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deanb
10-05-2011, 03:42 PM
I have a couple very hard (RC 64-66) knives that need their choils and spines rounded. I bought a Dremel today for that purpose. Any tips would be very much appreciated.

JBroida
10-05-2011, 03:43 PM
its freaking hard

Dave Martell
10-05-2011, 03:49 PM
One slip, just one, and it's scratch city.

Pensacola Tiger
10-05-2011, 03:50 PM
I'd suggest trying your luck on a beater knife, one that you don't mind messing up. Dremels are difficult to use without occasional minor loss of control.

I would have chosen to use files and sandpaper, or a 1 x 30 belt sander.

zitangy
10-05-2011, 03:55 PM
own one.. lack of control over such a long surface. I always prefer sandpaper where I have granular control ( By hand) and choose the appropriate grit for the task.

have fun..

rgds d

chazmtb
10-05-2011, 03:58 PM
If you have a variable speed, start slow. Also it would be wise to have a vise with some padding in between the blade to properly secure the blade without scratching it. Use both hands and start on the handle side. As you get towards the blade, it gets easier to slip. I would only go half way up the blade and finish the rest with some rasp or files. BTW, I cut myself very nasty when I was not carefull around the heel. Just be careful.

kalaeb
10-05-2011, 04:19 PM
I have tried the dremel route twice, and screwed up twice. I would say put the blade in a phonebook, put on a good movie and go to work with some sandpaper.

GlassEye
10-05-2011, 04:28 PM
I tried this last week on a beater I found in my garage, it now has a nice big swirl scratched into the face. If you care about the appearance of the knife at all you should do the phone book and sand paper method.

EdipisReks
10-05-2011, 04:39 PM
you should be able to get good results if you can mask off the areas you don't want affected with a durable material. a few layers of duct tape would probably do the job, as you only need to prevent brief contacts.

Mike
10-05-2011, 04:56 PM
I've had success making the dremel stationary and and moving the knife. Keep in mind, you MUST tape the edge, if you want to keep your flesh intact.

WillC
10-05-2011, 04:58 PM
I use something similar to a dremel for rounding the choll when making but I hate to use it after everything is all polished. Look for edm stones on ebay, they cut hardened steel much quicker than wet and dry and are surprisingly quick for rounding the spine and choil. 160gt ones cut good and are a good start to a polished finish get flat ones for the spine round for the choil. Use them dry and rinse everything down before wiping the knife with anything.

NO ChoP!
10-05-2011, 05:02 PM
I have a Dremel stone (about 1/2 inch) that is rounded out (concaved) in the middle; found it at Menards.... works like a charm. I just go back and clean the scuffs with different levels of waterproof sandpaper.

Jameson
10-05-2011, 06:25 PM
+1 on making the dremel stationary with a solid base. SOLID is a relative term, since your not going to put much pressure on the attachement anyway...

Whether your using the stone attachments or the sandpaper attachments (I prefer the latter) you should tape the edge AS WELL as the whole blade face up to just a few mm within the area your working on. You could catch a runner of a trace line if you slip. Finish the tippy tip by hand with stones for best result, I have not tried otherwise...

Once more your going to finish with wet-dry sandpaper to your desired polish level, I go to around 4-600. It isn't important to me on a working knife other than for comfort, so on many pieces I leave nearly all (save 2-3" for pinch) the original "sharp" edges on the spine if they came that way from the factory. They are good for scaling many types of fish in my region (Northeast Striped bass, blackfish, sea bass, various flounders etc.). My point is your going to finish with spaper so you get a smooth transition angle wise, as well as feel/polish. Why wet-dry? It lasts a LONG time, you rinse it often and it CUTS FAST and reuse again and again.... Value wise and performance wise it is better stuff.

My dremel is 15 years old, variable speed top of the line in its year model still runs like a TOP and has done some heavy work in its life. Buy a GOOD one, and it will last a while. I dont know if they make them now like the older ones, but I can't speak higher of it. This past year I bought a bunch of sets of things to experiment with my aging tool, and It has shown its value years over.

