I was using the slot-mortiser attachment on my combo machine to make mortises in cherry bench legs. The apron mortises, parallel to the leg length, caused no problems. However, I wanted a “horizontal” mortise for the arm attachment to the rear leg. This meant that I had to crank the table up and down to cut the mortise.
Movement this way was not fast enough to avoid burning. I now have a well-blackened birds-mouth bit.
(A) Is the bit still good?; (B) If so, can it be cleaned? and (C) If so, what material should I use to clean it?
Frosty
Replies
After 17 hours, there were no responses to my plea for help. I assume this is the reason the question did not appear in the General Discussion section this morning. I am trying this approach (commenting on my own post) to see if this will get it to show up.
Frosty
If it just needs cleaning, a bit of oven cleaner will do the trick. If it needs a light touch-up of the edge, I like to use a small diamond hone. Same goes for router bits that need care.
I forgot about the oven cleaner. I'll try that. Thanks.
Frosty
Ring,
Thanks for the tip about oven cleaner. But - I discovered that not all oven cleaners are created equal.
If it doesn't have lye (sodium hydroxide) in it, it won't remove the burnt-on black stuff. Stick with the 'nasty" stuff. The 'no bad smell' cleaners and Simple Green just won't work. Be sure to wear gloves and eye protection.
Thanks again, Frosty
My take, Frosty, is that it's impossible to tell from this end of the Internet. The blackening may be superficial, or it might reflect sufficient heating that the temper of the cutting edges on the bit has been affected.
If you'll hold the bit up to your screen, I'll hold my electron microscope up to my screen, and we can take a look. ;-)
I'd try to clean it up, and then test it for sharpness. If it has dulled, I'd send it to a good sharpening service for assessment. I don't trust myself to take precisely the same amount of metal from both sides, potentially affecting the balance of the bit. Out-of-balance bits spinning at 20K RPMs scare the who-hah out of me.
Ralph,
I've got my bit up next to the screen
I'll wait for the report from your 'electron microscope - but PLEASE don't feel it is necessary to hold your "hoo-hah" up to the screen.
Frosty
Oh darn. The cord on the electron microscope won't reach. Well, we tried. ;-)
Frosty
Saw something black and horrible but suspect it was your fingernail
wot
Frosty,
Those bits are expensive. For mortises, I use an old mallet and a mortising chisel. I go really fast, but I have not yet been able to blacken my chisel. But based on your experience, I am not going to risk it. I am going to slow down my mortising action. I love my LN mortising chisels and don't want to have to use oven cleaner on them.
Mel
PS other than that, are you having fun? Any really interesting jobs or pieces come up lately?
Some say that Simple Green is useless? I use it all the time on my saw blades and router bits. I have a tray and use it over and over. I let the part soak overnight and scrub off the gunk with a plastic brush. Works for me! I do not mix it with water and I never get any rust. But then again I never found a need to use it on anything but my saw blades and router bits. Some of my bits are solid carbide and some just carbide cutting edges on steel...
AND ALSO.. Some have posted to use oven cleaner.. As I recall my Forrest blades (as in those that made them) stated NOT to use oven cleaner as it may ruin the carbide. I do admit that I do not use woods with alot of pitch in them such as pine. My collection of gunk is probably oils from the woods that I use.
Mel - Yes! I'm having fun. I undertook a massive project- writing a book of about 350 pages. I was given, and became custodian of, genealogical materials dating back to a diary starting about 1800; also, another diary kept by a great aunt while she was 16 over the year 1864. I decided if those people kept contemporary info alive for 200 years, I could do my part. Through a series of essays, I have detailed activities and memories of my life. I am having hard-cover copies printed, hoping a few will survive for the next 200 years. Included in the book is the material from 200 years ago; photos from then and photos from now. I even include a full chapter describing in relentless detail the design, construction and finishing of my arch table.
My woodworking suffered, but I am back at it in full force.
Will - I tried Simple Green and ordinary oven cleaner. They work fine on sap and pitch but not on the burnt-on material. The 'harsh' oven cleaner did work. A router bit can plunge and 'stay put'. A 'birds-mouth bit' on a slot mortiser can not plunge more than about 1/16' and then it needs to be moved sideways to stay cool. On this project I wanted a mortise parallel to the seat on a curved back post - tricky. I had to crank the slot-mortiser table up and down. That motion was too slow to prevent burning. But - the bits are now clean and good.
wot - Black as in dirt or one that got in the way of a hammer. I use 'soft hammers' so it will have to be dirt.
Thanks for reading and commenting, Frosty
Frosty,
I have told you before that I thought we are twins who were separated at birth. My other hobby is genealogy. Glad to know there are two of us. Your big book sounds like a work of art and of love. I am sure that it will be appreciated by family members in the future.
I hope someday we can get together and swap some stories.
Mel
Mel, I take that as a great complement.
