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Shaun Mahood
05-16-2013, 10:48 AM
I've got an old wooden jointer plane with a blade that I have never been able to sharpen satisfactorily. I just bought a bench grinder and have given it another try. It seemed to take longer to grind than my other blades, and after that is taking much more time and effort to sharpen on my stones. I got it to the point that it was close enough to sharp to test, and had a ton of chipping on the blade when planing the long grain of a piece of cheap pine that I use to setup and test my planes after sharpening.

The same sharpening method I am using gets my Narex chisels nice and sharp with no chipping. I'm starting to think the blade is too hard - is there an easy way I can confirm this?

David Weaver
05-16-2013, 10:56 AM
It sounds useless, so you don't have anything to lose with it. Put it in your kitchen oven for 45 minutes at 300. If it's still chippy, put it in at 350,...

Keep going in 50 degree increments until you get something you can use. if it's old, it's probably simple carbon steel and unless it was starved of its carbon in heat treating, it should temper softer at a temperature your oven can handle. If it's very low carbon, maybe it can't, but if that's the case, you wouldn't want it, anyway.

Zach Dillinger
05-16-2013, 10:57 AM
I'd say you've done all the confirmation you need. Unless you are sharpening at a ridiculously low angle, the blade shouldn't do that.

Shaun Mahood
05-16-2013, 12:03 PM
Thanks for the help. I've never had a problem like this and just kept going back and resharpening it thinking I screwed something up.

george wilson
05-16-2013, 6:07 PM
I have actually had ADDIS vintage carving tools that were entirely too hard. I had to slowly heat them to a brown color in the musical instrument maker's shop. The only heating device was to lay them on top of the side bending setup. It consisted of an oval brass chimney about 4" tall,with a silver soldered on top. The chimney sat upon an open sided box,and we put alcohol lamps in the box to burn up into the brass chimney. It worked fine for drawing some temper from the carving tools. I also sometimes had to soften bundles of jeweler's saw blades which broke very easily. I did them the same way.


P.S.: These were a pristine set of PRE WAR(II) carving tools,too.

Mel Fulks
05-16-2013, 6:13 PM
Interesting post on the Addis tools, surprising .Not a carver ,but aware of their good reputation .

Steve Q Brown
05-16-2013, 6:45 PM
It sounds useless, so you don't have anything to lose with it. Put it in your kitchen oven for 45 minutes at 300. If it's still chippy, put it in at 350,...

Keep going in 50 degree increments until you get something you can use. if it's old, it's probably simple carbon steel and unless it was starved of its carbon in heat treating, it should temper softer at a temperature your oven can handle. If it's very low carbon, maybe it can't, but if that's the case, you wouldn't want it, anyway.
Good advice... I'

Steve Q Brown
05-16-2013, 6:56 PM
It sounds useless, so you don't have anything to lose with it. Put it in your kitchen oven for 45 minutes at 300. If it's still chippy, put it in at 350,...

Keep going in 50 degree increments until you get something you can use. if it's old, it's probably simple carbon steel and unless it was starved of its carbon in heat treating, it should temper softer at a temperature your oven can handle. If it's very low carbon, maybe it can't, but if that's the case, you wouldn't want it, anyway.

Good call...incremental tempering adjustment

@OP, my recommendation would have been for re-tempering to an appropriate hardness, though I like Davids step-by-check process a little better- especially for one (presumably) not accustomed to tempering steel....

If the (re)tempering doesn't work for you, $30 for a new, thicker, known quality iron would be a good investment, IMO.

Winton Applegate
05-17-2013, 1:31 AM
Ha Ha
Nah nah
Carbide tool bits for metal working and in the router bits etc., are harder than any plane blade that you will find (or make) and it is quite possible to sharpen them with home tools.
Are you using natural stones such as Arkansas etc ?
Try diamond plates.
Are you using one of the gray grinder stones that come with the inexpensive grinders ?
Try the white or pink power grinder stones (for the plane blade not for the carbides).
Chipping : Pine is weird stuff, there's that engineering term again. Some pine has really hard rings mixed in with really soft rings/fibers.
Use some walnut or straight grained hard maple to test the blades on.
I was thinking the same about the bevel angle being too shallow. When the angle is too shallow the "chipping" is just the edge folding over from hitting the hard growth rings.
PS: if you like soft easy to sharpen tools try the Sorbys from Woodcrap they are nice and soft. Not much use once a person gets them sharp though. A stern look makes them dull again let alone trying to cut a mortise with one.
PPS: I have made small plane blades out of old files I picked up at the local scrap yard. While keeping them wet to prevent tempering them I have ground the teeth off and ground a blunted bevel on one end then using my Shapton 120 white stone brought the edge up then using extra coarse and coarse diamond plates and the other Shaptons bada boom bada bing.
Alternatively one can anneal them, shape them and re-harden them, temper them, then do the final sharpening. Depends what mood you are in at the time.
I have made scraper tools that I use on brass brazed joints that still have some grit from sand blasting and the glass hard brazing flux inclussions still on the joint here and there. These scrapers I made from files, heated them red hot and shaped them then just quenched them and used them with no tempering (full hardness ) because I needed the extra hardness. These scrapers are so hard that they break in my hand while using them. But you know what ? I can still sharpen them using the above methods.
Just takes the right sharpening tools. One thing I discovered fairly recently : The Shapton white 120 stone cuts much better and faster than another white super coarse stone that was rated at 100 grit size. Quality is worth paying for.

