'Japanning' using Dupli-color engine enamel - what did I do wrong?

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Forum topic by Pendragon1998 posted 03-13-2015 07:40 PM 3317 views 0 times favorited 9 replies Add to Favorites Watch
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74 posts in 2587 days

03-13-2015 07:40 PM

I have a handful of old cast iron file handles and a pad saw handle that look to have been originally japanned. I read about using Dupli-color engine enamel semi-gloss black to replicate japanning, and it looked good online at

So, I cleaned up my handles in an electrolyis tank and ordered some paint (couldn’t locate it locally). I had to wait a few days to paint, so I stuck the handles in a jar of acetone to keep them from flash-rusting. Last night, I had the paint and I got a little excited and painted two handles. One I had previously hit with some rusty metal primer as an experiment (it was cracked to begin with). The other I just sprayed the enamel on the raw part.

I gave them an initial light coat, followed by a very heavy coat (had a couple drips on one because I was trying to get paint inside the handle and sprayed too heavily). It was about 60 degrees last night and raining, so humidity was high.

Also, I got the old paint / japanning off the exterior, but I couldn’t sandblast them, so there were apparently some flakes I missed on the exterior and interior. I’ll wirewheel the others before I paint.

This morning, I took a look at them and I was disappointed to see a very matte finish. There was no gloss at all, and compared to actual japanning, well, it didn’t look right at all. Any idea what I’m doing wrong?

9 replies so far

View lateralus819's profile


2243 posts in 2900 days

#1 posted 03-13-2015 08:17 PM

Ive had it dull over before. I just let it cure fully and re sprayed it.

The reason it doesn’t look like Japanning is because it isn’t japanning. Its enamel. Two different finishes. You CAN make real japanning but it’s a process.

View Deycart's profile


444 posts in 3269 days

#2 posted 03-13-2015 10:14 PM

I have stopped using that stuff for a while now. Its kind of a crap shoot. Sometimes its good, most of the time there is some sort of problem. I get dull, cracking, orange peel, and sometimes the finish is still soft after letting it sit for a few weeks. And before someone says well did you do … I have been using spray paint for years, so I know how to properly use it. It seams to be very very sensitive to temperature and humidity. It also does not like to build up fast. Put it on too thick an the stuff just never cures.

I like to use automotive build up primer that is black and then spray with regular gloss black. Works EVERY time and it is very consistent. I personally like krylons products.

View MrUnix's profile


8422 posts in 3210 days

#3 posted 03-13-2015 10:27 PM

Humidity plays havoc with gloss finishes. I’ve had stuff behave like that just by spraying right before dusk when the sun is just starting to set and the humidity is rising. I always make sure to spray in the middle of the day now, and make sure there is no chance of rain. I will also bring it into the house in a conditioned environment as soon as I possibly can; sometimes immediately after spraying, and letting it hang to dry. As mentioned, just let it fully cure, maybe hit it with a light sanding, and re-spray when the humidity is lower.


-- Brad in FL - In Dog I trust... everything else is questionable

View Deycart's profile


444 posts in 3269 days

#4 posted 03-13-2015 10:30 PM

Ditto on bringing it inside into a controlled environment. It really does not have much of a smell after leaving outside for a minute of two.

View Pendragon1998's profile


74 posts in 2587 days

#5 posted 03-13-2015 11:12 PM

There are a couple of spots where there is a much glossier effect, so maybe it was the humidity. I also want to try hitting it with more, thinner coats (I hurried it due to impatience last night).

Any hints for getting interior coverage without soaking the exterior? The handles are a weird shape for painting. I almost wanted to just dip them somehow.

View JayT's profile


6419 posts in 3222 days

#6 posted 03-14-2015 12:56 AM

I almost wanted to just dip them somehow.

- Pendragon1998

Then make some japanning and dip them, it’s actually not that hard. I did a japanning blog focused on hand planes that has the ingredients I used. No reason you couldn’t make up a batch of japanning from liquid asphaltum thinned to your desired consistency.

-- - In theory, there is no difference between theory and practice. In practice, there is.

View Pendragon1998's profile


74 posts in 2587 days

#7 posted 03-15-2015 08:17 PM

I would like to try japanning for real at some point, but I am hoping to get the paint working ok for this project. When I try it, I’m going to use the info in your blog – it was excellent. How well does japanning last once you mix it? Can you keep it in a sealed jar?

I had a little better luck with the dupli-color this afternoon. I stripped the pad saw handle and wire-wheeled the crap out of it, trying to do a better job than last time. Then I hit it with 2-3 light coats with about 5 minutes in between each, and then a couple of heavier coats. This time I was shooting it and leaving it hanging in the warm sun, about 72 degrees F, and 60% humidity. It’s still drying, but it looks a lot glossier than before. Thanks for the suggestions. I’ll post again when I get everything finalized.

I know the photo looks like it’s got some blue in the finish, but that’s the glossiness reflecting the sky. Hope it continues to look about like this once it’s fully dried.

View SST's profile


790 posts in 5206 days

#8 posted 03-16-2015 12:53 AM

I’ve had good success re-doing old planes using Valspar gloss black alkyd implement enamel along with their alkyd enamel hardener. Brushing it on insures a coat or coats that are way thicker than spray paint & the hardener results in a finish that looks, to me, like original japaning and is very tough.

-- Accuracy is not in your power tool, it's in you

View Don W's profile

Don W

19891 posts in 3578 days

#9 posted 03-16-2015 09:46 PM

I’ve only had the issue with Dupli-color engine enamel semi-gloss black once. At first I thought I had a bad can. I’m assuming it was weather related now. I’ve had good luck other than the once, and as LAt suggested, just give it another coat.

It may be region related. Some day when my arthritis acts up so bad I have to move, we I may find out.

-- - Collecting is an investment in the past, and the future.

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