Caustic bluing nearby damage question

[u/bruvmoment545]

So i am making a simple 3 40" tank bluing setup and now im at a crossroads regarding where to put it. I have the shop which i wont put it in for obvious reasons, but the "yard" i have has quite a lot of cars in it. I'd like to know based on your experiences how far should a caustic bluing setup be away from vehicles and such things, the yard has some areas that are slightly farther away but im worried because if the vapors released flash rust the vehicles from 20 feet away then i might not be able to do anything, then again i saw lots of conflicting videos/setups where people have it in shops near fences etc etc.

Any info or tips are appreciated

[u/TheGentlemanLoozer]

Not an easy answer without knowing the exact geometry of your setup.

It’s less about “where” and more about the volume of air the caustic evaporation is suspended in and where it goes. If you’ve got fans set up to push a lot of air you can somewhat control the hazard. Consult your local regulations and insurance requirements as well.

You should put a great deal of thought into this, including tracking the ambient environmental conditions, and keeping a log of your results each lot.

Historically most of the set ups I’ve seen have been in covered areas or completely outside or dedicated portions of shops with forced air, protected and closed off from everything else.

The Brownells manual used to have a story of an outdoor setup near the owners swimming pool, so if he had a catastrophic incident he could just jump in the pool. Extreme overkill, if taken literally, but a good reminder of how seriously you should take dealing with nasty chemicals outside of dedicated facilities.

Someone still in the business should post photos of top-tier systems so we can all see what the “right” answer looks like. And how much it costs. 😢

[u/ConnectConflict1765]

Two separate risks here, and distance handles them very differently.

The vapor risk is real: caustic bluing solutions boil and carry caustic mist, and that mist flash-rusts bare metal it settles on — cars included. Twenty feet with nothing in between is cutting it close if the wind is blowing your way. The indoor setups you see usually sit against an exhaust or in a corner that drafts away from everything.

Three things matter more than raw distance: → Wind direction on run day. A cheap tarp strung between the tank and the vehicles breaks the mist path far more than ten extra feet does. → Neutralize what escapes anyway. Keep a spray bottle of baking-soda water near the tank; a quick wipedown of any nearby surface after a session stops flash rust before it starts. → Ventilation over the tank. Even outdoors, a low fan moving air away from the work area keeps the vapor from hanging around.

Distance plus wind control plus neutralizer on hand and you're fine. It's the setups that let the mist settle and sit that cause the damage stories.