Belt Sanding Chisel or Plane Iron Back?

[Stew Denton]

A while back I think there was a post that mentioned use of a belt sander to sand out the corrosion on the back of a chisel blade or plane iron.

Am I remembering correctly? If so, what is the technique and how do you prevent getting the steel too hot? Finally, what grit belts, etc., do you use?

Is belt sanding the corrosion on the back of the chisel or plane iron a bad idea? It takes me a long time by hand.
Is there a better way?

Thanks and regards,

Stew

[Mel Miller]

I think you're going to spend as much on sanding belts as you would if you just bought a rust free chisel in the first place. Good chisel steel is hard and wears sanding belts rapidly.

[Jude Kenny]

http://www.sawmillcreek.org/showthread.php?117093-Belt-Sander-for-Chisel-Plane-Iron-Sharpening

Here's the link to a sawmillcreek post.

I've used a belt sander to fix up chisels that have been abused or if I were on a job site. Also, this was before I learned about diamond plates etc.

[Kees Heiden]

I've never been very lucky with the belt sander for the backs. they lead to dubbing of the edges in a hurry. And they also heat the steel pretty quickly. But we don't have these metalworking belts overhere easilly available, so I use a woodworking belt, which isn't too suitable of course.

On a few occasions I have use the beltsander to create a hollow in the back, a little bit like a Japanese blade, but not as nicely. That helps to reduce the workload on the stones.

[bridger berdel]

I've never been able to get backs flat with a belt sander either. What I've been doing lately for badly pitted or out of flat backs is alternating a few strokes on a very coarse diamond plate with a few hits at the high spots shown by the plate using a 2" disc on an angle die grinder.

[steven c newman]

I guess I have been the lucky one, then?

Yep, just used the sander the other day on two chisels that needed a bit of work:
Sander is a B&D Dragster 3x21
Belt on board at the moment is a WORN 80 grit. Have usually used 100-150 as well.
I use a honing guide to hold the item at the needed angle.
I will take the item, hold it at the side of the sander, to do the flattening of backs.
Fingertips are also heat-sensors. Too hot for a fingertip? Dunk it in the handy-dandy cup of water.

I use the sander to get a new bevel. Run until a wire edge comes up at the edge. Then the sander is turned off, and off to the regular sand paper on tile. I only go up to 2.5K, though. Still getting a mirror polish, though. Used it last week to bring a ParPlus 2" iron back from the dead. 295954

The sander is just to start an edge. Rarely use a grinder, unless the edge is way out of whack. The beltsander does a decent job of getting a flat bevel, so the honing doesn't take as long.

[Pat Barry]

I think trying to get the back 'completely' flat is not even a good idea. If it is 90% flat and all that you have is some pitting due to rust it will not matter in performance. Just get the cutting edge right. That's the only way a pit or two will cause a problem.

[Robert Hazelwood]

I've used a belt sander on some pretty bad chisels and irons. It takes a light touch, and care not to dub the corners (one 'oops' can cause a lot of extra work). Also I keep a jar of water nearby the sander and dip the blade in frequently- I sand in short increments of maybe 5-10 seconds, dip them in water then sand a bit more.

The consumer-grade belt sander I use is not going to make a perfectly flat back, and will require some touch up with manual sanding- I use a granite block with 80 grit sandpaper glued down to start with. But the belt sander will get major pits/problems out much faster than by hand. I wouldn't bother with some of these vintage chisels if I had to flatten them completely by hand.

[Jim Koepke]

I have not tried a belt sander on blades.

There are two alternatives in my shop. One is a 4 foot long hunk of granite on a tall horse with PSA backed 80 grit.

Here is the granite on the horse when it was first set up:

295988

Gee, my shop was much less messy back then.

The other is the Veritas® Mk.ll Power Sharpening System:

http://www.leevalley.com/US/Wood/page.aspx?p=48435&cat=1,43072

Both are great assets for working blade backs and bevels.

jtk

[Steve Friedman]

Like many, I just use sandpaper on granite. It's a lot of work if you're trying to flatten the back for aesthetics. Not so much of you're only doing 1/2 inch for utility.

I have my 1 x 42 belt sander and always end up making it worse than it was when I started. I then called Viel (the Canadian company that makes the 1 x 42 belt sander that LV sells. They have an attachment (S025) that's a carriage for sharpening Logosol-type knives. No idea what those are, but the attachment uses magnets to hold the blade perfectly vertical to the belt. You also need the hand wheel attachment for it to work. It turns out that Logosol-type knives are thicker or thinner (don't remember which) that chisel/plane blades, so they modified the jig to adjust the depth. It does work, but I virtually never use it. I still prefer sandpaper on granite because I'm only flattening a small part of the back and it just doesn't take that long with 80 (or 60) grit paper.

