Recently descaled some real wrought iron with a vinegar bath. Worked well on the glasslike forge scale, however the piece looked silver under the vinegar but when washed off and exposed to air it turned brown almost immediately. Is there a way to preserve the raw iron grey look?

On mild steel I have been able to wire-cup brush it to give it a lasting sheen. I can imagine WI would be different though, but why not experiment?

Yes, you can wash with something to neutralize the vinegar, I like dilute ammonia, ammonia based window cleaner is another option. Baking soda works, but is a pain because it is powder. I follow up with dish soap on a stiff plastic brush, however rinsing with lots of water should be adequate. This finish will last long enough to dry off (a couple hours).

Now you need to wax, oil, or paint the surface to keep it from quickly rusting.

Phil

does this really work as an effective stand alone descaler before paint? ive never tried it... do you Need to neutralize it too? sorry to ask basics..

I soak in vinegar then generally brush off the scale with a bathroom brush (or old toothbrush if it's a small piece) using soap and water.
I usually apply an oil/wax mix but have used a clear spray varnish with no problems.

ron

I like to use household ammonia in water to neutralize and I have found that it is best to force dry with heat. The heat prevents rusting before drying can be finished. Heat also gets all the moisture dried. I usually rinse in clear water after the ammonia and then heat dry immediately. A cheap propane torch works well for drying, or an electric heat gun... even just the sun on hot days is fine.

The natural state of iron is rust so whenever you clean off old rust you must do something to prevent new rust from starting.

Abeck said....

"Recently descaled some real wrought iron with a vinegar bath. Worked well on the glasslike forge scale, however the piece looked silver under the vinegar but when washed off and exposed to air it turned brown almost immediately. Is there a way to preserve the raw iron grey look? "



I suggest brush on some lemon juice (immediately after cleaning up after the vinegar), then dry and spray with a clear finish.

Lemon juice-vinegar, no difference, they are both acids. HEAT the piece to dry it or it will rust before it dries. Heat alters the reaction and creates a darker look but is not red like the rust. You can do a final rinse in boiling water which will provide the heat... for small pieces this is a good way to work. Heat will only work when the acids are well rinsed or neutralized... heat and vinegar saturated with iron filings is an old method for staining wood.

I switched to PH minus or PH down both the same thing sold by the same company mixed with warm water.
I get it at Walmart or sometimes garage sales.
Faster than vineagar.
Use it to descale and lately to take the plating off some hardware.
Do this outside and stand UP wind

Actually... My suggestion was based upon experience. Although I used a different acid for etching, my wrought iron piece literally transformed to a rust appearance when I cleaned it and blew it dry with forced air. The piece was BROWN. All I did was brush it with lemon juice and the rust color disappeared (the piece was then silver).

PH Down is a sulfuric acid solution according to the MSDS.

I recommend reading and understanding the MSDS for all chemicals in the home and shop.

Phil