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Bill Schmalhofer

Moldmaster "sandpaper"

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Has anyone else ever used Congress Polishing sticks like wet sandpaper?

Following advice I learned from this forum I bought a series of the gray Moldmaster polishing sticks (220, 320, 400, 600 grit) to help with keeping plunge lines sharp. On the current blade I'm working on I accidentally got a "big gouge" in the blade on the last step on the grinder. After going through two sheets of 120 grit rhynowet paper and STILL seeing a line, out of frustration I picked up the 220 grit stone and started using it like a file (there was a bit more in the thought process than this but I paraphrased it). When the stick started loading quickly I put some 50% isopropanol / water on the blade to see if that would float the "filings" away ( I also use 50% isopropanol for my sand paper - found it is less messy than oil and way better than water due to the reduced surface tension). Within 5 minutes the scratch was gone. Seeing how well that worked I went over the entire blade with the  220 grit before going to 220 sandpaper. I ended up using about half the amount of sandpaper I normally use - and the stick still looks almost new. Flush with excitement, I did the same process with the next grit (320). Again, about half the sandpaper used and (more importantly) half the time! With the next grit (400) I first tried using the stick in the same direction as the previous grit sandpaper (if the 320 was spine to edge I used the stick in the same direction first, and then used it ricasso to point - again much more in the thought process to get to that idea). So far it has been a resounding success for me. Have no idea if these stones are "permitted" to be used wet (they may just fall apart on me next time I go to use them), but they are fairly inexpensive and as they have significantly cut down on my sanding time, they are worth it (sanding really aggravates an old rotator cuff injury). The sticks leave a much rougher finish than the sandpaper does which is why I use the same grit sandpaper after to clean the blade up.

 

Sorry for the long post on what was a simple question - just curious. 

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Yep.  I still use them for stuff that's too small for the grinder and files, but I'm not crazy about the finish they leave.  And I do use them wet, with Windex as lube.  

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Sandpaper gets dull very quickly while a stone can stay sharp as long as it doesn't clog. I've used cheap diamond sharpening stones instead of sandpaper before, the final polish is better with sandpaper but you can keep edges and lines crisp because a stone doesn't bunch up and move like paper will. Stones can gall and need to be kept flat, or kept in the shape they need to be, as they do wear down. 

I would love a set of stones from 80 to 600 grit, someday...

 

My diamond stones are wonderful when I'm cleaning up the facets of a miniature knife where the facet might be a few inches long but only 2mm wide. 

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5 hours ago, steven smith said:

 

I would love a set of stones from 80 to 600 grit, someday...

 

Steven,

Congress Tools Inc.

https://www.congresstools.com/catalog/categories/get-category/id/72

 

I got the 3/4 x 1/4 x 6 inch Moldmasters - but they have lots of sizes. Roughly $4 each. 80, 120, 150, 240, 320, 400 and 600 grit.

 

I have Alan to thank for that website.

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I use the 220 and 320 sticks before the same grades of sandpaper with 5.56 -wd40 as lube but use CRC brakleen to blast the crud out of the stone. I have found my hand sand/clean up time and effort about halved and with a reasonably high output of knives that is a real bonus 

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So these stone things, can they remove more material faster than sandpaper?   These would be great to thin out the bevel and edge a bit more after heat treat.

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Yes and no.  They come in different hardnesses.  The soft ones remove material faster, but wear away faster and can blow your lines if they wear unevenly.  The harder ones keep your lines crisp, but can load up fast (thus Garry's brakleen) and stop cutting.  They were all the rage ten years ago, but seem to have gone a bit out of fashion.

 

 

 

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1 hour ago, Conner Michaux said:

 

Conner, they seem to remove material slightly faster than paper. They definitely get rid of previous scratches faster. As I and Garry noted, it cut sandpaper time in half. You do need to follow up with sandpaper though because they do leave an "unsightly" finish. Also, I found when I was using an oil as lube the stones did seem to load. When I went to 50% IsoOH, the loading was basically non-existent.

Edited by Bill Schmalhofer
posted in wrong area

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I may revisit these...

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1 hour ago, Bill Schmalhofer said:

Conner, they seem to remove material slightly faster than paper. They definitely get rid of previous scratches faster. As I and Garry noted, it cut sandpaper time in half. You do need to follow up with sandpaper though because they do leave an "unsightly" finish. Also, I found when I was using an oil as lube the stones did seem to load. When I went to 50% IsoOH, the loading was basically non-existent.

Getting rid of scratches Is what I need, definitely gonna try these out soon. 

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What is the reason to go over with the sand paper before moving on to the next grit stone? Would it make sense to go through the various grit stones and only sand after the last stone to improve the finish?

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3 hours ago, Jonathanbradshaw said:

What is the reason to go over with the sand paper before moving on to the next grit stone? Would it make sense to go through the various grit stones and only sand after the last stone to improve the finish?

I suppose you could try that, but at least for me, the "unsightly" finish the stones give made it difficult to see that I had removed all the previous scratches. The sandpaper gives a smooth shiny finish that made it easier to see the last little blemishes. It would really stink to make it up to the 600 grit stone, finish with 800 grit sandpaper only to find a 320 grit scratch...:angry:.

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That's exactly why I stopped using them, but it never occurred to me to sand before moving up a grit.  Makes perfect sense to do so.

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I have found that if I use the 220 stick I can see the difference with the 320 stick then I go back to the 220grit paper which allows me to see if ther are any areas to touch up with the stick before I go through the paper grits.

I know that for myself I have found my use of the 220 paper has plumeted. My sanding sticks are 5/8 square hardwood sticks about 6 inches long and with the paper sheets cut into 4 lengthways strips (2 3/4 wide) folded round the stick I have 4 faces of the stick as I use up each face and slowly use up the paper.  I have gone from using about 1/2 a strip per side of each blade to only 2 or 3 faces at most and the handsanding time per blade cut at least in half. Yesterday I finish ground about 15 blades and have 8 of them handsanded to 600grit then a medium and fine sandflex block rub over which is where I finish my blades. I got a set of stones but they were a 10 stick set from 120 through to 1000 grit but the only two I use are the 220 and 320 with 90% of use being the 220 stick. 

When the 220 stick gets worn down I will get a (3x13x150 / 1/8 1/2 x 6) 10 pack 240 grit set from Aliexpress with free shipping https://www.aliexpress.com/item/32838448174.html?spm=a2g0o.productlist.0.0.39c24486hlK566&algo_pvid=b6c0177b-ce74-4766-96ec-0bd7916dbc91&algo_expid=b6c0177b-ce74-4766-96ec-0bd7916dbc91-35&btsid=f2b304b3-508f-46e1-84e5-233b2226755e&ws_ab_test=searchweb0_0,searchweb201602_3,searchweb201603_55

Edited by Garry Keown

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