer lasting coating was introduced ~20 years ago

I am an aerospace engineer who has worked with coatings, epoxies and composites. And I also had a long time Summer job in a paint store and on a paint crew. I learned the lesson about surface prep from my job on the paint crew (the family had been house painters for a few generations). Even "decorative coatings" serve to protect the underlying structure. The crew that I worked with had painted houses in our home town for decades, and the duration and protection afforded by the house paint was directly related to the quality of the surface preparation (cleaning, sanding, and later a chemical bonding agent was used), as well as the quality of the paint and the number of coats. Even in the span of time I worked with them, I could see houses that had been painted cheaply and quickly by other crews having the paint deteriorate in a few years, whereas one with our quality job might last for 15-20. The protection against deterioration of the underlying structure was also evident: well painted wooden houses more than 100 years old were common, whereas houses that were left with poor coating, could start to deteriorate in a few years.

I recently refinished a very old pistol that had a rough duty life. Stripped it down to polished, bare steel. Then, coated it in corrosive chemicals that flashed rust all over it, then dipped it in boiling water to convert the iron oxide into black oxide. Had to repeat the process about 10 times to get a beautiful, dark coat of bluing. Chemistry is always baffling and truly amazing. I'm an Industrial Mechanic(mostly robotics), I fancy myself as a fairly competent mechatronic engineer as a hobbyist, but if there was one subject I wish I was smart enough to study and become an expert on, it'd be chemistry. You chemists are the real heros.

There are things that get painted continuously. I did my apprenticeship as a painter at a flower mill for Con-Arga Foods in Saginaw TX in my 20s. The guy who got the gig played in a band with me and hired the entire band as his painting crew so we could work around gigs easier. We painted the entire mill every year to prevent corrosion and flower dust build up. Raw flower is the most explosive substance I can think of matching some atomic blasts. We had to strip and acid wash everything then repaint it all which took a year. Once done we's start over. It was cool but we had to go a mile up road to even smoke a cigarette or anything because of how explosive the place was.

Before the Forth Rail Bridge was coated with a coating made for offshore rigs, they used to paint it every 6 years and it took 6 years to paint so they were always painting.

I’m pretty sure if engineers designed a similar testing apparatus for use in the industry they would also call it the Rust-o-matic 3000 in spite of what marketing wanted to call it.

I am an inspector for a civil engineering company in Alabama, and I recently got involved with inspecting Water Tanks during the sandblasting and coating phase. The Tnemec product data sheet that you showed was the EXACT type that the Contractor used in my job! I always learn something new from each episode you put out. Loved this video and always watch your content!