We’ll try and do a summary of everything learned here in one blog post.

Supplies needed:
Asphaltum—available in powder form or liquid, which is what I used. Art supply stores seem to be the best source, as it is used in acid etching.
Solvent—Xylol or turpentine should either work fine. Both are capable of suspending the heavy asphaltum solids.
Varnish—I used semi-gloss spar varnish that was already on hand. Other recipes I found used gloss or BLO. I might have to try BLO sometime in the future.
Artist brush—A small mop brush (about 1/2in wide) worked very well. Make sure to get one that is recommended for oil paints and finishes.
Air-tight container for mixing and storing the japanning mixture
Shop supplies—such as sandpaper, paper towels, masking tape

When all was said and done, there was about $30 invested in supplies, outside of normal shop stuff.

Japanning Mixture:
2 parts liquid asphaltum
1 part spar varnish
Mix well. The ratio doesn’t have to be exact as I also had success with a 3:1 ratio, but make sure it is thick enough that it will coat and cling to vertical surfaces. If the mixture is too thin, it will sag and is susceptible to bubbling when baked.

The liquid asphaltum is a 50/50 mix of xylol and gilsonite,by weight, so if you purchase the powdered asphaltum, you should end up using nearly equal amounts of the three ingredients.

One issue that came up is that the liquid asphaltum will thicken after being opened, even in the original container. Adding a splash of solvent will easily get it back to a usable consistency.

Process:
Starting with a stripped and cleaned metal surface, lay down an even medium coat of the japanning mixture using the artist’s brush.
Allow the finish to dry overnight.
Bake at 250-300F for two to three hours. Indirect heat is best, such as an oven. When using the grill, I did get some bubbling where part of the plane was directly above a burner. The areas around the lettering were much more susceptible to this. To avoid that issue, I used the side burner(s) and place the plane body in the center of the grate so that it wasn’t directly over the heat source. Also, baking for longer &/or at higher temps may result in an even harder and shinier finish. If you want to do higher temps, go progressive, i.e. two hours at 250, two at 350, one at 450. Starting at too high of temps may cause bubbling.
After allowing the plane to cool, scuff the finish with sandpaper. 220 grit seemed to work best.
Wipe the finish down with a solvent dipped rag or paper towel to remove sanding dust.
Repeat the process to add more coats.

Three coats seems to be about right. It allows the finish to fill the unevenness of the casting while preserving the details of the lettering. I tried a fourth coat once, but it caused the lettering to lose its clarity.

A note about masking. On early attempts, I was masking all the surfaces not being japanned. The problem is that the tape has to be removed before baking and then reapplied. Later in the process, I didn’t mask at all and didn’t have any issues. Any japanning that ended up on the sole or sides was removed with a razor blade scraper before flattening, which removed any left over traces. The frog mating surfaces were carefully “painted” around and the very little japanning that got on those was again scraped off with the razor blade.

Having used both spray paint and now playing around with this method of japanning, here are my conclusions.

What I like about japanning:
The end result seems to match up a bit better to the original Stanley finish.
The whole process can be done inside.
It fills the iron castings very well.
The japanning mixture goes a LONG way. I have now done the equivalent of six planes (four complete, with two done twice) and have probably used about 20% of the liquid asphaltum. Considering the size of the planes done (#5 & 6 each once, 5 & 8 twice) a single pint of the asphaltum should easily do two to three dozen plane bodies.

Considerations before japanning (not necessarily negatives, but things you would want to think about):
The japanning finish is best done in a dust free environment.
The whole process will take several days to complete. The individual steps do not take that long (I was able to scuff, wipe and apply a coat of japanning on three planes in less than 20 minutes total), but you have the time to allow the finish to dry, then bake, then cool before doing the next layer.
Must have the ability to bake the finish without being kicked out of the house.
Requires the purchase of some materials that probably won’t be useful for much else.

I think there are times/circumstances when both spray paint and japanning are appropriate. If you are the type that just want to get the tool protected from rust and move on to using it or you are just doing a couple of items, then spray paint is probably more for you. For me, I actually enjoyed the whole process, so am inclined to continue with japanning. I’ll probably play around with some aspects of japanning (such as using BLO instead of varnish) just for the fun of it. If anything interesting comes up, I can add another post, but otherwise, this blog series is a wrap.

Thanks to those of you who followed and encouraged during this blog. Special thanks to Don and Mads for providing links with lots of great information. If anyone does attempt this process, please let me know how it goes and if you learn something I missed.

