Wednesday 24 August 2011

Scrap the scrap scrapper

So I have begun another project this week, restoring an old dresser my family has from our old cottage.  The piece has a great deal of sentimental value as it is one of the few tangible keepsakes from the old cottage, but it is also an amazing piece of furniture.


However the dresser is the topic of Sundays post.  Tonight I am going to talk about everyone's favourite topic...SHARPENING.  There is a lot of information out there on sharpening, so much in fact that one little week day post could not possible cover it all.  So tonight ill talk about my sharpening mantras and how I sharpen an odd tool maybe so people often over look...the paint scraper.

My collection of paint scrapers and blades (front to back: new blade, blade in need of a tune up, blade in need of a miracle)

When I sharpen (and I buy no means believe I am a sharpen expert I just do what works for me) I have a three step process.  Flatten, to create a true surface on the apposing edge to the cutting face.  Grind, to establish an angle on the cutting face.  Polish, to create the smoothest finish on both faces.  Step one for my scraper blades is to remove all the crud built up on them.  The two scrapers are my grandfathers and have had many years of use and a good amount of paint and other shmutz built up on them.

Using a wire brush to remove old paint.  Soaking the blade in mineral spirits first helped to loosen and dissolve some old shmutz.

With a clean blade I can begin sharpening it.  First step it truing up the flat back.  These blades are not made of the same steel you would fined on other tools it is much softer and there for faster to work with, but requires more frequent sharpening.  To flatten the back I use a coarse diamond plate and then fine diamond plate.

Flattening the scraper back (you may notice it is not flat on the plate, there was some crud left on it before I started to sharpen, it went away quickly and the blade registered well to the plate).

So the back is now true, as close to flat as i could achieve, now I move on to the bevel.  I use the same diamond plates (one plate two different sides) to work the bevel.  A quick tip when learning to sharpen an edge you have not done before.  If you do not know what you are suppose to achieve when sharpening buy a new blade and study it to figure out what you need to achieve.  Ive never sharpened a paint scraper before so I didn't know what to work to, so I bought a new one and realised that a sharp burr is the final desired result.  So for two dollars I understood what I needed to achieve and I got a spare blade that was already sharp.


Working the chambered bevel.  Please ignore the sorry state of my thumb.

To deal with the chamber I start the blade in one corner of the plate and put weight on one side of the blade and then as I pull it across the plate I switch weight to the center then to the other edge.  Now to achieve the burr on the blade I could have used a burnisher but instead what I did was I sharpened the bevel until I had a uniform wire edge on the back and then stopped.  Final step is to apply a little oil to help prevent rust.

As the Shwarz calls it using my woobie to oil the blade.

OK to get a little side tracked here, my woobie is a proud little invention of mine.  I have a combination oil stone that I got as my first sharpening stone that I hated for ever, then I learned to use it and now I use it more and more.  My woobie is a oily rag that I wrap the stone in and when I got to oil a blade or a plane soul I just squirt oil onto the rag and rub it onto what ever I am oiling.  The nice thing about this is that the oil is absorbed through the rag and into my stone so it is always getting a fresh charge of oil.

Speaking of oil stones when I tuned up the other blade I used my oil stones.  I also didn't create a burr on one edge of the blade so that it would be a little gentler on the surface I was scraping.

Using an oil stone to create the wire edge.

In the end the newly tuned blades work just as well as the brand new blades.  They can scrap away paint and leave a surface ready for final scraping and sanding.  Until next time.  O yea I almost forgot if you want to learn more about sharpening I suggest looking into Chris Shwarz's method as well as Shannon Rogers method over at the Hand Tool School http://www.renaissancewoodworker.com/hand-tool-school-intro/ if you have any interest in hand tool woodworking I highly recommend joining the school, as well as looking into more of Chris Shwarz's work, both of these people really no there stuff.

Cheers
Hans Christopher Mueller

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