Thread: Flattening Glass Plate....

I'm curious about 2 things.

1/ How does one flatten a 3x11 glass tile with a 3x8 diamond plate ?
2/ Did you check the DMT for flatness ?

Originally Posted by onimaru55

I'm curious about 2 things.

1/ How does one flatten a 3x11 glass tile with a 3x8 diamond plate ?
2/ Did you check the DMT for flatness ?

1. It is surprisingly easy to flatten a glass tile with a 3" x 8" DMT diamond plate. I've done it dry or with water, and it works well with either. I mark the glass tile with a permanent marker so you can see the high/low spots when you begin to flatten with the DMT plate. I have flattened using the DMT plate moving on top of the stationary glass tile, or the reverse, both ways work well.

2. The DMT plate is made of steel impregnated with diamond dust. If you read the blurb on the DMT website they claim that the 3" x 8" plate is "flat" to their specification which seems quite "flat" to me. I doubt that this level of flatness will change with use, after all it is a steel plate. One could also buy the larger DMT lapping plate, which sells for around $170 that has guaranteed "flatness" to, I believe, 0.05% variation from flat. This plate, too, should not change much during use, since it too is a steel plate.

I did not check my DMT steel plates for flatness. I am comfortable going by the manufacturers claim and guarantee.

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Added later: regarding the Dia-Flat lapping plate, from the manufacturers website:

"..hand certified flat to +/- 0.0005”, the Dia-Flat™ Lapping Plate assures precise results when flattening stones."

I believe that the point he is trying to make is that if the item being flattened is larger than the item doing the flattening you probably aren't getting it flat. He would be correct. I tried the same thing with the same size glass and diamond plate and checked with a straight edge. Didn't get very flat. Closer than it came, but not flat enough to be acceptable to me.

It does not have to be, the film is only 9 inches long and while you lap the glass to get the film to stick better, it works even if you don’t lap it flat.

It is not like lapping a stone where a low spot may not be as smooth as the lapped surface, the flim is already smooth and uniform, you just will not be using the film to the fullest potential.

Yes, that is true if you do your full progression on film. But I thought the question was whether it's getting flat, not does it need to be.

You guys are overkilling things. Plate glass is flat, if you are honing properly...your blade will never know if the stone or whatever you are using is a few hundredths off. Pressure and "feel" is what you should be worrying about...

That is not true in many cases. I have had pieces of glass that look like motocross whoops. They need to be at least fairly uniform and without abrupt dips and/or twists or you will really mess up a razor. If it ever gets taken to a flat stone or film and flat glass plate afterward there will be a lot of work to do.

I agree Shooter. Are we talking about wet shaving or lenses for the Hubble? Abe Lincoln was probably in office when my best shaving razor was made. I enjoy the history and use of straight razors, but these guys need to get a life.