6 replies to this topic

[PURPLE_2L_LX]

Need to cold blue some small steel parts.  Seen some youtube channels use various brands and

types but often its only available as a kit and as usual in the UK its super expensive small sub 250ml

bottle costs more than they pay for 25 litres in other countries.

 

 

Selenium Dioxide appears to be the most common, safer than hot caustic treatments. But not as

rust resistant and may wear off when handling. These are machine parts so handled a fair bit

but stored for fairly long periods in an outdoor shed.

 

Cannot be primer or paint, it cannot add any appreciable dimensions to the parts.

 

 

Maybe a long shot but worth asking.

 

Thanks

 

 

[raynkar]

I’ve used this one for some time.

I use it on tools and gun parts. I re coated these squares some time last year, and they get regular use so it’s a nice permanent blue.

 

As with many cold blues it can be easier to apply if the item is heated a little. Not to the high temps needed for hot blueing, but maybe 100 degrees.

 

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[PURPLE_2L_LX]

Thanks will have a look, did you try any others?  Looking to buy it by the litre and use

submersed rather than brushed/wiped on if possible.

[raynkar]

Thanks will have a look, did you try any others?  Looking to buy it by the litre and use

submersed rather than brushed/wiped on if possible.

I’ve only used this one as it’s popular with gunsmiths.

I’m not sure how effective most cold blues would be with submersing parts, as you could end up reducing the effect of the blue, a bit like how you can’t return rust remedy into its bottle or place parts into the rust remedy bottle.

[PURPLE_2L_LX]

Bought a 250ml bottle of Phillips Professional Cold Blue and that seems to be doing the job.

£12.99 off Amazon with next day delivery.

 

Probably the same ingredients Selenium?  May get some Perma Blue and compare them.

 

Does it offer much rust protection? Seems to be mixed reviews on that. Some say yes

some protection and others say virtually none.

[raynkar]

I can’t really say.
My tools don’t tend to get wet, and gun parts would be cleaned before and after use.

[PURPLE_2L_LX]

Not as organised as you.  

 

Had a leak and found water in the trays i kept my lathe and mill tools in...

Even though they were oiled, sitting in a puddle didnt protect them.

 

Got an old Bisley 15 drawer cabinet, but some draw bases have surface rust, need to

treat it.

 

Maybe line it with paper with a drop of oil soaked in or the old fashioned brown paper

that some tools came wrapped in?

 

Scroll saw table is just pressed steel and that took the brunt of the water. Thats quite

rusty.