Replacing Black Japanning HELP

[Old Man Oakley]

Dear All

I have just bought a nice fly box from the 'Bay of Goodies. It has been repainted at some point in its long illustrious past and I hope to remove the old paint and replace it with something which resembles the original black japanning more closely. In the past I have used black enamel spray paint, which looks OK but does not adhere well to tin.

Can any recommend a better solution?

Many thanks

OMO

[Paul D]

I would advise you to use a "acid etch primer" first, if your able see if you can find a local bodyshop to give it a coat, the stuff they have access to has a much higher acid content than rattle cans.

[Old Man Oakley]

Many thanks I'll give it a go.

OMO

[Santiago]

You could always try tea and coke! Simply bring a small pan of coke slowly to the boil and add about six tea bags and allow to simmer for about ten minutes. Allow to cool and then test the liquid by painting thinly onto a test patch. After several minutes the metal should turn bluey black. I know this solution works great for iron and steel and ought to work on tin plate, depending on the thickness of the micro layer of actual tin.

The coke provides the phosphoric acid for the etching etc. and the tea provides tannic acid which reacts with iron to make bluey black Iron tannates. If you make a really strong brew one might be able to mix with a water based varnish and achieve the same effect, but it's probably best just to varnish after the colour has developed and dried. I did this with steel nails and it worked within minutes. And instead of tea bags one can also use homebrew tannic acid; a few teaspoons mixed into 1/2 pint boiled coke (or any pop) will suffice!

[Old Man Oakley]

It sounds like the tea my secretary makes.

[Santiago]

Them try her tea. You'll be surprised by the result!

[Beresford]

I do like the idea of the coke/tea method. Might have to try that sometime.

You can buy two part acid etch primer for model makers. It only etches once dry and I presume it knows when to stop etching ; ) but being two part you have to add the catalyst to set off the reaction. It's rather more than rattle can money. You can buy it here (see link below) and their information may be interesting to read. Given that it's sold for model makers working with relatively thin metal it's probably not the most caustic however it is designed for brass which is a horrible metal to paint being naturally greasy and a pain to get really clean. The one I've used successfully on white metal and brass, is sold by Cloistermans. Halford sell one called U-Pol, I've not used it but assume it's a good product. I use a combination of a fibreglass pencil and then Vim with a wash in cellulose thinners to clean brass but there are one stop products you can get so you may want to consider buying a proper degreaser as well as etch primer.

I think those etch primers in rattle cans, certainly the one I use, is the same in that it only etches once dry otherwise it would presumably eat the rattle can it comes in.

http://www.phoenix-paints.co.uk/etch-primers/

An alternative method, if you want a really super smooth 'thin' coating, is to have it powder coated. However, that is unlikely to be cheap unless you can find a sympathetic supplier.