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Pasted Strop How Much?

My first attempt at a pasted strop was a bit of a bust, I ended up with a paste, which when I reread the main thread was supposed to be bad. What should the strop look like at the end? Should I see any paste at all or should it be a very thin film? Could someone post a picture of what their strop looks like so I can see what I should be aiming for?
 
Here are views of some I did recently.

I use high quality 2"x3" balsa, with no backer. I flatten with extra fine sandpaper lightly wetted onto a granite 12x12 tile.

I use Tech Diamond Tools 50% pastes, diluted with acetone just to the point where the suspension seems watery rather than pastey. I apply using my fingertip, inside a nitrile medical glove. I rub it in with light pressure, using just enough of the diamond suspension that I can see that I have coverage.

I am perfectly happy with my stropping results.

L to R: 50k, 100k, 200k
7571DB99-718A-426F-917C-F3BC4DD3040E.jpeg
 
To answer your question directly, you should have a thin film. Your 0.25 looks crazy pasty/thick to me.

Diluting is absolutely a key step to my way of working. I probably use about a 5-8 mm extrusion of 50% diamond paste from the syringe to do 12"x3" of strop surface.

My first set of three were all 12" long. My newest set are 10" for the coarser grits and 16" for the 200k (most frequently used). I use both sets.

Over time, my first set of pasted balsa strops darkened, showing that steel was removed from my blades. When the surfaces started looking glazed, I sanded/flattened them again and applied new diamond coats.
 
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Thanks, I'll grab some new balsa and try again soon. There is always something new to learn when dealing with SRs!
 
Both your 0.25μm (100k grit) and 0.5μm (50k grit) efforts appear far to heavily applied. Did you get also get some 0.1μm (200k grit)?


Here are two of my diamond pasted balsa strops. Both have been lapped flat and re-pasted and then been used for about 20 x 50 lap progressions each.

IMG_20210722_165853.jpg
Here is an end view of my 0.25μm balsa strop. Top layer is 8mm this balsa. Middle layer is a smooth ceramic floor tile cut to size and the bottom layer is 20mm this structural PVC foam (painted with acrylic paint). Rubber glue is used between the balsa and tile while structural epoxy glue is used between the tile and foam. This arrangement is much lighter (and cheaper) than using cast acrylic sheet as a substrate but is more work to put together. Being lighter makes it easier to hold in-hand and, when using a balsa strop "hanging", allows for even lighter pressure.

IMG_20210722_170820.jpg

I do not recommended using just a solid balsa piece as a strop due to problems that can develop from the balsa warping and shrinking/expanding unevenly. These problems can however be overcome if you lap flat and repaste before each use. I use my 0.1μm after each SR shave so that would not suite me.

Like @Tanuki I use about 5mm to 6mm extrusion out of the Diamondteck syringe for each balsa strop. It is easier to spread if diluted with acetone. After application, just remembered to try and run it all off the balsa. Then you should have about the right amount applied.
 
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After 1½ years, I have used about 1.0g of 0.1μm paste and about 0.25g of both 0.5μm and 0.25μm paste. My 5g syringes should last me about 7 to 10 years or more. If buying 0.1μm paste, I recommend getting two 5g x 0.1μm syringes (saves on shipping). 0.1μm paste is used the most if you maintain your edges on a 0.1μm pasted hanging strop after each shave (and you should).
 
I’ve attempted to follow ‘The Method’ exactly.

Diamond Tech Pastes in 0.5, 0.25 and 0.1u
Thin 1/4” thick balsa cut in thirds to 12x3”
3/4” solid acrylic backing
Stuck together with contact spray adhesive

Balsa lapped flat with a full sheet of sandpaper on a certified flat granite surface plate. To apply dot a pinto bean sized piece of diamond paste around evenly and rub in good with bare hands. You can thin out really thick paste with a finger tips worth of mineral oil if required. Wipe off all excess with soft T-shirt material after application. It will look like there’s no paste left on the balsa but there is.

Stick to the proper method for the best results.

