Lapping film sticky side has grit? How do I use this??

[CpnStumpy]

Bought a pack of lapping films because they're cheap and I was curious after reading positive things on here.

It came with a nice big piece of glass and instructions to cut a piece of film, wet the glass, and stick the lapping film to it.

The films are completely smooth on the non-sticky side that's presented after sticking the sticky side (which seems to have grit like sandpaper) to the glass.

What the hell? Do I pretend it's got grit on the smooth side and it will abrade the metal properly with the grit from the other side?

Also if I stick a film to the glass, how do I use the next grade of film? Peel the first off and throw it away? I'm not concerned I wasted money because these were cheap and I have Naniwas, but I feel I'm completely misunderstanding how these work because I sense zero grit on the non-sticker side

 

[Derwent]

Did you get the adhesive backed, or plain backed?

 

[ewk]

The dull side is the abrasive side, facing up. The smooth glossy side faces the glass. Water holds it in place. Spray some water on the glass, apply the paper glossy side down, and smooth out any air bubbles.

The sheet can be used several times.

 

[PintoPlain]

Assuming you don't have adhesive backed film, you should be able to peel the film from the glass. You can reuse the film multiple times.

As @ewk said above, the smooth side is held on to the glass with water, and you hone with the rough side. I have a spray bottle with water to adhere the film to the base and to wet the film for honing.

 

[H Brad Boonshaft]

Which film did you buy?

Go to any big box hardware store and buy 3X12” glass tiles, as many as the number of grits you will be using,$ 3-5 each. And a sheet of 220 wet & dry.

Lap the glass tiles flat, 220 cuts them easily and will leave a frosted surface that will hold film much better. You will also see how, out of flat glass is.

Multiple glass substrates will make your life so much easier. For not PSA film smooth side down.

 

[CpnStumpy]

It's adhesive backed, what's that mean? Perhaps I messed up because I can't figure out what the adhesive side having the grit can possibly do other than abrade the glass it sticks to except not really because it's stuck in place so what the hell is this product.

This seems literally useless. It's like skateboard grip tape if the sandpaper part stuck down on the board, what the hell is this for?

 

[H Brad Boonshaft]

Adhesive backed, means there is an adhesive, (glue) on the back covered by a thin film of plastic. Probably what you are seeing (Smooth Side) is the adhesive backing. Try peeling a corner to get the backing off but have your substrate ready. Put down one end and smooth with a credit card to get the sheet down without bubbles. If you do not burnish with a card, you might be able to get back up for a second attempt, but it is like hanging wall paper.

You do not need adhesive backed and non adhesive backed is much easer to use, once on it will not come off unless you peel it off, it is just like a stone unless you do something crazy.

I don’t know about adhesive backed film, I have only used non adhesive film. Water alone will cause a suction and stick film to flat glass or any flat surface, until you peel it off. It can be removed, allowed to dry and reused until all the grit is exhausted. I store mine in a business envelope and write on the envelope how many razors it has honed, you will know when it stops cutting.

I have use adhesive backed sandpaper and Wet and dry, it is one time use as it tears or distorts when peeled off, usually requiring a single edge razor blade and WD40 to get it all off the substrate.

Get the glass tiles and glue the paper to the tiles. I use a guillotine paper cutter to cut my 9X11 sheets, razor knives and scissors also work.

There are different qualities of lapping film as well as abrasives, I use Aluminum Oxide and Silicone Carbide.

Diamonds do the same thing for a much higher cost, some folks say they last longer, but you are approaching finish stone prices, so it does not make a lot of sense.

3M film is about $1.50 per sheet that can be cut into 4, 3X9 inch pieces, around 37 cents per piece.

If used only as a finisher from a good 8k edge a piece will last a long time 10-15 horning’s.

 

[Darth Scandalous]

I think people who have used the sticky back film found that it doesn't lie flat because of inconsistencies in the adhesive. I vaguely recall someone talking about using some kind of solvent to remove the adhesive.

Maybe a picture is in order.

 

[CpnStumpy]

I think got a defective product, both sides are smooth, then I peel one side exposing the sticky, and abrasive side. The sticky side isn't on opposite side of the abrasive side, it's the same side when I peel the smooth part off

This absolutely can't be how this was intended to be

 

[Frinstance]

The peeled off layer may be protective and the smooth a spray & stick side. I've never heard of a product like that but I can't think of any other reason to cover the abrasive.

 

[CpnStumpy]

The peeled off layer may be protective and the smooth a spray & stick side. I've never heard of a product like that but I can't think of any other reason to cover the abrasive.

It's not covering the abrasive, it's covering the adhesive, it just so happens they're one and the same. It's a classic slick peel covering for any sticky adhesive things, except it's covering the adhesive which is also the abrasive. It's not spray and stick, it has actual adhesive glue. This must be a defective product

 

[Slash McCoy]

First of all, film at 1µ or finer will appear rather smooth on the abrasive side. At 0.3µ, it can be easy to mistake the abrasive side for the slick side.

If you have the right stuff except you made a mistake and bought the PSA backed (sticky back) film, the sticky side most definitely does not contain the abrasive. I have never seen or heard of film that has abrasive mixed with adhesive. Of course there are all sorts of posers out there selling "polishing film", "polishing paper", "microfinishing film", and other misleading product names that are NOT lapping film. All genuine real-deal lapping film sold by any reputable vendor is called L A P P I N G F I L M . Period. Get the right stuff, not the cheapest, or the top of the Amazon search feed. I get mine directly from www.nanolaptech.com though someone told me he does not do direct retail sales anymore. In the past I often from him and usually only 10 sheets per grit. That hones a lot of razors, by the way.

Definitely the plain back film is easier to use. PSA sucks. Been using the good stuff almost exclusively for about 10 years now. I have revisited sticky back film and always find it lacking in versatility, efficiency, and convenience.

The glass plate so often supplied is not the best option. It is much too thin. It is too flexible. It can BREAK if you drop it. Acrylic, at least an inch thick, is the way to go. Unbreakable, light, and easy to manage in hand, without getting your fingertips sliced off.

You will probably notice that when a piece of film is nearly at the end of its useful life, that the wear is greatest at the right hand edge, assuming you hone with the razor in your right hand. With plain back film you can simply cut off a 1/4" or 3/8" or so wide strip and reapply it to your plate, for a slightly narrower honing surface but you can get 3 or 4 more razors from that piece of film. With plain back, if you get an air bubble or piece of lint or a hair or fiber or dust under the film, it is easy enough to remove it, rinse the plate and the film, and stuck them back together. Not so easy with sticky back. If you use sticky back, apply VERY CAREFULLY, and have a separate plate for each grit of film. Acetone is good for removing adhesive residue but don't leave it stand long on acrylic.

I get my acrylic from www.tapplastics.com with pretty decent service and prices. I started out using half inch, then 3/4", but finally decided that 1.5" was the bee's knees. Since it doesn't wear and doesn't break, it is a one time, lifetime purchase, so don't let a few bucks worth of sticker shock discourage you from going a minimum of an inch thick.