How To Use a Pasted Balsa Strop

[Slash McCoy]

I currently do the balsa after a Naniwa 12k. I'm waiting for a Suehiro Gokumyo 20k to arrive. Will I still see a significant benefit from the balsa after the 20k?

Of course. .1u is about 200k grit. .25u is somewhere in the neighborhood of 100k. .5u is around 50k grit. Will you like it? Will it be worth the extra work to get a 200,000 grit edge instead of a 20k edge? Probably, but you will know for sure when you have tried both.

 

[Tester28]

Ive just finished pasting these strops. L to R: .1/.25/.5 microns
Either Ive used too much on the .1 or too little on the other two.
I think I used pretty much the same amount for each. Its just that
the .1 micron is the darkest and the other two are very light in appearance
so maybe that's why you cant see it on the wood.

I did the .1 first and that's where the mistake occurred...did not
think and used a little too much pressure on the syringe and nearly
3-4 uses worth of compound came out. I didn't want to force it back
in the syringe from the other end so just wrapped it in aluminium foil.
Does this stuff harden up if stored this way....I'd like to be able to use
it for refreshing the strop periodically.

 

[Tester28]

Good news....I have just completed the progression. This time I did
not bother to tape the razor. I find it annoying to do do.

1mic film 50 laps (stiction was achieved)
0.5 balsa 50 laps
0.25 balsa 75 laps
0.1 balsa 100 laps

The first three stages left traces of some fin when I did the 6 side strokes,
the fourth one produced nothing of note.

Then:
15 laps on linen strop
50 laps on leather strop

The razor is now treetopping hair mercilessly on the forearm at about quarter inch height.
I would like to thank Oberstürmbannfuhrer Slash McCoy for keeping me on track and not
allowing me to deviate even a little. 'Twas for mine own good. To any newcomers reading this,
follow exactly what the man says and curb the urge to experiment...this method does wot it
says on the can!

 

[Ray Settanta]

Glad to see that you are pleased. As the man says, follow the method exactly and you will get great results. After that, you can experiment if you want. BTW, I had the same problem with my paste. Way too much came out but I just took the plunger out and put the paste back in the tube. Also, you don’t want a heavy coating of paste on the balsa. I can’t see mine either but I know it is there. The razor isn’t getting sharp on just the balsa alone!

 

[Tester28]

BTW, I had the same problem with my paste. Way too much came out but I just took the plunger out and put the paste back in the tube.

I tried to get the plunger off but it was resisting...so I stopped before I made things any worse....might
try again.

BTW, I shaved with the razor and it was sharp as hell..but extremely smooth.

 

[rbscebu]

Making My Balsa Strop

The substrate of a balsa strop needs to meet the following requirements:

• Of a size suitable to take the balsa that you will be using.
• Provide a flat surface on which to glue the balsa.
• Structurally stable so as to prevent the balsa from warping.
• Thick enough to protect your fingers from the blade edge when in use.
• Not too heavy so as to reduce fatigue during use.

As Slash has suggested, a solid block of cast acrylic about 20mm (3/4") thick is quite suitable. Others have suggested 20mm thick aluminium alloy bar, also good. My problem was that I did not have ready access to either thick acrylic or aluminium alloy bar.

To solve my problem, I decided on 6mm (1/4") thick glazed ceramic tile as a suitable flat surface with structural stability to prevent warping. For thickness, I was going to glue 15mm (5/8") thick plywood to the underside of the tile. Fortunately I was able to obtain some 8mm (5/16") thick PES closed cell structural foam to use instead of the plywood. This foam is much lighter and easier to work with.

With all my materials in hand, I cut the tile with an angle grinder and diamond blade to 300mm (12") x 73mm (2 7/8") and similarly the foam using a box knife. All three pieces were then epoxy glued together to form my balsa strop substrate.

​

The completed substrate has a relative density of about 0.9. Acrylic is about 1.18 and aluminium allow is about 2.7. This makes my substrate about 1/4 lighter than acrylic and 2/3 lighter than aluminium alloy. This is not a big concern but nice to have.

The following day after the epoxy glue had set, cut my 10mm (3/8") thick balsa to size to match the tile. This was then glued to the ceramic tile using "rubber" glue (called rugby glue here in the Philippines). This glue is preferred as it is cheap, easy to source, holds the balsa well and allows the balsa to be relatively easily removed later when it needs replacing.

I will post a photo of my finished balsa strop here once the rugby glue has fully set.

 

[steveclarkus]

If you think you need more work before the balsa, then you probably do. Then again, it could be that your lap count on the balsa is a little short, particularly at the .5u stage where you are trying to pick up where the stone left off.

