Old plane blade too hard?

[Shaun Mahood]

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]

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]

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]

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]

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]

It doesn't matter, just take it out of the oven and let it cool off until you can touch it.

[Steve Voigt]

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]

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]

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]

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-Knif...8856047&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]

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]

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]

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]

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-Riffle...=riffler+files
My files turned out very much like these
http://www.toolsforworkingwood.com/s...asps_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-fue...ng_and_cutting


with a tip for the torch handle called a "rose bud".
http://www.google.com/search?q=roseb...w=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]

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.