Recycling carbide into parting tool

[sumu]

Hello,

I'm not much of a wood turner at all, mainly interested in the topic. Therefore I wonder if this is already known thing here?

My pal was recycling material from a thicker and used up circular saw blade to make a modified riving knife.

There was some longer leftover slices the carbide bit still attached, and it came to me whether it would be feasible to recycle those slices for wood turning, to make thinner parting tools or such. Just add handle.

The cutting plan in the pic maybe has too narrow shank, and shape or angle is perhaps not the best there would be, but then again, can't get much cheaper to get a grip on a parting tool having quality steel body and well-brazed carbide tip.

What would you fellas think?

kippis,

sumu

[Frank&Earnest]

Hi Sumu,
I am not much of a turner myself, but I love experimenting and making tools. Your idea looks good, don't know whether it will work but given the chance I'll certainly play with it, if cutting is not too difficult. Would a hacksaw and a grinder be enough?

[joe greiner]

Don't see why not. Probably could use only every other tooth, and make several, for spares/gift or sell to others.. A cutoff wheel in a right-angle grinder would be less purgatorial than a hacksaw. I'd also use a cobalt drill for mounting holes, depending on hardness of the parent blade. Might even be worthwhile to use a new blade if not too dear.

Joe

[hughie]

Absolutely!

Just heat the tips up till the silver solder melts and the tips drop off. Then resolder them on to your new turning tool.

[TTIT]

1mm cutting disk in an angle grinder would cut it out like butter but I'm not sure that it would be rigid enough for a parting tool :shrug: . Circular saw blades are surprisingly flexible so a thin section might be a bit floppy - but I'd be interested to know how it goes!!!

[joe greiner]

Actually, the carbide might be overkill. Especially considering the amount of work to make it.

A few months ago, Gil Jones gave a demo at our WT club of turning his flowers from fresh small branches (posted on this forum). He uses a DIY parting tool made from a saw blade (hacksaw or bandsaw IIRC). After the demo, I had a go at it. Once the parting tool has engaged the work, the kerf maintains stability, so floppy wasn't much of an issue. Perhaps Gil will chime in with more insight.

Joe

[artme]

Sumu's idea is good but I'm wondering if the TC tip shouldn't be ground down on either side to blade level. This way it shouldn't get the wanders in the slot during parting.:?

[orraloon]

The TC tip being wider than the blade is a plus and will prevent the blade binding in the cut. The blade tip will be doing just what it did on the saw It looks like a good idea and I will be pulling the shed apart looking for old blades.

Regards
John

[tea lady]

You'll be using a diamond grinding wheel for a couple of hours grinding the tungsten carbide flush. It can cut metal and stuff. I covet some of the stuff to turn my pottery. Anyone near Belgrave with a spare blade kicking round? I'm real' nice and everything.:;

[hughie]

Actually, the carbide might be overkill. Especially considering the amount of work to make it.



In parting tools your probably right. Hacksaw blades are right up there with Files in hardness, especially the power blades.

But for the rest, they do make a good tool for rough outs etc. HSS will sharpen to a finer edge and so will always be better for finish type work.

[sumu]

Hello fellas,

There was a lot of feedback, all quality stuff, thank You very much :). I really wonder should I now purchase a real lathe of my own. My experience is limited there I have occasionally had a chance to try out my pals' lathes.


You'll be using a diamond grinding wheel for a couple of hours grinding the tungsten carbide flush.


Oh, not really. A bench grinder equipped with a green silicon carbide wheel (and a wheel opener/dresser) will do the job cheaper and quite fast. Go for Norton green SiC wheels for carbides, those are good ones.



I covet some of the stuff to turn my pottery.
Honestly, I would recall I have never even heard about pottery turning work. Does it happen in green state or in fused state?

I wonder if you thwacked some bench grinder SiC wheel in smaller pieces and took one suitable piece and glued it halfway in the other end of a steel tube with a generous amount of thick epoxy. Would it make a pottery turning tool? When it wears out, just a minor thwack against some granite or with a sharpened mason's hammer and there is a new sharp edge again.

I wonder if suitable pieces of angle grinder stone cutting wheel would do the same?

kippis,

sumu

[artme]

You are wondering whether you should get your own lathe?:doh:

Are you a bloke? If the answer is yes then you know not what you should do, but what you HAVE to do.:-:p

[JDarvall]

I think thats a great idea Sumo. Giving me some other ideas too. Thanks.

[sumu]

You are wondering whether you should get your own lathe?:doh:

Are you a bloke? If the answer is yes then you know not what you should do, but what you HAVE to do.:-:p

The problem is the small shop I have, not the thing I have to fit in it.

