Question on 154CM

[SC_Dave]

Will 154CM respond better to Bark River white compound or DMT .5 Diamond spray? My substrate is a DLT leather strop.
David

 

[Obsessed with Edges]

Either should work. My preference is to use a compound that's 'just abrasive enough' for a particular steel, without running the risk of stripping too much of the teeth out of an edge. In this case, I'd probably lean to the white compound for this steel. I haven't yet tried the BR compounds, but if their white performs as well as other whites I've tried (Ryobi has been my favorite), it should work pretty well. Assuming it's aluminum oxide, white is a pretty agressive polisher, even at relatively small grit size.

I'd more likely save the diamond compound for use on a hard strop of wood; diamond really seems to excel when used this way.

The catch-all answer would be, 'Try both of them'. Maybe get another decent piece of leather, something similar in texture and firmness to your DLT strop, and try them side-by-side. Go as firm as you can, with any of your strops. Softer strops will compromise the benefits of most compounds, and it's easy to get misleading impressions this way, about particular compounds.


David

 

[SC_Dave]

Either should work. My preference is to use a compound that's 'just abrasive enough' for a particular steel, without running the risk of stripping too much of the teeth out of an edge. In this case, I'd probably lean to the white compound for this steel. I haven't yet tried the BR compounds, but if their white performs as well as other whites I've tried (Ryobi has been my favorite), it should work pretty well. Assuming it's aluminum oxide, white is a pretty agressive polisher, even at relatively small grit size.

I'd more likely save the diamond compound for use on a hard strop of wood; diamond really seems to excel when used this way.

The catch-all answer would be, 'Try both of them'. Maybe get another decent piece of leather, something similar in texture and firmness to your DLT strop, and try them side-by-side. Go as firm as you can, with any of your strops. Softer strops will compromise the benefits of most compounds, and it's easy to get misleading impressions this way, about particular compounds.


David

Thanks David for your usual quick and precise response.

One of my DLT paddle strops is one sided, so one side is plain wood. You mention wood above, would the plain side of this paddle strop be suitable for this?

David

 

[Obsessed with Edges]

Thanks David for your usual quick and precise response.

One of my DLT paddle strops is one sided, so one side is plain wood. You mention wood above, would the plain side of this paddle strop be suitable for this?

David

If the back side of the strop is smooth (minimal bumps/ripples/dents/dings/etc), I'd see no harm in trying that. Even different woods will make noticeable differences in how a compound behaves, so I'd still encourage you to try the compounds on as many as you can. The possible downside to using the back of your strop paddle for the small diamond grit is, you might run into issues of contamination from other gritty agents, like dirt, or particles/dust from your white on the other side. At sub-micron grit levels, keeping the strop as clean as you can (aside from steel swarf deposited) becomes more important.


David

 

[AFAustin]

I have bars of the 3 Bark River compounds and they do their grit progression/colors a little differently. Their white is actually finer than the green. The vendors who sell the BR list the black compound at "3000 grit", the green at 6000, and the white at 12,000.

I have found the black and green to have good effect and to be pretty easy to apply. I haven't been impressed with the white---it's more difficult to apply and it's hard for me to see much effect from stropping with it.

A great combination for me is stropping with the Ryobi "H" white (2-5 micron) (thanks to David for talking this up), followed by BR green if an even more refined edge is desired.

Andrew

 

[Obsessed with Edges]

I have bars of the 3 Bark River compounds and they do their grit progression/colors a little differently. Their white is actually finer than the green. The vendors who sell the BR list the black compound at "3000 grit", the green at 6000, and the white at 12,000.

I have found the black and green to have good effect and to be pretty easy to apply. I haven't been impressed with the white---it's more difficult to apply and it's hard for me to see much effect from stropping with it.

A great combination for me is stropping with the Ryobi "H" white (2-5 micron) (thanks to David for talking this up), followed by BR green if an even more refined edge is desired.

