Novice question – I understand the flattening and squaring the edge on a hand scraper. I am about to try the “scary sharp” system on a number of tools – I even found 2 foot long piece of plate glass and made a skinny shelf for it and I created a step-by-step instruction sheet (works best for my brain). I have studied their instructions on adding an edge to a scraper –
- ADD THE EDGE – scraper flat, 1/4″ from edge of bench, light oil, 15 degrees, lots of even pressure
- HOOK THE EDGE – use vise, 1″ protrusion, oil, 15 degrees, lots of even pressure
But I want some other advice before I buy a burnisher. I have no WW mentor so I do my work in isolation. I am not sure what a good hooked edge feels like. It seems like a good idea to ask so I don’t waste a lot of time going down blind allies.
- SCARY SAYS (paraphrased): the burnisher should be a hardened high-carbon steel rod…and be perfectly smooth – any irregularities in the burnisher surface will be transferred to the scraper
- I had planned on using a decent sharpening steel from a good kitchen knife set – comfortable handle, finger protection, long, strong, etc. But it ain’t smooth – it has tiny grooves (maybe a 100 on the circumference – the diameter is 7/16″).
So, my questions –
- Is the sharpening steel appropriate?
- Is there a test or measurement (I have auto mechanic feeler guages) so I know I have enough edge?
- Scrapers seem really cheap, even for good names. Is there much difference in how long they hold their edge?
As always, thank you, thank you.
Replies
GDH2, you do not have to purchase a burrnisher. Suitable burnishers are the round shanks of twist drill bits or screwdrivers. Do not use the kitchen steel for the reason you mentioned.
The best test to see if you have a good burr is to use it on a piece of wood. I know of no gauge that you could use. Keep in mind that the burr does not have to be very large to work properly.
I have an old scraper that I bought at a yard sale. It seems to hold an edge well. I am sure there would be differences in edge holding ability across the brands. This would be based on the quality of the steel used. However, I do not have first hand knowledge of one brand being better than another.
Steve Pippins
You can use almost anything that is very hard for a burnisher,does not have to be round. I have a burnisher, but sometimes grab a large twist drill that has no burs for a burnisher. Even the back of a chisel or gouge will work.
One thing you posted I disagree with, I do not put a lot of pressure on the burnisher.I start out by drawfiling the burnisher,make sure you do it square to the scraper. I use a fine double cut file pulled towards me on an angle,usually four or less times. Then I use a stone ,hone it square like the file,8 or 10 passes. Place the scraper on a bench with the scraper over hanging 1/8" or so. burnish flat on the surface 4 times.Pretend you are spreading cold stick butter,this is the amount of pressure to use. Then turn it over and repeat. Now hold the burnisher almost vertical,about 85°,pull the burnisher at this angle,push back,repeat both.Your done, try it on a scrap, you should get fine shavings,not dust. Hold the scraper at different angles,push or pull,see which way works best.
Putting a lot of pressure and too much angle burnishing will not give you the small burr you want. I usually only do the two long sides of the scraper. When the scraper gets dull, only repeat the burnishing,skip the file and honing. When the scraper is so dull the burnishing doesn't work,repeat the entire process,drawfile,hone and burnish.
mike
I agree, the knife steel will not work. I use the shaft part of a solid carbide router bit, but any piece of smooth hardened steel should work. If you want to learn this fast, Lee Valley sells a burnisher that you can't go wrong with, you dial the hook angle right in:
http://www.leevalley.com/wood/page.aspx?c=2&p=32633&cat=1,310,41070&ap=1
I bought one for my father and was impressed at the ease of use. I notice they also sell a burnishing tool for six bucks which would probably make me less nervous about slipping and cutting myself with what I use now.
I've only used bahco (used to be sandvik?) scrapers, and the one which came along with the burnisher, didn't notice much difference in how long the edges lasted. BTW, I only do the long ends also, and you might just want to do one for starters, and you can cut yourself if you're careless.
Edited 12/2/2005 2:15 pm ET by Bepperb
The knive steel will not work. You want and need a highly polished surface.
I greatly favor a real burnisher for two reasons. First, it is really hard metal. Second, it it highly polished. Both of these attributes mean that there is little chance of galling (or tearing metal from) the scraper edge. Galling makes for less than a smooth cut. The smoother the burnisher, the smoother the burr. Screwdriver shafts may or may not be hard enough and the chrome plating will eventually deteriorate. Drill bits are also variable in hardness. Using a valve stem from a car engine that has been highly polished is an alternative but, why not just get a burnisher?
GDH2,
The key outcome of a well functioning scraper are thin shavings(little curls)...not dust or chips. A 15 degree means tilting the scraper forward quite a bit..and don't push too hard, let the tool do the work.
A burnisher is not necessary, in additon to what was mentioned, a router shank will do too. However, I like the Veritas tool that allows me to set the angle and get high repeatability very quickly on all faces as a work.
This forum is so massively great!
first... Thank everybody!
Steve Pippins,Mike , and Howard - Thanks for the ideas on alternatives - I was thinking long strokes would be required - a valve from an engine appeals to me (I also have one on hand)
Mike - I was just quoting the "scary sharp" notes about pressure, but I hear you and I will explore
Beppard - Wow - I have never seen this burnisher - damn, if I just weren't so cheap I'd jump on it (and I might anyway - I added it to my shopping cart at Lee Valley... maybe the next time I order something from them...)
BG - I think I actually do have a good sense of what the shavings should look like - I have seen David Marks scrape a lot (Wood Works on DIY TV)
> BG - I think I actually do have a good sense of what the shavings should look like - I have seen David Marks scrape a lot (Wood Works on DIY TV) <
Now, this might just be me, but I hate the way Marks rubs his scrapers up and down the wood. Think about what's happening when you scrape. Lift the scraper up off the wood when you fetch it back towards you at the end of the stroke. Dragging it back must shorten the edge life!
And it loolks so naff!
Malcolmhttp://www.macpherson.co.nz
I use a 6" extension from a 3/8 socket set for burnishing
I have used some recycled valve stems as a burnisher and they work fine
I bought a set of scrapers from woodcraft and followed the directions that came with it (I had an idea what to do) and what i can tell you in my brief experience you will get better results if you scrape uphill, like you would do with a hand plane and i feel you get a better finish. And when it is right you know it because it pulls shavings not dust. I use a screwdriver as a burnisher and it works fine.
Steve
This forum post is now archived. Commenting has been disabled