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In reconditioning some plane blades I've literally spent tens of hours on stones flattening the backs, and so far I've only done 3 properly for my 4" x 36" belt sander I have some belts up to 400 grit, I'm a blacksmith and have ground heat treated knives I've made on it, my only concern would be the accuracy, I usually hold blades with a magnet using light pressure and frequent quenches so I don't over heat them.

Anyone else do this? Should I just use 120-220 grit on a glass first or use a small back bevel?

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Formerly JJH

I learn more from my mistakes than my successes

Yes, you can use a stationary belt sander for flattening plane irons, I do it all the time. Just make sure you don't overheat it, and pay attention! I hold the irons diagonally over the belt, so my fingers also monitor the heat.

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Rian Gitar og Mandolin

Figure your "Standard" plane iron is something like 1095 plain carbon steel.... As a blacksmith, you know the heat treat behavior of various alloys... so handle this accordingly.

I have ruined edges on grinders before. It is just too easy for me to go from "Dusting the edge" to "Blue."

If you have experience with this sort of thing, then have at it.

Now... if it was one of those fancy HSS irons -- Throw it on the grinder without fear.

Good luck

John

Cheers I know what I'll be doing in future just as a useless piece if info that some will know HSS can only hold an edge to 2 microns because of the alloying elements in it, carbon steel can take 1/2 micron edge so can be 4 times sharper the only trouble is getting it that sharp

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Formerly JJH

I learn more from my mistakes than my successes

I would agree with you on some of the new "Modern" high-carbide HSS blends like the CPMs and such... I tried out a CPM15 tip silver soldered on a low carbon blank. Didn't work out so good... It would get crazy sharp, but wouldn't hold any sort of an edge.

My M2 HSS Irons cut great, though... and run about 3x longer than plain Carbon steel. I tried out some M2, both an Academy tool M2 iron and a home-made M2 iron -- Great results, but only with the Expensive American tool bits... The cheap Chinese stuff was trash and would crumble when cutting.

The only problem with HSS is it is a ROYAL PITA to sharpen.. I can't really get it to really sharpen well it without Diamond.

Take a look here for specific info into all sorts of different blades including HSS.

http://www3.telus.net/BrentBeach/Sharpen/bladetest.html

Thanks

John

-In Western blades, I think the Hock hcs irons strike an excellent balance between edge-taking, holding,
and ease of sharpening. This conclusion comes from using a few of his blades for 10+ years. I mainly use
Japanese tools, but the Hock high carbon steel are very good. I think that ease or difficulty of sharpening
are very imp't in the long run, and speaking generally, the high alloy steels need more time and care in sharpening
and the edge typically breaks up such that renewing it is a chore. Again, this is a generalization. YMMV.

PS: I agree that Brent Beach has done some fine work in this area; however, Steve Elliot has covered the same
ground with imho a less dogmatic, doctrinaire approach, more in the spirit of true research, rather than proselytizing.
Both worth looking at, I think.

btw- if you need to quench anything other than HSS when grinding or sharpening, it's *already* been too hot.

I hope this is the link you referred some good reading here http://bladetest.infillplane.com/

btw Carey water boils at 100c and light straw which I think would still chip out for this application is around 230c plus my fingers although they have callouses from guitar playing and blacksmithing still smart before boiling.

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Formerly JJH

I learn more from my mistakes than my successes

As a machinist , there is flat , and then there is FLAT. What depends most is how flat the platen is on the sander . I think in most cases it us what you want to call flat. Grit , speed and material are the factors of what you can expect. As truckjohn points out you can ruin the blade very fast. The object is to get the heat in the chip not the work.
Todd Stock has a great sharpening demo in youtube, From that I went and got invested in proper sharpening stones and a tormek . Worth every penny. I can sharpen any steel but for carbide. High Carbon , High Speed Tool Steel , will sharpen easy and accurately. I have the guide to roll on the stones. I have a collection of water , carborundum ( oil ) and diamond stones. In all I have about a $50 investment in the 8 stones. They are not that expensive and will last a long time.
If you can't shave it ain't sharp. The night I got this stuff I sat down with about 10 chisels that were chisels only by name and 4 plane irons. Within 2 hours I have reset all the angle bevels , sharpen , honed and stropped my way into the world of sharp tools. It does make a difference. A sharp plane cuts and it is a joy of a tool to use. The chisels remove wood as effortless as if they were powered , The secondary angle allows you to enter and leave the wood without tearing . Cuts are controlled and clean as a whistle. I tested the edges by shaving hair off my legs. I looked like a model . LOL
Thanks again Todd for the tutorials . They worked well for me and it is a nice diversion to spend a few minutes sharpening a tool.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

