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Frost steel blacking kit.

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Robin Graham07/02/2020 22:40:22
947 forum posts
296 photos

Has anyone had any experience with the Frost Metal Blacking Kit?

It's a three component kit consisting of one litre each of Light Alkaline Degreaser (15 quid), the Blacking Solution itself (28) and Dewatering Oil (19) so 63 quid all told. That's pricey for what I want to do.

I'm pretty sure I can do without the de-greasing solution - but what is de-watering oil? WD40? That's what it's designed to do isn't it? If I could get away with just the blacking solution it would be a more attractive proposition.

I know blacking/blueing comes up from time to to time and there are ways to do it involving heat and oil quenching, but for the mo I'm only asking about this or similar systems.


Steviegtr07/02/2020 22:57:54
2436 forum posts
336 photos

Baking soda does most of the cleaning action needed.


Martin Thomson07/02/2020 23:44:29
11 forum posts

That is somewhat expensive, and you almost certainly have some variation of two thirds of the kit already...

I recently ran out of cold blue, and bought this ebay item to replace my stock: **LINK**

£19, but 500ml is a massive amount and will last me years. I've done a few parts with it and it is as effective as any others I've used.

You need some kind of degreaser, ideally a water based one rather than a solvent or a light oil etc. I use Screwfix no nonsense degreaser: **LINK**. Be sure to read the instructions, and dilute appropriately, as you only need a tiny amount. 5l will last years. I also use this as my default ultrasonic cleaner solution.

Clean the parts well, with a water based degreaser. I tend to clean parts in an ultrasonic cleaner if they'll fit.

Don't touch the parts with bare hands again - you should be wearing gloves when using the selenium dioxide anyway, but also avoid greasy fingerprints.

Rinse the parts off in clean, hot water - close to boiling ideally as that both heats the parts and allows them to dry quickly. Hotter parts react with the solution better.

Allow the parts to dry - don't try and speed this up by blowing oil over them with a compressor, as that will defeat the object of the degreasing step.

Decant a small amount of the bluing solution - maybe a capful, probably less. Don't dilute it, and never return used solution to the original pot.

Don't try and submerge the parts, that really doesn't work. Use a toothbrush, and rub the bluing solution into the surface. I don't know where I got this particular bit of advice from, but it is pretty much the most important step in getting a good finish. You need to break down any remaining surface tension, and a toothbrush is the ideal tool.

Use a clean (brand new) piece of fine scotchbrite (or scouring pad) and rub over the surface - this will remove most of the finish, don't worry, the next time round applies a much thicker coat.

Repeat the bluing and scotchbrite steps 2-3 times, until you're happy.

Submerge in wd-40 (or alternate water displacing, pretty much just paraffin, equivalent).

Allow to dry again, and apply a light oil - I like sewing machine oil for anything I have to handle regularly.

The result you get will vary a little with both the surface finish you start with and the type of steel. You are literally applying a thin coat of rust, so anything that inhibits rust will reduce the effectiveness of the bluing. Mild steel works best. Tool steels are more difficult. Highly polished surfaces also resist bluing. You want a good consistent surface finish, but not a high polish.

Manofkent08/02/2020 08:17:13
142 forum posts
29 photos

I have used the Frost Blackening kit. It is easy to use and the results are very good.

You will need a timer for the immersion times. I used my iPad.

The first cleaning/degreasing is essential, and when I have used other cleaners the results are not as good.


Baz08/02/2020 08:35:53
725 forum posts
2 photos

I have used Metalblak cold blacking kits for many years and have never had any problems getting a lovely black finish on steel, the smallest kit is 100ml and is available for about £20 from model engineering suppliers, GLR kennions, EKP supplies and Blackgates, just to name a few.

not done it yet08/02/2020 08:47:22
6812 forum posts
20 photos

The first cleaning/degreasing is essential, and when I have used other cleaners the results are not as good.

Too true! The cleanliness of the item, before blueing/blacking, is probably the most essential part of it. No point at all of only just removing most - it has to be 100%.

