Hi, I have jus received my T8 and I wish to sharpen my long aquired Bowie Knife, some 50 years ago.
Now, what would be the right bevel, and when one say for an example 40 deg what are we refering to since the knife has to 2
bevels on each side of the blade. ( chisels have one ) I am not so versed in this terminology, sorry to say.
From the photo, maybe one can see the the bevel is so small that I could hadly measure it, so any help is much appreciated.
Thanks
Alf
Alf,
I have no doubt that you will be able to sharpen your fifty year old Bowie knife. However, I suggest you spend some learning/practicing time with inexpensive knives first. Jeff Farris, the founder of this forum make a good knife sharpening you tube. Search "Farris Tormek knife sharpening" to find it.
Enjoy your new Tormek.
Ken
Quote from: Ken S on June 13, 2019, 01:28:50 PM
Alf,
I have no doubt that you will be able to sharpen your fifty year old Bowie knife. However, I suggest you spend some learning/practicing time with inexpensive knives first. Jeff Farris, the founder of this forum make a good knife sharpening you tube. Search "Farris Tormek knife sharpening" to find it.
Enjoy your new Tormek.
Thanks Mate, much appreciate your advice.
Alf
Ken
A Bowie knife is an all purpose knife. It was all a frontiersman had for a knife so he needed it to hack small timber or branches to make kindling and to skin animals and cut meat. About 40 degrees is a good all purpose edge, that means 20 degrees on each side added together equals 40. This edge will excel at nothing but will do good with anything.
Quote from: jeffs55 on June 13, 2019, 04:25:52 PM
A Bowie knife is an all purpose knife. It was all a frontiersman had for a knife so he needed it to hack small timber or branches to make kindling and to skin animals and cut meat. About 40 degrees is a good all purpose edge, that means 20 degrees on each side added together equals 40. This edge will excel at nothing but will do good with anything.
Great jeff, now it is clear, I need it for general purpose task, nothing special, the important that it is sharp :D thank you.
Alf
It is good that you have asked before grinding. To consider if he Tormek knife jig is suitable for your knife let us know how thick is your blade at the spine. Some Bowie knives may be ¼ inch (6 mm) thick and that is too much for the standard knife jig. Sharpening of thick knives requires special care otherwise you will not get the same bevel width on both sides. ;)
Jan
Hi jan, thank you for your reply.
The thickness at the most wide part, because it seems that the back of the blade is not even, it looks like a tapperd back, the middle is the tickest section.
Alf
Seeing the image I´m sure that, with the standard Jig SVM-45, you will have bevels with diferent size.
In this case is suitable to use a modified SVM-45 jig or one self-center jig.
In the absence of a solution for this, it is advisable to read this thread: https://forum.tormek.com/index.php?topic=2962.0
I have a modified SVM-45 jig and it works fine. It's not the perfect solution, but it's the best there is ...
I think too that 20 degrees per side (40º included) is an appropiate grinding angle for this kind of knife.
Regards.
Dusmif,
I recently sharpened a Filipino bolo knife about the same thickness as your Bowie. The bevels will be way off as in several degrees. I don't have a modified jig so my solution was to use the angle finder every time I flipped the knife over and recalibrate the support bar to the same angle on each side. It was a pain but with patience it turned out pretty darn even and razor sharp. I'm not recommending what I did. Do as I say and not as I do. Also I wouldn't sharpen a sentimental family knife (if that is what is is) as your first knife. Took me about 15 or so knives before I started feeling confident on the machine. Just my .02¢.
Best of luck,
Antz
Ps: maybe I just have a longer learning curve than others. I'm not trying to discourage you in anyway. Best of luck
Quote from: Josu V on June 13, 2019, 08:23:29 PM
Seeing the image I´m sure that, with the standard Jig SVM-45, you will have bevels with diferent size.
In this case is suitable to use a modified SVM-45 jig or one self-center jig.
In the absence of a solution for this, it is advisable to read this thread: https://forum.tormek.com/index.php?topic=2962.0
I have a modified SVM-45 jig and it works fine. It's not the perfect solution, but it's the best there is ...
