Thread: Lapping plane soles ... once more with feeling

I use W & D on glass. I've got some 1m long pieces of laminated glass that I spray glue W&D to, then have at it. I have found that if I use an up and back motion, it introduces rocking, and produces the not-flat surface that you've referred to in this thread.

But, if I just go one way - not up and back but just in one direction, then lift and again in the same direction, being careful to keep my weight balanced and use the same action each time, the surface ends up much flatter. Much less rocking. So that works for me. But I am intrigued by you saying that the results happen much quicker with your method - doing a number 6 on glass does tend to take forever!

Yeah, bigger is buggerer ;-}

Good to hear about your technique Bob. Grist for the mental mill. The weighting is clearly critical.

How have you been measuring flatness may I ask?
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I've had very good luck with sticky back 120 grit aluminum oxide paper stuck to a large surface plate (we can get large surface plates 12" x 18" and 3" here for about $30 Cdn). Shipping to Oz would be brutal though - about 30 kg. Can't see why good glass backed by a flat substrate wouldn't do the job. FWIW I use a felt tip marker to cross hatch the sole and quit when the marks are gone (or nearly), depending where they are.

Yes, I do the same flattening coarse whetstones with loose SiC grains on glass. The results are good enough.

I've found that half or quarter filling a small sauce bottle with the SiC grains, and the rest with water, provides a much neater, more accurate and cleaner way of adding water and abrasive to the lapping plate / glass. Just shake it up for a second first, then add a few drops where needed.

Good idea Eddie.

Sprinkling the dry grits means some escape and careful cleaning up afterwards is needed.

I wonder is anyone interested in going halves in a buy of 500g of #60 SiC grains? One bag would last me beyond the grave. It'd be about $10 plus onward postage.