WOW this is frustrating!

[Josh]

There’s an interesting effect that happens when you pull the film off of a platen. It takes quite a bit of force, which stretches the film and the adhesive backing. Unfortunately, the film is elastic, but the adhesive is not, so when the film is free, it retracts, trying to go back to its original length. Since the adhesive is not elastic, it does not retract, leaving the adhesive side longer than the film side. This results in a curl. Probably best to lay them out straight and lightly stick ’em to some temporary surface. If you wanted to reuse the film, as you apply it, you’d have to re-stretch it to a length longer than the adhesive. Not difficult, but I’m not sure how flat it will be when you stick it down.

Not to mention the fact that the adhesive doesn’t like to release from the platen readily. If it separates, I think you’re SOL. Maybe if you change frequently it will separate more easily. Applying heat with a hair dryer will help.

Tom, have you used the lapping film without the adhesive? Then you wouldn’t have the stretch problem. I’ve been wondering how well that non adhesive film stays in place on the glass platens. Does anyone have experience with the non-PSA lapping films they can share?

Marc[/quote]

Marc,

If you watch Tom Blodgett here he goes over the difference… basically I would not use the non PSA if I was doing anything but straight razors or only for the very last micro bevel on a knife due to the low pressures needed not to cause slipping.

[Kyle]

for this reason, I am considering investing whatever I need to in going completely over to lapping films after the diamond stones. Any thoughts much appreciated![/quote]

What is the difference between using lapping films and leather strops? Do you not have to change the degree when using lapping films like you do with strops?

[CliffCurry]

I know you guys will probably scoff & scowl, not really, but Im trying to soften you up… :S

Eventually I would like to upgrade to glass platens, but I have been achieving excellent results simply using non PSA backed films secured with painters tape to each end of a clean 1000 grit paddle.

Swap out time between films is under 10 secs and bevel angle is identical because Im using the same paddle.

There could be a further discussion of pros/cons of the very slight ripple the slack causes in the film. I use it to a theoretical advantage for apex refinement. Without a SEM its hard to confirm. 😉

[Josh]

for this reason, I am considering investing whatever I need to in going completely over to lapping films after the diamond stones. Any thoughts much appreciated!

What is the difference between using lapping films and leather strops? Do you not have to change the degree when using lapping films like you do with strops?[/quote]

Lapping films create a clean, crisp apex with no rounding. Leather strops round it up to 4-5 dps, which is all dependent on pressure used. So strops are kinda variable whereas the lapping film is not. No, you match the angle EXACTLY of the last stone used using an angle cube. 😉

[Josh]

I know you guys will probably scoff & scowl, not really, but Im trying to soften you up… :S

Eventually I would like to upgrade to glass platens, but I have been achieving excellent results simply using non PSA backed films secured with painters tape to each end of a clean 1000 grit paddle.

Swap out time between films is under 10 secs and bevel angle is identical because Im using the same paddle.

There could be a further discussion of pros/cons of the very slight ripple the slack causes in the film. I use it to a theoretical advantage for apex refinement. Without a SEM its hard to confirm. 😉

Cliff, it’s as simple as finding some glass and having a local glass shop cut it up for you…really!

But yeah, I’ve seen it done that way. But as you say I have concern for the rippling/convexing effect it would create. But I know you get good results! With this lapping film on glass I am getting edges around HHT-4 with going down to just 1um + 100 passes 3um strops, 100 passes 1.5um, 50 passes .5um

[Aaron kimpton]

i picked up double sided tape, scotch tape, not the foam kind. I plan on picking up lapping film and trying the combo out.

[sksharp]

I’ve seen your problem and the responses to it and it seems to me that taping a blade with wet stones would be counter productive because I don’t think you can find tape that will hold up to the constant motion of the sharpening process especially if you are come into the edge instead of away from the edge. Any abrasive that is caught under the edge of the tape has to cause problems. I have limited experience but have had great results by using kangaroo strops and only 1 deg. more acute angle with very light pressure. The kangaroo is harder and thinner than leather and balsa, and doesn’t bend over the cutting edge as much as the other 2. Have you had problems without taping using wet stones in the past? I get a very crisp line that eliminates all scratches  with the for mentioned method. Interested in hearing your opinion and solutions to your problem.

[Mark76]

Any I idea where the buffing came from, Josh. Your hypothesis sounds reasonable and I think I’ve noticed it too. I never had a marker line I couldn’t remove with acetone, so Clay’s theory could be correct.

Only clamping the blade without tape seems a bit risky.

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Jende Industries]

Josh – I think there may be something different going on – do you happen to have a “before” picture of the edge? The waves in the blade make it look more like left over, but hidden polish marks from the maker as they prepared and polished the blade.. The residue from the choseras would not cause a mirror finish on the waves if you simply wiped it off, especially with a clean tissue every time.

[M1rrorEdge]

I have never observed this effect with the lapping films.  I skipped the leather strop (Only used for convexing now) and Chosera generation  and don’t know what I am missing.  I’m very satisfied with the Lapping Film.  As TCMeyer has said above, I have three sets of glass platens and they are so easy to use.   I also have a few sets for many other lapping films I am experimenting with.    They are clean, they last longer than you would think, and are easy to use (No tape necessary other than to protect the blade from the clamp).  My only observation with the glass is that you must make sure the edges are rounded.  One of my glass platens had sharp edges that where scratching the blade with each pass.  After scratching the hell out of a non customer blade (Thankfully)  A little sand paper corrected the problem. It took me a week to figure it out.  Just one corner was sharp on one glass platen.

I did have a idea however.  Why not color the whole shoulder with the sharpie to help protect the finish during the sharpening process.  With a little alcohol it should come off without damage.  The marker will protect the shoulder from the tiny abrasive caught under the tape if that is the problem.  My thinking is that the marker itself could provide a thin protective film over the shoulder.  At the very least, it could just be used as a diagnostic for further discovery.  It is a weird effect that shouldn’t be happening  thanks  for sharing it Josh. 

Eddie Kinlen
M1rror Edge Sharpening Service, LLC
+1(682)777-1622

[tcmeyer]

The scratches caused by the glass is what drove me to using brass as a platen surface.  Mine are entirely home-made, so all of my glass edges were sharp.  Going to brass was a huge improvement.  Aluminum would be just as good.

I think I’ve explained before that I stretch the PSA film really tight when I place it on the platen.  The film is soft and if not anchored securely on the platen will produce a pressure wave as you firmly move it across the bevel shoulder.  I’m guessing this is what’s causing the polishing above the shoulder

[NotVerySharp]

No offense bud, I’ve been known to waste a few thousand on some dumb stuff, but……. what do you get for 10K in a knife?  Is this the OJ commiserative series or what?

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M1rrorEdge

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