scraper question.

jdm61

jdm61

itinerant metal pounder
Joined
Aug 12, 2005
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I was watching some You Tube videos about making cabinet scrapers. The guys said to use a "hardened flexible piece of steel" but they must not mean too hard because the are cutting the steel with hacksaws, not worrying much about burning the temper with an angle or bench grinder and using a burnisher to roll a final "hook" onto the edge. Do you guys think that 15N20 as it comes from Aldo et al would be hard enough?
 
I've got piles of real ones, and have spent a lot of time using them.
It isn't that hard, as you dress the edges in use with a file. It needs to be soft enough to roll a good Burr over the edge too. I'd say somewhere on the soft side of a spring.

I'm all for making my own tools, but personally this isn't something I'd bother with. A good Sandvik cabinet scraper is $10-15 and will last for your entire life
 
Geoff, the readily available scrapers do not have the profile that I want so I figure why pay good money if I have to modify it anyway when I may have the raw materials for "free" to make one without an involved HT process?
 
You can use unhardened carbon steel, on wood anyway and push (burnish) a burr on the edge with a screwdriver shaft. These will cut for a LONG time on even hard woods. I've done it a bunch. If it stops cutting, just push a new burr over or resquare the end up on a belt and push a new burr over on it.
 
The handsaw makers on the woodworking forums used to sell 1095 cutoffs for that purpose.
 
Learning to use a scraper is a worthwhile project . The steel must be thin enough to flex it and easy enough to burnish it. I wonder if the new powder steels are significantly better ? My scraper days are in the past ! A good exercise in balancing thinness, hardness, and the steel you will work harden and shape to a fantastic fine cutting edge !! :D
 
Now I understand why you want to do it.
I see no reason it wouldn't work.
If you don't have a scraper burnisher for rolling the Burr, a piece of hardened round stock is ideal, although as mentioned a screwdriver shaft will do it.
 
I tried a piece of 15N20 tonight and it may be too hard to burnish. But when I used the edge at 45 degrees, it worked quite well on edge grain African blackwood. It left a very smooth finish that 600 grit sandpaper actually dulled up a bit. When I tried it on the edge of a piece of very curly maple, it left a rippled finish. You may have to use a plane on that stuff. The really good news is that I had intended to use my little "custom" concave scraper for blackwood anyway so it looks like I will be okay.
 
Greenberg Woods said:
45 HRC is pretty standard scraper hardness
Click to expand...
Ben, I don't remember what the hardness of 15N20 is from the factory. Do they even heat treat it once they turn it into big bandsaw blades for the lumber mills or do they just use it as is comes off the roll?
 
jdm61 said:
Ben, I don't remember what the hardness of 15N20 is from the factory. Do they even heat treat it once they turn it into big bandsaw blades for the lumber mills or do they just use it as is comes off the roll?
Click to expand...

Depending on what the saw is for they run different hardness. I got a pack of the bandsaw blades from @JTknives "Sick deal guys"

Im sure he could get an exact hardness but id bet they are in the high 40's. Scrapers are normally made out of the exact same stock as handsaws, and think about how easy a handsaw is to file.

When i made a super fast scraper i used some thin 15N20, heated it cherry red and cooled it in air. Followed that up with a quick torch temper and it worked fine.
 
as I recall, the 15N20 from Alpha is hardened, The 15N20 from Aldo may not be..? I've made wood scrapers
from 15n20...hardened & tempered them back to dress them with a file. Held perpendicular to direction of pull,
they usually work well, but when they want to chatter a bit, just turn the scraper at a slight angle. I sharpened mine
square, so they could be reversed so as to extend time between dressings.
 
I think the traditional cabinet scraper is 1095/W2 type steel, very thin ( 1mm or less), and hardened to a spring temper in the mid to upper 40's. The burnisher is highly polished and in the lower Rc60's. A scraper holder will make one work much better than holding by hand.

Hint, a small scraper can be clamped in your shoulder grinding jig as a substitute holder.
 
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Stacy E. Apelt - Bladesmith said:
I think the traditional cabinet scraper is 1095/W2 type steel, very thin ( 1mm or less), and hardened to a spring temper in the mid to upper 40's. The burnisher is highly polished and in the lower Rc60's. A scraper holder will make one work much better than holding by hand. Hint, a small scraper can be clamped in your shoulder grinding jig as a substitute holder.
Click to expand...
Good hint. I have one of those side Bruce Bump file guides.
 
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