If anyone is interested in trying out the attachment(s), PM me and I'm happy to lend it out. You just have to pay return shipping.

Steve

[David Weaver]

You need a belt grinder with good tension and a hard platen. I've recovered otherwise kaput vintage irons for about 80 cents (the cost of an 80 grit belt in 1x42.)

I wouldn't use a cheap belt sander.

[Steve Friedman]

One is a 4 foot long hunk of granite on a tall horse with PSA backed 80 grit.
Jim, you may have posted this before, but where did you find that piece of granite? How much does it weigh? How did you get it home? I have a piece that's 12 x 18 x 3 and it weighs 80 pounds. I would love to get a larger slab like yours, but can't imagine where to get one and, even if I find one, how to get it home and move it into position.

Steve

[Jim Koepke]

Jim, you may have posted this before, but where did you find that piece of granite? How much does it weigh? How did you get it home? I have a piece that's 12 x 18 x 3 and it weighs 80 pounds. I would love to get a larger slab like yours, but can't imagine where to get one and, even if I find one, how to get it home and move it into position.

Steve

The piece was found at the local monument maker, (tombstone cutter). The guy let me have it for $25 and helped me to get it in the car. Someone estimated by the approximate volume that it is about 150 Lbs. If you go this route you may want to bring a straight edge with you to select the best piece.

Here is how it got home:

295990

That is in the back of a Chevy Tahoe.

I learned a lot from my father about handling heavy loads. My folks had a furniture and appliance store and I was often used as a delivery person.

It was carefully slid out of the back of the car onto a hand truck. it was then positioned to lean on one end of the horse. The free end was carefully lifted and slid on to the horse. The abrasive hasn't been changed in awhile. It was used recently to clean the back of a chisel and the sole of a K3 plane from last weekend's rust hunt.

jtk

[bridger berdel]

You need a belt grinder with good tension and a hard platen. I've recovered otherwise kaput vintage irons for about 80 cents (the cost of an 80 grit belt in 1x42.)

I wouldn't use a cheap belt sander.

I have one like that. I still havent had much luck with it on backs.

[steven c newman]

The Dragster has a solid platten that does not move. It is a 3" wide belt. I use the belt sander mainly as just the first step. I place the iron/chisel in the guide. I can set the guide right up to the side of the sander and flatten the backs. I set it at the center of the platten when doing backs. Fingertips to check for heat. Usually just a single finger to press down onto the item getting it's back flatten.

Have another beltsander in the shop. A 1" x 30". Not too great for this type of work. It WILL round over about anything i press against it. Can never get the table to 90 degrees to the belt and platten. Rarely use it for metal objects...

Like i said, the beltsander is usually step #1 in the process I use. Just a step, is all, not the whole process.

[Steve Friedman]

The piece was found at the local monument maker, (tombstone cutter). The guy let me have it for $25 and helped me to get it in the car. Someone estimated by the approximate volume that it is about 150 Lbs. If you go this route you may want to bring a straight edge with you to select the best piece.

Here is how it got home:

295990

That is in the back of a Chevy Tahoe.

I learned a lot from my father about handling heavy loads. My folks had a furniture and appliance store and I was often used as a delivery person.

It was carefully slid out of the back of the car onto a hand truck. it was then positioned to lean on one end of the horse. The free end was carefully lifted and slid on to the horse. The abrasive hasn't been changed in awhile. It was used recently to clean the back of a chisel and the sole of a K3 plane from last weekend's rust hunt.

jtk
Thanks Jim,

It may be weird, but I may need to go visit some local monument places. Not sure what they're called, but I have seen pieces in cemeteries that are shaped like that bordering the grave sites. Thanks.

Steve

[ian maybury]

As Jim I've had good luck getting granite offcuts from local monumental masonry place too. That long piece looks like a great idea. Even larger sized surface plates from China these days have got very cheap too.

Recent experiments here suggest that what works best depends quite a bit on the size and type of chisel or plane blade, and on how much metal needs to be removed to flatten it - and that what works well on smaller hollow back blades is too slow for wide flat ones.

I've had great luck on Japanese chisels flattening backs on the top of the disc on a WorkSharp with the stock 80 or 120 grit discs or diamond lapidary discs (like a slightly smaller version of the Veritas Mk 2 power sharpening system) - then on to 400 grit before the waterstones. Narrower Western chisels that don't need a lot of metal off the backs work OK on it too. It's probably 2 or 3 times faster than a 120 grit waterstone.