Kees Heiden
05-17-2013, 2:58 AM
There are three modes of edge failure. When the blade is too soft, it just folds over. When the hardness is just right, the edge wears gradually to a blunt round edge. And when it is too hard and brittle, it chips. And of course there are gray areas in between, depending on the honing angle and the type of wood. We all want the edge to be as hard as possible, so it doesn't wear as quickly, whithout it being chippy. Some smiths manage to create harder and tougher angles then others, through skill and secret trade pratices and what not.

In practice, when you happen to find a blade which is really too hard, I would first try a higher honing angle. Up to 35 degrees is practical. If the blade doesn't tend to chip with the higher honing angle, but it remains to be too hard for your sharpening system, you have (again) three choices. Tempering the blade to a lower hardness. Investing in a diamond sharpening setup and learning to use it (might be a bit excessive). Or sell the blade. The fourth choice of using the blade only in benign wood is not practical.

george wilson
05-17-2013, 9:02 AM
Why would you use fully hard file steel scrapers?

David Weaver
05-17-2013, 9:06 AM
Blades that aren't as hard as carbide can literally chip when you're sharpening them. That is, carbon steel blades that are overhardened or that are defective. In razors, it's described as microchipping. In plane blades like the one being discussed, the chipping is probably larger. In a microchipped blade, the blade chips while you're sharpening and it will not get sharp like what you'd expect from a better blade. If you look at a microchipper, you can see a glint of light across the edge. When a fresh blade is truly sharp, you will see nothing on the edge no matter the angle you look at it. If you strop it hard on a bare strop, you can see just a bit of wear on the edge (though the edge will perform as though it's more sharp if the strop is clean and good quality, because little microscopic bits of scuzz have been worn off).

Anyway, being able to sharpen carbide without chipping doesn't equate to being able to sharpen a softer than carbide but overhardened carbon steel without chipping.

george wilson
05-17-2013, 9:09 AM
Plus,carbide blades are ground with an extremely blunt cutting angle on router bits. They cut by virtue of the very high speed of the router.

jamie shard
05-17-2013, 9:43 AM
If you look at a microchipper, you can see a glint of light across the edge.

Thanks for that tidbit. It seems like I've encountered this in the past, not fully knowing what was going on.

David Weaver
05-17-2013, 9:59 AM
Sometimes it happens on blades that aren't that hard, but not too often. If you go through enough vintage planes, you'll eventually find one like that - one that you can't ever seem to get sharp. A milder abrasive will sometimes not chip the edge while you're sharpening, but there's no reason to do that because the iron will probably just fail in use.

I've never seen it on a modern heat-treated blade, though.

Shaun Mahood
05-17-2013, 10:19 AM
I'm definitely going to try putting the blade in the oven this weekend. The chipping was not even remotely minor - the blade edge was chewed up like crazy on a soft piece of wood that I can take massively thick shavings from with little effort using one of my other wooden planes. It was sharpened at about 25 degrees so I will probably go up to about 30 for my next test.

As far as sharpening medium, I am using Spyderco ceramics after the grinder. I figure if George recommended them to me they aren't the issue.

The blade on this plane is 2 1/2" wide - does anyone know where to get good blades at that width? I've only been able to find 2 3/8" and 2 5/8" blades so far.

David Weaver
05-17-2013, 10:23 AM
2 1/2" blades aren't uncommon. Check ebay. The only modern repros that I know of are parallel irons for infill planes, and that's something you don't want.

You should be able to find a good vintage blade for 10 or 20 bucks.

Try the oven trick, but don't be surprised if the iron is junk no matter what. If you've gotten your iron out of the oven around 400 degrees or more and it's a nice very apparent straw temper and it's still chippy like that, it will be junk.