Yes, I look forward to the opportunity to get together, see samples of your work, your shop and your bowls. If you come North in the hot weather, give me a call. I'll do likewise in the cold weather.
Frosty
Frosty,
I have only made one bowl in the past year. I believe my bowl-making was an aberration -- an adventure caused by meeting three guys who make bowls and sell them for many hundreds of dollars. I was impressed with their ability to take a fallen log and turn it into a few thousand dollars. So I bought an adze. That didn't work out well. It was recommended by a bowl maker, but it didn't work well. When I looked into it further, I found that the bowl carver and the tool maker were in cahoots. I found a website for the bowl maker, and he did not use the adze to make the bowl, just in the later stages. He actually uses a full size chain saw. So, do to my not doing full research ahead of time, I got taken. BUT it was a good adventure and a great learning experience. So I learned how to use a mallet and gouges to make bowls, and I found it took a long time and was tiring. So I learned about using a pair of small chain saw blades on an angle grinder, and I made a lot of bowls. When I felt like I really had that process down, I moved on to other things. I can always go back and make a bowl whenever the feeling strikes, but I don't think it will strike often.
The reason is that I have been moving out smartly on a path to hand tools. In the past five weeks, I have made about ten dovetailed boxes, all with hand tools. My purpose was not to go into business, but to gain some real skill in dovetailing. I could see my skills increasing with each box. Now I am ready to move on to the next adventure. My goal is to be able to make large casework with dovetailed carcasses (top sides and bottom), and intermediate crosspieces which are put in with long tapered dovetails or with wedged through tenons, along with hand made mouldings all around (using hollows and rounds). And just for the heck of it, I would like my hand dovetailing to get through to the houndstooth pattern.
That adventure will take a while, but I find it more exciting than making bowls with a chainsaw. I made my first cross grain grooves by knifing the lines, cutting with a saw, and then removing the waste with chisels and a router plane. I am also working on attaining skills with my Stanley 45.
So right now, I have a glut of boxes, but the kids will be home for Easter, and I expect the boxes to go fast at the low price of zero.
The older I get (and I am getting there), the less I am impressed with tools, and the more impressed with developing skills. I have some Lie Nielsens and some old Stanleys that I fettled. While the LNs are more fun to use (easier to set precisely), no one can tell which planes I used to finish a piece. I takes more skill to use wood planes than to use the old stanleys and more skill to use the Stanleys than the LNs. I am coming to the conclusion that for only a few thousand dollars, that is, one fifth the cost of a Holtey plane, one could acquire a set of tools that would enable you to make furniture equaling that of the Goddards and the Townsends. Of course, to achieve that goal, one would have to attain the skills that the Goddards and the Townsends had, and that ain't easy.
Well, now you know what is going on in my shop and in my head.
Enjoy,
Mel
Why a bird's mouth?
Frosty,
Why are you using a bird's mouth bit to cut a mortise?
Presuming this is a carbide bit you should be able to clean it off by soaking it overnight in some thing like Simple Green and then scrubbing it with a brass or stiff plastic brush. If you have a diamond sharpening stone you can touch up the face and beveled edges of the carbide without throwing the bit out of balance.
John,
A few years ago I purchased a MiniMax combo machine. I love the 12" jointer, the long bed and the floor space saved. It takes about 90 seconds to switch to the planer function, again 12" wide. A slot mortiser was a fairly reasonable attachment, so I went for it. It attaches to the side of the combo unit and the bits fit in a chuck attached to the cutter head. The table, with a locking clamp moves in X-Y-Z axes; X and Y with handles; Z (up and down) with a hand crank.
I am not an expert on these things but I understand a birdsmouth bit is the appropriate bit to use on a slot mortiser - perhaps because the reverse rotation would limit the selection of 'normal' bits.. In operation, a mortise parallel to the table, I plunge the bit about 1/16" to 3/32" and traverse the table. At the other end of the cut I repeat the plunge and traverse. It is easy, simple, fast and accurate to cut mortises with repeatable locations.
In the instance in question I needed a mortise at right angles to the traverse motion. (A rare situation.) I locked the table traverse, plunged the bit, as above, and cranked the table up, them plunged and cranked the table down. The motion was too slow and being cherry, smoke arose. I tried Simple Green, undiluted and overnight. No action on the black stuff. The lye-containing oven cleaner worked. I used a brass brush, the bit is clean and sharp.
In my opinion, after trying many methods of cutting mortises, a slot mortiser is the fastest and most accurate method I have tried.
I suspect that what you are calling a bird's mouth bit isn't what I know as a bird's mouth bit. The bit I'm referring to is used to make grooved lengthwise edges on stock so it can be glued up into 6 to 12 sided cylinders.
John, Now I know the bit
John,
Now I know the bit you were thinking of. No, I don't use them on my slot mortiser.
See the attached photos. It cleaned up pretty well, don't you think?
Frosty
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