Thread: stones to lapping film as a finisher

hi guys can i have your advice and opinions on my honing progression m thinking about getting some 3m lapping film for finishing i already have hones i have diasharp 325 , 1k 4/8k norton combo , 6/10k combo 12k superstone.

is it possible to go from 12k super stone to lapping film? then crock paste , leather strop

Yes, go from the 12k to 1um. 10- 15 laps usually. And then 10 laps on 1um with a sheet of copy paper under the film, to finish.

If you use the copy paper, you won’t need Chrome Oxide and should have a very savable edge. You can touch up on 1um with paper when the edge starts to flag.

Use the 1, 4. 8 and 12K progression leave the 6 & 10k out of the progression altogether, you do not need them.

Do not buy diamond film, use Aluminum Oxide, or Silicon Carbide film from Thorlabs, (the best deal, with quality film). It works just as well, for literally 1/10 the cost of diamond film. Comes in 9X13 in sheets and you can cut into 4, 3 in pieces with a paper cutter.

Get a glass 12 X 3 in glass tile from Lowes for about $4-5. You will have to lap it flat with 325 wet & dry or a diamond lapping plate, it laps easily and will make the film stick better.

If you go from a 12k Super Stone you only need 1K film, .3 film is too harsh, for me and most folks.

If you want a film progression, set the bevel on 1k and do a 5, 3,1um progression. Either way works. Film is excellent for hard, chip prone razors.

A couple drops of Smith’s Honing Solution works well on the finish film.

Good advice given above!
If you want to save a few dollars you could skip getting the glass plate. When I use lapping film I place it on top of the last stone I used (currently a Norton 8K), just rinse the stone of to remove ALL traces of grit, swarf and other debris.

Yes, go from the 12k to 1um
is 1um 1 micron

Yes. 1um (micro-meter) is 1 micron, both of which are one millionth of a meter.

Originally Posted by Utopian

Yes. 1um (micro-meter) is 1 micron, both of which are one millionth of a meter.

ok great so i would like to apply the film to a hone so i dont need to buy a tile and flatten it so do i buy Aluminum oxide abrasive on 3 mil polyester film backing?
or do i buy film with no backing?
is 3m brand good enough quality or is there a better quality film?

is there any benefit in progressing down to .3 or even 0.05?
is Smith’s Honing Solution necessary/ do you need to water the film or use it dry?
when doing the paper technique do you use damp paper?

I have had little interest in, and therefore little experience with, lapping film. I see not problem applying a non-backed film to a slightly wet hone as long as you roll it flat to get all air bubbles out. I have used 3m film and it seems acceptable, but I am not aware of a particularly better brand.

The grit you chose for final finish depends both on personal taste and the particular razor, as well as your honing skills. Stop at a particular grit, strop and shave, and then later drop to a lower grit and see if the edge improves. Your honing will improve by experimenting and that includes finding things that make the edge worse!

I don't think Smith's is necessary, but then again I have never tried it on film. I have only used water on the film and confess that I have never considered trying it dry. I do suspect that it will work better wet.

I only tried paper under the film once and did use it on top of a slightly but uniformly wet (with water) hone.

You could use a smooth flat hone to lap on, but the “slightest” singular grit under the film and you will cut the film, rendering it useless. You would have to scrub your stones immaculately clean of any grit. A five dollar piece of glass is much easier, it’s up to you…

One micron is about 15k grit comparison, but is a more uniform grit than a stone and will leave a straighter edge. Compare the bevel and edge to a 12k and you will easily see the difference.

You can try .3um film, about (50k grit) it is harsh.

I don’t understand what you are asking about backing, do not buy PVA glue backed film, you don’t need it.

On a clean smooth substrate, wet the substrate and the film with clean water, pass the razor on the film and it will stick to the smooth grit free substrate and you can do anything on it you would do with a stone, until you peel it off.

The link will take you to Thorlabs Lapping film. Buy the largest sheet at the lowest price, if you want to shop around. It is $13.80 for 10 sheet that will give you 40 pieces, about 35 cents per piece.

Do use it wet, yes the paper will get wet, that is the point, it acts as a cushion and polishes the edge for comfort. You don’t need Smith’s, it is about $6 a bottle and you use a drop at a time.

Actually from a 12k Super Stone edge, you don’t even need film, just strop on Chrome Oxide and shave.