Try the lather on your ILR, maybe? And spend more time on it. Keep going for a few dozen lightest laps after you get strong stiction, then a few pull strokes and finally a half dozen or more of the lightest laps, maybe even spine leading, to peak the apex back up. That should have you set nicely for the balsa. It should feel, at the end, as if your rock is having no effect on the steel, due to no contact or fleeting contact. Kinda guessing here since I have not used that stone. You could also try 1u lapping film on acrylic after it, or instead of it. Or a well lapped Naniwa 12k if it fits in your budget and you just like the stones.

The balsa doesn't give you the strong feedback that stones or film do. You basically have to count laps and observe sharpness and smoothness results, and adjust lap count as indicated. I find that with pull strokes after every stage, and with the balsa held vertically and only feather light pressure applied, it is nearly impossible to overdo it. So too many laps is no big deal, but too few and your edge is not done. I never go fewer than 50 laps. Usually these days I go 100 when honing a new-to-me razor, and reduce to 50 for daily maintenance on the .1u diamond. The balsa behaves much differently than stone or film, and you can't be stuck in the rock-rubbing mindset and techniques.

MAYBE before doing anything else, take it back to the .5u and do a couple hundred lightest laps with the balsa held vertically, end-up. If you have been resting it on a bench, stop. There is likely your problem. You need for the balsa to yield and not resist the pressure of the razor. Then 3 or 4 pull strokes, a few more regular laps, and 100 each on the final two grits, not forgetting the pull strokes. Be sure you are getting the razor very clean between grits. A few half micron particles rolling around on the finer balsa will sabotage your edge.

There is more than one way to skin that cat. This is my way and it most definitely works.

For some reason my honing went to hell. Read your post on pull strokes and thought about verticals scratches. Pulled out my cnat I bought 20 years ago and did a bunch of circles then to balsa with pull strokes every ten laps on all three balsa grits and the edge is fuzzy now. Will give it a go in the morning and see if I have better results. Very curious as to why my edges aren’t as good as they once were.

 

[Slash McCoy]

For some reason my honing went to hell. Read your post on pull strokes and thought about verticals scratches. Pulled out my cnat I bought 20 years ago and did a bunch of circles then to balsa with pull strokes every ten laps on all three balsa grits and the edge is fuzzy now. Will give it a go in the morning and see if I have better results. Very curious as to why my edges aren’t as good as they once were.

First thing is to figure out where the failure is occurring. If it is your balsa, maybe your balsa is loaded up with swarf, or just needs another BB's worth of paste on it.

 

[steveclarkus]

First thing is to figure out where the failure is occurring. If it is your balsa, maybe your balsa is loaded up with swarf, or just needs another BB's worth of paste on it.

Thanks Slash. I flattened the .1 but will do the other two. Could be the problem. The .5 is rather blackened and a bit slow.

 

[Biglo13]

Thanks Slash. I flattened the .1 but will do the other two. Could be the problem. The .5 is rather blackened and a bit slow.

Do you know the history of razors in question?
Is the pre-finish work on point!

 

[rbscebu]

I was a little worried about cutting my balsa strops with the pull strokes. I know this shouldn't happen when done properly, however I still worry.

To solve this, I use three small pieces of balsa left over from making my balsa strops. I past each small piece with a very little 0.5um, 0.25um and 0.1um paste respectively and use them for my pull strokes.

Works well for me and puts my mind at easy.

 

[Tester28]

Very curious as to why my edges aren’t as good as they once were.

3 days ago I had an absolutely awful shave with a straight...had to stop almost
immediately as it was pulling...it was treetopping like crazy before so the only
possible explanation to me was that I had somehow rolled the edge while stropping.

Anyway...stropped on linen a dozen times to clean the edge....then 50 laps on 0.1 micron balsa.
Today I gave it 50-60 laps on leather and the shave was back to normal.
I reckon the weak link for me was stropping it earlier...thats the thing with straights:
every part of the regimen needs to be perfectly executed or it could affect the edge adversely.

 

[MO1]

Have done a bit of experimenting. 2 balsa strops one with 0.25u diamond and the other with 0.1 cbn. The 0.25 diamond paste was hard as clay and had to dilute it the best I could with alcohol and then I put a tiny bit on my finger and rubbed it in evenly, could not even tell that it was on the balsa. Then a paper towel to rub off any loose diamonds.
The Ken's cbn spray, water based usually used for leather and I can see why, the balsa is eager to soak up any water. Very hard to get an even distribution, so I relapped it and sprayed a small amount in a cup and placed small dots over the balsa with my finger. Then rubbed it good with paper towels.
The reason I started at 0.25 is that I don't want to lose any comfort or forgiveness from my jnat edge, so I did maybe a total of 20-30 passes on it, I had a hair to test the sharpness gradually.
Then onto the cbn balsa I did maybe about the same amount of laps, same here had a hair to test how it was cutting gradually.
On the arm it just slices hair cleanly without almost no feedback post stropping.
Then strop and test shave.
My God this is a good edge, I can almost swear the balsa gave the edge a bump in comfort aswell which I did not expect.
Many thanks to @Slash McCoy and @Chan Eil Whiskers for the information!