Andrew

That sounds as if the BR white may not be AlOx, both due to the very small spec'd grit size (if it's actually finer than the green), and also based on the apparent lack of aggressiveness as compared to the green, which is generally much less aggressive than AlOx white compound. Interesting to hear that feedback about this compound.

I'm always somewhat cautious about attempting to predict performance of 'white' compounds for this reason. Some 'white' compounds are composed of something other than AlOx, such as tin oxide (very soft & intended for softer metals).

(The other thing that bugs me about the labelling of such compounds is the seemingly arbitrary assignment of 'grit' numbers, which don't provide any useful indication of how they perform. This contrast of BR's 'green' versus the 'white' is a prime example, seeming to generate more confusion than anything.)


David

 

[awestib]

That sounds as if the BR white may not be AlOx, both due to the very small spec'd grit size (if it's actually finer than the green), and also based on the apparent lack of aggressiveness as compared to the green, which is generally much less aggressive than AlOx white compound. Interesting to hear that feedback about this compound.

I'm always somewhat cautious about attempting to predict performance of 'white' compounds for this reason. Some 'white' compounds are composed of something other than AlOx, such as tin oxide (very soft & intended for softer metals).

(The other thing that bugs me about the labelling of such compounds is the seemingly arbitrary assignment of 'grit' numbers, which don't provide any useful indication of how they perform. This contrast of BR's 'green' versus the 'white' is a prime example, seeming to generate more confusion than anything.)


David

Can't agree more David! That's why I hope that folks like HeavyHanded do more work on analyzing compounds on their microscope and he has done quite a job already. The problem is also that the manufacturer may change their composite over time which is not helping. I guess in the end what matters is how they perform on a given steel and backing. That's where the fun (and unfortunately time) comes in, doesn't it? Martin (HeavyHanded) already composed his own SiO compound (4000 JIS) and maybe that's the way to go.

 

[HeavyHanded]

Can't agree more David! That's why I hope that folks like HeavyHanded do more work on analyzing compounds on their microscope and he has done quite a job already. The problem is also that the manufacturer may change their composite over time which is not helping. I guess in the end what matters is how they perform on a given steel and backing. That's where the fun (and unfortunately time) comes in, doesn't it? Martin (HeavyHanded) already composed his own SiO compound (4000 JIS) and maybe that's the way to go.

If anyone wants to send me some, I'd be happy to take a look. The finest aluminum oxide I'm aware of is the Linde "A" at .3 micron. Being white and made (offered) by a reputable maker is about what I'd assume. That would put it slightly finer than the .5 micron usually found in the green CrO.

From my own testing, is my opinion that the binder and the backing/stropping surface generally have more of an effect than the actual size of the grit - up to a point. Once it gets larger than 25 micron or so it starts to have some properties that aren't easily manipulated anymore, but that's about the range where one would be better off switching to a fixed abrasive anyway if available.

 

[SC_Dave]

So, can you guys recommend the white Ryobi that they sell at Home Depot?

David

 

[Obsessed with Edges]

So, can you guys recommend the white Ryobi that they sell at Home Depot?

David

I'd think it's worth a try. I've got the older version that HD used to carry, in a larger tube (looks more like most hardware store tube compounds). Mine is specifically labelled as 2-5µ particle size, and it works very aggressively to strip burrs away and also polish very fast (this is how I'm certain it's AlOx). The current Ryobi packaging for their compound includes (I think) black, yellow and white, in rather small blocks (much smaller quantity than the older tube I have). I think Martin (HeavyHanded) has some of this newer stuff, and has posted his impressions of it previously.


David

 

[AFAustin]

When I was doing a little Ryobi compound research recently, I was able to find the discontinued "H" compound (4 oz. tube) on the familiar auction site. If you do a search on the Home Depot website for "Ryobi buffing compound", you'll see not only the sets of 3 small compound bars, but also the 4 oz. tube. The difference is the 4 oz. tube is the "E" version, which I believe is 4-7 microns rather than the 2-5 microns of the "H". The "E" tube is available online only, but ships free to the store. It's cheap at $3.64 and I've actually thought about trying it as well, to see if I can see any performance difference from the "H".

Andrew