Hello, it’s me again. Having sharpened my chisels and cut a dozen or so mortises I decided to craft myself a small oak mallet. After drilling out most of the waste it was time to clean and square the hole in the mallet head. I didn’t get a single pass thru before the beautiful edge I’d made was folded and dented. All that work down the tubes.
My question, I guess, is threefold. First, is this typical of cutting hardwood? I think I know the answer to that one, but have to ask. Second, should I perhaps be using a skew chisel as its angled blade will lend itself more to a cutting action rather than a crushing action? Third, should I just grow up, bite the bullet and beg the wifes permission to buy a set of chisels from an actual woodworkers supply outlet?
Fortunately my current project is made of pine, so it’s easy on the blades, but I have piles of cherry, oak and hard maple that need to be made into learning experiences. I’ve taken the micro bevel off of one chisel with little or no improvement.
Also, because I hate shopping of any kind as one can never believe ads, if I simply go to Lee Valley for all my beginning woodworking needs is it the general opinion that I’ll not likely buy garbage? I realize there’s many local suppliers, but LV is right here in the living room which makes it convenient. They also have a good reputation as far as I know.
I truly hope I’m not wasting anyone’s time with frivolous questions, but advice from people who’ve been doing this awhile carries a lot of weight and helps me keep on track. Thank you all.
Chris.
Replies
I truly hope I'm not wasting anyone's time with frivolous questions, but advice from people who've been doing this awhile carries a lot of weight and helps me keep on track. Thank you all.
There's no such thing as a frivolous question, Chris. We've all been there at some time or other
Just grind the primary bevel steeper, maybe to 30-35 degrees (gives a tougher edge) and rehone to a couple of degrees higher. Oak can be tough on tools. Same fix applies to plane blades when they're not lasting.
Cheers,
eddie
Edited 12/22/2003 7:28:19 AM ET by eddie (aust)
15broad, Are you trying to chop off too much material at once? Is the oak bouncing on your work surface? Any serious mortising requires a heavy dense back up, to absorb the shock and eliminate vibration. (Think massive old workbenches) If you are working on a vise, is it solidly fastened to the bench directly over a leg to the floor?
You are cutting across grain, so pare gradually toward the center of the hole. Using a smaller (In width) chisel presents a smaller 'Footprint' and requires less effort.
Some times a shorter and thicker bodied non beveled chisel works better as it won't vibrate . A Firmer chisel with a (Socket) in stead of a 'Tang'is the best tool for that purpose.
The instrument you hit the chisel with should be dense and heavy. A round one piece mallet(Maul) or the flat, but angled face Mallet with a wedged end handle beats a hammer and is easier on arm and wrist bones.
One other suggestion; After boring the round hole use a coping or sabre saw to remove the waste and finish up with paring to the finish. Stein.
Edited 12/22/2003 8:02:15 AM ET by steinmetz
15,
As Eddie indicated, we have all been there. A couple of years ago I had an experience like yours with a brand new, fully sharpened Sorby...the tip would roll...and therefore determined the Sorby was crap. I bought a couple of Japanese chisels and their point is terriffic but brittle...gotta be careful not to chip...and just not long enough for mortices. Then I heard about Two Cherry....but I don't want to buy a set, just one...and prefer to see them before I buy.
This past summer I picked up a couple of firmer chisels and mortice chisel at tag sales...real cheap. My point is I'm still in pursuit of the ultimate set of chisels. I don't think there is a 'one set fits all' solution....and, so what...having a super sharp chisel for mortices is not all that important...it really helps with paring.. So along the way I've gotten used to the chisels I have ...sorby, japanese, old stanleys....and my confidence has grown..and I think that is what really matters. I love the Sorby for paring shoulders and tenons...the japanese for dovetails...the firmers and mortice for mortices. With LV near by, you have a terriffic resourse to custom make your own set of different brands.
Many thanks everyone. I'll try different angles, but am leery of getting too far away from the ages old angles of attack. As far as how much material I'm removing, if three holes are bored so that they touch, you're left with only about 1/8" of stock to remove before the hole is made flat. The work is well supported and not bouncing. Now that I have a mallet I'll be using it to help. It's just that I find it hard to believe that the chisels should dull that quick. I don't even get a single mortice cut before having to return to the sharpener. I did find that the smaller chisel worked a bit better, so maybe that's the key. If I didn't enjoy my shop time so much I'm pretty sure I'd hate this.
