The second rust removal experiment I performed using Restore Rust Remover Gel. This gel contains both etidronic acid, and trisodium nitrilotriacetate. Both are chelating agents, pH neutral. For testing the gel, I used the sole of a plane body covered with rust. The choice of a plane body for the gel makes sense, as it is most likely that the gel would be used for larger objects, that can’t be submerged in a liquid, e.g. saw blades.
To test this gel, I brushed a layer of it onto the sole of the plane, which has quite ingrained rust. I split the sole in half using painters tape. The instructions say that “Application is by means of a scouring pad (not supplied) which is moved gently over the surface until the rust is removed and the surface is left bright and clean.”. This is not a “thick” gel, I would agree with the manufacturers description of a “thickened liquid”. First off I thought I would test leaving the gel on the plane for 20 minutes.
The end result was that the gel actually dried in 90% of the test area, so obviously the best approach is to scrub. I then followed the instructions exactly, using an abrasive “Chore Boy® Golden Fleece” scrubbing cloth. The results were… underwhelming to say the least.
The orange flash-type rust was vanquished, as were the black regions. The deeper rust? Still there. Does this product actually remove rust? Maybe, the kind of rust that is surface rust, and may be just as much attributed to the scouring action than to the gel itself. For all the scouring action involved, it would have been easier to sand the sole down.
Just to be sure I wasn’t going crazy, I tried a second test on another block plane sole (I have a bunch of these relics in a box – think spare parts). The rust on this sole was much lighter, and it was possible to still see steel. The results show less surface rust, but were again, not great.
After two tests that didn’t really produce the results I had hoped, I would not use this product, nor recommend it. There is also a liquid concentrate for soaking which makes 5 litres of solution, which I did not try. In reality, both products are C$39.50 which is super expensive. A litre of Evapo-Rust is C$14.50 (and a 5 gallon pail (18.9l) is C$108 on Amazon.ca).
Here is a photo of the sole of the first plane, to give an overall perspective.