You can see in the picture above the low and high spots in the cast iron (white/silver high spots of bare metal and the dark black being low spots not hit by the sandpaper). A third coat levelled these out nicely. This coat also got a bake after being allowed to dry overnight.

Here is the result on a 606.

I was very pleased with the color and sheen of the final product. My only real complaint is that I didn’t have a dust free room, so there are blemishes in the finish from dust landing on and sticking to the japanning while it was still tacky and before baking.

Since Don asked in an earlier blog post about comparing with the Duplicolor Ford Semi Gloss black engine enamel, I did the tail of a broken #7 for a comparison. Left to right is the 606 with three coats of my homemade japanning, an unrestored Type 11 #4 and the #7 with four coats of the Duplicolor spray paint.

It is tough to make out in the photo, but there is a very subtle difference in color. Personally, I think the homemade asphaltum japanning mix is a better match to the original Stanley, but it is very close. The spray enamel just seems to have a slight greenish gray tinge to the blackness of it. The sheen level of both finishes is very similar, with the japanning maybe a bit more glossy.

If presented with one plane by itself, I don’t think I would be able to tell if it was Duplicolor or my japanning recipe by the color alone. The one way that I would be able to tell the difference is that the japanning seems to fill the unevenness of the casting much better. That might be solved by heavier coats of spray paint, but I haven’t had a chance to try that. Maybe someone else who has used that method more often can chime in.

Well, that is the majority of the journey. There will be one more blog post summarizing the recipe, process and lessons learned.

Well, I did have another “oven” outside, so decided to try it. How do you like your #5, medium rare?

I turned the center burner on low to see what temps would result. Checking the thermometer after about 15 minutes showed it holding a temperature of just over 250 degrees, that should be fine. I was a little worried about putting a plane that may give off flammable fumes in a gas grill, but figured that there is enough holes in a grill (vs. the gas range in the kitchen) to keep a steady supply of fresh air. The plane was set on the grate and left for a couple of hours. Checking on it after 30 minutes showed fumes coming off and a slight odor. Not enough to be really annoying, but I wouldn’t want to use the range and have SWMBO come home and smell it.

After turning off the grill and allowing the plane to cool, I checked the finish and found a very hard, slightly shiny result. The finish was then scuffed with 400 grit sandpaper, wiped down with a paper towel dipped in xylol to remove sanding dust and a second coat of japanning applied.

Finally feels like real progress.

Remember this?

The plane I used when testing the finish blends didn’t have any brush marks, and it was the same formula that I had first used that didn’t sag.

What was the difference? When testing the blends, I used a cheap flux/glue brush, not the artist’s brush. That resulted in more than a few bristles in the test finishes, but it didn’t matter for that purpose. Could it be that the flat brush was applying the finish too thin and it was setting up too fast to self level? A quick trip back to Hobby Lobby to see what else might be available and I purchased an inexpensive set that included two mop brushes,.

These had a thicker head than the flat brush I started with, thicker even than the glue brush, but with much finer bristles.

With a renewed sense of purpose, it was time to try again. This time I used a old Bailey No 5 (I believe it is a type 9) that was picked up at an auction in a lot with another 605 I actually wanted for the parts. It had been broken in the past, so one side was brazed and two corners were still chipped, but it had almost no original japanning. Using this plane would allow me to work on the japanning without fear of doing any additional damage to the Bedrocks.

After wire brushing off the little bit of remaining original japanning, the Bailey was wiped down with xylol to have a clean bed. By the time I had a paint brush out and the jar of japanning open, the solvent had dried and so a first coat was laid on—this time using a mop brush instead of the flat brush.

The result was a much thicker first coat than my original attempt, but within a short time of applying the japanning, there were no brush marks!

Encouraged by this, I left the plane overnight and mentally attacked the problem of getting a good cure on the finish.

Even given 24 hours in a very hot and dry Kansas summer, the finish was still a bit tacky. The few internet posts I had found said that you needed to either bake the finish or allow it to cure 30 days or so. A couple also mentioned applying two coats before doing either of those, so I pressed on with another light coat and let it set overnight.

In order to try and help the curing process, I decided to leave the plane outside in the sun the next day for several hours on a 100 degree afternoon. The hope was that I could cut the 30 day cure time down quite a bit. While the resulting finish was more cured than just air drying inside the shop, I ran into a new issue—brush marks!

If you look at the above picture, you can see the slight brush marks from the first coat. Instead of the second coat filling and leveling those out, as I had hoped it would, it amplified them. No photo of those. I was so disgusted that it didn’t even cross my mind to take a picture.

