Thursday, June 10, 2010

Buffing and Grinding Wheels

Tod Herrli has a speedy way to hone his complex-profile moulding plane blades—with buffing wheels.

Ever the resourceful fellow, Tod makes his own using cardboard from cereal boxes and tablets.*

By gluing discs of cardboard together, he creates various thicknesses of buffing wheels according to his needs.

He bores a hole in the glued-up wheel, mounts it on his grinder, and shapes a rounded profile with a shop-made tool that looks a lot like the rounded profile on a woodturning scraper (photo 1).

I took a class taught by Tod a few days ago on making side escapement planes (blog post to follow) where we used his wheels to do the final sharpening on our blades.

Buffing wheels need to spin in the opposite direction (away from you**) than grinding wheels, so Tod built a sharpening station that captures the catapulted rouge when it's applied to the spinning cardboard wheels (photo 2).

He also showed us another trick (photos 3-6). The center holes on grinding wheels need to fit the arbor on your grinder. So if you have a wheel with too large a hole, here's how Tod remedies the situation.

He glues a dowel, which matches the diameter of his arbor, into a hole in a board; draws a 6" diameter circle around the dowel to help him center the grinding wheel; wraps a piece of paper around the dowel; and fills the cavity with hot glue. The paper keeps the glue from sticking to the dowel. Once dry, the grinding wheel fits perfectly on his grinder.

He then uses a dressing tool to round the profile on the wheel so it can be used for grinding moulding plane profiles on newly-made blades.

*MDF will also work. **Buffing wheels must spin away from you, otherwise, the tool might catch in the wheel, resulting in injury.


Adrian Baird Ba Than said...

Hey Kari,
I don't see the upside to honing on a wheel that spins away from you,I do all my power sharpening on my standard grinder & having the wheel spin toward me it's much easier to see what it is doing in terms of contact with the edge.This is especially true if most of the shape I'm honing is filed as opposed to hollow ground,I don't want to be spending a lot of time honing far back from the edge.
It may be better Todds method,am I missing something?

Adrian Baird Ba Than said...

I like his idea for using cardboard though,I use thick leather 2-3mm thick glued up to the thickness I need but I think I'll give the cardboard a bash the next time I need to build a wheel...

Charles "Sunshine" Davis said...

Wonderful ingenuity here... seems much more efficient that using slipstones... a setup and technique to learn one day for me!

Did you guys rough the iron shape with files?


Kari Hultman said...

Black, you can tell when the cutting edge contacts the cardboard because the green rouge starts to collect on the back of the blade. It's an extremely fast way to hone. Tod freehands it, but you can use a tool rest if you rock too much (like me). I like your leather idea for buffing. I thought I'd give MDF a try, too.

Sunshine, it's definitely faster—way faster—than using stones. It takes a light, steady touch, though. I usually round over the edge by mistake. We rough-shaped the blades on grinding wheels—flat ones and ones that had rounded profiles and different thicknesses. It's because of taking one of Tod's sharpening classes that I own three grinders!

Woodbloke said...

Hi Kari - cunning and devious...but I like it! That's just given me an idea for honing scribing gouges, which are a pain in the aris at the best of times. I've just resurrected my old mains power drill and I know that I've got a redundant grinding wheel for it somewhere, so I guess that if I dig that out as well and replace it with one made from Mr Kellog's finest cardboard... - Rob

Damien said...

Next time
Thank you for showing this. I was complaining that adding a felt wheel nearly doubled the price of my cheap grinder. Next time I will use cardboard or mdf

Anonymous said...

You can buy commercially made cardboard wheels for this purpose but they are easy to make. I have used MDF also, MDF is softer in the middle than on the outside faces. On softer wheels like cardboard, felt and leather you must always polish away from the cutting edge or you are in for one nasty catch that will wreck your wheel and throw your tool from your hands. In other words it is dangerous.

Adrian Baird Ba Than said...

I think I should clarify that although I hone with the wheel running toward me I am still honing away from me as I am using the underside of the wheel.This method allows you to see exactly where you are honing without having to flip the tool over,you simply withdraw a little & make an adjustment if necessary.I have been doing this for over 10 years & have yet to have a tool catch.Mike is correct though,attempting to hone into a soft material is asking for trouble,damaged tools & injured persons at best.

Kari Hultman said...

Rob, he's a clever fellow. Good luck with your new Kellog wheel!

Damien, it's definitely less expensive to make your own. You can even buy MDF-type wheels, but it's cheaper and easy to make them. Plus, you can make them to whatever thickness you need.

Mike, thanks for pointing out why you shouldn't have a buffing wheel spin toward you. I added a notation in the post.

Black, I hadn't thought about using the underside of the wheel. Thanks for clarifying.

garage equipment said...

In addition to being used to finish new metal pieces, a buffing wheel can also be utilized to rehabilitate older metal pieces. Metal that has been allowed to tarnish or stain can be buffed to gently remove the discolorations and restore the finish.

Jeanette West said...

Using a cardboard to make buffing wheels is absolutely very resourceful. I haven’t tried making buffing wheels using this, but I think this could be a great alternative tool. I bought the buffing and grinding wheels I have at home, and it’s almost five years now and it’s still doing a great job.

ermel said...

Ok, but I have the opposite problem. The arbor hole is too small.
How do I enlarge it, without damaging the buffing wheel? I was thinking to drill it out with a 1/2" drill bit. Any suggestions?

Kari Hultman said...

If the center of your buffing wheel is cardboard, I would try drilling it very carefully with a drill press. Secure the wheel so it's perfectly centered. If the hole you drill is off a bit, the wheel won't spin smoothly.

Conversely, you could try drilling a too-large hole and then back fill it with Tod's method.