AB7C04B3-188D-4255-93DF-D1D99C3A46F9.jpeg 6AE9AB21-38FF-484E-BC42-9F26162F106D.jpeg
 
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@Tomo has the right idea. Follow the instructions to the letter for the best results (and who doesn't want the best results for their SR edges?).

I unfortunately could not source ¾" thick cast acrylic when making my balsa strops so I had to devise what I considered the nearest replacement. Fortunately that replacement (tile on PVC foam) worked well - if not even better.
 
You will need to replace your balsa on the substrate once it gets to about 3mm thick. A 6mm thick piece of balsa should last you about 4 to 7 years, depending on use.
 
Every attempt should be made to follow the method as precisely as possible.

The biggest challenge I had was finding a truely flat surface for lapping. A truely flat surface is actually very hard to find. Eventually I broke down and bought a surface plate to be done with it once and for all. But even the very best granite surface plate have a few microns of error. If you want to be really anal they should also be used at the right temperature and support configuration.

In practice others have found that large thick acrylic plates or thick pieces of plate glass are sufficient. Do not confuse plate glass with float glass and remember to evenly support the glass to avoid flexing. Non slip carpet mats on a table top work well to support the glass. Pavers and countertops should all be viewed with suspicion and checked with a quality straight edge. If you can slip a brass shim or piece of foil under the straight edge at any point, the surface isn’t flat enough. Machined metal plates exist for lapping but they tend to be small. You want something big to avoid overrun.
 
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Thanks, I like the looks of those strops and the idea. I found a tile that is exactly the size I want so I'll use that but I might paste it on another substrate after that.
 
Every attempt should be made to follow the method as precisely as possible.

The biggest challenge I had was finding a truely flat surface for lapping. A truely flat surface is actually very hard to find. Eventually I broke down and bought a surface plate to be done with it once and for all. But even the very best granite surface plate have a few microns of error. If you want to be really anal they should also be used at the right temperature and support configuration.

In practice others have found that large thick acrylic plates or thick pieces of plate glass are sufficient. Do not confuse plate glass with float glass and remember to evenly support the glass to avoid flexing. Non slip carpet mats on a table top work well to support the glass. Pavers and countertops should all be viewed with suspicion and checked with a quality straight edge. If you can slip a brass shim or piece of foil under the straight edge at any point, the surface isn’t flat enough. Machined metal plates exist for lapping but they tend to be small. You want something big to avoid overrun.
Lee Valley near me sells those metal lapping plates. Unfortunately, they are over $30 a plate, but they are guaranteed to be flat within a very tight tolerance. I actually did go to buy them as a substrate but they were out of stock at the time, then I reconsidered because I don't want to spend $100 for my balsa strops right now.
 
If you want to be really anal they should also be used at the right temperature and support configuration.
I am not quite there on the anal retentive scale of SR maintenance. I do have a granite surface plate and too many acrylic plates. (In my early Method days, Tap Plastics was very generous about cutting up a big remainder piece.)

However, my 2" thick high-quality balsa and my stone tile suit me fine for making stable, effective balsa strops. I do not live in a hotter climate, near a warm salty ocean (unlike New Orleans, Melbourne, or Cebu). Portland, Oregon is quite temperate and razor operations are conducted on the north side of the house and in a cool basement. So my mileage may vary.
 
I am not quite there on the anal retentive scale of SR maintenance. I do have a granite surface plate and too many acrylic plates. (In my early Method days, Tap Plastics was very generous about cutting up a big remainder piece.)

However, my 2" thick high-quality balsa and my stone tile suit me fine for making stable, effective balsa strops. I do not live in a hotter climate, near a warm salty ocean (unlike New Orleans, Melbourne, or Cebu). Portland, Oregon is quite temperate and razor operations are conducted on the north side of the house and in a cool basement. So my mileage may vary.
I'm using tile and 1/3" balsa right now. I have to grab more because the clamps slid and ruined the bonding last night, but it's probably good enough for my area.
 