This poor experience led to several attempts to redo the process that the only thing they accomplished was to allow Murphy’s law to intervene. Using another plane, I tried thinning the mix to get better flow. That was accomplished, but it also resulted in sag and bubbling around any vertical surface. I tried allowing the plane to cure in the sun after every coat, but still ended up with brush marks and a finish that, while not tacky any longer, also wasn’t as hard as necessary. A couple other ideas also backfired, so finally it was time to for:

I stripped the two planes I had been using, put everything on the workbench and just had to walk away for a few days before starting over.

In testing, I tried adding various amounts of spar varnish to the asphaltum, painting on a plane bed and letting it dry overnight. Here is one such test comparing a 2:1 asphaltum to varnish blend with the pure liquid asphaltum.

This ended up being the ratio for my first attempts. The addtion of the varnish helps thin the mixture a bit so that it is easier to apply and flows much better and I also found it seems to slightly lengthen the intial work time so that the solvent doesn’t flash out before allowing the japanning to self level. If you thin the mixture too much, it doesn’t coat the vertical surfaces well and will sag before setting up. (Hint: that would be one of the abject failures mentioned earlier)

Before continuing further, I need to ask for some leniency and understanding. I didn’t set out to write a blog when first attempting to figure out this process, so didn’t do a good job of documenting & photographing everything along the way. For the pictures I have, you will see several different planes used. These are all planes that have gone through my japanning process and I have tried to pick photos that best show what was going on at various stages.

Carrying on. After working with several different asphaltum to varnish ratios, raging from 1:1 to 4:1, I settled on 2:1 as the best combination of coverage, flow and appearance. I used semi-gloss varnish to try to tone down the high sheen of the asphaltum. My test bed was a Bedrock 605 that needed a complete makeover, so it was masked off and a light coat of japanning applied. Here it is part way through laying on the first coat.

You will notice that the brush is not the same as those pictured in the first blog installment. I first used a flat brush to try and get into the nooks, crannies and corners of the plane, this thinking was to change later. In spite of the asphaltum looking black in the can and jar, it is really a dark brown. If you look again at the picture of the test, you may be able to see that the thinned finish has a slight brown tinge, while the undiluted asphaltum is nearly black. The light coat that was applied really shows the actual brown color.

The plane was set aside to dry overnight before a second coat.

Before you jump right in and follow these steps, please note that this plane got completely stripped and redone again a bit later. It turned out much better the second time, using things learned from this first try.

We’ll leave it there for now and pick up the next installment with more coats, application errors and attempts at curing the finish.

This blog series is my journey of trying to replicate the japanning process used on many tools, especially hand planes, that has been used for over a century. It will include some abject failures, as well as what was found to work for me.

This blog is not a commentary on how someone else might choose to finish their planes when doing a restoration and I am not necessarily advocating japanning over any other finish. There are many people on this site that are much more experienced and talented than me that use other methods. The blog is more a result of my curiosity as to how the tools were originally finished and to see if I could come close to replicating that.

A little backstory. After getting bit by the hand plane bug this summer, I started trying to do some restorations. The first couple were simple clean-up, tune up jobs, but soon I ran into one that needed completely stripped. Following and researching how several other LJ’s perform restorations, I decided to try Rustoleum Hammered Black spray paint. This was the result.

It looks good and is very functional, but is so obviously not that similar to the original finish. The color is more charcoal gray than black.

Doing some more looking around, I found that others had success with Duplicolor Ford Semi-Gloss Black, but that the original finish was something called japanning. I had never heard of this finish, so started to dig to see what that really was and if it would be possible for me to reproduce it in my little shop and on a budget. A bit of research showed that japanning on Stanley tools in particular was a finish made from gilsonite, a tar solid found in the western US and commonly known as asphaltum.

Even more digging/searching through Google showed that I could purchase gilsonite in powdered form or as liquid asphaltum from Dick Blick Art Supplies for a reasonable amount. (as opposed to the $60 quart of japanning found on another site. I’m sure it is great stuff, but I wasn’t going to spend that much right now) I ordered one pint and set out accumulating the other materials.

In addition to the asphaltum, I bought some xylol for thinner/brush cleaner. Xylol is an excellent solvent for heavy solids and is the solvent used in the liquid asphaltum, so there would be no compatibility issues. Turpentine would probably work, too, but as I had neither on hand and they are about the same price, xylol it was. Artist brushes for applying the finish and glass jars—one for cleaning the brushes and the other for blending the finish.

Next installment: Testing different finishes using the asphaltum and initial applications.