woodbloke
Established Member
Following on from the thread on lapping plane soles and after a quick perusal of GW in WHS t'other day I had a go at lapping the back of my 'house' chisel, a Marples blue chip...pay no attention to the edge 
The first shot shows the original state of the back, very roughly flattened with a load of the factory grinding marks still present:
These shots show the back after about 30 mins with 80p paper held in my plane sole flattening jig, using 10mm thick float glass, the chisel was used here across the short end of the jig:
This next pic shows the back of the chisel polished down to 1000g. What's interesting is that there was a fold in the 800g w/d paper (I was using up oddments of paper and this bit was folded in the drawer when I found it) which has produced a slight 'drubbing' at the front edge:
In the article in GW, a block of end grain was planed flat and then impregnated with a polishing compound and some oil for lubrication:
Very little metal is being taken off at this stage, just enough to polish to a mirror finish:
...and you can see my ugly mug in the back of the blade. I think that the w/d paper needs to be held down onto the glass with some spraymount adhesive to ensure flatness and there must be no kinks in the paper. This was done pretty quickly as a bit of a test, even so, this chisel took about 90 mins to do, so my set of LN's (which are partly done, but not mirror polished) and the skews are going to take about a day, once I've got hold of some more decent bits of w/d paper - Rob
The first shot shows the original state of the back, very roughly flattened with a load of the factory grinding marks still present:
These shots show the back after about 30 mins with 80p paper held in my plane sole flattening jig, using 10mm thick float glass, the chisel was used here across the short end of the jig:
This next pic shows the back of the chisel polished down to 1000g. What's interesting is that there was a fold in the 800g w/d paper (I was using up oddments of paper and this bit was folded in the drawer when I found it) which has produced a slight 'drubbing' at the front edge:
In the article in GW, a block of end grain was planed flat and then impregnated with a polishing compound and some oil for lubrication:
Very little metal is being taken off at this stage, just enough to polish to a mirror finish:
...and you can see my ugly mug in the back of the blade. I think that the w/d paper needs to be held down onto the glass with some spraymount adhesive to ensure flatness and there must be no kinks in the paper. This was done pretty quickly as a bit of a test, even so, this chisel took about 90 mins to do, so my set of LN's (which are partly done, but not mirror polished) and the skews are going to take about a day, once I've got hold of some more decent bits of w/d paper - Rob
