Rookie sharpening question

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Sandman84

Joined
Dec 4, 2014
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So I've been reading through this category and I see lots of mention of sharpening with sandpaper. So am I misreading this or can I in fact sharpen with sandpaper? If so what type grit should I buy and how would I set it up? For example glue to a board or what not. Keep in mind that I'm very new to sharpening so try not to give me a hard time. Thanks in advance.
 
I know this isn't the ideal way for me to learn to sharpen but I would like to try it out on some of my cheapos. You guys have already told me about a lot of good set ups but until I get Christmas out of the way I won't be able to buy any of them.
 
Sandman84 said:
I know this isn't the ideal way for me to learn to sharpen but I would like to try it out on some of my cheapos. You guys have already told me about a lot of good set ups but until I get Christmas out of the way I won't be able to buy any of them.
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Sharpening with sandpaper is a perfectly good method, just have to be aware of the pros and cons. I make a block that is intended to be used with sandpaper, lapping film, and plain paper, and just posted a video showing how it works and best practices:
http://www.bladeforums.com/forums/showthread.php/1242011-New-Washboard-video

A great deal of the content is applicable to sandpaper sharpening with or without the Washboard, so is (if I do say so myself) very good resource just for the references to sandpaper usage even if you have no interest in the sharpening base itself (which is a pretty effective widget in its own right, again - if I do say so myself!).

Key issues are to use as little pressure as possible, the sandpaper has flex/give and can round an edge just as a strop might, even if used over steel plate or glass. Also it can clog very rapidly and suffer greatly reduced lifespan. So - light applied force, and clean it often - will work very well. Is important to use a good progression and patience, leaning on the paper to get better grinding speed will kill it and change the geometry of the edge. A good selection of papers is imperative.

In general it is versatile, robust, and very convenient. Do not forget that lapping films can be had in a variety of abrasives and they work pretty well too. They all need to be used with care.
 
You definitely can get a great edge w sandpaper. You can use as many grits and go as fine as you want. I don't like it cuz the paper wears quick and I didn't have a system to easily change them out. I had glued them to thick glass slabs I had cut to the size of a nice stone (length and with, not thickness). It took some work, and they were AWESOME...until they lost their grit after sharpening two knives.
 
HeavyHanded said:
Sharpening with sandpaper is a perfectly good method, just have to be aware of the pros and cons. I make a block that is intended to be used with sandpaper, lapping film, and plain paper, and just posted a video showing how it works and best practices:
http://www.bladeforums.com/forums/showthread.php/1242011-New-Washboard-video

A great deal of the content is applicable to sandpaper sharpening with or without the Washboard, so is (if I do say so myself) very good resource just for the references to sandpaper usage even if you have no interest in the sharpening base itself (which is a pretty effective widget in its own right, again - if I do say so myself!).

Key issues are to use as little pressure as possible, the sandpaper has flex/give and can round an edge just as a strop might, even if used over steel plate or glass. Also it can clog very rapidly and suffer greatly reduced lifespan. So - light applied force, and clean it often - will work very well. Is important to use a good progression and patience, leaning on the paper to get better grinding speed will kill it and change the geometry of the edge. A good selection of papers is imperative.

In general it is versatile, robust, and very convenient. Do not forget that lapping films can be had in a variety of abrasives and they work pretty well too. They all need to be used with care.
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Yeah, I must have used too much force. Funny your name is heavy handed but you use a light touch! Lol

Edit: P.S.- Just watched the video. Well done. :)
 
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A nice little trick to freshen up you sandpaper is to rub a big pencil eraser on it and it will clean the metal powder off the paper. If I recall correctly, I learned that in a video from Mr HeavyHanded himself
 
Sand paper just didn't work for me. I procured many different grits and glued them to plate glass and usually on the first or second knife I sharpen I'd slice into it. Doing a leading edge stroke. Doing an edge trailing method I could not get the edge I liked. So, I scrapped the idea and use the sandpaper for other tasks. Stones are much more resilient and last sooo much longer. DM
 
I didn't do any good with sandpaper either. I used spray glue and plate glass. I didn't cut into it, but didn't get good results. It didn't last long and wasn't for me.
 
I like taking a foam rubber backed mouse pad foam side up and place a sheet of 1000 grit to bring a blade back from every day use. Then 2000 grit to polish the edge.
the edge of this combo also works well with serrations.

