Recently I used a new Crown Tools burnishing tool unsuccessfully to try to turn a burr on a card scraper. The scraper edge tore up the smooth finish on the burnishing tool rod and left a series of gouges, cuts and abrasions and I was not successful in turning a burr. In trying to turn the burr, I did rub the burnisher quite hard along the scraper edge.
On the tool handle it also says High Speed Steel.
The Garrett Wade catalog lists a Veritas burnisher which is hardened to Rockwell 62. The Woodcraft catalog lists this Crown Tools burnisher (polished HSS) as well as a Woodcraft burnisher made for them by Pfiel which also is hardened.
Is the problem in the way I tried to burnish the scraper, or in a defective, non-hardened tool or is that just the nature of High Speed Steel when used for burnishing?
Edited 8/24/2004 9:32 pm ET by Larry Martin
Replies
First of all you do not need excessive pressure to turn a bur. That being said, send the burnisher back because it is obviously defective.I do have a teardrop and a round burnisher, I believe they are both Veritas. Both work well. Trying to describe how much pressure to use is tough. All I can tell you is use firm pressure, about the same pressure needed to spread hard, cold butter on a roll. You will have to practice a bit to get the feel of it. In the mean time, if you have a large machine drill that is new or at least has no burs on the shank, use it for a burnisher. Many times I have used a 1/2" drill shank for a burnisher before I bought one.One drop of 3 in 1 oil on the burnisher is a good idea.
mike
Check out the video on forming a bur. Always use a light oil on the burnisher. I use the shank of my phillips screwdriver and use the oil from the back of my ear so I don't have to carry around the 3 in 1 oil. I have the triangle burnisher and the Veritas carbide adjustable burnishing tool as well, they sit in the tool box most of the time. Also, try drawing the edge back, then tick the scraper to draw the edge, then turn it back.
Larry,
I want to second Craig's suggestion...the video clip on the home page is excellent....and is written out in the latest issue of FWW. For the first time all my scrapers are working perfectly. I use the shank of a router bit to lightly roll the bur...in the past my bur was too big and aggressive...
You don't need to buy another tool to burnish your card scraper. Simply use the shank of a large screwdriver and lighter pressure.
Personal rant, this is the problem I have with the newer woodworking articles; they make ya feel that new tools are always necessary,when they are clearly not.
I use the back of an old chisel, just like Tage Frid taught me, it works EVERY time.
Shaft of an engine valve works well - mine is froma 4-stroke mower.
As others have said, you have either used too much pressure turning the burr or you have a defective burnishing tool. Lots of pressure will not turn a good burr even with a good burnisher. It is likely to gall (tear) the metal leaving a rough burr if you attempt to use too much pressure.
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. Using a valve stem from a car engine that has been highly polished is an alternative but, why not just get a burnisher?
Thanks very much for the advice which makes me pretty sure I caused my own problems by being so aggressive in trying to turn the burr. I'll tape off the jagged part of the burnisher and use the new, smooth part in the future with a lot less pressure.
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