Why do I need VS disc sander?

For me, the increased surface area allows me to grind things ENTIRELY flat on the disc, and I can bring a blade up to a damn near perfect finish to 2000 grit and above without belt bump, strange squiggles from belts bulging (man, I wish there were higher grit X weight belts), etc. Coming off the disc at 1200 grit takes seconds pre-HT to bring a blade to a mint 800 grit hand satin, with no risk of the dreaded 'belt bite' or other anomalies associated with a narrow grinding surface.

Nick Wheeler's videos are perfect studies in this, but I learned from Burt Foster. Same practice.

If you think your flat grinds off the belt are flat, make a pass or two on your disc grinder and see if that holds water. I'm guessing you'll be surprised...

Also, I don't use a work rest - all freehand. I'm not even sure I could figure out how to do what I do with a work rest, at this point.


razor-edge-knives said:
I still don't understand why one would use a disc to grind knives on instead of a 2x72... in my experience the disk paper wears out way quicker than a belt will because of the difference in surface area. And you can get grinds pretty flat on a belt grinder, why would you need flatter? I understand that it's great for getting stuff flat (like for guards and tangs/scales and stuff). But I have a vs disc grinder w/ KMG's work rest and I very rarely use it (not that I'm a knifemaker specifically, but I do most things involved in knife making).

Just trying to wrap my small brain around this, thanks guys =)
Click to expand...
 
Matthew Gregory said:
For me, the increased surface area allows me to grind things ENTIRELY flat on the disc, and I can bring a blade up to a damn near perfect finish to 2000 grit and above without belt bump, strange squiggles from belts bulging (man, I wish there were higher grit X weight belts), etc. Coming off the disc at 1200 grit takes seconds pre-HT to bring a blade to a mint 800 grit hand satin, with no risk of the dreaded 'belt bite' or other anomalies associated with a narrow grinding surface.

Nick Wheeler's videos are perfect studies in this, but I learned from Burt Foster. Same practice.

If you think your flat grinds off the belt are flat, make a pass or two on your disc grinder and see if that holds water. I'm guessing you'll be surprised...

Also, I don't use a work rest - all freehand. I'm not even sure I could figure out how to do what I do with a work rest, at this point.
Click to expand...

Ahhh that totally makes sense as I see how this would be huge when it comes to handrubbing a knife as yes I do know that there is slight convexing from the belt but enough to throw handrubbing way off. I don't ever do this part so that's why I am ignorant of this hehe.

Question Matt, with each progressive grit how many sheets of sandpaper do you go through on the disc at each level? Does it go fairly quickly after the initial 'flattening' faze (i.e. from belt to disc)?
 
Depends entirely on the steel, the width of the blade, and whether or not I'm stupid enough to decide to do a hand finish AFTER heat treat.

Last year I make a 13" wakizashi in CPM-4v and elected to bring it to a hand finish after heat treat (I'd only gone to 220 with a belt pre-heat treat). That took over 32 sheets of 320 grit Rhynowet. The vanadium carbide in the steel made useable life of the paper about three seconds, and you'd just feel it get glassy. Learn from my mistake!!!
 
Well, I got the Tim Hancock grinding video, and while the audio was moderately difficult to follow in a lot of places, and the video quality left a little to be desired, it actually was full of a lot of good information, and gave me a different perspective on grinding and finishing.

A good supplement to the ABS video is on Travis Wuertz's channel:
https://www.youtube.com/watch?v=MAgD3bvsY1o

The video/audio is similar, but you get some additional perspective I think. Each presentation has a little something that the other doesn't, so I would recommend watching both.
 
Yeah I bought the same video and agree on the video production BUT you sure can learn a new way to grind I'd never imagined possible. I basically wonder if that technique isn't better suited to thick blades instead of the 1/8" still or less I normally use. However I learned a lot watching that video! I can't help but think watching the video you could learn ALOT more than what the folks in attendance watching could of, as they couldn't watch him on the grinder at all!
 
LCoop said:
Yeah I bought the same video and agree on the video production BUT you sure can learn a new way to grind I'd never imagined possible. I basically wonder if that technique isn't better suited to thick blades instead of the 1/8" still or less I normally use. However I learned a lot watching that video! I can't help but think watching the video you could learn ALOT more than what the folks in attendance watching could of, as they couldn't watch him on the grinder at all!
Click to expand...

It looked like there was a video monitor in place to help the crowd see what the cameraman was filming. You can see a similar set up in the Wuertz grind in video I linked to above.

As for the technique on thinner blades (which is what I primarily make as well), I'd imagine you're probably not gaining much with the contact wheel passes, as you're not removing that much material anyhow, so I would probably just start and stay on the flat platen. The rest of the techniques for plunges, blending, disk grinding, etc... should still translate well regardless. I'm looking forward to trying some of this stuff out.
 
