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Restoring My Grandfather's Whetstone

rbscebu

Girls call me Makaluod
A few weeks ago I was rummaging through my "treasures" box I found the whetstone used by my grandfather who passed away 62 years ago at the age of 81.

Burrow Whetstone.jpg

The stone is 230mm x 50mm x 3mm to 7.5mm thick. It has about 0.4mm concavity longitudinally on its upper surface. The wooden support block has a concave cut-out underneath, probably for when it is being used on his thigh. The stone is currently loose is the wooden support block.

I have spent the past week or more lapping this stone flat again. It is the HARDEST whetstone that I have ever lapped. I first spent an hour lapping on 160 grit wet W&D but was getting no where. I then switched to 80 grit and started to see some very slow progress. After another 7 hours (about 1 hour each day) of heavy lapping and numerous new sheets of 80 grit, I got this stone flat! I finish the lapping by 30 minutes each on 160 grit and 320 grit.

The stone had been heavily used on both sides, more particularly the underside that has up to 5mm (3/16") concavity in it. From the look of it, it appears that my grandfather gave up on trying to lap this underside flat again and just reversed the stone in its holder and glued it into place.

IMG_20200123_080604.jpg
After I eventually lapped the top side flat, this stone had the following thicknesses (in mm):

IMG_20200123_080628.jpg
Next in this restoration is to soak the stone in a degreaser to remove any oil residue. While that is soaking, I will remove the old glue in the support block before re-glue the stone into place using epoxy glue.

Once all is well, I will clean up the support block and give it a few coats of spar varnish.
 
the only problem I see with this being an Escher is that if you did 7 hours on 80 grit on any of the Escher's i've owned, you wouldn't have much stone left. They don't tend to be a hard stone, so much as even and smooth.
 
the only problem I see with this being an Escher is that if you did 7 hours on 80 grit on any of the Escher's i've owned, you wouldn't have much stone left. They don't tend to be a hard stone, so much as even and smooth.
Good point, I missed that. Probably not then.

Chris
 

rbscebu

Girls call me Makaluod
True, it really did take that long to lap the stone on 80 grit W&D. I had to take up to 0.4mm off.
 
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