JC

Eamon Burke
10-05-2011, 06:47 PM
I have a Dremel, and a Harbor Freight 1x30 belt sander. I don't use the Dremel on knives anymore.

I'm not being snide, I seriously think you should return the Dremel and get a Harbor Freight 1x30 belt sander. Or even a delta 1x30, since a Dremel is much more than a HF 1x30.

tk59
10-05-2011, 08:56 PM
Yup. Belt sander is the only way to go. It takes me about three minutes, I'd say. If I did ten knives it would probably take me ten min. Choils are tricky though.

deanb
10-05-2011, 09:01 PM
When I looked up Harbor Freight 1"x 30" sanding belt it said wood only. This does sound like a neat idea, how does it work on steel? Thanks for all the input folks! I ended up attacking the choils with the Dremel with a grinding cone. After 20 minutes I was starting to see some progress but the grinder was starting to go. Do they make diamond grinders?

tk59
10-05-2011, 09:07 PM
It works fine on steel. Most of the time it takes will be from switching belts and you don't need anything too fancy if you're not regrinding an entire knife. I just use whatever I can get at Lowe's or Home Depot and then polish up with a scotchbrite. You'll have to cut the SB belts down to 0.5 inches though or it won't turn, lol. If you want it to be really pretty, you might have to switch several times and be careful with the tip. Coarse grits and/or heat build-up can fry a tip in a second...or so I've heard. :O

Mike
10-05-2011, 09:30 PM
Enco carries one for 99.99 that is rated for metal and wood that is of much better quality than the HF model. PM me if you want a direct link. (not sure on link policies)

tk59
10-05-2011, 09:44 PM
I see two that are around $100. One of them looks exactly like the HF and has the same hp ratings as far as I can tell only it says that it cuts metal. What is it that makes you think this one will work better?

JohnnyChance
10-05-2011, 10:05 PM
On my A-type I used a 4.5" angle grinder with a flap wheel to do the spine, and an air powered die grinder (same thing as a high powered dremel basically) with a stone bit to reshape and round the choil. I did not tape up the blade and did not scratch up my knife, but it is a good suggestion. I also had removed the handle. Dremels can be tricky to control, rounding a spine is not an ideal first project for your new tool.

Mike
10-05-2011, 11:31 PM
I see two that are around $100. One of them looks exactly like the HF and has the same hp ratings as far as I can tell only it says that it cuts metal. What is it that makes you think this one will work better?

TK59, I've killed 3 of those HF models doing small wooden pieces (payed for one and the warranty covered the broken ones) and the enco is still going strong. For that matter so are the Craftsman (2x42) and Hitachi ( 4x36). But honestly, everyone is free to do as they see fit. I'm sure the HF model will work fine under the right conditions.

tk59
10-06-2011, 12:04 AM
Thanks for the info. What do you like using each of these grinders for?

Mike
10-06-2011, 07:41 AM
Well, I use the 4x36 for general wood working, the 2x42 for handle shaping (mainly because I got a ton of low grit belts very cheap), the Enco for small detail on blades and handles, a 20" disk grinder for wa handles and a 2x72 (GIB) for everything else.

WillC
10-06-2011, 03:15 PM
Its a fun game with cheap tools though, try and burn them out before the year warranty runs out:D

Mike
10-06-2011, 05:43 PM
Just for s**ts and giggles, here is a shot of the gigantic disc sander...

http://1.bp.blogspot.com/-_5xT4Iw9JrA/TmwgSVNYvYI/AAAAAAAAAUQ/Rj53lXKJAZg/s1600/DSC_0005.JPG

WillC
10-06-2011, 05:49 PM
Whoop thats a biggie, ideal for rounding the spines of giant knives.:D

iceman01
10-06-2011, 06:17 PM
I tried using a Dremel, but you have to pay so much attention not to work too long on a single spot. Using two different grits of sandpaper and a piece of wood or hard rubber are so much more convenient and decrease the likelihood of accidentally ruining the knife's finish to almost 0.

SpikeC
10-06-2011, 06:26 PM
Whoop thats a biggie, ideal for rounding the spines of giant knives.:D

Swords more like it!