Krenov style high angle smoother

[Doug B]

Since Racers`s demonstration of hardening a plane blade at Lurker`s Midland micro bash, i`ve been dead keen to have a go at making not only a plane but also the blade.

With this in mind i`ve been researching, reading Philly`s 2007 plane making articles in The Woodworker, reading past forum posts & then to my delight finding on my yearly shopping expedition to get the good lady wifes Xmas present, the Christmas F&C, with an article on Krenov style smoother.

So progress so far with the blade, cut to size, machined square & the bevel cut.

So now the questions

This is how i think i need to proceed next.

Heat the blade until cherry red, checking with a magnet that it is no longer magnetic, then keep it at this temperature for 15 minutes The blade is 1/4" thick.

Immerse the blade in oil *, moving it around to dissipate the heat for several minutes, then allow to cool naturally.

Clean off the oil, place in a hot oven 200 degrees C for 1 hour, turn off the oven & leave inside to cool with the oven.

* Philly in his article recommends peanut oil, though i`ve been told i should use old oil, i know pete used old engine oil.
Any info on this, or how i think i should proceed next would be gratefully
received.


& finally in this installment :shock:

These are the blanks i`ve prepared.

They are Pakauk, hopefully this timber will be ok? As it`s the only hardwood i have in 8"x 4" sections that i know is well seasoned.
With its wonderful tearout i could do with a nice high angle smoother for preparing them :lol: :lol:.


Thanks for looking, all helpful advice welcome, i`m off to find a BBQ, charcoal & hair dryer, as a short hair veggie these are the most difficult items to source so far. :-k #-o

 

[frugal]

If you have a hot air paint stripping gun then they work wonderfully for getting a good heat up in a barbeque style forge as they also help to heat up the air.

 

[woodbloke]

Don't forget the plane in F&C had a lignum sole, so you might need to source a bit of something nasty and heavy :wink: - Rob

 

[Philly]

Doug
Old motor oil is fine - use whatever is handy or cheap!
Paduak should be perfect - its a very hard timber. A separate sole is not going to be needed.
If you need any help just shout!
Philly

 

[woodbloke]

Paduak should be perfect - its a very hard timber.
Philly

Philly is correct, paduk is hard, but not that hard (50lbsish/cu') whereas lignum is around 80-90lbs/cu'. If you do go down the separate sole route, it does make the process more difficult - Rob

 

[Philly]

Most British woodworkers have managed quite nicely for centuries with planes from Beech - 'nuff said! :lol:
Philly

 

[Racers]

Hi. Doug

Just heat the blade up and quench it, you don't need to hold it at red heat, and you will burn off all the carbon from the outside of the steel. You will need to hold the tempering tempriture so pop the blade in the oven after sunday dinner!


Pete

 

[woodbloke]

Most British woodworkers have managed quite nicely for centuries with planes from Beech - 'nuff said! :lol:
Philly

...and who am I to argue Philly :lol: :lol: :lol: - Rob

 

[Modernist]

Go for it Doug - there's no backing out now.

Did Cromwells come up with that size steel?

 

[Aled Dafis]

Hi. Doug

Just heat the blade up and quench it, you don't need to hold it at red heat, and you will burn off all the carbon from the outside of the steel. You will need to hold the tempering tempriture so pop the blade in the oven after sunday dinner!


Pete

Hrdening, Tempering and Heat Treatment - Tubal Cain clearly states

"...metallurgists and generations of blacksmiths over a century or more have established the rule : heat for ONE HOUR PER INCH OF THICKNESS, once the tool is up to the hardening temperature.

...yes I know! You have never held the heat for as long as this! I am sorry, but this means that you have never achieved the maximum possible hardness either!"

Cain goes on to describe how he carried out a test with 4 pieces of 1/4" stock, and heats them for 1min. 5min, 10min and 15min respectively. he states

"The reduction in hardness for the shorter time is quite evident - the "one minute piece" is softer "as hardened" than the tool should have been when tempered"

The book is a little hard going, but is packed with really usefull information, it should be on the bookshelf of anybody interested in doing a little hardening/tempering at home.

