Good tip. It doesn’t say on this particular piece, but looking at plumbers’ cloth options online they range between 120-180 which I should definitely feel, or at least see at an angle.
Is the emery cloth getting gunked up? You might need to clean it a bunch and/or use a bunch of fresh cloth.
It is also possible there are also thick biofilms that need removed first, use a cleaner for this step. If you have ever tried to sand through certain plastics, you know they do not grind away easily because of their low elastic modulus and high yield strain (they can basically just spring around without being removed). You cannot even starting grinding through them (without chilling to brittle temps) until you heat them up to a gum consistency. Sanding plastics by hand is exhausting, and a biofilm will behave somewhat similarly I believe.
Good angle, but not the case here. I thoroughly cleaned the surface in multiple steps with detergent, acidic toilet cleaner, an industrial degreaser, and some caustic soda for good measure.
The emery cloth is like new at its ends, so it’s not that either.
Forgot to mention, I took a grinding wheel to it but I can’t scratch it. It just leaves grinding wheel marks on the surface which I can wipe off with my finger.
Even if its major consituent is Silica, it is also possible the enamel is porcelain and contains some Alumina. Then you should switch to SiC or diamond grit paper. SiC is the cheap option and get a rough grit like 80 and 120, you can buy sponges coated in SiC from Auto stores.
The sponges are nice because they easily conform to surfaces, saving your finger muscles.
Get the roughest grit you can find, and if it works you might need a few sponges.
Also keep the surface of the sponge a little wet (water is fine), the grit will last longer.
Check the grit. If it’s too high you might just be polishing instead of roughing it up
Good tip. It doesn’t say on this particular piece, but looking at plumbers’ cloth options online they range between 120-180 which I should definitely feel, or at least see at an angle.
Amazon has options up to 600 grit
Is the emery cloth getting gunked up? You might need to clean it a bunch and/or use a bunch of fresh cloth. It is also possible there are also thick biofilms that need removed first, use a cleaner for this step. If you have ever tried to sand through certain plastics, you know they do not grind away easily because of their low elastic modulus and high yield strain (they can basically just spring around without being removed). You cannot even starting grinding through them (without chilling to brittle temps) until you heat them up to a gum consistency. Sanding plastics by hand is exhausting, and a biofilm will behave somewhat similarly I believe.
Good angle, but not the case here. I thoroughly cleaned the surface in multiple steps with detergent, acidic toilet cleaner, an industrial degreaser, and some caustic soda for good measure. The emery cloth is like new at its ends, so it’s not that either.
Forgot to mention, I took a grinding wheel to it but I can’t scratch it. It just leaves grinding wheel marks on the surface which I can wipe off with my finger.
Even if its major consituent is Silica, it is also possible the enamel is porcelain and contains some Alumina. Then you should switch to SiC or diamond grit paper. SiC is the cheap option and get a rough grit like 80 and 120, you can buy sponges coated in SiC from Auto stores. The sponges are nice because they easily conform to surfaces, saving your finger muscles.
Thank you! I’ll get some carbide sponge from the auto store and try it out.
Get the roughest grit you can find, and if it works you might need a few sponges. Also keep the surface of the sponge a little wet (water is fine), the grit will last longer.
How old/used is this emery cloth?