Zach Dillinger
05-17-2013, 10:26 AM
2 1/2" blades aren't uncommon. Check ebay. The only modern repros that I know of are parallel irons for infill planes, and that's something you don't want.

You should be able to find a good vintage blade for 10 or 20 bucks.

Try the oven trick, but don't be surprised if the iron is junk no matter what. If you've gotten your iron out of the oven around 400 degrees or more and it's a nice very apparent straw temper and it's still chippy like that, it will be junk.

Agree 100% with Mr. Weaver. No sense in scrapping the blade until you've given it the ol' oven treatment.

george wilson
05-17-2013, 10:43 AM
i agree with using the oven,but I also caution you that kitchen ovens CAN BE 75º off,so start low. It would be very good if you could put a reliable high temp. thermometer in the oven so the real temperature could be checked. I'd think a 400º soak would be o.k.. Start with 325º then. Let the blade cool off,try it for durability,then raise the oven 25º and try the blade again. If you go too high,and soften the blade too much,you will be in trouble. With the bevel on the iron,you will be risking almost certainly warping the blade if it has to be re hardened.

As I've said many times,I found the old style blades to be the best when I could BARELY get a NEW fine cut file to bite the blade a little bit. Make sure you aren't using one of these new Mexican Nicholson files if you try to file the blade.

Noah Wagener
05-17-2013, 9:08 PM
How should the blade be cooled? slowly reducing oven temp? I have Old cast steel blades that, while they get sharp (to me anyways), they don't shine like the Bailey irons do. I assume they are both just carbon steel?

David Weaver
05-17-2013, 9:10 PM
It doesn't matter, just take it out of the oven and let it cool off until you can touch it.

Steve Voigt
05-17-2013, 10:16 PM
The blade on this plane is 2 1/2" wide - does anyone know where to get good blades at that width? I've only been able to find 2 3/8" and 2 5/8" blades so far.
I assume we're talking about tapered double irons? I have an extra Moulson iron (see pic). It's a little funky--you can see the left left side curves in a little--almost looks like someone ground a little away. But the bottom inch and a quarter or so is about 2.475 wide. You can also see that it has a nut and screw, instead of a threaded hole in the chipbreaker (the nut would've been spot welded on, but must've broke free at some point). It works, but you have to have a slot in the wedge. Of course, if you already have a chipbreaker, you can probably use it.
Anyway,as you can see, it's no prom queen, but if you want it, PM me--I won't charge you, except for shipping cost.

george wilson
05-17-2013, 10:42 PM
Yes,just let it cool in the air. It is safer than quenching it in water,which is not necessary in tempering. Quenching in a medium like water,oil OR air,depending on the type of steel you are using,is only needed when hardening,not in tempering.

Winton Applegate
05-18-2013, 1:12 AM
Why the full hard file scrapers.

Well I thought I put that in the post. The brazing flux is as hard as glass and there was sand blasting sand in and about the structures.
The harder the scraper the better.
But
Here is how it came about :
I needed curved files for filing the brass fillets into jewelry like joints on larger (large compared to jewelry) steel structures. Fine art things if you will. I don't want to get all off on that and high jack this thread so I won't get too into all that.
Sooo I heated the files, bent them as I needed. Reheated to red and quenched in water. Then I thinks to me self; self , why not leave it alone and see what happens without tempering. Well the file broke in use. Obviously. THEN the revelation . . . I had already found my self pushing the files side ways scraper like when I needed to chip off a bit of flux that was left after sand blasting. Can't file them they are glass. Right ?

Well this broken edge on the end of the file was the cat's meow for scraping forward rather than side ways with the file. Sort of like pushing a chisel. Admittedly the "sharpening angle" was on the order of 70 or 80° but any way that was how I came to use them and why. With care I didn't break the files and the edges lasted.

Winton Applegate
05-18-2013, 1:57 AM
I been doing some reading and it seems to me the steel in his blade may have had a bit too much carbon added. (and yes it probably just needs to be tempered. I don't disagree with that of course) Could it be the carbon was not evenly dispersed when the batch was in the crucible ?


Also
maybe control of the medium was lost when the blade was made and the grain of the steel grew rather than keeping it fine grained.


Interesting about the micro chipping. One of my favorite books on hand tool blades is this one.
http://www.amazon.com/Step-step-Knife-Making-You/dp/0878571809/ref=tmm_hrd_title_0?ie=UTF8&qid=1368856047&sr=1-1


He has a lot of good info about hardening, tempering and various hand tool (knife) blade steel alloys.
No mention of micro chipping (I am not saying the problem doesn't exist).
He just says when the blade is too hard it breaks instead of bends when under extreme loading.


