Scraper sharpening

[David Ragan]

Hi,

After reading on this list, I got me a couple of Bahco scrapers. Wow-really hard.

I jointed the edge, smoothed the face on a stone, then drew the edge with a burnisher-fancy one from somewhere....then, tried to put a hook of 5-10 degrees on the edge. I got no real burr.-well not impressive, anway.

Initially, I thought-Hey--if it just takes a little more work to get a burr on the much harder SandVik/Bahco than LN scraper, and I don't have to sharpen as much, why not?

But-so far, I am not able to do very well. Maybe I am just really loosing strength in my hands.....The Bahco does do exceptionally well as something to dress my benchtop.

In the past, I have not even bothered to draw the edge and did pretty well I guess w my LN.

Do you all draw the edge/burr first?

Are Bahco scrapers worth it?

[David Weaver]

I always draw a burr. You might need a harder burnisher and to do more to draw the edge out before rolling it. IIRC, they are still spring temper.

That reminds me, the LN blade for the scraper planes is about 54 hardness or something, which is hard for spring temper, and it still rolls a burr very well. If you got blades that temper a few points harder than that, then they will have trouble rolling a burr to some extent, but the fact that you're rolling it on a 90 degree edge should still allow for something (Whereas it would just chip off on a chisel type edge)......if you have a burnisher capable of rolling a burr on steel that hard.

If you can't feel any burr at all with your fingernail, then increase pressure. If you can feel a fat burr, that's too much on a first roll - something in the middle is nice. I'm not sure it matters much soft or hard scrapers once you get a setup that works. The LN scrapers are a little soft, but not compared to junk scrapers. I can get along with anything that's commercially available and decent quality, as can most.

[john zulu]

Draw the burr to creating shavings. If not it is scraping :)
Cabinet scraper works both ways.

Here is a video I did on scrapers:
https://www.youtube.com/watch?v=OPemR86l74M

It depends on the application if the burr is needed.

[Prashun Patel]

I have a Bahco. Are you sure the issue is just that the Bahco is harder to flex? I find that a high flex (or smaller contact point) makes cutting easier. It's the main reason that my favorite scraper is now a slightly convex. It cuts easy enough off the file or with the tiniest of burrs.

[Bill White]

I have some Sandvic and Bahco scrapers. Each seem to have a different "personality", so burnishing is tuned to each scraper.
Made me crazy at first until I modified the turning of the edge to each scraper. Flex is individual per scraper.

IMO, it seems that each scraper will need to be carefully burnished for the edge required.

Bill

[David Ragan]

John- your video is wrong one. I did watch some others tho. I could improve w better polish of edge after filing, One guy said drawing is actually work hardening metap there
i also have a couple of wrist pins waiting iver at mechanics shop

[Adam Cruea]

I draw out a burr then roll it over.

I use the LN scrapers/burnisher though. I also hold the scrapers in my hand and free-hand the roll-over.

On the thin scraper, it works a charm. On the thicker scraper they offer, it can get a little tedious. *shrug* It just takes a few more swipes, though.

I found on the net that the Bahco's tend to be 48-52, and the LN's from 49-51. So they should be about the same hardness (all other things being equal).

This was the video I used to learn to sharpen: https://www.youtube.com/watch?v=4SG2LUdk-VE

[bridger berdel]

Not strictly answering the op question, but I'm pretty casual about scrapers. I seem always to have a donor saw blade about, and I'm not willing to sharpen 4 edges on a card scraper, so I make extras and round over the edges and corners of the back, where my hand is. I also make them in a variety of shapes, and I'm not just referring to curves- in straight scrapers I make them in different lengths and widths. A long narrow scraper, say 7" or 8" long by 2" wide is very interesting. Not only is it easy to flex but your fingers are well away from the hot edge. It's also useful to have a scraper where the ends are ground to a slight angle to make getting into corners easier.

[glenn bradley]

I prep all four sides, draw and hook. There are a surprising number of "burnishers" on the market that are not hard enough to do the job. Be sure to use a little bit (very little for me) of lube to avoid galling. I have very flexible through very hard scrapers. As mentioned, they all milled and hooked with a different approach to match the beast.

[David Weaver]

I prep all four sides, draw and hook. There are a surprising number of "burnishers" on the market that are not hard enough to do the job. Be sure to use a little bit (very little for me) of lube to avoid galling. I have very flexible through very hard scrapers. As mentioned, they all milled and hooked with a different approach to match the beast.

I have a crown burnisher that is supposed to be HSS. It's hard enough for saw steel in some spots, but close to the ferrule where one would actually like to use it, it's not.

[john zulu]

Hi David,

Which part of the video is the wrong part? It is meant to demonstrate the use of the card scraper.

[john zulu]

David Ragan,

I think I understood what you meant. I learnt cabinet scraper sharpening through this video. William Ng:
http://www.thewoodwhisperer.com/videos/scraper-sharpening-w-william-ng/

John

[george wilson]

The 1095 spring steel we used on our saws,and which I'm sure the other small makers of quality saw use,is 52 R.C.. This is hard enough to file. Files pretty soon got grooves in them sharpening our saws. I don't see how they could be much harder,and still be filable. Nor could the teeth be bent to set them if harder. It was bad enough occasionally breaking a tooth as it was. Once sharpened though,such saws stay sharp a lot longer than ordinary Disston saws of any period. They all felt softer when sharpening compared to what we used. I'd say most were in the high 40's at best.