 

[kohalajohn]

Some changes in how I do this.

I like using a full sheet of 400 sandpaper to lap the balsa. I bought an acrylic plate the size of a full sheet, for this.

But I grew tired of using paint thinner to remove the sandpaper, cleaning off the plate and then gluing a new sheet on it.

I realized that my kitchen counters are granite. So I just placed a sheet of sandpaper on the counter, held it in place with fingertips and it worked fine. Good for balsa, probably not enough for actual stones though.

The other thing is I made a fourth lapping plate. I made a second of the .1u, one designated just for the daily stropping, one that lives in the bathroom. This means my trio of .5u, .25u, .1u will wear at the same rate.

You can see in the photo that I indulged in a thick, one inch acrylic plate for the new lapping plate. Nice to have the fingertips way back from the edge.

Photos attached

 

[kohalajohn]

I know most folk here already know this, but this was new to me.

Had my first problem with fin edges.

I had lapped and pasted my three balsas, and decided to really give my nice razor the treatment. So lots of balsa work on the progression. No pull strokes, because, well, I just don't bother with pull strokes.

And then suddenly a bad shave. What? It should have been super excellent. I mean, I just did a super special and careful and high lap number honing on the three balsas. But it was so rough I finished this morning with my DE.

But of course that was the problem. Large number of laps. And on freshly pasted balsa. So I had finally done enough work to create fin edges. Finally, my lack of pull strokes created a problem.

So I decided to experiment. I put away my very nice razor, a vintage Filly, and dug out a gold dollar from the cigar box.

Did the three balsa progression, but this time gave it a few pull strokes on the bottom of the balsa, at the end of fifty laps, and on each balsa.

And it shaved fine. It was no Wacker, but it gave a perfectly good shave. Not rough anyway.

So I guess I'm doing pull strokes now.

I guess my question is this. Do you gents do pull strokes after your daily .1u? Or do you reserve pull strokes for the time when you are doing the full progression?

I'm guessing my daily fifty laps on the .1u won't create fins. Never has before.

 

[MO1]

I know most folk here already know this, but this was new to me.

Had my first problem with fin edges.

I had lapped and pasted my three balsas, and decided to really give my nice razor the treatment. So lots of balsa work on the progression. No pull strokes, because, well, I just don't bother with pull strokes.

And then suddenly a bad shave. What? It should have been super excellent. I mean, I just did a super special and careful and high lap number honing on the three balsas. But it was so rough I finished this morning with my DE.

But of course that was the problem. Large number of laps. And on freshly pasted balsa. So I had finally done enough work to create fin edges. Finally, my lack of pull strokes created a problem.

So I decided to experiment. I put away my very nice razor, a vintage Filly, and dug out a gold dollar from the cigar box.

Did the three balsa progression, but this time gave it a few pull strokes on the bottom of the balsa, at the end of fifty laps, and on each balsa.

And it shaved fine. It was no Wacker, but it gave a perfectly good shave. Not rough anyway.

So I guess I'm doing pull strokes now.

I guess my question is this. Do you gents do pull strokes after your daily .1u? Or do you reserve pull strokes for the time when you are doing the full progression?

I'm guessing my daily fifty laps on the .1u won't create fins. Never has before.

I've just done the balsa once which I described over your post. But I do a few pull strokes on the 0.1u cbn one aswell, slightly spine leading so I don't cut into the balsa, just in case I have a fin edge developing. cheap insurance^^

 

[Slash McCoy]

Remember with a freshly pasted balsa, it is essential to rub it down with a tshirt. Also when you are getting fin, think about pressure, more than laps. If you do not hold your balsa vertical, with one end up and one end down, try doing so. It will help you to regulate your pressure. Anyway the pull strokes, yeah they are magic, and remedy a lot of minor mistakes. Glad you had your epiphany and your shaves are back on track.

 

[Tester28]

I guess my question is this. Do you gents do pull strokes after your daily .1u? Or do you reserve pull strokes for the time when you are doing the full progression?

I do half a dozen pull strokes with slight pressure (both sides)....after every stint on the 0.1 mic balsa.

 

[kohalajohn]

You said both sides. I’m not clear on this. I thought pull stroke means you lightly cut straight into the wood

 

[rbscebu]

You said both sides. I’m not clear on this. I thought pull stroke means you lightly cut straight into the wood

A pull stroke is laying the blade flat on the balsa (like when you are stropping) and pulling it about 10mm to 15mm (about 1/2") across the balsa grain (i.e. at about 90° to the normal stropping direction). This is done on both sides of the blade just once each time. You use the same pressure when pulling as you do when stropping.

I normally do a pull pass about every 10 strip pass on all 0.5um, 0.25um and 0.1um uses. To protect my balsa strops from accidental cuts, I perform my pull strokes on pieces of spare/scrap balsa that have been given a very light pasting of diamond paste.