Phenolic composite (Micarta) laps?

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Mr.Wizard

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Feb 28, 2015
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I would like to try a hard lap for coarse diamond compound. I am hoping that the diamond grains will embed in the surface of the lap such that swarf can be washed off without removing the diamonds as well. Has anyone tried phenolic composite (Micarta) as a lap? Does anyone have some scrap linen or canvas Micarta they would be willing to test this with?

Regarding other materials: some use hardwood strops but I do not believe that will be sufficient for what I envision, and I know that cast iron and copper laps are used industrially but I don't have the tools to work those materials.
 
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It seems I'll need to test this myself. What is the least expensive source for a single 1" * 6.25" or larger piece of canvas or linen Micarta?
 
Good thinking.
I use MDF coated with 1.0 micron mono-diamond paste for hand strops, and it works like you describe, in that acetone removes (most of) the swarf while the partially embedded diamonds stay behind to keep working.
Sometimes i add a few tiny dabs of diamond paste.
Also have some pro-Chefs using these strops to great satisfaction from what they tell me.
Still have to experiment with coarser compounds though, not counting playing around a bit with 3.0 and 6.0 on the same MDF substrate.
 
Mr.Wizard said:
I would like to try a hard lap for coarse diamond compound. I am hoping that the diamond grains will embed in the surface of the lap such that swarf can be washed off without removing the diamonds as well. Has anyone tried phenolic composite (Micarta) as a lap? Does anyone have some scrap linen or canvas Micarta they would be willing to test this with?

Regarding other materials: some use hardwood strops but I do not believe that will be sufficient for what I envision, and I know that cast iron and copper laps are used industrially but I don't have the tools to work those materials.
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Flattening plates known as Kanaban are used for big jobs, is an unhardened steel plate that works well with diamond or SIC - I have never used one.
 
I might have a piece you could use, let me check. I have a pretty large scraps pile of G-10, including some quite thick pieces. I think you'd want to use a fairly thick piece to avoid flex and warpage. What exact size would be your "perfect" size?
 
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Sounds like you're essentially trying to make a fancy strickle. Take a piece of wood and tap it with a saw to produce a bunch of little pinpricks, then slather it with grit. The little pinpricks retain the grit.
 
HeavyHanded said:
Flattening plates known as Kanaban are used for big jobs, is an unhardened steel plate that works well with diamond or SIC - I have never used one.
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I've seen big, cast iron plates used to flatten granite reference plates for machine shops.

Apparently the diamond particles are embedded with a heavy steel roller, and refreshed frequently.
 
HeavyHanded said:
Flattening plates known as Kanaban are used for big jobs
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That term is new to me; thanks.

eKretz said:
I might have a piece you could use, let me check. I have a pretty large scraps pile of G-10, including some quite thick pieces. I think you'd want to use a fairly thick piece to avoid flex and warpage. What exact size would be your "perfect" size?
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Thank you. I don't think I want to try cutting G-10 myself, so if I can buy it from you I would need it cut to size for Edge Pro: 1.0"×6.0", and between 1/8" and 1/4" thick. (I would use an aluminum backer.) If you have any canvas or linen Micarta I could cut that myself; do you?

FortyTwoBlades said:
Sounds like you're essentially trying to make a fancy strickle.
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Also a new term for me. I don't think wood is hard enough make good use of the coarser grit I wish to use. I have only tried a paint stir stick and it wasn't as aggressive as it should have been; the particles embed too deeply.

mattmanyam said:
I've seen big, cast iron plates used to flatten granite reference plates for machine shops.
Click to expand...

Yes, I've seen that too. Cast iron is apparently the preferred material for steel stock removal using diamond compound, but I think that would be prohibitively expensive as I don't have the tools to cut cast iron so I would have to have them made. I think it would be more economical to buy Edge Pro Diamond Matrix stones instead. I am seeking an inexpensive way to use diamond compound I already have.
 
Strickles were traditionally used for fairly coarse sharpening work, and part of the key is the little recesses, as they hold the grit in place like little wells of sorts. Some sort of grease was usually used to adhere the grit to the strickle so you'd want to use either a diamond paste or grit mixed with some sort of thick carrying agent if taking that approach. If not wanting to use diamond grit in the experiment initially, you can use silicon carbide grit of roughly equal size.
 
FortyTwoBlades' mention of a strickle lead me to a new thought: could the pores of hard anodizing serve the purpose of holding diamond particles? The structure is quite similar, on a microscopic scale. D Diemaker do you have an estimate of the pore diameter and depth (film thickness) of the anodizing on the Tape Blanks you manufacture?

This is probably uneconomical and applicable only to a specific range of particle sizes, but it is an intellectual curiosity.

img-structure-size.jpg
 
I imagine it would be quite possible so long as sufficiently porous anodizing was used. Looks like hard anodizing results in generally larger pores, and that it's possible to control pore size and wall thickness to a reasonable degree. CLICK.
 
Hard anodizing, Type III, has smaller pores than Type II which is why you can't color it. Both have the pores filled, sealed, as the final step in the anodizing process. If memory serves Type III pores are around .0005".

IMO what you can make with a lap of some sort will not perform nearly as well as embedding the diamond in a bond for coarse or medium grits. The fine grits are where a lap startes to work better than the bonded method of holding the abrasive. Your barking up the wrong tree.

I think the best material may be a softer plastic, some type of polyethylene. The downside is it has very very poor dimensional stability.
 
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