10-18-2018, 11:30 AM
Thanks KG and Grepper. Yes we think that reaction time could be a factor of some significance. We did test that variable at some level by placing a pyrex glass dish in the oven at 350°F for about twenty minutes, removed it from the oven and painted on a streak of the 325° Tempilaq. The Tempilaq triggered about as fast as we could paint. So given enough thermo mass and thermal conductivity the stuff goes off pretty quickly.
We didn't thin the Tempilaq in our experiment (thereby supposedly yielding a faster reaction) at all and something that could be tested in the future. We think that this is an experiment for the masses. It's cheap, it's fast and it's easy. KG is right. Finding the fail point is important as well. Around here we call this "locating the fences". This then would let individual sharpeners know just how much margin they actually have. I think that if we were going to conduct another experiment we'd get a bottle of 250°F and see what happens under the same circumstances. Kwakster will be using some even lower temp stuff so it will be interesting to see what he finds.
In the arena of having fun and satisfying curiosity we made a few passes on the edge with a Scotch Brite belt and tested the edge in the area where we had conducted the tests. BESS 135. From the micro pics we took we think it could have stood a little more deburring but not too bad. In our experience chisel grinds test sharp. Sharper than double bevels quite often. We weren't quite as successful at converting the test knife into a genuine chisel grind as thought. After we cleaned it up we could see that some bevel still remained on the back side. Here's a couple of pictures, grind and backside, of the cleaned up test area. The lopsided width of the bevels are pretty obvious.
Grepper raises some good questions concerning the relationship of temperature and time and then the speed with which cooling occurs. If the steel nevers get to a temperature where any loss of temper effects can come into play these questions may be moot from a practical standpoint but if it does prove necessary to hold steel at a certain high temperature for a significant amount of time before deleterious effects occur, it could provide additional peace of mind for sharpeners.
We didn't thin the Tempilaq in our experiment (thereby supposedly yielding a faster reaction) at all and something that could be tested in the future. We think that this is an experiment for the masses. It's cheap, it's fast and it's easy. KG is right. Finding the fail point is important as well. Around here we call this "locating the fences". This then would let individual sharpeners know just how much margin they actually have. I think that if we were going to conduct another experiment we'd get a bottle of 250°F and see what happens under the same circumstances. Kwakster will be using some even lower temp stuff so it will be interesting to see what he finds.
In the arena of having fun and satisfying curiosity we made a few passes on the edge with a Scotch Brite belt and tested the edge in the area where we had conducted the tests. BESS 135. From the micro pics we took we think it could have stood a little more deburring but not too bad. In our experience chisel grinds test sharp. Sharper than double bevels quite often. We weren't quite as successful at converting the test knife into a genuine chisel grind as thought. After we cleaned it up we could see that some bevel still remained on the back side. Here's a couple of pictures, grind and backside, of the cleaned up test area. The lopsided width of the bevels are pretty obvious.
Grepper raises some good questions concerning the relationship of temperature and time and then the speed with which cooling occurs. If the steel nevers get to a temperature where any loss of temper effects can come into play these questions may be moot from a practical standpoint but if it does prove necessary to hold steel at a certain high temperature for a significant amount of time before deleterious effects occur, it could provide additional peace of mind for sharpeners.