Etchant causing rusting

Thread Starter


Joined Dec 8, 2008
Hi everyone,

Since I have been using Muriatic acid and Hydrogen peroxide for etching, my tools have started to rust.
I am going to store one or both of the solutions in an air-tight container.
Which solution is causing the problem?



Joined Feb 5, 2010
acid and oxygen.

both are death to iron.

antirust compounds wear off and then those two elements destroy iron. I recommend using lanolin. it will last longest and provides great protection to metal


Joined Mar 24, 2008
The acid is the big culprit, I wrap a papertowel tightly around the lid and tape it in place. then for good measure I double bag it, with a toilet paper bag of bicarbonate in the middle bag.

I described the problem in How I make PCBs

All etchants do it.

Thread Starter


Joined Dec 8, 2008
Thanks Bill and R!f,
The strange thing is that both bottles have screw caps.

@ Bill --- What is the purpose of the paper towel ?


Joined Oct 29, 2009
Just keep them away from metal
Duh. right?

I store mine under the sink. Mix as needed. Unmixed both can be useful products around the house.

I etch in the bathroom since that mixture does not stain like muratic acid (yes I am single :)).

Actually since switching from muratic acid, I have far less issues with rust.


Joined Feb 3, 2014
Peroxide is an oxidant as you can see from the air bubbles. Any acid is bad for steel tools. I like to pour vegetable oil on pliers every once in a while to keep the joint from rusting too.

Take care of your tools as you will be lost to your own device if you abuse them or lose them...


Joined Apr 28, 2012
Some kinds of corrosive liquids can creep out the smallest gap as vapours, or maybe as ions when the conditions in the air are right.

Metals magically attract them even over some distance.

Sorry maybe it is incorrect not ions but it has baffled me a few times.

Or if there is no air circulation, the reaction of a few molecules creates a tiny bit circulation to attract more vapours.

I don't know exactly.