I have a bayonet that I couldnt sharpen no matter what I did. I put the mouse pad foam side up and started with 400 grit, 600, 800, 1000 grit and put a wicked edge on it.
 
FWIW, I tried sandpaper sharpening a few years back for quite a few of months when I was big into convexing all my knives. I never did warm up to it for V bevels even when used over a metal plate, especially mating up the grinds on tanto edges - shoulder transitions were a little too soft as well. Also had issues consistently getting a totally clean deburr with a trailing pass on the sandpaper. Had better luck using a bonded belt over a brass plate. Ultimately this spurred me to learn convex and recurve on waterstones and vitreous oil stones, and abandon the wet/dry entirely for a time.

Not until I went back and tried it over a Washboard did I come around to using it regularly again. I highly recommend using it over, if not a Washboard, at least some sort of grooved surface that has relatively sharp high points. Makes a huge difference especially when using with a leading pass or scrubbing technique - far less softening of the surface, and a lot less abrasive gets knocked loose on the leading pass - and this relative even to using it over steel or glass (IMHO). Between this and compulsively keeping it clean while working, a huge improvement can be had in how flat the surface grinds, and how long the paper lasts. I cannot remember the last time I pitched a sheet because it had been worn out, I always manage to nick them first - usually after doing maybe half a dozen or more knives. Having the paper wrap around the long edge of whatever surface rather than the ends is also a good move - the edge of the sheet catches and gets cut a lot more easily than a folded corner.

Here is a reference to using wet/dry over the back of certain grooved ceramic tiles:
https://asahasah.wordpress.com/2013/10/23/lekukan-lekukan-yang-menggoda/
 
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Best results with sandpaper will always come with the paper firmly-affixed or held to a HARD backing like glass, stone or hardwood, so the paper doesn't lift away or roll underneath the edge. Edge-trailing strokes, as with stropping, always work better when setting initial geometry, up to and including reaching the apex; when the edge becomes more refined, very, very light edge-leading can be used (works well for cleaning up burrs), but isn't really necessary. The upside to edge-leading on sandpaper is, it'll teach your hands very quickly to the use of light pressure (else you'll cut the paper and/or scrub abrasive off the paper backing); it's a great training aid for sharpening in general, in that respect. Also a great way to teach the hands to 'feel' for the apex; when the apex touches the paper, it'll really dig in and it's hard to ignore.

A lot of people use and recommend softer backing like a mousepad, but I don't really see any additional benefit to it, other than it 'feels' a little more forgiving to the beginning sharpener, and will add more convexity for those looking to do that. It increases the likelihood of rounding over the apex with anything less than perfect technique (held angle & use of pressure), and the softer backing really slows the grinding speed of the paper (this is what really steered me away from softer backing in general). The softer backing also increases the likelihood of the paper rolling or lifting up into the blade, creating scratching issues above the edge grind.

All that said, I LIKE that sandpaper can be a sharpening solution, if or when other tools aren't available; and it's dirt cheap. That's reason enough to learn how to get the best out of it.


David
 
Obsessed with Edges said:
All that said, I LIKE that sandpaper can be a sharpening solution, if or when other tools aren't available; and it's dirt cheap. That's reason enough to learn how to get the best out of it.


David
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Another good reason for some to use it is that it can easily be made into a progression that makes sense. Many other grinding media have a totally different feel from the coarse to the medium to the fine etc, but sandpaper (wet/dry) has a continuity of "feel" that lets one learn it as system pretty rapidly. Is also pretty neat in that one can finish with a few light backhone passes to good effect, similar to a waterstone. Pros and Cons, but is a 100% valid way to go as long as one understands the strengths and limitations.
 
HeavyHanded said:
Another good reason for some to use it is that it can easily be made into a progression that makes sense. Many other grinding media have a totally different feel from the coarse to the medium to the fine etc, but sandpaper (wet/dry) has a continuity of "feel" that lets one learn it as system pretty rapidly. Is also pretty neat in that one can finish with a few light backhone passes to good effect, similar to a waterstone. Pros and Cons, but is a 100% valid way to go as long as one understands the strengths and limitations.
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Good points, all. :thumbup:

Speaking of 'progression', the other thing I like about it, is the vast range of available grits. Hard or impossible to find such a neatly-stepped range in virtually any other media, without spending a ton of money.


David
 
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