After some discussions on Facebook’s Unplugged Woodworker group on what is the best technique to remove rust from the sides of a rusty old plane, I decided to do some comparisons. When you are restoring a tool, you have choices. These choices should be selected based on the tool at hand and the intended outcome.
Note these tests were performed on broken hand planes unless I’m showing the previous failures.
First let me explain, this is for those concerned about keeping the original look of the plane. Maybe you found a fairly rare plane in really really bad shape and you need to restore it, or maybe you found a common bench plane, but want to try and maintain its original look.
This discussion came about after I posted my Hand Plane Restoration by the no soak method.
It will also be relevant for all of my restoration guides including Bench Plane Restoration Guide. Part 1 and 2
None of my processes are not meant to be a valuable antique restoration guide. This is meant to be a way to get neglected and rusted hand planes ( and possibly other metallic tools) back into nice looking and usable conditions. If in doubt, please see “To Restore a hand plane or to not restore a hand plane”***
I’ve heard using a rotating wire wheel on an old tool is a bad idea as it creates tiny pits on the surface finish, and creates a finish that looks nothing like the original factory finish. I can’t say that I’ve seen this, but each wire wheel is different, so test your wheel before taking it to a valuable tool. And you’ll read this warning twice, but I want to recommend using some caution around the edges when using a wire wheel. It’s not so important with a soft wheel, but as the wheel gets more aggressive, its more of an issue. To much time or force will round the edges more than time itself has done. This is especially true around the mouth area. You do not want to round the edges of the mouth off.
I recommend using the softest wire wheel that will get the job done. I like this one, 8″ Crimped Brass Wire Wheel from TNM and for tougher jobs I use this one a lot DEWALT DW4908 10-Inch Crimped Bench Wire Wheel, 3/4-Inch Arbor, Wide Face .014-Inch Wire.
I’ve read that Stanley used a form of precision sanding called linishing, it is said to be still in use today. True milling or high precision surface grinding takes too long, and its overkill, linishing is close enough and its a whole lot quicker. I have not confirmed this, but it makes sense. I know I read it on the internet, so it must be true! <sarcasm folks>
Just one more note, I have read (and I agree) that polishing your bare metal to more than 400 grit tends to make them harder to maintain in the shop. You will start to see finger prints, and quicker corrosion.
First off is the bench mark for this post. I will admit not everyone needs or wants to bring their plane back to original, and not everyone cares. Some of you may even want to improve on the look of its original look and get your plane a little spiffier. Its all a matter of personal preference.
This is a “New old stock” Stanley plane. (Picture immediately below) (my collection)
And here is the one I did for my original blog on a belt sander. It’s the plane sitting on the belt sander in that blog. Unfortunately its been so long I don’t remember the grit size. I would guess it was about 180. (Picture immediately below)(my collection)
I will only use a belt sander if the pitting is bad enough that there is no other way.
Next up we have one cleaned up with a wire wheel. It’s a course wire wheel. (Not knotted or extra course). Note the pitting from the rust, it would have taken to much sanding to get it out, even if I wanted to (which I didn’t)
Also I want to recommend using some caution around the edges. To much time or force will round the edges more than time itself has done. This is especially true around the mouth area. You do not want to round the edges of the mouth off. (Picture immediately below)
This next picture is with the belt sander and 80 grit.
This next picture is with the belt sander and 100 grit.
This next picture is with the belt sander and 120 grit.
And if the plane has obvious pitting and you belt sand, then it comes out like this. So the other thing this shows it the current condition of the plane may very well have an effect on the decision of which process to use.
I also want to show what acid can do if left to long. The problem is “to long” can’t really be described. There are to many factors involved. Temperature, type of metal, concentration of acid, brand of acid, length of time, and consistency of rust. Acid doesn’t stop attaching metal when the rust is gone, so if one side is rusted and the other side is not, you’ll get rust removed on one side and metal pitted and disfigured on the other.
This would need to get cleaned up with a belt sander to get it back close.
I’ve heard that evapo-rust doesn’t do this. I’ve never done any real testing however.
Edit: Since writing this I have received several messages of parts being left in evap-o-rust over couple of months or so and in some cases until the stuff actually evaporated. Except for the a sticky residue left behind there was no damage. Keep in mind however if the piece is not fully submerged an etch line is created, so I wouldn’t trust this.
After talking to many restoration folks, most who use any type of acid (keep in mind some products like evapo-rust is not acid) will use it until they ruin their first piece. But even products like evapo-rust should be used with caution and the process understood. With a little experience, you’ll soon start picking out the restorations that have been soaked in something.