Clear enough? :D

kippis,

sumu

[sumu]

I think thats a great idea Sumo. Giving me some other ideas too. Thanks.

You realized it too? :D

kippis,

sumu

[JDarvall]

You realized it too? :D

kippis,

sumu


:wink: brilliant. Durable edge ready to go. Best to cut up a new blade though I reakon for sharper tips. An old one maybe a bit on the blunt side. But maybe still good enough ? ....Have to try.

Maybe I could buy a cheapy brand new blade and cut it up. Make a dozern parting tools......chop up a dozern little handles from a strip of dowel. Drill holes in the handles. Knock them in with a bit of epoxy.(thwack) Stick them all on the shelf and never have to sharpen a parting tool ever again ! now that sounds good.

KIIIIIIIIIIIIIPIS Jake. :D

[Gil Jones]

I have standard carbon and HSS parting tools, but for my favorite one I used a fish fillet knife with a 1/16" thick blade. That may be what Joe saw me using. It is not fancy steel, but I like the way it parts off with a nice thin cut. Carbide seems a bit of overkill for a parting tool, and it will not take as keen an edge as carbon or HSS. Plus, it requires a special wheel to properly grind it (green or diamond).

[tea lady]

Most pottery is turned on the base if it is hand thrown. Usually done at the "leather hard "stage, half way to dry. It is inverted on the pottery wheel and fixed temporarily to the wheelhead with clay or on a chuck of some sort. The difference from wood turning is only the direction of the turning. The tool is effectively pulled across the work instead of pushed. The tools are always going blunt because clay has quartz in it, so even though it is soft the tiny particals are wearing away the edge. I have a silicon carbide turning tool that is doing pretty well. but you know the law about tools. One can never have enough.

[sumu]

Thanks, now I got it. As you might have guessed already, I got an association where a vase or similar is put spinning in a lathe :? :).

You see, there is some very rare techniques in high-end technical ceramics processes where sintered ceramic components are actually turned in a special lathe using diamond honing tools. It is most demanding job, because if it's done too aggressively, the surface of the ceramic piece will be loaded with microfractures not possible to recover. Strength of the piece will be anything between 0%...50% of the original. If done too slowly, it will never be finished. A very rarely seen technique for extremely special applications for refractory industry, chemicals manufacturing stuff and such. That's why ceramic blade knifes are difficult to sharpen, to get both sharp and lasting edge.
That's why I was a bit amazed, would the sintered pottery be as strong after turned with a carbide tool just like that :).

kippis,

sumu

[Frank&Earnest]

:wink: brilliant. Durable edge ready to go. Best to cut up a new blade though I reakon for sharper tips. An old one maybe a bit on the blunt side. But maybe still good enough ? ....Have to try.

Maybe I could buy a cheapy brand new blade and cut it up. Make a dozern parting tools......chop up a dozern little handles from a strip of dowel. Drill holes in the handles. Knock them in with a bit of epoxy.(thwack) Stick them all on the shelf and never have to sharpen a parting tool ever again ! now that sounds good.

KIIIIIIIIIIIIIPIS Jake. :D

Jake, if that is what you want, why not just use the blade as such and avoid all the trouble? Once kept in position by a suitable handle/rig, you present a tooth to the piece and the rotary motion is provided by the lathe. You just "saw" the piece off. If you lower the blade with a counterweight, you do not even need to guide it with your hand, so you have both hands to support the piece. Wonderful for large pieces. Makes sense?

[joe greiner]

Jake, if that is what you want, why not just use the blade as such and avoid all the trouble? Once kept in position by a suitable handle/rig, you present a tooth to the piece and the rotary motion is provided by the lathe. You just "saw" the piece off. If you lower the blade with a counterweight, you do not even need to guide it with your hand, so you have both hands to support the piece. Wonderful for large pieces. Makes sense?

I'd suggest extreme caution in trying this trick. The extra teeth may grab the kerf, and create lots of excitement. I tried something like this once with a hand saw or hack saw, and didn't enjoy it at all.

Joe

[RETIRED]

I'd suggest extreme caution in trying this trick. The extra teeth may grab the kerf, and create lots of excitement. I tried something like this once with a hand saw or hack saw, and didn't enjoy it at all.

JoeOr excrement? :roll:I know what you mean Joe, did the same thing myself early on.:D

[NeilS]

I tried something like this once with a hand saw or hack saw, and didn't enjoy it at all.

I wouldn't recommending it to others, but I frequently use a hacksaw (not just the blade) to cut off small spindle work....a sharp and well set blade is best. I brace the rear of the blade assembly against the tool rest to counter the thrust (sudden and fast if it grabs) towards me. The finish is not as clean as you can get from the skew or bedan in expert hands, but its quick. As always with any turning, I wear a face mask which is even more necessary given the brittleness of the hacksaw blade.