Lee Valley near me sells those metal lapping plates. Unfortunately, they are over $30 a plate, but they are guaranteed to be flat within a very tight tolerance. I actually did go to buy them as a substrate but they were out of stock at the time, then I reconsidered because I don't want to spend $100 for my balsa strops right now.
The flatness of the backing is not critical, since you will glue the balsa to it before lapping it. The plate that you use for lapping is somewhat critical, the flatter the better. I decided to buy a Grizzly granite plate, level to better than .0001" or something like that. This is probably better than the thickness tolerance of the sandpaper so good enough.

The proper way to check flatness is with a machinist quality straightedge, and three identical feeler gauges. Set the straightedge along the diagonal between two corners. Set one piece under either end. Try to slide the third one beneath the straightedge in the middle and at various points between the two end ones. The resistance should remain the same along the entire distance between the two end supports. Then turn the straightedge to the other diagonal and perform the same test. This test will detect variations that the backlight test will not detect. However this level of precision is not really needed for lapping your balsa. Your lapping technique will introduce more error than that, what with overtravel and imbalanced pressure and all.

I just bought some sandpaper roll, so I could use a longer piece and avoid overrun. Looking forward to the next balsa lapping session.
 
I am not quite there on the anal retentive scale of SR maintenance. I do have a granite surface plate and too many acrylic plates. (In my early Method days, Tap Plastics was very generous about cutting up a big remainder piece.)

However, my 2" thick high-quality balsa and my stone tile suit me fine for making stable, effective balsa strops. I do not live in a hotter climate, near a warm salty ocean (unlike New Orleans, Melbourne, or Cebu). Portland, Oregon is quite temperate and razor operations are conducted on the north side of the house and in a cool basement. So my mileage may vary.
Ummmm... okay..... but you will still get some swelling. I would lap frequently. Me, I much prefer a thinner piece of balsa on a thick and stable backing.

I have been experimenting with 6" long pieces. Heresy, I know. The thing is, I find myself using more and more short x strokes and pull strokes, and fewer full length strokes. Guys keep bugging me to sell them kits all set up and ready to rock, and I just can't do it without losing money. Maybe with shorter pieces I can do something like that, I don't know. I want to use the short balsa for at least a year first. Jury is still out. I haven't been messing about with razors very much lately, just having my normal shaves with maintenance, but I might jump back into the fray in a few months.
 
The flatness of the backing is not critical, since you will glue the balsa to it before lapping it. The plate that you use for lapping is somewhat critical, the flatter the better. I decided to buy a Grizzly granite plate, level to better than .0001" or something like that. This is probably better than the thickness tolerance of the sandpaper so good enough.

The proper way to check flatness is with a machinist quality straightedge, and three identical feeler gauges. Set the straightedge along the diagonal between two corners. Set one piece under either end. Try to slide the third one beneath the straightedge in the middle and at various points between the two end ones. The resistance should remain the same along the entire distance between the two end supports. Then turn the straightedge to the other diagonal and perform the same test. This test will detect variations that the backlight test will not detect. However this level of precision is not really needed for lapping your balsa. Your lapping technique will introduce more error than that, what with overtravel and imbalanced pressure and all.

I just bought some sandpaper roll, so I could use a longer piece and avoid overrun. Looking forward to the next balsa lapping session.
Thanks for the information, I do have feeler gauges and a machinist straight edge, I've done this type of leveling check a few times for some other projects so I'm comfortable with that, just never figured I need that for shaving lol.

How often do you normally need to lap your strops?
 
Thanks for the information, I do have feeler gauges and a machinist straight edge, I've done this type of leveling check a few times for some other projects so I'm comfortable with that, just never figured I need that for shaving lol.

How often do you normally need to lap your strops?
No schedule, here. Usually after two or three reapplications of paste, or when it just looks or feels like it needs it. You can lap every time you need to reapply, if you like. Only harm is wearing the balsa down quicker. And balsa is pretty cheap; it's not made out of gold.
 
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