Shop Talk
"Application of Wrinkle Paint"
by Keith Kramer
The material for this article was compiled from a "thread" of messages posted in the Internet newsgroup, rec.antiques.radio+phono. These posters kindly agreed to my request to publish their messages on the HVRA website.
Question
I am looking for advice on how to repaint a cabinet in the "black
wrinkle" finish. Anyone have any ideas?
Suggestions by Larry Wilson
Do you need to start over or just touch up the existing "black
wrinkle" paint? If all you need to do is repaint over the existing
paint I have found that dabbing the black paint on with a lint-free cloth
is better than using a paint brush or foam pad. By dabbing on the paint
you don't fill in the "cracks" of your wrinkle finish. You can
rub a little too. Just don't apply so much paint that you literally fill
in your "crinkles".
Suggestions by Riggs Smith
I have used "wrinkle" spray paint on several Atwater Kent
speakers and radios with good results. I purchased my paint from Antique
Electronics at that time. Don't know if they still have it. I always stripped
the old finish off the metal and used extra fine steel wool to make sure
all rust was off the surface and all flaws were smooth. Make sure no grease
or residue is on the surface prior to painting----I washed in a mild detergent
like I wash dishes and dried them. I have found that the spray does not
wrinkle well in cool or cold weather. When I set the piece in the sun and
let it get warm on a nice warm day, then sprayed it, it really wrinkled
good. I believe the warmer the piece is, the faster and better it wrinkles.
I was using brown and gold colored paints. I assume black would have the
same properties---but you know what they say about the word "assume".
Suggestions by Randy Guttery (The
Mississippi Historical Radio and Broadcasting Society)
Most any quality wrinkle paint will do - the stuff that AES carries
has worked fine for us. BUT!!!!! Successful wrinkle painting requires
a lot of work - 90% of which is preparation - and the other 10% is the
oven in the kitchen (but be sure and note the caution below!!!!). If you
are after a wrinkle finish that looks like an original factory finish -
you generally have to strip the old wrinkle paint down to bare cabinet.
For reasons I don't really understand - any cracks, chips, etc. or areas
that are worn will take on a different "wrinkle texture" than
where it goes over the old wrinkle surface -- in other words - for a wrinkle
finish to look really good - the surface it goes on must be very
good. We've tried "feathering" and other usual prep methods -
but have always been less than pleased with the results - and so every
cabinet we've "wrinkled" to date - has been completely stripped
to bare metal (we've never wrinkled wood). An interesting thing - the wrinkle
paint we use does better directly sprayed on to bare metal - i.e. a primer
coat seemed to cause the wrinkles to be "splotchy"... have no
idea why. We've tried zinc chromate and a common gray auto primer - same
results. With most paints - you have a lot of leeway of how you apply it
- how long between coats - how many coats - (like several very light coats
- or one heavy coat, etc.). With wrinkle paint - follow the instructions
exactly. Make sure the item(s) to be painted are at the correct
temperature - make sure the paint and the items to be painted are
at the same temperature... Here is the one place you can take the instructions
to a little bit extreme. Most instructions will note that some heat (hair
dryer, etc.) will "aid the wrinkling effect"... and that is one
understatement. We had always wondered how they got those gorgeous uniform
finishes on military radios (BC-348s, etc.) - where the wrinkling is uniform
all over. We tried using a hair dryer - but inevitably we would get areas
that had more and less wrinkle. Not bad - but not that "factory"
look either. Letting it dry / wrinkle on it's own gave more uniform results
- but the wrinkling seemed muted. Then we found the answer. Heat the oven
to 200 - 225 degrees F. Spray the item. Just as soon as that second coat
hits - turn the oven off - and put the item in the oven and close the door.
DON'T TRY THIS WITH A GAS OVEN WITH ANY PILOT LIGHT!!!!! I'm afraid
the fumes might get to the pilot light and explode. Use either an electric
oven - or if you have a pilotless gas oven (and stove!) like we have -
that would be OK. Anyway - the uniform heat causes the wrinkles to be heavy
- uniform and have that "factory" sharp look. After about two
hours - the oven should be about room temperature - and the item will likely
be tack-free - though I usually let them sit overnight in the oven - a
nice dust-free place to dry. Since we found this "dryer" trick
- we've also found that other finishes (including tung oil) can be forced
dried in a couple hours - so we can three or even four-coat a cabinet in
a single day... really saves time. Some of the cabinets we've done this
way were done over 6 years ago - and so far none show any ill effects from
accelerated drying. If you'd like to see an example of a refinished radio
using this technique - there is a BC-348R in the museum that we did about
4 or 5 years ago. There is a secondary challenge to the front panel of
the 348s -- all of the legends are "reverse" punched - i.e. when
the aluminum panel was punched out of a sheet of aluminum - the lettering
was in relief - in other words it sticks out - rather than being punched
in. When you refinish the front panel - you have to paint the whole thing.
then ever-so-carefully sand down through the paint to the letters - so
they can be seen. as thick as wrinkle paint goes on - it's almost as thick
- as the letters "stick out"... so it is a real challenge to
get the letters exposed without marring the surrounding paint.
Suggestions by Frank Adams
I have found that both the temperature and the method of heat transfer (convective, radiant or both) give quite different degrees and profiles of the final wrinkle, and this seems to be more true of black formulations than gray or brown. You may wish to experiment with test plates if the final finish is important to you, or to learn firsthand how your particular paint behaves. My kitchen oven (radiant only, unlike a gas unit - mine is wood-fired) is on the small side; infrared heat lamps give me heavy, crisp results; hot summer sun gives me a finer wrinkle. An effective reflector oven can be fashioned for either source with scrap pieces of Tuff-R (or similar) foil-coated urethane insulation board. I concur with Randy on going to clean, smooth bare metal. I had the same disappointment with metal primers and incompatibility; if nonferrous, I etch it with whatever acid I happen to have too much of, which gives excellent surface keying. Few of us have been able to fully achieve the very deep, heavy, fine wrinkle seen on (example) prewar gear using today's spray cans, and I am not one of them, but the more typical wrinkles are easily duplicated, and the old ones passably so.