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Lapping film questions

I've just received my lapping films. I must say I was impressed by the image of edge they put on my blades, well, until the third one. The first cut of films lasted only 2 blades after which they stopped abrading.

Also they did not stick to the several glass plates I tried. They kept moving annoyingly. I could use them by sticking them onto my Naniwa SP 10k which did a good job there.

These are the films I have. Are they the right ones? Or should I have bought something else?


  1. 3M 261X Aluminum Oxide lapping film, 9" X 13" sheet, grit 3μm
  2. 3M 262X Aluminum Oxide lapping film, 9" X 13" sheet, grit 1um
  3. 3M 261X Aluminum Oxide lapping film, 9" X 13" sheet, grit 0.3μm

On a side note, I can't report on the shave results. Because of the above problems, I only tried on 2 blades, which I took all the way to the 0.3μm. I didn't expect them to be comfortable, I just meant to see how sharp it'd go. And, man, I got the worst shave ever since my first!
 
Hello Focus,

Could you perhaps begin by giving us an idea of what kind of state your razor was in before you started honing it. What i mean is, is it a new razor or are you just touching up the edge of a razor that has gone a bit dull? I assume it is the latter.

I am still pretty new to this but I have found a hassle free way of going about it using a 5 micron film followed by the 1 micron. The abrasive is the same as yours. I bought the lapping film from Thorlabs, making sure it was the non-PSA adhesive backing film and then cut it to an appropriate size to fit on a polished tile that I got from a DIY-home improvement store. To apply the film I go through the routine of:
1. dampening the tile with a water spray device and wiping it clean with a kitchen plastic dough scraper to get rid of any material that may be stuck to it.
2. dampening the reverse side of the lapping film, put it on the tile with the abrasive facing the tile and wipe the reverse side clean with the dough scraper.
3. turning the lapping film around such that the abrasive side is facing up and again wiping the abrasive side clean with the dough scraper.
After that you should be all set and the film should be well stuck to the support.

In your case, I suspect that you have too much water between the support and the film. It is important that the surfaces, to be adhered, are only damp.

I have successfully use 1 strip of lapping film for 10 razors. In your case, I suspect that you may have damages your film whilst it was sliding around on the support and/or you might have applied too much force. I read somewhere that the force should be roughly around 1 lb and less as you approach the finishing stage. I suggest you take a look at Slash McCoy's youtube vids on the subject. That should give you some idea of how to do it and what force to use.

I hope this helps and that you can get more milage out of your film. If not then post again and hopefully someone else here can give you better advice.
 
Thanks a lot for your detailed reply Gustav.
My mistake. I should have made it clear at the beginning.
I started with a shave ready razor, that I hone and shave everyday. :001_smile
I reset the bevel with a Naniwa Professional 1k and then took the razor to the films.

I used very little pressure to no pressure, much less than 0.5 lb. But the film was still moving around almost every stroke.
I also tried very little amounts of water on glass and only dampened it. Those didn't work either. I already watched the excellent Slash McCoy videos.
I think it's the films. I might get some more from Thorlabs. But 10 pieces of each is too many for trying I guess.

What brand are those from Thorlabs?
 
I usually ensure I spray the plates liberally with water, then use a credit card to kind of squeegee it from the center out. Make sure you have the shiny side against the surface you are adhering to.

Also, it's kind of a big jump going from a 1k to a 3um. You may need a ton of time on the 3 um to progress past that grit.
 
I usually ensure I spray the plates liberally with water, then use a credit card to kind of squeegee it from the center out.
Maybe that's what I am missing. I found it hard to do with my hands. There were usually left some air pockets, even though small and flat.
 
Maybe that's what I am missing. I found it hard to do with my hands. There were usually left some air pockets, even though small and flat.[/QUOTE
Air pockets are no good, they will catch the bevel of your razor and cut open, and potentially damage your edge.
 
Just as an addendum, after bevel setting I progress to 12,9,5,3,1,1 with paper. So going from bevel set to 3 is a big jump. You may not have gotten it sharp enough because you didn't spend enough time to polish out the scratches from the 1k.
 
Just as an addendum, after bevel setting I progress to 12,9,5,3,1,1 with paper. So going from bevel set to 3 is a big jump. You may not have gotten it sharp enough because you didn't spend enough time to polish out the scratches from the 1k.

Actually I got my sharpest edge off it. My problem is, the film doesn't stick and gets ineffective after 2 razors.
 
Actually I got my sharpest edge off it. My problem is, the film doesn't stick and gets ineffective after 2 razors.
Interesting. How long, or how many laps did you need to spend? I would assume that even if it were sticking properly you's burn it out faster due to having to use it longer to properly remove the scratches from a 1k.

Though I suppose it makes some sense as the majority of sharpness comes from your bevel set.
 
Interesting. How long, or how many laps did you need to spend? I would assume that even if it were sticking properly you's burn it out faster due to having to use it longer to properly remove the scratches from a 1k.

3μm: 60 laps
1μm: 60 laps
1μm with Pico Paper: 30 laps

Interestingly, the first two times, 3μm was able to remove the 1k Chosera scratches completely and polish the blade. And then it almost stopped working at the 3rd.

Yesterday, I put a Naniwa SP 5k in between. I couldn't evaluate the effectiveness of the 3μm after that. I'll report back when I test it.
 
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