I think too that 20 degrees per side (40º included) is an appropiate grinding angle for this kind of knife.
Regards.
Thank you Josu for this infomation and advice, I am lucky that I asked for advice, other wise I would have ruined my Bowie Knife,.
Regards
Alf.
Quote from: Antz on June 13, 2019, 08:30:34 PM
Dusmif,
I recently sharpened a Filipino bolo knife about the same thickness as your Bowie. The bevels will be way off as in several degrees. I don't have a modified jig so my solution was to use the angle finder every time I flipped the knife over and recalibrate the support bar to the same angle on each side. It was a pain but with patience it turned out pretty darn even and razor sharp. I'm not recommending what I did. Do as I say and not as I do. Also I wouldn't sharpen a sentimental family knife (if that is what is is) as your first knife. Took me about 15 or so knives before I started feeling confident on the machine. Just my .02¢.
Best of luck,
Antz
Ps: maybe I just have a longer learning curve than others. I'm not trying to discourage you in anyway. Best of luck
Thank you Antz, it seems it is too complicated for me being a novice, so I think I better leave it untill either I find a fool proof and safe solution.
Alf.
Alf, I think you have reached a wise conclusion. Your knife will wait for you until you feel confident to sharpen it. You will be more satisfied with your sharpening then.
Ken
Quote from: Ken S on June 13, 2019, 09:43:54 PM
Alf, I think you have reached a wise conclusion. Your knife will wait for you until you feel confident to sharpen it. You will be more satisfied with your sharpening then.
Ken
It waited for 50 years, so another one or two would not make any differnce. :D
Thank you
Alf
Hi, just to justify my curiosity, I made a dummy run without turning the stone to see what is exactly is being said.
Painting the bowie with black felt pen and simulated the sharpening path I found what will happen ( I think ) if I try to do it this way, as You all said, after all.
In the photo I tried to show you what happened, the top image is the starched line marked with red and the bottom image it is how it is without the red line. I hope it is clear for you to see.
Thank you for your time and advice.
Regards
Alf.
What we are saying is that if you now flip the knife jig and run the other side of the blade on the stone, the grind line will be higher; the grinds be of different height on the sides of the blade. Thick blades (i.e. where the blade centerline is above the jig centerline) get a higher bevel on the base side.
Quote from: wootz on June 14, 2019, 12:15:27 PM
What we are saying is that if you now flip the knife jig and run the other side of the blade on the stone, the grind line will be higher; the grinds be of different height on the sides of the blade. Thick blades (i.e. where the blade centerline is above the jig centerline) get a higher bevel on the base side.
Thank you wootz. I apoligies for my lack of expertise, this is something new to me.
I am getting the bevel higher in the front/point of the knife, as you can see from my photo, should I not get the bevel at the bottom of the knife and not 5mm higher up.
Now as you clearly explained I will get a differnce bevel on the other side, which that is insult to injury.
This is a disapointment for me after I spend € 800 and I can't get my Bowie Knife sharpened.
To tell you the truth I bought it to sharpen my working tools, but at least I was hoping I could do even my Bowie. :D
I am sure that a more experience person can do it, so it seems I can't do do it to lack of my ability.
So, the Tormek it seems is restricted to paricular knives only, others with a knife like mine had to modiefy the jig, which I do not know how.
Anyway, thank you for your help and to all those who took the time to post their advice, at least I didn't ruined my Bowie with the help of the forum members.
Regards
Alf.
This spring my countryman shared his unique simple way for sharpening thick knives. He designed eccentric cam for the SVM-45, which should enable to mount also thick knives symmetrically.
https://forum.tormek.com/index.php?topic=3918.msg26586#msg26586
Recently I have received a sample of this cam printed on a 3D printer. I plan to test it soon.
