James Spangler
06-03-2021, 4:15 PM
I have a question about corrosion on plane irons, and I hope some folks in this forum can help me understand the unusual corrosion pattern I’m seeing on this cutter, (I know nothing about metallurgy, so maybe it’s not so unusual).
This particular iron is from a Bailey No. 4 plane that I’m in the process of restoring and it’s a Type 9, so its age goes back to approximately 1901 to 1904.
When I first acquired this plane, there was a thin layer of rust over everything (see photo) and a few spots where corrosion resulted in some pitting. I was rather lucky with the iron, I think, because even though the upper 2/3 of it had some corrosion, the business end – at least on the cutting side – had no corrosion. That may have been because that was a tightly-packed layer of wood shavings and dust around the bottom of the frog and sandwiched between the iron and chip breaker which protected it somewhat.
So, as I cleaned up the iron with a wire wheel and sandpaper, I uncovered a corrosion pattern on the bevel side that I had seen before on a couple of old blades that I had previously restored. Near the bevel was a small patch of pitting and surrounding it are tiny fissures or cracks in the surface that don’t seem to go very deep. I’ve included a photo of this.
Since I have seen this before on a couple of other old irons I’m just wondering if anyone else has noticed this and can offer some insight. Can anyone explain how this pattern occurs? Is this type of corrosion perhaps peculiar to hardened steel? Or perhaps related to the age of the steel or the tempering process used back then?
Note that the opposite side which had no pitting is fine – I’ve included a photo of that side after I’ve flattened it.
Since this corrosion is only on the bevel side, it doesn’t hamper the ability to sharpen and use this iron, but from an aesthetic aspect I’m concerned that the iron looks somewhat flawed.
Thoughts?
458882458883458884
This particular iron is from a Bailey No. 4 plane that I’m in the process of restoring and it’s a Type 9, so its age goes back to approximately 1901 to 1904.
When I first acquired this plane, there was a thin layer of rust over everything (see photo) and a few spots where corrosion resulted in some pitting. I was rather lucky with the iron, I think, because even though the upper 2/3 of it had some corrosion, the business end – at least on the cutting side – had no corrosion. That may have been because that was a tightly-packed layer of wood shavings and dust around the bottom of the frog and sandwiched between the iron and chip breaker which protected it somewhat.
So, as I cleaned up the iron with a wire wheel and sandpaper, I uncovered a corrosion pattern on the bevel side that I had seen before on a couple of old blades that I had previously restored. Near the bevel was a small patch of pitting and surrounding it are tiny fissures or cracks in the surface that don’t seem to go very deep. I’ve included a photo of this.
Since I have seen this before on a couple of other old irons I’m just wondering if anyone else has noticed this and can offer some insight. Can anyone explain how this pattern occurs? Is this type of corrosion perhaps peculiar to hardened steel? Or perhaps related to the age of the steel or the tempering process used back then?
Note that the opposite side which had no pitting is fine – I’ve included a photo of that side after I’ve flattened it.
Since this corrosion is only on the bevel side, it doesn’t hamper the ability to sharpen and use this iron, but from an aesthetic aspect I’m concerned that the iron looks somewhat flawed.
Thoughts?
458882458883458884