Larger areas/wide blades, tougher steels, more depth to remove and non-hollowed backs can need something a quite a bit more aggressive/slower to burn up self adhesive abrasive paper. Then there's lot more risk of overheating, dubbing and doing other damage in a moment. It's all in the judgement and the touch.

Inspired by Derek's rig I cut a new bevel on an A2 plane iron at low speed on a stock Bosch belt sander on 120 grit AlOx last night, and got close enough in a few minutes that i could quickly finish it on the WorksSharp and then on a coarse waterstone - but realistically it was living dangerously and needs a flatter and harder platen than stock to be properly controllable. Seemed to remove metal 2-3 times faster than the WorkSharp depending on the grit. It would be no use for flattening backs as stock - they just wouldn't come out flat enough. It stayed surprisingly cool though. Lots of potential to end up with bleeding/sore fingertips..

I've had good luck with a UK market Record disc sander with 80 or 120 grit self adhesive AlOx paper on the disc to flatten the back on some wider (1 1/2in etc) cheap Western chisels and gouges that needed a lot of metal removed too. Similar rate of metal removal to the belt sander, it also stays cool if cut in short bursts (aluminium disc), and is dead flat and a solid surface. Also risky for the fingers without jigs. Im in the process of building a rest to accept a honing guide (a la the top of the disc on the WorkSharp) and/or other grinding aids (I have quite a few of the Tormek jigs) to take some of the risk of messing up blades through poor control. Probably shorter abrasive life due to the reduced area, and definitely slow self adhesive grit/paper changes compared to a belt are factors - but it has potential if as in my case you already have one.

Chances are that a highly variable speed belt with a flat and hard platen, and quick change belts may be close to a (cheaper) universal solution. Or maybe one of those larger water cooled horizontally mounted waterstone disc machines with lots of spare stones in different grits in a high very budget scenario?

ian

[David Weaver]

With a belt grinder, belt use isn't so much of an issue. Most of the stuff we grind is well ground with cheap aluminum oxide belts. I ran off a third of the thickness of a 2 1/2 inch plane iron with a 1x42 80 grit generic belt. The real issue when you're grinding like that is to have the discretion to grind a little and keep the iron cool, because you have the urge to really remove a lot.

This is something that you do only when a blade is too far gone for anything else (including loose diamonds on a lap). I rarely do it, there is still a fair bit of hand work left after you do it - another 10/15 minutes worth to get things dead flat. It is something to do for irons that are complete lost causes, well beyond the condition you'll ever find any new tool.

Pat - in regard to the flatness comment, the part where it really counts is right at the edge of an iron. if you can't get your stone on the back of an iron to move a wire edge, you have to either finish with superfine abrasives or strop like crazy. It's a lot nicer to thin the edge with a fine stone than it is to remove a very thick wire edge by stropping.

[Pat Barry]

Pat - in regard to the flatness comment, the part where it really counts is right at the edge of an iron. if you can't get your stone on the back of an iron to move a wire edge, you have to either finish with superfine abrasives or strop like crazy. It's a lot nicer to thin the edge with a fine stone than it is to remove a very thick wire edge by stropping.

Thats the same message I was going for when I said
Just get the cutting edge right. That's the only way a pit or two will cause a problem.

[Winton Applegate]

post that mentioned use of a belt sander

We were talking about belt sanders but this "belt" is stationary and the blade is moved over it by hand force.

You may be thinking of Derek's fine blog entry (http://www.inthewoodshop.com/WoodworkTechniques/Lapping%20the%20Backs%20of%20Blades.html).

[Casey Gooding]

I have used a belt sander on irons and chisels in bad shape. Generally OK results as long as you know you will have to do more work by hand. A ceramic belt helps as it won't wear out as quickly as many others.

[ian maybury]

For sure stock (faster running) belt sanders and discs (even if they have flat platens etc) tend to come in right on the upper end of metal removal rate and risk of heating/dubbing/limited precision and flatness/sanded fingers - and hence require lots of caution. So perhaps best reserved for use with care on jobs requiring large volumes of metal removed over large areas.

I'd be reluctant to try doing very much on e.g. a narrow (say 3/4 in and smaller) chisel on a belt unless there was the option to reduce the speed right down, and if required change to a finer grit belt. (below maybe 800 ft/min) - which seems to be the way the purpose made belt sharpening systems like the Sorby are set up http://www.robert-sorby.co.uk/proedge.htm This is roughly the surface speed of the Work Sharp too.