As far as razors the angles are so acute razor micro chipping may not apply to plane blades.
I will hastily say I DON'T KNOW.
Sounds like a problem I would like to experience. Most blades I come across are too soft.

It is nice to come to a forum where I am learning new stuff again.
Thanks

Noah Wagener
05-18-2013, 4:09 AM
thanks George and David. i do not think the blades are too hard after all. I broke down and got some nicer stones and they polish up on them. I am glad to know that tempering does not require quenching for future reference.

Winton. i am interested in scraping like machinists do rather than lapping planes on sandpaper stuck to glass. They use carbide scrapers that cost like ninety. I use old files with very little bevel which work well on aluminum and iron but not on steel. I'd like to try full hardening like you did but am not sure how. i assume kitchen ovens don't get hot enough? I don't have any kind of torch. would a wood fire be hot enough? Did you heat the entire file to red hot as you stated they broke or just the business end? Did you try using the teeth after hardening?

thanks

george wilson
05-18-2013, 7:32 PM
You can make a file cut like a scraper o.k.: Grind the end of the file slightly convex. VERY slightly,just enough that the corners don't dig in. Hold the file nearly vertical,tilted a few degrees towards the direction you want to scrape. Bump the file sideways with your palm. With a little down pressure,it will scrape a dollop out of cast iron or steel. I don't know how long it will stay sharp enough. Probably several cuts at least. I use a Biax scraper with carbide blades made for scraping machinery,but they run about $2500.00.

Shaun Mahood
05-18-2013, 9:15 PM
It looks like the oven tempering like David suggested did the trick - 45 minutes at 300 degrees. I followed the same steps as before with the same bevel angle, planed the same piece of wood, and I'm not seeing any chipping on the blade.

Thanks a lot for the help - best outcome in anything I've baked in years. I'm especially glad I didn't have to know what I was doing or have any sort of skill to fix the problem!

Winton Applegate
05-18-2013, 11:58 PM
Hi Noah,

Yes I used the teeth of the files in normal filing mode to blend the brass fillet joints into the surfaces of the steel. Basically the curvy files I was making were the equivalent of large "riffler files".
http://www.amazon.com/Corradi-Riffler-Rasp-Cut-Flat/dp/B0037MDCWG/ref=sr_1_54?ie=UTF8&qid=1368938782&sr=8-54&keywords=riffler+files
My files turned out very much like these
http://www.toolsforworkingwood.com/store/dept/TAU/item/AU-CI.XX/Hand-Cut_Curved_Ironing_Rasps_by_Auriou
When I found a chunk of flux I scraped it off and went back to normal filing mode. In areas I couldn't get the file into I would scrape at the brass brazing fillet and later use emery cloth to further blend the joint .


A wood fire would not be hot enough without some very fancy manipulation.
Basically you would go with a coal fire but that would not be hot enough without a forced air stream. In other words a black smith's forge. This is not beyond the means of a back yard project but not an indoor project unless you have a set up specifically for this and it probably voids your home owner's policy all to hell.


I have done a bit of black smithing and it is not worth it just for this project.
So
Here is the direction I would go :
At the least multiple propane torches all directed onto the small file.
Or
One oxyacetylene torch which is the most common of the oxy-fuel torches
http://en.wikipedia.org/wiki/Oxy-fuel_welding_and_cutting


with a tip for the torch handle called a "rose bud".
http://www.google.com/search?q=rosebud+torch+tip&safe=off&client=safari&rls=en&tbm=isch&tbo=u&source=univ&sa=X&ei=OkOYUdCXPIfziQL5tIGoAg&ved=0CFkQsAQ&biw=1289&bih=621


If you are a nervous sort I would recommend avoiding a rose bud heating tip. When in use it sounds like a little jet motor and if you shut it off wrong or some times if you have the pressure set too low or it just has an off day
: )
they pop and go out. Well that pop is one surprising loud pop the first time you hear it. After reading in the manual, you always read manuals right ?, that acetylene gas has about the most energy that you can get from a gas and that if a good deal of it leaks out and is ignited and explodes your house will just be a smoking hole where the house used to be, and this thing pops, well bangs, VERY VERY LOUDLY right in front of you, you may find your self running down the street intending to ask questions latter.
It doesn't bother me but I grew up with it and was using such scary stuff when I was fourteen or so. The first time I burned through some thin little micro torch hoses and they began to whip around, on fire, I did in fact run and jump over a red brick outdoor incinerator for cover. I thought the big tanks the torch was connected to was going to explode. If they had I would still be on a trajectory toward Mars or there abouts.
Ha, ha, ha,
After a minute or so of watching them just burn and crawl around I walked over and just turned off the valves.
I am sure this is nothing for some people here but don't say I didn't warn you.


