Recommendation for metal bluing (saw rehab)

[SeanA]

Hey all,
What is the current recommendation for how to blacken (blue) the spine of old back saws? Last time I read about it (a long time ago), Brownells Oxpho-Blue was recommended, but I want to say some folks felt it comes out a bit more of a blue tint than a pure black. A) is that correct, and B) is there something better?

Just for reference, here is Brownells Metal Bluing page I found when looking up how to spell "Oxpho" (-;
Dicropan T-4 and Express Blue #1 also seem to get good reviews. Anyone have experience with these vs. Oxpho?

TIA
Sean

[bandit571]

Been using their Gun Blue Paste....wipe on, let is dry...done



Disston used to take the HOT spines, and dunk them in Mineral Oil.

..then let them cool...the paste is way safer...

[SeanA]

Disston used to take the HOT spines, and dunk them in Mineral Oil.

..then let them cool...

That sure sounds exciting!

[Mike Brady]

Brownells or any gun blueing will work really well.  You can get it at gun shops or online.  Don't be tempted to put it on saw plates however.

[bandit571]

Can be used on saw plates....to bring out the etch better...wipe the paste over the area the etch is in...allow to dry...block of wood with sand paper around it, sand away until just the etch remains.   Most etches are below the surface of the plate...sanding the plate but not into the etch....leaves the blue down in the lines...

[Phil Thien]

Have you guys found one bluing agent which is more durable than others.

In rehabbing tools over the years, I've resorted to taking stuff to a bluing shop where they do hot bluing.  But I'd sure like to find something I can use at home.

[Mike Brady]

Birchwood Casey Perma Blue was by far the best I found to put on common Steel tool parts.  After it dries, put a little oil on the blueing  and spread it with a rag.  I did saw backs and old squares with it.  Hot blueing is like powder coating:  great results, but is it cost effective for tool restoration?

[SeanA]

Birchwood Casey Perma Blue was by far the best I found to put on common Steel tool parts.  After it dries, put a little oil on the blueing  and spread it with a rag.  I did saw backs and old squares with it.  Hot blueing is like powder coating:  great results, but is it cost effective for tool restoration?

Thanks for the ideas and your experiences. These cold-bluing chemicals are cheap enough to experiment with. My saws don't get enough use so I'm not super worried about durability. 

Out of curiosity I messaged a local gunsmith to see if hot bluing was an option (and at a reasonable cost). Guns are expensive but intricate, whereas a saw spine is about as simple as it could get. Will report back if I hear anything.

Update: Gunsmith was interested in the question, but said (roughly paraphrasing) that hot bluing was very toxic so subject to a lot of regulations/permitting etc. so isn't done as much anymore. The main alternatives (nitriding, anodizing, phosphating) are better, are more capital intensive so require larger production runs of manufacturers but aren't really available to local gun shops. He did suggest Cerakote as a good option, guessing it would be less than $40 for a spine. I'm gonna try out the cold blues.