That same set up would seem quite slow on the back of e.g. a 1 1/2 in western chisel or a badly out of flat plane blade though unless it was reasonably close to flat as received. (but would likely be a big mistake with/would probably actually worsen e.g. an already lapped/very flat as delivered Veritas/Lee Valley blade that only needs a few minutes on a flattened 1,000 grit waterstone to get it ready to polish)

Speed may not be so important on a one off job, i'm probably a little sensitised having just finished setting up a whole set of Japanese chisels and a bunch of older Western ones. Some of the wider Western ones were badly bellied.

Chisels come with a handle that gives good control, but i'd be cautious about trying to flatten the back of even a rough old plane blade on a belt sander unless it was set up with a flat platen, and especially not without some sort of handle to help with handling it. Lots of risk of doing more harm than good, and there's other options. Jim's long abrasive strip on granite/Derek's abrasive strip on glass http://www.inthewoodshop.com/WoodworkTechniques/Lapping%20the%20Backs%20of%20Blades.html, or presuming no ideological opposition :) there's the ruler trick to polish just the area adjacent to the edge on waterstones. (see the latter part of the other thread on suction)

[Brett Robson]

This guy has the belt sander sharpening technique down -- can't see anything wrong here!

https://www.youtube.com/watch?v=aKzZ6-dQ2C0

[David Weaver]

Do you think that video is a work (intended to be dumb?) or do you think that guy was serious. It's been posted places several times....if you've ever sharpened something trailing or against a hard wheel like the roller on a belt sander, it can turn things cherry red. (maybe I should say ground instead of sharpened).

[Steve Friedman]

Do you think that video is a work (intended to be dumb?) or do you think that guy was serious. It's been posted places several times....if you've ever sharpened something trailing or against a hard wheel like the roller on a belt sander, it can turn things cherry red. (maybe I should say ground instead of sharpened).
I thought it was a joke as well and expected him to hold up a blued chisel at the end. I have blued lots of steel with a lot less heat than that. The chisel is obviously getting very hot. At the 1:14 mark, you can see him flinch when his fingers are near the edge of the chisel. For the next 25 seconds or so, his fingers keep moving farther from the edge of the chisel until he leaves at 1:40 to put on gloves. Looks like a plain Marples chisel, but maybe it's made from some kind of magic steel. I don't have any magic steel chisels, so I won't be trying that anytime soon.

Steve

[Tom M King]

I use various grades of this Wet-or-Dry on a granite surface plate for flattening. It lasts many times longer than the hardware store variety, and even at the price per sheet, it's probably still cheaper than buying the cheap stuff in the long run. I don't know that it cuts any faster, but it definitely lasts longer. Most of the time, one grit gets rinsed off, and allowed to dry hanging on a line until the next time it's needed.
http://www.multitechproducts.com/100-grit-carborundum-silicon-carbide-diamond-grit-wet-or-dry-sandpaper/ Or 3M Imperial AO for the finer grits.

Final polish is done on stones, and finished on Diamond Lapping Film.

I've never bothered to flatten the whole back of a chisel or iron. It doesn't take very long if you don't do but the last inch or two

[ian maybury]

I'd be very cautious of the belt speed and amounts of time he grinds for without cooling in water too. Especially at the bevel. Once the main body of the blade gets hot enough to be hard to handle it's very easy to overheat an edge - having burnt lots of other tools over the years I prefer to keep the body cool/cold so there's always a heat sink available to cool the edge area.

That said belts don't heat that badly, and he may be used enough to doing it to get away with it. Or he may just have polished off the blued/burned bit at what is a pretty thin bevel - hard to see. Either way he's on a relatively fine (120 grit he said) belt that's quite worn, over a flat platen, and it's quite a wide chisel. It'd be a much more difficult/probably impractical job on fresh 80 grit with a narrow chisel. i.e. it's a lot to do with the specifics.

It demonstrates nicely the point that when a large area is in contact/there's a lot of metal to be removed from the back of a blade that even quite an aggressive belt (or disc) is with enough skill fairly controllable. Provided the back of the blade is got down into contact with it neatly - without knocking a corner off or something (a wrong touch could destroy a tool), and provided the back is bellied so that it's possible to sneak up to and instantly stop at the cutting edge before overheats. It'd be much more controllable and a lot less risky if the belt was running much more slowly. It's not the way I'd want to try to flatten the back of my (mythical) $400 Japanese chisel....