I agree there was a monitor for the attendants to view but it would be like looking at a postage stamp from their prospective! I know this video was made years ago and the possibilities now to view by the audience has changed dramatically! But I think I would have been hugely disappointed having spent the time and money (gas, motel, food, etc) for attending I would have been ahead to buy the video! I learned a ton of info from watching the video don't get me wrong! I don't regret buying the video but it's wasn't the quality I expected for the price but some how feel the real audience got cheated. YMMV
 
LCoop said:
I agree there was a monitor for the attendants to view but it would be like looking at a postage stamp from their prospective! I know this video was made years ago and the possibilities now to view by the audience has changed dramatically! But I think I would have been hugely disappointed having spent the time and money (gas, motel, food, etc) for attending I would have been ahead to buy the video! I learned a ton of info from watching the video don't get me wrong! I don't regret buying the video but it's wasn't the quality I expected for the price but some how feel the real audience got cheated. YMMV
Click to expand...

I don't disagree. It's difficult to show and talk about a lot of the nuances in a group setting like that. The still pictures and zoomed in camera shots did help a little, and I'm sure are much better viewed at close range on a tv or computer screen, rather than the back of a pavilion.
With the quality and usability of cameras and editing software now days, I'm surprise to not be seeing a lot more videos like these coming out, but perhaps a little more "watchable". Maybe they are out there, I don't know. I've only seen a small handful, but compared to, for instance, some of the well produced YouTube channels I watch (for free mind you), it seems that there is room for improvement now days.

I do still feel like I got a good value for my money though, and if it supports the ABS or Mr. Hancock, all the better.
 
"I do still feel like I got a good value for my money though, and if it supports the ABS or Mr. Hancock, all the better. " On that we agree plus every thing else! I'm now even more convinced me getting set up with a reversible VS disc sander was the right decision to dump more money in this money pit! My equip is all in possession with the exception of the reverse switch for my existing VSD which should be here tomorrow. lol thanks

With that, it reminds me of a story when I did electrical contracting work and was working for a saw mill company. A timber buyer screwed the saw mill that I was doing electrical work for. The timber buyer was trying to explain WHY he screwed the saw mill when the owner of the saw mill said " Nope it's all good! You cost me a ton of money, probably less that people pay for a college education every day for. I figure you gave me more of a education of buying timber than I could ever have learned paying tuition at a college ! LOL Life can teach you more than you ever learn from books or videos. BUT the right videos and forums like this can cut your learning curve down a tremendous amount.
 
Last edited:
Kevin Powers said:
Even grinding on a flat disc can produce a slight hollow if you're grinding on the outside edge of the disc and not holding the blade parallel to the disc. The benefits of a variable speed disc are tremendous in my opinion. I use my disc more than my belt anymore. I use it to dovetail bolsters and handle material, flatten blades, smooth blades after surface grinding, flatten scales, square guards, square spines, just about everything that needs flattening or shaping that isn't a tight radius. The biggest thing that has helped on the disc for me is purchasing a rubber backer from K&G. I haven't taken it off since I glued it on.
Click to expand...

Do you have a link to the rubber backer? Is this better than cork/gasket material that I've seen used?
 
You can get a 12x12 piece in whatever thickness and hardness you'd like from McMaster.
 
Drew, autozone has a 1/16" cork made for gaskets. You can buy a sheet big enough to line 2 discs and some sanding sticks for like $10. That 3m feathering disc adhesive from k&g is great for holding it on too.
 
Quick question... So you guys who use backing permanently attach the rubber/cork to the disc then use the feather adhesive on the rubber/cork for the sandpaper? How do you clean off the old 3m feathering adhesive every once in a while without destroying the rubber/cork? I cleaned it off of the bare metal disc and it took forever with acetone...
 
If I may suggest a product that was recommended on this forum a couple years ago...try Blaster all purpose CBD citrus based degreaser. I bought a half dozen cans after using it to clean off 3M f eathering compound. It melts the stuff off. I have not used WD 40 but if Matthew Gregory says it works I would try that first. Matt is a no nonsense straight shooter and a favorite source of mine for info...and a really nice guy. If you want to buy some the can reads www.blasterCorp.com . Larry
 
Ha!

Thanks for the props, Larry, but YOUR suggestion actually sounds like a better one. Any chance to using a safer alternative is a better one, in my book, and I'm going to see if I can dig up some of that PB product you're referring to. I just used WD40 because it seems to work well against sticky stuff, and there's always a can in reach.
 
LARRYZ10 said:
If I may suggest a product that was recommended on this forum a couple years ago...try Blaster all purpose CBD citrus based degreaser. I bought a half dozen cans after using it to clean off 3M f eathering compound. It melts the stuff off. I have not used WD 40 but if Matthew Gregory says it works I would try that first. Matt is a no nonsense straight shooter and a favorite source of mine for info...and a really nice guy. If you want to buy some the can reads www.blasterCorp.com . Larry
Click to expand...

Have you tried the 3M adhesive remover? I've seen it recommended a couple of times, but it's nearly twice the price of the PB. Just curious if it's worth the extra cost or not.
 
You must log in or register to reply here.
Back
Top