Sharpening a curved adze

discussion of anything related to tools

Moderators: jrccaim, Bob_Fleet, gavin, Robin Fawcett, HughSpencer

Sharpening a curved adze

Postby mrcharly » Tue Mar 12, 2013 10:20 am

I have a German (or possibly Austrian) adze, similar to this model:
Image

The bevel is on the inside and is much steeper than on the Mueller adze.

I've tried sharpening this with wet and dry wrapped round a broomhandle, with very limited success. The steel seems very hard - the wet and dry skates off with no 'bite'.

Does anyone have any suggestions for techniques?
mrcharly
Regular
 
Posts: 29
Joined: Sun Mar 10, 2013 10:18 pm
Location: York

Re: Sharpening a curved adze

Postby gavin » Tue Mar 12, 2013 2:22 pm

If the blade is circular in profile, you could use a drum sander ( similar to Veritas' blade sharpening)
Yours looks approx 50 mm diameter. If so you'd use a 50 mm drum with variously decreasing grits.
You could probably turn a drum or mandrel to the required diameter and fix sandpaper to that drum. How you'd fix the blade relative to the rotating mandrel and how you'd power it is up to you. You could (possibly) use a pole lathe and a slave to treadle it whilst you held the blade, but you'd be better on an electric lathe's chuck-mounting to get one end accessible.

Some belt grinders have a variety of wheel diameters e.g. RadiusMaster - I find this brand very useful :D
Image
Gavin Phillips


- teacher, demonstrator & supporter of greenwoodworking & human-powered turning
- Supplier of Fun & Confidence

info@shed-therapy.com
http://www.shed-therapy.com
User avatar
gavin
Regular
 
Posts: 1595
Joined: Mon May 16, 2005 4:17 pm
Location: Dalbeattie, near Dumfries, Scotland

Re: Sharpening a curved adze

Postby mrcharly » Tue Mar 12, 2013 2:57 pm

That's an interesting thought - I don't have access to such a machine, but I do have a bench grinder with a slow-speed waterwheel. I wonder if I could take the stone wheel off and replace with something suitably radiused? Sticking the wet and dry down could be difficult tho.
mrcharly
Regular
 
Posts: 29
Joined: Sun Mar 10, 2013 10:18 pm
Location: York

Re: Sharpening a curved adze

Postby ToneWood » Tue Mar 12, 2013 3:21 pm

There is a video tour of Ben Orford's workshop on youtube and he too has a fancy belt grinder. A very expensive piece of professional kit I would imagine though.

Have you tried using your adze yet? Are you just looking to sharpen it or to grind a new outside bevel? I believe forum member David Fisher re-ground one of his adzes (a Pfeil, I think), he may be able to offer some suggestions/insights. If it were me, for sharpening I would just use sharpening/strop sticks (flat & dowel) - if the cutting edge is hard as you say (my HK seems to be too) it shouldn't need much sharpening because it won't easily become blunt. But to regrind a new outside bevel, I'd probably work the outside bevel free-hand on my big wet grinding wheel and/or my little bench-top wet grinding wheel (Westfailia sell a couple of relatively inexpensive models, haven't tried them though). Alternatively, diamond stones (about £5 for a cheap, largish set of flat ones) should cut through most things - but I expect it would be long, hard work to grind a new outside bevel by hand.

I don't really have anything to grind an inside bevel (not something I'd have much use for), except maybe:
  • a small inexpensive hand-drill mounted sharpening stone/wheel (have a couple of these)
  • or perhaps my Dremel-like mini-drill with one of its grinding attachments -- I guess the miniature size should help minimize damage if you make mistakes :^/
  • the 12", coarse, round cigar shaped carborundum stone that I use for keeping billhook & reap hooks keen (about £2 if you shop around, about £6 if you don't - quality varies, higher price not nes. better) - could use it like a large, rough slip-stone I suppose.
Although I'd be loath to recommend any of them for this purpose.
Last edited by ToneWood on Fri Mar 22, 2013 1:47 pm, edited 2 times in total.
ToneWood
Regular
 
Posts: 1846
Joined: Mon Jan 30, 2012 2:21 pm

Re: Sharpening a curved adze

Postby mrcharly » Tue Mar 12, 2013 3:26 pm

I've used it a bit.

I bought it, tried it, couldn't get on with it. Stopped doing any woodwork.

Then tried again, just for a laugh, shaping a wooden kitchen spoon out of some rubbish pine. Apart from a bit of sanding, did all the shaping with the adze.

I think the problem was that I initially tried it on seasoned fruitwood. It's not suited to that. The blade is too thick with a steep bevel.

Been shaping some hawthorn into a rough bowl, including taking off the bark. This has inevitably dulled the blade a bit, since there was a bit of dirt in the bark.
mrcharly
Regular
 
Posts: 29
Joined: Sun Mar 10, 2013 10:18 pm
Location: York

Re: Sharpening a curved adze

Postby ToneWood » Tue Mar 12, 2013 3:29 pm

mrcharly wrote:That's an interesting thought - I don't have access to such a machine, but I do have a bench grinder with a slow-speed waterwheel. I wonder if I could take the stone wheel off and replace with something suitably radiused? Sticking the wet and dry down could be difficult tho.