Douglas Johnston08/02/2020 09:18:54
770 forum posts
34 photos

Martin, that link to ebay for the cold blue does not seem to work. Not for me anyway.


Clive Foster08/02/2020 09:47:03
3137 forum posts
109 photos

The cold blue systems all seem to be much of a muchness if you follow the instructions and are appropriately careful. Main variation seems to be how many coats needed to build a decent colour, how tolerant they are of residual contamination and how wide a range of materials the stuf can be applied to with good results. Probably a strong element of personal voodoo as well.

At 3 litres total the Frost kit is, relatively, huge so objectively pretty good value per litre. Its a dip in rather than rub it on system too so rather less work. Presumably the contents can be stored and re-used several times. £60 odd for a one time set would be costly!

Frost also do an even more expensive phosphate / black oxide kit made by Eastwood which is implied to be up to factory durability standards. I wonder if its worth the cost.

Personally I find the heat and dip in oil method works well enough for me. But generally I wand quick and reasonably effective protection for un-paintable things not exhibition finish.

As ever its choosing the product and method giving the best price / performance / hassle ratio for what you do.


Nigel McBurney 108/02/2020 10:21:45
1000 forum posts
3 photos

A long time ago maybe 20years ago I did a test and review of the Frost blacking kit,for a Magazine, so got a free kit, and I still have it.I found it was very good, On new steel it works well on cleaned up new steel ,on the other hand rust pitted steel like we get when restoring stationary engines the rust pits cannot easily be blacked.Its useful on parts that were originally made from thin blued steel, ie some magneto covers and the main bearing oil cap lids on certain Ruston Hornsby engines, I also tried it on some mild steel sliding die holders and it lasted for several years and resisted a fair amount of handling, The degreaser worked well though petrol and aerosol carburreter cleaner works just as well and the dewatering oil is a bit messy,I use wd 40 to remove any water ,wipe off the wd 40 and then apply a light coat of 3 in 1 oil, so its only the oil black that is essential,and the blacking solution lasts a long time,as I said mine must be 20 years old and I have used about half of the contents of the container,last job was a couple of tears ago when I made new oil lids for my 1911 Hornsby petrol engine,The solution would be good for treating the blacked fasteners when restoring say a Myford lathe. The black solution can used by pouring into a plastic tray,when finished pour it back into another clean sealable container ,this fluid can be used again a number of times an then disposed of,this will keep the bulk of the new solution clean,

Russell Eberhardt08/02/2020 10:31:11
2743 forum posts
86 photos

Abbey Blue Gel works well for me. OK, it's for blueing but three or four applications gives a deep black. Only about £8 on ebay.

I degrease with nothing special - just isopropyl alcohol.


Edited By Russell Eberhardt on 08/02/2020 10:35:28

Neil Wyatt08/02/2020 17:06:54
19040 forum posts
734 photos
80 articles
Posted by Steviegtr on 07/02/2020 22:57:54:

Baking soda does most of the cleaning action needed.


It's worth stepping up to soda crystals (Sodium Carbonate), cheaper, easy to get, more powerful but nowhere near as nasty as caustic.


Robin Graham08/02/2020 22:58:54
947 forum posts
296 photos

Thanks. It sounds like my suspicion that the degreasing/dewatering components of the kit are unnecessary if you already have degreasing stuff and oils is warranted.

I was interested in the Frost kit because it had been recommended to me, but thanks for suggestions of alternatives. Martin's link didn't work for me either, but it's easy enough to find the product by searching for Phillips Professional Cold Blue. Perhaps I can save some money by going elsewhere for the bluing solution. I probably don't need a litre.

I can well believe that surface preparation is key to the success of this process. I have some learning in this area - my first job involved preparing metal samples for etching and photomicrography. If one came back from metallurgy with a scratch or even a fingerprint on it my son-of-a-bachelor boss made me take it back to 200 grit and start again. Sadistic but effective - you didn't make the mistake three times!



Edited By Robin Graham on 08/02/2020 22:59:30

Grindstone Cowboy09/02/2020 00:26:53
859 forum posts
64 photos

This link should work for the cold blue on Ebay

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