Diamond lapping films

[Lance Waller]

I have a suggestion. We need the lapping films to come in a assorted set instead of having to buy 10 strips of the same grit. Is that possible?

[Aaron kimpton]

And in bulk

[tcmeyer]

Lee Valley has diamond film in 3X6 sheets, which they sell individually @ $6.50 or as a set of four @ $23.50. You could cut four strips from each sheet. They have 15, 3, 0.5, 0.1 micron grits. http://www.leevalley.com/US/wood/page.aspx?p=68943&cat=1,43072

WE has a much wider selection of grits, but the 10-strip sheets are pretty pricey and for a hobbyist maybe not the best option. I bought a complete set, as much as a courtesy as for my needs. My glass platens are 1″ wide, so the 3/4″-wide strips work, but not as nicely as I had hoped. You can get non-diamond film in 8.5X11 sheets, which produce 16 1′-wide strips or 22 3/4″ strips and at a much lower cost per strip.

[Mr.Wizard]

Have you directly tested how long the diamond film lasts compared to the far cheaper alumina film? I have read that the diamond film lasts longer but does it last enough longer on common knife steels to justify the greater cost?

[Todd Simpson]

I have done a fair amount of experimenting with lapping film on honing razors. I find diamond is faster, but also makes deeper scratches than the comparable Al2O3 film. Anecdotally, I don’t think the diamond lasts longer, it just removes more metal during the same time.
I did not like Lee Valley film – made wire edges very easily.

IME, It is an easy transition from 1k stone to 3 micron lapping film. I would not recommend any film coarser than that. It does produce some convexity because it is compressible. I had some 5 micron, but it was silicon carbide and seemed to shed particles more than the Al2O3.

I have posted this image before – 3 micron Al2O3 film.

[Aaron kimpton]

Super cool war are you using to put it on the plattens

[Pat]

Again, stupid new guy here to the whole lapping concept. What is lapping film vs lapping to even up dished out stones?

[Lance Waller]

Again, stupid new guy here to the whole lapping concept. What is lapping film vs lapping to even up dished out stones?

Lapping film is the sand paper type stuff that wicked edge sells that has a sticky background that you can mount to the blank paddles that they have. It’s diamond impregnated but at very fine grits so it will sharpen but mainly polishes and finishes. Lapping a stone is just a term we use to “flatten” a stone after it dishes out. The two words are the same but don’t mean the same thing here.

Sent from my iPhone using Tapatalk

[Pat]

Many thanks…I get it.

Again, stupid new guy here to the whole lapping concept. What is lapping film vs lapping to even up dished out stones?

Lapping film is the sand paper type stuff that wicked edge sells that has a sticky background that you can mount to the blank paddles that they have. It’s diamond impregnated but at very fine grits so it will sharpen but mainly polishes and finishes. Lapping a stone is just a term we use to “flatten” a stone after it dishes out. The two words are the same but don’t mean the same thing here.

Sent from my iPhone using Tapatalk[/quote]

[Marc H]

I too am trying to learn about lapping films and diamond sprays. I haven’t found a video on them to watch, (Hey, Josh?). So I have a bunch of questions:

When do you use blank metal plates and when do you use blank glass plates? Can you use them interchangeably?

With the PSA Diamond film can you use both edge leading, edge trailing and scrubbing motion albeit very lightly? Same question with the Diamond Sprays.

How long does the Diamond spray last? Roughly how many knives? Do you store theses paddles, both spray and films, similarly to the leather strops to avoid cross contamination? What do you use to clean the spray off the blank paddles?

If you know of a video please steer me that way.
Thanks.

Marc
(MarcH's Rack-Its)

[tcmeyer]

I think that film can be used on metal just as well as on glass. The metal, however, should be “lapped” to ensure its flatness. I have a set of blocks from WE with the aluminum platens. I lapped the aluminum down to a flat and smooth state; result? Works fine. Glass is theoretically more effective because it is very hard and very flat. Users should take care to smooth the edges of the glass, as it can very easily scratch any of the steels we use.

I find I can use the edge-leading or scrubbing motion where the edge is relatively straight. A point, or a deep belly profile will bite into the soft plastic film, resulting in an oops. Generally, you’re better off with edge trailing (upward) strokes.

I have not used the spray applicators enough to give you any data. In fact I have not been wetting my film as is recommended. Simply a preference. I don’t like the messy swarf on my sharpening table

[CliffCurry]

TC, just off hand do you or anybody know the thickness of the stock diamond plates used on wicked edge paddles? Hoping to get glass of similiar thickness…Thanks in advance 🙂

[CliffCurry]

Borrowed from the zknife link that Leo Barr provided on another topic. I found this information very useful:

http://zknives.com/knives/sharpening/abfilms.shtml

[tcmeyer]

Hi Cliff:

I checked a set of 400/600 disassembled paddles/handles/blocks I had lying around. The platens are about 0.120″ thick. The 3M tape that WE uses is about 0.025″ thick, after application. The stuff I have comes out to only 0.006″ thick. I did buy some of the stuff Clay recommends, but I haven’t tried it yet.

Just to record the dimensions, the plastic block measures out at about 0.905″. The platens measure out at 0.120″ for a total of 0.240″. The total block thickness of 1.195″ leaves a remainder of 0,100″ for the tape, so each strip adds up to 0.025″

Tom.

Edit to correct my late-night math: The fully assembled block measures 1.195″. the platens are 0.120″ each and the plastic block is 0.905″.

1.195 – 0.120 – 0.120 – 0.905 = 0.050″ (total tape thickness)
0.050″ / 2 = 0.025″ (single tape thickness)

According to Clay, the tape is 3M’s VHB Tape 4932 (Very High Bond strength)

[CliffCurry]

Thanks Tom for checking that so accurately, I dont have a micrometer(yet) as I am affraid what it would do for my dormant OCD I try to pretend doesnt exist!

So If Im reading those numbers right( I wrote them down for future reference too) a 1/8″ strip of glass cut to size would be just a couple hairs thicker then the stock platen/paddle assembly depending on how heavy the glue was etc.

Its what I needed to know to move to the next level…preciate it!

[Author]

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