Cheers

Aled

Edit: I just found in the Tempering section, that the same rule applies. i.e. the tool should be held for one hour per inch of thickness once it's up to the required temeprature (generally about 220 degrees C for plane irons)

 

[Doug B]

Thank you for the replies so far chaps, most helpful.


I`ve found a hot air gun, thanks Frugal, though my wife is refusing to go to B&Q to find out if they`ve got charcoal in stock at the moment :lol: :lol:

Hopefully the snow will stop sometime in January :roll: & i`ll be able to get outside & get tempering .


Brian, "I phoned a friend" to find out if gauge plate was the same as o1.
After explaining what i was wanting to do, i got a dogging for wanting to "waste money on stuff he`d got, & to get over there with the sizes i needed".

So i never got as far as Cromwell, though thanks for the recommendation.

Cheers.

 

[paulm]

Like the timber choice and the nice thick steel.

What thickness and width are you making the blade ?

Cheers, Paul

 

[Racers]

Hi,

I have not had any problems with my hardness :wink: in fact my scraper blade was to hard to roll a burr on, you could hear it fracturing so I had to temper it again.

Pete

 

[Doug B]

Today i finally managed to get some charcoal, you`d think with this glorious weather all the shops would have BBQ charcoal. :lol: One of the mums from my son`s school kindly donated a disposable BBQ, though i wish i hadn`t started to explain why i wanted it, i think it would have been easier to say i wanted a BBQ in the snow :shock: :lol:

So after doing a risk assessment, i figured i couldn`t do anything more Heath Robinson, so ploughed on un-deterred.

The hot air gun worked a treat, in no time the blades were bright red, i decided to leave them for 15 minutes, more so because i was worried i wouldn`t have enough charcoal if it didn`t work first time.

After cooling in the oil, i noticed the oil didn`t coat as well where the blade was bright red, i`m hoping this is a good sign

To answer Pauls question the blades are 1/4 gauge plate, 1 being 47mm the other 43mm.

Finally i`d like to say i have no connection with Cadburys, other than my wife being a very happy consumer :lol: :lol: :lol:

 

[JonnyD]

Just noticed this Doug and its looking good. Ive always fancied having a go at making some woodies but never seem to get the time. Hurry up and get them finished so I can have a go with them when i come over.

cheers

Jon

 

[Mr Ed]

I've always thought making blades seemed a ball-ache so never looked into the detail. Your sequence of photos makes it look quite straightforward though. Maybe I'll give it a go (in the summer though!)

Ed

 

[Philly]

Doug
That looks right - the scale seem to come away from the red hot areas.
Get them tempered then look forward to the wonderful experience of cleaning them up and flattening them :wink:
Cheers
Philly

 

[xy mosian]

If you've finished all those chocs since Christmas ..... well done. As for the forge I'm mightily impressed. I especially like the cut-out for the heat gun nozzle, well thought out! I suppose along with disposable BBQ if one were to add disposable forge that could be quite enjoyable.

Keep up the interesting WIP's please.

xy

 

[paulm]

To answer Pauls question the blades are 1/4 gauge plate, 1 being 47mm the other 43mm.

Thanks Doug, took a chance in the meantime and ordered some 6mm thick by 50mm wide by 500mm long stock from Cromwells, which seems about right then, inspired by the F&C article and your own efforts.

Don't know when I'll get time to do anything with it though !

Ordered some 1/2" diameter silver steel rod too to supplement my Hamlet Little Brother hollowing tool and perhaps make some pick type hollowing tools in George's (Cornucopia) style, again time permitting

Cheers, Paul

 

[Aled Dafis]

Looks great Doug.
A simple (completely unscientific and very subjective) way to check that the blade is now hard, is to try and file the blade, you'll find that the file will just skate along the steel without even thinking of taking any metal away. Dont get carried away though, as this will blunt your file in no time.

Paul

I've also been considering making a few "pick" turning tools, David Ellsworth's book covers this in good detail. Do you have any other links/info on the subject.

Before long we'll have a seperate toolmaking section on here.

Cheers

Aled