Jan
Quote from: Jan on June 14, 2019, 05:27:50 PM
This spring my countryman shared his unique simple way for sharpening thick knives. He designed eccentric cam for the SVM-45, which should enable to mount also thick knives symmetrically.
https://forum.tormek.com/index.php?topic=3918.msg26586#msg26586
Recently I have received a sample of this cam printed on a 3D printer. I plan to test it soon.
Jan
Thank you Jan, It seems promising, but I hope that you or someone will make a video how to use it, because I am still not able to understand how to use it. Again thank you.
Alf.
I made two, one with more offset than the other. Works well.
Alf, we've all been there with thicker knives. The fact is that no slow wet grinder, Tormek or else, has a self-centering knife jig.
Any local machining shop at your place should be able to mill the 0.5 mm and 1 mm recess for you, using an end-mill. Bring the 2 knife jigs to them disassembled, give them only the lower static part, and draw a line in front of the pins with a permanent marker to show them where to mill. It is a 5 min job for the machinist/turner.
Show them a photo from my website to illustrate what is be done: http://knifegrinders.com.au/05Equipment_jigs.htm (http://knifegrinders.com.au/05Equipment_jigs.htm)
For the bevel not to widen towards the tip, clamp the knife not in the center of the blade, but closer to the tip - this is explained in the Tormek manual.
Quote from: wootz on June 14, 2019, 10:46:02 PM
Alf, we've all been there with thicker knives. The fact is that no slow wet grinder, Tormek or else, has a self-centering knife jig.
Any local machining shop at your place should be able to mill the 0.5 mm and 1 mm recess for you, using an end-mill. Bring the 2 knife jigs to them disassembled, give them only the lower static part, and draw a line in front of the pins with a permanent marker to show them where to mill. It is a 5 min job for the machinist/turner.
Show them a photo from my website to illustrate what is be done: http://knifegrinders.com.au/05Equipment_jigs.htm (http://knifegrinders.com.au/05Equipment_jigs.htm)
For the bevel not to widen towards the tip, clamp the knife not in the center of the blade, but closer to the tip - this is explained in the Tormek manual.
Thank you wootz,for your time to post this advice and explanation. I will study your photos and I can do the milling myself, ( I have to buy another jig, just in case I make a mistake :D ) because I have a milling machine along with a lath too. Regarding the clamping of the knife, it is a very good advice, I will try it too. I have not read the manual because mine is in German, since I bought the T8 fom Germany; no agent here in Malta for the Tormek. :( But I try and download it and print it.
Thank You.
Alf.
Quote from: Antz on June 13, 2019, 08:30:34 PM
Dusmif,
I recently sharpened a Filipino bolo knife about the same thickness as your Bowie. The bevels will be way off as in several degrees.
This is my pet peeve, biggest complaint with the Tormek. There is no way around this issue using Tormek supplied jigs.
Quote from: jeffs55 on June 16, 2019, 04:47:48 PM
Quote from: Antz on June 13, 2019, 08:30:34 PM
Dusmif,
I recently sharpened a Filipino bolo knife about the same thickness as your Bowie. The bevels will be way off as in several degrees.
This is my pet peeve, biggest complaint with the Tormek. There is no way around this issue using Tormek supplied jigs.
That is really very disapointment, as you said. I would except Tormek should solve this problem, knowing this issue.
Alf.
Quote from: wootz on June 14, 2019, 10:46:02 PM
...snip...
Any local machining shop at your place should be able to mill the 0.5 mm and 1 mm recess for you, using an end-mill. Bring the 2 knife jigs to them disassembled, give them only the lower static part, and draw a line in front of the pins with a permanent marker to show them where to mill. It is a 5 min job for the machinist/turner.
Show them a photo from my website to illustrate what is be done: http://knifegrinders.com.au/05Equipment_jigs.htm (http://knifegrinders.com.au/05Equipment_jigs.htm)
...snip...
It is a very easy operation. I clamped the fixed jaw (static in Wootz' terminology) directly to the mill table, using precision parallels to lift it off the table to clear the "Tormek" logo raised lettering. I used other precision parallels in the mill table slots to align the front edge and clamped it using standard mill table clamps. This placed the upper/inner surface of the jig parallel to the table top and locating pins parallel with the longitudinal axis. If you don't use the parallels under the jig, the locating surface of the inner jig jaw will not turn out parallel and the knife will mount canted.
