Hey fellas, I've been doing some experimenting with asphaltum paint in hopes of replicating Henry's finishes during the Model T & Model A eras.
Here's test panel #1; made from Liberty on the Hudson's "Black Japanning Ashpaltum". I mixed 2/3 cup straight out of the can with 3 tbs mineral spirits, 2 tbs Japan drier, and 2 tbs of turpentine. 2 coats of this concoction were sprayed on bare steel, approx. 10 min apart.
To my surprise, each coat was dry to the touch in 5 min. To ensure proper hardening, I baked the test panel at 350* for about an hour, allowed to air cool, then cut/polished/buffed.
Here is the result along with a mint '17-23 hood (also cut/polished/buffed)
One thing I'm noticing is that my test sample is slightly more plumb color than the original paint. To correct this, I added a small amount of Prussian blue pigment (per the Trent Bogguss article), but the blue only made the mixture more of a dark chocolate brown color.
At this point, I believe the issue is the drying agent...Japan drier is primarily composed of Cobalt drier and has a distinct purple cast. I may experiment with some other driers to see if I can obtain a better match.
Great test! Old Henry would have been proud
Is it Gilsonite in your "Black Japanning Ashpaltum"?
Unfortunately, I have not been able to verify whether the asphaltum used in the base material is Gilsonite. I suspect it is not.
At some point I may experiment with Gilsonite, but I fear that the heat required to melt/dissolve the material into linseed oil might be quite the fire hazard.
Gary was this sprayed with an HVLP gun or did you use an old school gun?
This was a very small batch (the Asphaltum paint is very expensive) I sprayed on with a Preval sprayer. I would have done better just pouring the paint onto the surface, as the Preval sputtered and spit, allowing for very little control.
I also believe I thinned the paint way too much - I probably need to cut back by at least 1/3 on the turpentine and mineral spirits.
As soon as I get a better pigment match, I'll experiment with proper spray equipment. I'd really like to get this right so I can paint my roadster pickup with it!
Great work, Gary!
I've said for a long time a car isn't original or restored if it has modern paint. That's the first thing you see. It's too bad judging standards don't take originality of paint into account.
There's a lot of info on Gilsonite on wikipedia.org .
I'll go ahead and 'out' myself now; I'm building a hot rod...a late 30's - early 40's era hot rod (mid-26 RPU on a Winfield-equipped A chassis). As the focus of the MTFCA forum is stock/restoration, I'll withhold further comment as it is off-topic.
I am aiming for a "period-perfect" build, so duplicating these finishes is extremely important...as you say Ricks, paint is the first thing you see. IMO, modern acrylic enamels and urethanes just don't look right to my eye.
Besides, this is a ton of fun!
Neat project! Who knows, doing the research in support of your "period perfect" rod might plant a seed of interest in a stock restoration some day.
Did a 2nd, 3rd, and 4th spray out - 2nd formulation kept the 'mixture' the same, only adding a small amount of Prussian blue pigment. Result - a deep chocolate brown color, similar to the "first coat elastic Japan" (M-101) under the finish coat on my hood (I uncovered the M-101 on my hood as a result of over-aggressive polishing).
3rd try was with the Prussian blue and only 1 tbs Japan drier. Close but no cigar.
4th try I left out the Prussian blue and used only 1 tbs Japan drier. I believe this is a perfect match.
Where can you buy this paint? It was also used on Edison cylinder phonograph bedplates. I've never been able to find any in Canada, and it's the exact thing to use when you need it!
So Gary are you showing and saying this is a shiny and deep finish? Can I get the material and spray it myself? Is the price in the same range as what we can get at the paint store? I like it and want to play also. Iam thinking that it is a very hard finish. And it will hold up under the sun. Thanks, Scott
Darren, my asphaltum/linseed oil base paint came from Liberty on the Hudson; it's their "Old Pontypool Black Japanning Asphaltum".
My method of application was extremely crude; I used a Preval (aerosol) sprayer, which basically spat and sputtered paint on the test panel. I would think that proper spray equipment should work perfectly, but would definitely need to be thinned out, as it is fairly thick right out of the can.
The finish you see here was obtained after wet sanding with 800, 1500, 2000, and 3000, then compounding, waxing/buffing. I'd imagine that a finer 'mist' from an automotive-quality spray gun or HVLP setup would clean up/shine with minimal wet sanding.
Cost is $62 per quart not including shipping, but a little goes a long way!
I'm planning on leaving my samples out in the weather for a few weeks to see if the intense Texas sun has any chalking affect.
To compare prices, because I know sometimes Model T'ers are a bit on the stingy side, I painted my car with a 50/50 mix of Gloss Black Rustoleum and cheap paint thinner from the farm store or the hardware store, whichever was open at the time. The Rustoleum was about 13 bucks a quart and the paint thinner about 9 bucks a gallon. I think I went through two quarts on the whole car, maybe three. It's hard to remember exactly, and I used spray cans on some of the smaller parts. So if you're just doing a black car that you want to drive around and have fun with, my method would get you by. If you want an exact replica finish for a perfect restoration, Gary seems to have it figured out. Once again, it all comes down to the end use of the car.