Neil

[Frank&Earnest]

Yes, there are always opportunities for fun (including changing pants:D) when experimenting different ways of doing things, that's why I love it.:)

The hacksaw solution, although feasible, as Neil and I can attest, should be a totally different proposition, though.

Virtually only one of the widely spaced teeth should engage the wood at any one time (except for a short transition time from one tooth to the next if a pivoting point is used ) because its tip is the tangent point of two circumferences, there is ample space between teeth and there is no set to change the point of contact.

And with a 2.5 mm thick blade flexibility is not an issue.

Terrible sketch to show what I mean:

[Skew ChiDAMN!!]

There're two or three reasons I wouldn't use something like that, FE.

I'd quickly become sick 'n tired of setting it up all the time. I certainly wouldn't leave it permanently set up - I have this thing about having axes hanging overhead. :roll: Wood can (and does) jam up big time with a single kerf cut. On a tablesaw this shows itself as kickback. On your setup, well... I suspect it wouldn't be the timber that comes flying out... :oo: (Like Joe & , I've scared myself with a handsaw.) It could only be used for cuts straight across. When parting off I usually make the cut double or triple width to not only avoid any jamming issues but to also allow me to undercut the foot. ie. make it concave. As often as not I don't need to reverse mount the piece to clean up the foot that way! Just a quick clean of the final "break" with a chisel, et voila.

Mind you, that's just my opinion. I've no intention of trying to stop you from building one. :U

I rather like the original idea of making several tools from an old blade, though. I shouldn't think the side flex would be much of an issue, unless you're trying to make a single plunge cut. Which ain't a good idea even with a "proper" parting tool. Resharpening the tip(s) - I've too much need for my good CS blades - in the first place would be of more concern to me.

And if the first tool doesn't work well enough for me, the rest of the blade could always be cut up into card scrapers... for which it does work well. :2tsup:

[joe greiner]

No matter where you place the saw (circular, hand, hack, etc.) - top, bottom, one side or 'tother, this cut is particularly hazardous between centres. The workpiece is a simple beam between the centres, and the cut is on the compression side of the beam. As you reduce the cross section, the bending becomes more severe precisely at the location of the cut, and pinching becomes worse. This occurs even with an ordinary parting tool. Like Skew says, extra width (only needs a mm or two) helps to prevent pinching as the cut gets deeper.

The hazard can be reduced by placing a support on the side opposite the saw to prevent flexing. This could be a wheel (e.g. steady rest) or even an assistant with a crowbar if it doesn't mar the surface beyond repair.

I'm not saying that a saw shouldn't be used for final separation. In fact, it's one of my favourite methods for largish diameters; but I do it with the lathe stationary, and rotate the workpiece by hand with the same hand providing support on the far side. For faceplate turning, the hacksaw can provide a "window" to prevent dropping the piece onto the lathe bed. Like this for the bagels for my recent "eccentric" platter. The spanner handle resting on the motor provides resistance for the cut - about the only benefit from having the motor where it is.

Joe

[JDarvall]

Well, I still like your idea FE ! :wink:...may not work, but one idea often leads to another eh.

[Frank&Earnest]

Well, I still like your idea FE ! :wink:...may not work, but one idea often leads to another eh.

Yep, that's the spirit... but, as usual, Skew is right. Even assuming that this rig would cut as expected (still can't see why not) it is not practical for the reasons he mentioned, and the compensating advantage of hands free operation would be rather little, it would appear. :shrug:

I just had one good reason to use the hacksaw recently, though: having left very little room to cut off my first goblet, I could not do it with a parting tool, so used the hacksaw to cut into the first centimetre of the radius, dismounted the finished goblet and then carefully cut off the rest with the bandsaw, rolling gently. Would not recommend that to the squirmish either, especially with fingers millimetres from the blade!:D

[JDarvall]

I wish I could give you a decent conversation FE on that. I haven't had that much lathe experience. Just the odd thing here and there. Never made a goblet.

Whenever I do saw off though, its always with the engine off.

I really do like Sumos idea though on making a regular parting tool.

[soundman]

But is it all worth the bother.........stock parting tools seem to work fine for me.
By the time you cut the blade up and solved the various geometry & presentation problems....... and so forth..... just too much fiddle.

Yep I have been known to use a hack saw in the lathe.... works fine.

now if you set up a metal work parting tool complete with the replacable carbide insert...... that might be a bit more viable.
But i think the cut would be a bit rough....... carbide might hold an edge fro a long time but it is never as sharp as HSS.

cheers