---   Black-Wrinkle Paint   ---




It all seemed so easy!

In days of yore, good electronic gear and components, were they pieces of professional test equipment from General Radio, high-quality transformers from Hammond, or well-built ham transmitters, were nearly always finished in textured black-wrinkle paint. Well, the days of the ‘30s and ‘40s have long passed. I know of no current electronic gear finished in black-wrinkle paint, and knowledge of professional wrinkle-painting techniques lies only in the memory of “good old George,” who in his youth many decades ago, worked in the painting department of the Soandso Company.

Good old George doesn’t remember a whole lot about it these days, so people restoring ancient radio “boat anchors” work tirelessly by trial and error in attempting to duplicate the old finishes. They have varying degrees of success. Even the paint itself is a problem. I’ve read that the wrinkle-finish paint of old, achieved its heavy wrinkling because of an ingredient called “tung oil,” but that today’s environmental regulations prohibit its use in paint. Why, I don’t know. I’ve seen gallon cans of tung oil for sale at the local hardware store.

Several manufacturers offer aerosol cans of black-wrinkle paint, but seem unable to truly duplicate the old finishes. Whether because of the lack ot tung oil, or because it’s coating thinness, or because of user error, I don’t know. Some writers endorse Brand X wrinkle paint while other writers harshly criticize it. Others endorse and criticize Brand Y. Perhaps all aerosol-based wrinkle paint is limited by the relatively thin paint layer deposited, compared to conventional spray techniques. Yet, the paint manufacturers don’t seem to offer bulk-packaged wrinkle paint for brushing or conventional spraying. After a full year of detective work, I’ve found but one exception - where one can buy quart cans of black-wrinkle paint for conventional spraying. Naturally, that information is a closely-guarded tippy-top secret, but if you buy me a coffee, I might tell!

A remarkable discovery over a couple of years of digging into black-wrinkle painting, is how little the very manufacturers seem to know, or perhaps how little they’re willing to tell, about the application of their products. Definitive answers on how to use aerosol wrinkle paints are just not to be had from any of the several manufacturers. I even found a ham working in the customer service department of a prominent paint manufacturer. He was quite friendly, I’m convinced he was trying diligently to be helpful, but he just didn’t have many answers, and couldn’t seem to get them from the technical departments of his company.

So, knowing that all the fuss was overstated, I set out to do all the repainting for my transmitter restoration. It was clear from voluminous internet reading, that one important issue in aerosol wrinkle painting was careful preparation of the work, but an equally important issue was the drying times and temperatures. The writers all seemed to agree that drying temperature was critical, although some writers said to dry the work in the warm sun, and others said to dry it at 250 degrees Fahrenheit.  So much for critical!

Whether the tempature should be hot or be real hot, the engineer in me said that good results could be achieved only by one exercising precise control of the temperature. I ruled out the kitchen oven because of its imprecise temperature control, its inadequate low-temperature temperature range, the mess, the terrible odor, and because my large chassis and panels wouldn’t fit inside. So, I built my own oven. It took several months, way too much money, but I finally finished building an 220 volt 3200 watt oven with a 30 x 30 x 30 inch cavity and an accurate and precise temperature controller. Parts had come from lumber yards, hardware stores, junkboxes, eBay, and friends. The electrical circuits were breadboarded openly on top of the oven, making it a bit of a safety-hazard. I was probably safe, being the congnizant builder, but several times had to warn visitors to keep their hands away from the top of the oven.

The oven was surely everything one could want to re-paint his vintage transmitter in wonderful black wrinkle! Everything one could want, except for the results. The results were disastrous! I started with a certain paint and a procedure sensibly distilled from the dozens found on the internet. The wrinkling wasn't bad. It was awful. I tried this temperature and that, and I tried this time and that. I tried five brands of paint. I tried this brand of primer, that brand of primer, the other brand of primer, and I tried no primer.

With all the combinations of paints, primers, times, temperatures, and application techniques, I was painting my fingers to the bone!

And, every time I tried some new painting procedure, I had to strip off the paint previously applied. Paint stripper was going for $20.00 a gallon, and I tried this brand and that brand. They were all caustic, smelly, and only marginally effective. I used up a box of face masks, hundreds of rubber gloves, and the strippers ruined a couple of nice trays.

It was too dark in the corner of the garage where I had built my “paint facility,” so I had to buy and hang a couple of flourescent fixtures to light the place. Soon, it became too cold to work in my better-lighted garage, so I bought a propane space heater and propane. I stripped paint using the gawd-awful impossible-to-dispose-of chemicals that made the horrid smells and made me cough. I ruined my clothes. I deposited black overspray over everything in my garage. At least I knew to leave my car outside. I walked back and forth to my outdoor car through cold, rain, and snow, because BigRig had unceremoniously taken over the entire garage.

One day, I actually ended up with a couple of black-wrinkle transformers that didn’t look all that bad! I was excitedly inpsecting one when I saw an ugly scratch. Examination revealed that the paint was soft. Why soft? I had dried the paint exactly as specified on the back of the can. I called the paint manufacturer and demanded an explanation. He said: “Yes, you dried it correctly, but you didn’t let it cure.” Cure? What’s cure? I never heard of cure! The paint maven explained that drying and curing were two totally different processes. Drying just made the paint handleable without any tackiness. It had to “cure” to achieve its ultimate toughness. Curing would take 2 to 4 weeks, he said, depending on several variables. I asked why nothing about curing was mentioned on the can. He explained that if the paint cans said anything about 2-4 weeks, nobody would ever buy the paint! Bah! Sure enough though, a couple of weeks later, the paint had satisfactorily hardened.

Encouraged, I started looking into painting the much larger chassis and panels. Disasters, debacles, wrinkling catastrophes, and stripping headaches, abounded. I just couldn’t get it right. End of encouragement.

Over the many many months, several suggestions arose as to powder-coating, an elecrostatically-deposited finish available in wrinkle, and very durable. I had rejected all thoughts of powder-coating because I thought that it would be prohibitively expensive, entail large set-up charges, and I thought it was the exclusive milieu of large painting and finishing operations. One day, my web-surfing uncovered a local fellow who did small powder-coating jobs in his garage, as a sideline business. After a short visit with him, some conversations with the powder supplier, some new powder samples, some discussions of light wrinking and heavy wrinkling, some more samples, and discussons of which parts I needed finished in black satin instead of black wrinkle, I gave him some parts to finish. His work turned out to my total satisfaction, and I can’t tell the finished product from my memory of new black-wrinkle parts! If I hadn't needed to pay him, his work would have been be perfect! The speech amplifier pictures now posted, show both the black-wrinkle and the satin finishes. Lunch, or another cup of coffee, will get you his name!

So, after about two years of research, reading, telephoning, priming, painting, stripping, cleaning, and painting again, and after two years of buying oven parts, paints, primers, expensive White-China brushes, heaters, thinners, strippers, lights, heaters, and assorted other widgets, I’ve pretty much given up on showing the world how to do black-wrinkle painting.

Powder-coating is the way to go, at least for the panels, chassis, and supporting brackets. Some originally black-wrinkle transformers cannot be powder-coated because of the high temperatures involved in the coating process, and those transformers must still be painted. So, I just can’t seem to make it all go away, and I’ll have to do a wee bit of black-wrinkle painting until the project’s over.


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