After painting our NKP baggage car, Penn Central boxcar, NKP gon, and other pieces of museum equipment, Mark found an old can of oil based paint. He estimates the can is at least 30 years old and after struggling with the rust on the lid, was finally able to get it open disclosing a heavy skin on the top. After working through that, he discovered that there was still paint at the bottom. He mixed it and found that it was good enough to put on the stairs leading into one of our display cars. The motto might be to "never give up on an old friend" (or can of paint)!

Les

So what's older, the paint or the stairs?

Charlie -

The stairs were made by one of our members. Not sure how old they are, but nowhere near as old as the paint. The next time I see the guy who made them, I'll ask him.


Les

Paint chemistry has changed a lot in the past 40 years. Old paint can't be trusted to dry satisfactorily. Check it by painting a piece of scrap wood or scrap metal first. Give it plenty of time to dry, then try to scrape it off. You may find a sticky mess under the dry top skin. That means it will never cure all the way through the paint layer.

Many communities have programs to encourage proper (and very inexpensive, or free) disposal of unwanted oil- and water-based paint. See http://www.paintcare.org for more info.

- Doug Debs

Hmmm...Imagine that...paint that never dries.
It would then be just like lots of modern latex paint!

You can add drier to that paint to get it to "trigger"--used to be any good paint store would carry drier, I don't know about today though!
Decades ago when I was working at what was then known as the Portola Railroad Museum, we had a LOT of Rust-O-Lem paint donated by Chevron when they changed their gas station paint scheme (Black, Grey and Blue). There was concern about its usability, so I called the company. I was told that as long as it was liquid, and stirred together smoothly, it would be fine; and would be more rust inhibiting than their current formula, which no longer contained fish oils. Even the company was willing to admit that reformulation to meet newer environmental standards did not result in product improvement!

Mark is going to died of lead poisoning now. ;)

[quote="Doug Debs 2472"]Paint chemistry has changed a lot in the past 40 years. Old paint can't be trusted to dry satisfactorily. Check it by painting a piece of scrap wood or scrap metal first. Give it plenty of time to dry, then try to scrape it off. You may find a sticky mess under the dry top skin. That means it will never cure all the way through the paint layer.

Sort of like what they now call paint in California, no dryers no VOC no nothing, takes 3 months to sort of dry. Don't believe me, buy a can of rustolium oil based paint and try to brush it on.

Taking the fish oil out to meet environmental standards?

Granted, the reformulation may have been done to cut costs, but at the time my understanding was that it was to meet modern standards (usually caused by legislation).

Short follow up to the my original posting. A photo of the finished painted steps is attached. The paint appears to be tight. Did not scrape off a spot in an inauspicious location to see if it might be "a sticky mess under the dry top" as Doug suggested might be the case. Time will tell if it holds up. As to Charlie's question about the age of the steps, they are older than I thought. They have been repaired a couple of times as Bob Jachim advised when I asked him. Bob had recently repaired them to remove old deteriorating parts. It's the old story about "my great grandfathers original axe" (and its many replaced handles) but this in the form of a set of stairs. My "guestimate" might be about 20 years old. Like many museums, Hoosier Valley reuses whenever possible.

Les

Looks good! I know the steps aren't exactly a historical artifact, but I was curious about the last time something was painted at a museum with paint that was older than the item being painted.

I now regret getting rid of several gallons of 30+ year old Rustoleum paint awhile back.

I'm always skittish about using paint of unknown provenance. The problem is if that paint proves to be defective, you now have one mother of a mess to clean up. You'll end up having to put a LOT of hours into the cleanup - enough that you'd probably be better off working at McDonalds for 1/4 of those hours to earn the money to buy paint of good provenance.

Paint is not whitewash. Paint is nothing short of magical: it stays stable and liquid indefinitely in the can, but massively polymerizes "on cue" when painted onto a surface, even though no additional chemicals have been added for it to react with. (the choice of catalyst are limited to what comes free with air: N2, O2, H2O, very limited amounts of CO2, and useless argon.) The peculiar alchemy that *makes that work* is fragile, and not to be taken for granted.

At the very least, thoroughly test any "found paint" or paint of dubious storage history.




One of our great volunteers once said it's easy to dispose of old paint legally. "Paint something you don't want, then throw it away". Having some modest knowledge of paint law, he's right.