[steven c newman]

Just finished up working on a Ohio Tool Co. tapered iron for a coffin smoother. Set the guide to 30 degrees and gave the iron a ride on a worn down 80 grit belt sander. Cup of water was nearby. Ground the bevel until a wire edge had started. Then went to a 220 grit on a tile, still with the guide in place. Then three wet7 dry papers of 1500,2K, and 2.5K. Back and bevel both.

Reset it up in the smoother, had it a bit rank, but it did gave a nice full width shaving296063

This was the $5 one i found. It was missing a bolt for the iron. Got a tap and made a new bolt as well
296068
Tap was a 10-1.5 Metric Plug type. Bolt was a 6mm allen wrench to tighten. Came from a shelving system they use at work. Had to shorten the bolt a bit, to clear the wedge296069

Edge of the iron seems to be sharp enough, and the back shines like a mirror. Not even a mark in the shaving
296070
Yep. I think it just might work, IF I can adjust it a little bit better.

[Chris Fournier]

Things get hot really quickly on belt sanders, you could easily draw the temper out of your tool steel so caution is required. Personally I don't think that this would yield accurate results in your average shop.

[Pat Barry]

Edge of the iron seems to be sharp enough, and the back shines like a mirror. Not even a mark in the shaving
296070
Yep. I think it just might work, IF I can adjust it a little bit better.
Holy cow Steven. Very nice work finishing off that table top. I don't think you need to do much more with that iron. Great job!

[Pat Barry]

By the way Steven, what did you use for a finish on that table top?

[steven c newman]

That table top was a Yard sale find, I had to make a base for it. Tapered Black Walnut legs and pine aprons, took an afternoon. The little coffin smoother was just tried out on a piece of Pine scrap, the width of that shaving. had the iron set a hair deep. Been also refurbbing a few chisels and other plane irons since the Tool Chest #2 build. Recycled lumber tends to have a piece of hidden metal, now and then. May try the coffin out later, to see how thin a shaving will curl out of it.

[steven c newman]

A while back I think there was a post that mentioned use of a belt sander to sand out the corrosion on the back of a chisel blade or plane iron.

Am I remembering correctly? If so, what is the technique and how do you prevent getting the steel too hot? Finally, what grit belts, etc., do you use?

Is belt sanding the corrosion on the back of the chisel or plane iron a bad idea? It takes me a long time by hand.
Is there a better way?

Thanks and regards,

Stew


One: I keep a cup of water sitting nearby.
Two: I use a worn down 80-120 grit belt. Do NOT use a brand new one for this.
Three: Fingertips are very good as heat detectors. When they say the metal is getting hot, take the metal to the cup of water.
Four: I use a honing jig. This will keep the bevel at the angle I want. I run the metal until the wire edge appears. Meaning I am at the edge. And I am done.
Five: I do the backs with the guide in place. I go to the side of the sander, lay the entire back flat on the spinning belt. The guide acts as a stop. I try to keep the metal flatall the way around. I also count the time. Maybe 5 seconds, lift straight up( no rocking about) dunk, check the back, and go again until done.
Rarely use a grinder for this, only on the worst ones. I do have a grinder jig set up on one wheel. I can put a new straight edge or cambered edge on even the worst of the rusty ones. Then to the honing guide and the beltsander. Then to the sandpaper on a flat floor tile. 150 grit 220 grit, 1500, 2000 and a final finish at 2500 grit. I leave enough room on the end of the tile so I can rub the back as well. I go side to side on the backs. More to polish them than to get them flat. Beltsander already had done that.

Beltsander is usually just the start in the process, if the edge needs it. To refresh an edge after a day or three of working, I just drag out the sandpaper and tile.

[ian maybury]

+1 that there's big variations in what delivers a reasonable metal removal rate depending on how much metal has to be removed and the area/width of the blade Stephen. To the point where it's advisable to have several solutions available with varying metal removal rates. As before i use the top disc on a Work Sharp for smaller stuff.

Found myself cutting new 25 deg primary bevels on a couple of 50 deg Veritas A2 plane blades a few days ago on a modified 12 in disc sander using 80 grit - also with a honing guide to get tight control of the bevel angle/flatness. (built up from what was to hand to have reasonable fast grinding option available) The sander is modified so that there's a flat table surrounding the disc for the guide to rest on - it also has a DIY stand that allows placing it on end so that the disc is horizontal for use in this mode. Probably very similar to using a belt sander except that changing the self adhesive abrasive is more awkward.

It shifts metal quite fast, but even at that it was a slow job. The limitation is heating - especially as the bevel starts to approach a sharp/thin edge. It's possible only to grind for a couple of seconds between coolings. It'd in comparison probably refresh a primary bevel to take a nick out much more quickly - there's far less volume of metal to remove...