Cast iron/diamond sharpening question

Some good threads on this here

Bill Houghton, avoiding work in Sebastopol, CA


>you might try searching the archives. As I recall, aluminum (aluminium to y'all over the pond on the Mother Island) was found too soft.

I'll be watching this thread, though, since I recently picked up a free Craftsman table saw from one of the richer-than-our-street houses around the corner, partly for this very purpose in the future. I was good - waited a week to see if someone needed it as an actual table saw before picking it up for parts, including a pretty flat cast iron top.

Surprised Bill Tindal hasn`t posted

Bob Hackett


>That`s who I got the bulk of my help/info from.Thanks Bill.

Anyway,Bill steered me toward acrylic for the coarser grades and cast iron for the finer/finishing grades.

The substrate must be made from material that allows the diamond to imbed itself(fixing it in place) and yet still leave enough exposed to act an as abrasive.That`s why the finer grades don`t work well in acrylic or aluminum,the fine particles inbed too deep quickly and cease to work.

The cast iron I`ve been using has also come from TS,DP,jointer and other electron eaters who have found thier way to the local dump.I pull the tables off and then bring the rest back.Our dump has a liberal return policy.

For diamond abrasive I bought off Ebay and got 3 lifetime supplies of 1/2 micron dust for less than $15 including shipping.The rest I wasn`t so lucky on but it was still cheap.Look under lapidary supplies.

I`m getting by nicely with only 3 grits with 1/2 micron being the finest.Depending on what type of steel you`ve got in your plane irons you may get by with less.Buy an assortment of the cheap tubes to see what you need and then keep your eyes open for what you really use when it comes up in quantity.The tubes will keep you going till then.

Mainely,Bob

Re: Cast iron/diamond sharpening question

Frank House


>There was a brief mention of copper in the past, but no follow-up from anyone with experience (or I missed it).

I plan to try it out, but that particular round tuit is near the bottom of a large heap, so it will be months ... :-(

Has any member tested copper? E.g. circuit boards, copper sheet, copper plumbing pipe for gouges? Any difference if it is work-hardened? How about brass? My guess is copper and brass should be more resistant to deep embedding of diamond than aluminium.

Frank

substrates

bill tindall


>I have been off camping in the leaves at Big South Fork. Perfect timing for the soft maples that are there in profusion. (very nice area and they separate tents from motor homes and horses from people trails) Drove 20+ miles on a gravel ridge road to get out only to have it end at a dirt path down the ridge. I don't go down hill on slippery dirt trials. The leaves slowly coming the 20 miles back out were also nice.

There is little I can add that has not already been said.

cast iron- the lapidary folks have used it for centuries, and likely for good reason.

aluminium- I use diamond charged cylinders spinning slowly in drill press for sharpening curved things like gouges and curved plane irons. 30 or15 micron works well. I have not tried a plate for straight edges. I'll bet it is grabby though.

brass-not tried

copper- promptly rejected circuit boards. Can't remember why as it was years ago. I think not flat.

Acrylic- very good for coarse grits, less so for fine grits. It is grabby in the fine grits