I used a 1/2" carbide end mill and made a couple passes, shifting to ensure full coverage. To start, I brought the end mill down to just touch the jig surface and then using the knee of the mill, raised the table the desired amounts of stock removal. I did use the DRO readout to know how much to raise the table, but using the knee screw, the DRO is not necessary at all. If using a mill that does not have a knee, bring the quill down to just touch and use a spacer in the quill stop to set the depth. Check your work as you progress to be sure to not over-shoot the desired depth/stock removal.
Didn't take any photos of it, but I could set it up again and take some, it is that easy.
Rick
Thank you Rick.
When I decided to buy the Tormek, I thoght, well my worried days are over for sharpening my tools, first week I was a bit confused, now after trying to read as many as threads as possible on this subject: Now I am lost :-[ That what old age dd to you. ;D
Alf, J.W.Goethe said: 'All theory is gray, but the tree of life, my friend, is green.' :)
I thing that after successful sharpening of first couple of knives you discover the wonderful world of sharpening and forget the initial stumbling.
What concerns your Bowie knife, the Tormek knife jig is not suitable for such a thick knife. When you mill away 1 mm from the static clamp (as mentioned by Wootz and Rick), you will get a jig for a 4.5 mm thick knife. For your Bowie knife it would be necessary to mill away 2 mm, but this is not possible because the static clamp has not enough material.
Recently I have built a self-centering knife jig for Tormek which was inspired by the Lansky knife clamp.
https://forum.tormek.com/index.php?topic=3834.msg25694#msg25694
This simple jig guaranties the same bevel angle for both sides of thick knives. It is an easy afternoon task if you have a shop with drill press and a belt sander. ;)
Jan
Quote from: Jan on June 18, 2019, 03:19:11 PM
Alf, J.W.Goethe said: 'All theory is gray, but the tree of life, my friend, is green.' :)
I thing that after successful sharpening of first couple of knives you discover the wonderful world of sharpening and forget the initial stumbling.
What concerns your Bowie knife, the Tormek knife jig is not suitable for such a thick knife. When you mill away 1 mm from the static clamp (as mentioned by Wootz and Rick), you will get a jig for a 4.5 mm thick knife. For your Bowie knife it would be necessary to mill away 2 mm, but this is not possible because the static clamp has not enough material.
Recently I have built a self-centering knife jig for Tormek which was inspired by the Lansky knife clamp.
https://forum.tormek.com/index.php?topic=3834.msg25694#msg25694
This simple jig guaranties the same bevel angle for both sides of thick knives. It is an easy afternoon task if you have a shop with drill press and a belt sander. ;)
Jan
Hi Jan,
You are a lifesaver, I was worried sick thinking about how to modify the Tormek jig, knowing that 50% if not 75% I would destroy it.
With your idea I am more at ease doing this jig, knowing that if I am not satisfied with the result I just try another, time is no problem for me.
I assume that to find the bevel with your jig is the same as one do with the Tormek knife jig?
I never thought that to sharpen a knife involves so much calculations, and special jigs.
Thanks mate.
Alf.
Alf, you are welcome! :)
Yes, the bevel angle setting process for the self-centering jig is the same as for the Tormek knife jig. It is descried in the hand book.
Knife sharpening is a specialised know-how, but do not be worried about many calculations. Later you will see that sharpening a knife with standard thickness (2-3 mm) is a routine task.
In the attached picture you can see how typical sharpening process works geometricaly.
Jan
Hi Jan, Thank you.
It is good to know that there is always online help for any future problems, thanks to members of this forum.
I tried several chisels and in that regard I am very happy with the results, they are the easiest to do, I think, now I will try some of my plane blades, I assume these will be no problem too.
The knives are the tricky ones, it seems, but in time I am sure I will find a way how to do them, I am in no hurry and willing to learn.