I'll mix and match to find the right combination that works for me. Just for the sake of satisfying my curiosity, what time frame would be "appropriate" for cutting four 3/4"deep 1/4"wide 1"long mortises in oak door stiles. I know there's lots of variables, so a ballpark is all I'm after. I'm just trying to get a handle on how long these processes should take. As time goes on I'm confident my pace will pick up, but I'd like a realistic idea of what I'm getting into.
Thanks again. Chris.
Chris,
For what it's worth, the 'ages old angle of attack' specified in old textbooks (1940's) and also when I was trained was 30-35 degrees on the secondary bevel when morticing, 25 degrees for benchwork, 15-20 degrees for paring.
Don't take one source as gospel - keep working at it and you'll figure out what works.
Cheers,
eddie
Edited 12/22/2003 8:46:59 AM ET by eddie (aust)
15Broad
Heed eddie in post #6. I was just going to post that when he did. There is a difference in paring, bench and mortice chisels. Low angles on mortice jobs will roll an edge on even good steel. You need a steeper angle ( 30 to 35), a thicker blade and a connection to handle that is solid. That is what a mortice chisel is made to do. Absorb impact and "get down" with heavy removal.
The 25 degree bench is a compromise between paring and mortice. Does all but not excellent on either end of the spectrum. Won't cut as delicate as a paring angle and will roll with heavy usage and hard-wood.
The lower angle paring chisels are for fine work. That angle won't last one pop with a mallet in a mortice. The low angle is made to slice finely, not gouge.
Bottom line is no matter how great of steel and price of chisel, the wrong angle applied to the wrong job will get you poor results. Keep em sharp and and apply proper angles and you will learn to love your chisels. ha.. ha...
Off to work, hope I didn't confuse...
sarge..jt Proud member of the : "I Rocked With ToolDoc Club" .... :>)
15,
Time line for cutting mortices? Very steep learning curve and really depends on if the mortice is for a stub tennon or a thru tennon....on the ones you describe 1/4" wide, 1" long, 3/4" deep...without drilling first...maybe 20 mins. for the first...and by the 3-4th maybe 5-7 mins. ...with drilling first..cut those times in half. I'll use my former chisel which is 1/4"...
Great! I'll play around with angles and see how I make out. I haven't yet put a chisel on a grinder, but maybe I'll try concaving one to see how it goes. The chisels are Footprint bevel edge chisels, purchased at Sears. I think this is something I'll have to work out between myself and my tools. I appreciate all the advice. Maybe after Christmas I'll find a set of proper mortise chisels. I'm also on the lookout for a local woodworker to kind of apprentice with part time.
Maybe I'll even hit the local library if I find a time when its not too crowded and score a copy of the Lee book.
Anyhow, lunch is over, back to the grind.
15Broad
Just a last thought. If you go to hollow grind, I would not use it if you do get dedicated mortice chisels. That 30 to 35 degree bevel needs all the support it can get chopping heavy hard-wood. That's why mortice chisels are thicker. They don't have bevel edges.
The hollow grind makes sharpening the chisels easier on the bench and paring, but by grinding the center of the bevel hollow you take away needed support for the mortice. It would sharpen quicker, just as the other two. But it takes structural support away from the tip that is needed for the more brutal cut that characterizes morticing.
Regards...
sarge..jt Proud member of the : "I Rocked With ToolDoc Club" .... :>)
Chris,
From your description, it sounds like the metal in the chisel is possibly too soft. I've never seen a blade in a decently made chisel curl back the way you describe, if the type of chisel and the blade angle was proper for the job. The more common problem is that the blades dull quickly or chip readily.
Years ago I had a set of four chisels, three of them sharpened well and stayed sharp, the fourth chisel, which appeared to be identical to the other three except for the width, wouldn't hold an edge for a tenth as long as the other three, it was probably never tempered properly.
I just went back to your earlier postings about sharpening. My impression is that you are spending way too much time sharpening and fussing over the edges. There are a half dozen basic ways to get a good edge on a tool, none of them should require more than a few minutes, certainly no more than 15 minutes, to put a good edge on a chisel, no matter how dull it started out. After that, touch ups should take just a minute or so and the blade should stay sharp long enough to clean up at least a few mortises in a hardwood between touch ups.
You never mentioned the brand of chisel, or the blade style, or whether or not you are using a grinder before you go to the stones, all of which could give some hint as to why you are having so much trouble.
John W.
Edited 12/22/2003 11:19:41 AM ET by JohnW
Edited 12/22/2003 11:27:03 AM ET by JohnW
This forum post is now archived. Commenting has been disabled