Your files might make a nice mini project in an adult education night welding class. I would not recommend using this equipment with out some community college quality instruction. That was what I did. A little kid in an adult class. Long story. Your buddy next door may take too many chances and not really be the best source of knowledge for this sort of equipment.


Full hard can not be easier :
Get some fire brick ( light weight crumbly brick they line various kinds of ovens with )

The fire brick gives you a place to put the file that won't burn up and will hold the heat around the file while it heats through.
Do this in dim light (not in direct sun light) so that you can see when the file becomes a good red color.
Have a five gallon bucket of water standing by and some large pliers or vice grips.
Do this on a non burnable floor/driveway/dirt. I would tell you about the time I dropped a hunk of red hot steel on a wood floor in a rental and just stood there dumb founded while it sank into the oak flooring but there isn't space so later perhaps.
Grip the red hot file with the pliers and plunge it into the bucket of water. The vibration on the end of those pliers is pretty interesting and surprising the first time you feel it. Kind of like the thing is alive.
Hold it in the water gently moving it around until it is cold, room temp or cool enough to handle with your bare hands.
Done. Full hard. For what it is worth.

george wilson
05-19-2013, 5:08 PM
A water quench will do,but if you want the best watery type quench,add ice cream salt to the water until a potato floats in it. This gives a 7% brine solution. Brine is better because the salt prevents the gas "envelope" from developing around the red hot metal,and ensures more even cooling. However,do rinse the brine thoroughly off your tool after quenching. The brine really rusts tongs,even if they are rinsed. Being rusty in the first place,the old tongs I was using at work,probably got salt down in the porous,rusted surface,which rinsing didn't get all out.

Why ice cream salt is the best,I don't know. Maybe no iodine? You can easily get non iodine salt at the grocer,though.

If you're going to temper,have an old toaster oven all ready heated up to tempering temp. I put a long tailed high temp thermometer into mine,because I don't trust the built in ones. There is only a 25 deg. window that allows you to get the best use from your steel. I pre heat mine to 400º for A2,01,and W1,depending on the intended use. When you quench the part,it should be put into the hot oven immediately when it is just barely cool enough to hold briefly in your hand. If you let it get fully cooled,mthe tool won't be as good.

These things become vastly more important when very expensive die sets are made four manufacturing. For home woodworking use,it's not AS important,but I like to make the best possible tools. My high temp. outfit is thermocouple controlled,too.

Winton Applegate
05-19-2013, 5:24 PM
George,
Thanks, I am over here humbly taking notes (on the scraping as well as the quenching). So many of the old ways call for animal urine. Ice cream salt I can deal with. Makes one wonder how they collected it. Ha, ha, ha, Or not, or not.

Winton Applegate
05-19-2013, 5:43 PM
300° nice one !
I read in Toshio Odate's book ". . . Spirit of Tools . . ." that the old guys would take a blade that was a tad too hard and put it on a metal roof when the sun was at its hottest of the year and that was enough to temper the edge. I would think just using the tool would generate that much heat. But what do I know I am still learning about this blade that can be too hard thing.

george wilson
05-20-2013, 12:00 PM
They seemed to have 1000 ways to use urine in the old days. It was even collected from houses and sold to various manufacturers for a myriad of reasons from washing clothes to making alum. They even included it as an ingredient in hardening steel. It added no value what so ever in that last use. It was the charcoal that case hardened wrought iron bars to make blister steel and ultimately shear and double shear steels. They were made obsolete in the 18th. C. by the invention of cast steel.

David Weaver
05-20-2013, 12:06 PM
Don't forget that they put the aged urine in beer and bread and pitched it as an enhancement.

Of course, they enjoyed a tobacco enema or two, also, and I'm sure that didn't help anyone (did give us a useful saying, though).

Chris Griggs
05-20-2013, 12:10 PM
My cat peed on one of my plane blades once but all it did was pit the steel...I don't think it enhanced the blade at all. Though I do use that blade in my main smoothing plane..Hmmmmmmmmmmmmmmm

Steve Voigt
05-20-2013, 7:16 PM
It looks like the oven tempering like David suggested did the trick - 45 minutes at 300 degrees. I followed the same steps as before with the same bevel angle, planed the same piece of wood, and I'm not seeing any chipping on the blade.

Thanks a lot for the help - best outcome in anything I've baked in years. I'm especially glad I didn't have to know what I was doing or have any sort of skill to fix the problem!
Congrats! That's awesome!
-Steve