John I must admit the accuracy and flattness was really my concern about this luckily mine is an old cast iron jobbie which seems pretty flat, I'm also helping a friend setup a surface grinder, but that may be months in the offing with some of the problems of a £60 surface grinder, and the planes I've bought have all been second had stored in damp workshops and thers pitting on the back of the blades which is why I'm getting bored with it, I must admit I've used others diamond stones and loved then (http://www.dmtsharp.com/products/diasharp.htm) but they are out of my price bracket, I've also glues wet and dry to glass fantastic too, I like oil stones, but can't get on with waterstones.

Sharpness is all relative so is the sharing test, I've always laid the blade near flat and moved it side to side, but a luthier friend holds the blade at 90 degress to the arm and moves it back and forth to shave and I must admit it takes sharper blade to shave doing it his method.

Also how many people strop their blades?

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Formerly JJH

I learn more from my mistakes than my successes

John, where can you get 8 sharpening stones for a total investment of $50?

I need some,
Joe

The Padma once chided me about worrying too much about sharpening and such... He was right -- you gotta decide whether you want to cut wood or obsess about sharpening.... If you decide you want to spend time cutting wood -- your sharpening regimen has to be optimized to get you back into business Cutting.

Sharpening can be a "Religion"... but it doesn't need to be. .... From my experiments Sharp is sharp is sharp...
If you can't feel it dragging as the hair comes off your arm... it is probably sharp enough for our work. An angle that is close enough will cut really well and last a good long time.

Many folks "Flatten" their irons and it works for them. I don't. I use the "David Chatsworth Ruler Trick." My own rationale is that Planes aren't chisels -- I probably won't use a raw plane iron for "Paring" to clean up a joint like a Chisel. As such, a little back bevel may actually help edge ruggedness.

I also strop. At first, I refused to strop. I read the hype about trying to maintain some "Optimum" blade angles and such... but found since my crude jigging took so long, I would run the blade too dull between sharpening.... Then, when it was dull... It was DULL and needed to be reground from scratch... and I would spend an entire night getting my blades all sharp again.

Since I have gone to stropping, I strop when the blade just barely starts getting dull, put it back in and off I go again. I find I get about 30x more work done this way...

I use Flexcut Gold and Veritas Green on a shoe-leather "Strop" (scrap left over from the local cobbler's)

Good luck with your adventure.

John

Both of those guys have done some really good work. I agree about the danger of the Slippery Slope of falling for the "Sharpening Religion".

I found Brent's cutting tests really interesting.... that basically so long as they are properly heat treated... All plain CS irons seem to run about the same... All A2 irons run about the same... Most of the M2 irons run about the same... etc. This mirrors my own use... My old Laminated Stanley irons honestly don't have anything on the New Stanley irons... which cut about as well as my Hock CS irons.

Personally, I found that a Hock Chip Breaker + the Plane's original iron made a far bigger difference in cutting than a Hock iron + standard Chip breaker... and the Hock Chip Breaker also runs ~10.00 cheaper than the Iron per plane!

Thanks

John

http://grizzly.com/products/searchresults.aspx?q=stone
check these out. I found them to be adequate for what I do. For oil stones I use mineral oil . I soaked mine overnight so they saturate. Never use any stone without the coolant . I use water on diamonds . I also love the Japanese water stones for the finer grits and finish honing.
Oil stones for trueing and hoggin off. Diamond for prep and water on finish.
A side note is that the diamond stone makes a fret fret flatener .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I always taught my apprentices to sharpen tools right away. In Williamsburg,I was also asked to go to other shops and teach them,too.

Do be sure that the platen on your belt sander is not worn. A belt sander is for wood.A belt grinder runs faster,burns wood,and is for grinding metal. I use a Wilton Square Wheel grinder. The cast iron platen gets a groove pretty quickly,and is expensive to replace. Therefore,I make dead hard plates of A2 or D2 steel than screw over the cast iron platen. They can be turned over,and replaced when worn.

On a woodworking belt sander,the platen is frequently sheet metal,save for the more expensive ones,which are cast iron. Sheet steel wears much faster than cast iron which contains graphite. You may have graphite cloth over your platen,but it can still get grooved,and might need replaced. I wouldn't try flattening plane soles on a belt sander.

We flattened hundreds of plane irons made by the blacksmith shop in Williamsburg with the Square Wheel Grinder.They were hand forged,with the steel bit welded in.