I will start with some old knives ( not important ones ) I have and leave the bowie until I get some experience and finish your jig ;D
Thanks.
Alf.
Alf,
If your initial attempt to modify the knife jig does not go well, here is a link to the part replacement:
https://advanced-machinery.myshopify.com/pages/replacement-parts-for-svm-45-svm-100-and-svm-140-knife-jigs
https://advanced-machinery.myshopify.com/pages/replacement-parts-for-svm-45-svm-100-and-svm-140-knife-jigs
Also, be sure to register your Tormek online (www.tormek.com). Once you log on, you can download the latest version of the handbook in multiple languages at no charge.
Ken
Quote from: Ken S on June 19, 2019, 11:05:24 AM
Alf,
If your initial attempt to modify the knife jig does not go well, here is a link to the part replacement:
https://advanced-machinery.myshopify.com/pages/replacement-parts-for-svm-45-svm-100-and-svm-140-knife-jigs
https://advanced-machinery.myshopify.com/pages/replacement-parts-for-svm-45-svm-100-and-svm-140-knife-jigs
Also, be sure to register your Tormek online (www.tormek.com). Once you log on, you can download the latest version of the handbook in multiple languages at no charge.
Ken
Thank you Ken, for the information and links, at least one does not have to buy the full jig.
I have registered my Tormek as soon as I received it last week, I think, and I have downloaded the manual and printed too.
To day I manged to sharpen one of my planes blade, I can't understand how I used to work before I bought the Tormek, the differnce in sharpnes I can't believe it, I could not stop trying the new blade, it is joy to work with so sharp blades ;D
Thanks.
Alf.
Quote from: dusmif on June 19, 2019, 11:35:20 AM
... I can't understand how I used to work before I bought the Tormek, the differnce in sharpnes I can't believe it ...
Amen brother.
Gentlemen, I do not have as much experience, possibilities or resources as many of you, but I have been using my tormek T-8 for more than a year and many years in sharpening with different methods, and I have had to sharpen knives of more than 2.5mm. thickness that I understand is the standard groor of a kitchen knife, for which the tormek plates for long and medium knives were destined.
I can not buy a replacement template so easily, I live in South America, and that would involve at least 20 days of waiting, higher extra shipping costs, and I can not afford to try to engineer my jig and take the risk of it going bad.
So in my case I did something that took only 2 more seconds when I sharpened both sides of a 4, 5, or 6 mm thick knife.
This is what I usually do:
If for example I'm going to draw a 20 dps edge, with the tormek turned off, I measure any of the 2 faces of the knife mounted on my template svm-45 or svm-140 with my tormek anglemaster template at 20 degrees, and with a permanent marker fine tip, I mark a line on the stone SG-250 where the edge of the knife rests on the stone, step then, I turn the knife to the other side, that we all know that will not be touching that line, because the knife is thicker than what the jig requires, then I draw with a white permanent marker, the black paste base of the jig "the one that makes contact with the usb", and I draw on the jig another white line, so that the white line of the jig, is with the white line of the black round paste that rests on the usb, and with the help of the angle master I start to move the black paste of the jig that has contact with the usb until it re-marks the 20 degrees, and I verify that the edge is again on the black line marked on the stone, once I have these 20 degrees, I look at the distance of the white line of the paste in relation to the white line of the jig and I return to mark a new white line, that gives me an exact information of the displacement that I must do in the black jig dough wheel for that side of the knife, and I mark an arrow in the direction of the turn that I must make.
When I turn the knife to sharpen the other side, I just have to go from one white line to the other, and with a little more time I have achieved a correct angle of sharpening on each side of the knife.
it may be that all this is too obvious for many, inpractical for others, a lot of delay for some others, but someone who does not want to take risks, who wants to keep his jig tormek original or who had not thought about this possibility before, can reach him to serve this advice.
Apologies for the length of the message but I wanted to detail it as best as possible so that it is understood.
Thank you Fernando, that is helpfull. ;)
Alf