Most carvers seem to prefer an outside bevels on tools - probably because outside bevels tend not to bury the tool in your work. My HK adze appears to have both inside & outside bevels - but if you watch Jogge Sundqvist's excellent DVD the outside one seems to be considered the main bevel. Outside bevels, it seems, are also easier to maintain without special tools than inside bevels.
Last edited by ToneWood on Wed Mar 13, 2013 2:29 pm, edited 1 time in total.
ToneWood
Regular
 
Posts: 1846
Joined: Mon Jan 30, 2012 2:21 pm

Re: Sharpening a curved adze

Postby ToneWood » Tue Mar 12, 2013 3:33 pm

mrcharly wrote:...I think the problem was that I initially tried it on seasoned fruitwood. It's not suited to that. The blade is too thick with a steep bevel...
Yes, I tried that too :(. Green wood is definitely the way to :). Sounds like a small wheel on your wet bench grinder might work - or perhaps one of those paper/cotton/felt wheels with grinding paste/compound then polish?
Image
Last edited by ToneWood on Tue Apr 02, 2013 7:38 pm, edited 2 times in total.
ToneWood
Regular
 
Posts: 1846
Joined: Mon Jan 30, 2012 2:21 pm

Re: Sharpening a curved adze

Postby DavidFisher » Tue Mar 12, 2013 3:36 pm

I would suggest a simple sanding drum in your portable drill. The firm rubber cylinder with the cardboard sanding sleeves. It is surprising how fast these will remove metal, but not build up heat. I wouldn't recommend it at all for regular sharpening, but for reshaping/grinding an inner curve, works great. With a reversible drill, you can switch directions of spin, which helps to maintain control as you approach the corner of the adze. pull against the rotation. The diameter does not have to match the curve of the adze. You just don't want something too narrow and make ripples. Keep it moving steadily.
DavidFisher
Regular
 
Posts: 126
Joined: Sun Dec 24, 2006 3:27 pm
Location: Greenville, Pennsylvania USA

Re: Sharpening a curved adze

Postby mrcharly » Tue Mar 12, 2013 3:48 pm

Something like this?
http://www.screwfix.com/p/rubber-drum-sanding-kit-25pcs/19906

Seems amazingly cheap. Thanks for the tip. I'll probably get one this weekend and will report back.
mrcharly
Regular
 
Posts: 29
Joined: Sun Mar 10, 2013 10:18 pm
Location: York

Re: Sharpening a curved adze

Postby DavidFisher » Tue Mar 12, 2013 8:06 pm



Yep. That's not the same brand of kit I have, but it looks to be essentially the same exact thing. Maybe get a few extra sanding sleeves while you're ordering. I'd use a variable speed drill so you can, well, vary your speed. Hold the drill firm and steady, and build up to speed.
DavidFisher
Regular
 
Posts: 126
Joined: Sun Dec 24, 2006 3:27 pm
Location: Greenville, Pennsylvania USA

Re: Sharpening a curved adze

Postby ToneWood » Sat Mar 16, 2013 7:44 am

Just noticed something that might be useful in Wille Sunqvist's book (P82 of German version) he uses a conical extension to what looks like a bench-grinder or Tormek bench wheel (can't tell as only the end is shown). Possibly a grinding and/or honing accessory. In the picture it is being used on the inside of a spoon-knife/hook-knife.
http://books.google.co.uk/books?id=qgZS ... st&f=false
ToneWood
Regular
 
Posts: 1846
Joined: Mon Jan 30, 2012 2:21 pm

Re: Sharpening a curved adze

Postby mrcharly » Mon Mar 18, 2013 10:13 am

I bought the screwfix drum sanding kit. Unfortunately they only had 80 grit sleeves.

It's a brill bit of kit, for the price. Put the adze in a vise and used a cordless drill. I've slightly reprofiled the bevel and sorted out the edge. Removed the blue paint from the blade section, then finished off the edge with a waterstone.

Much much better now. Chopping there isn't much difference, but I can also use the adze as a gouge, pushing it through the wood.

Made an adzing log from a large willow log and shaped a spoon from the waste. So much faster and more precise with a decent worksurface and sharpened tool.
mrcharly
Regular
 
Posts: 29
Joined: Sun Mar 10, 2013 10:18 pm
Location: York

Re: Sharpening a curved adze

Postby ToneWood » Mon Mar 18, 2013 1:42 pm

Excellent - I'd never come across drum sanders for drills before.

BTW I think jrccaim meant to post this post to this thread (rather than Sundqvist Schliefstock - Sharpening/Grinding stick?):
jrccaim wrote:Sharpening curved edges is always a bear. My experience is with big gouges. But ideally what would you do? Well, you would find a "stone" that exactly matched the edge you would like to have. Further, you would have this stone in varous grits, so that you could refine the edges. Alas, we live in a non-ideal world. So we have to find substitutes.

To my mind the best thing available is a slipstone. Look at http://thebestthings.com/newtools/norton_slips.htm. Here you have a nice assortment of slip stones meant to sharpen round tools, and this was found with about 2 minutes google search on slipstones. I am sure you can do better with more time invested. The stone in the middle of the pic might do your business, but if you search further you will find some more. For an adze you want the biggest radius you can get. For a big gouge the above might suffice. Point is, try to match the sliptone to the radius of the adze. Look also for japanese tools. They are much more aware of tradition than we are. It is very nice to have an assortment of slipstones. Both concave and convex. Oh and BTW a slipstone is nothing more than a rounded sharpening stone.

If what you have is an outside bevel, then you can get away without slipstones. The trick is to constantly rotate the tool. Use a flat stone. Use the grit you want. Much easier to find flat stones than slipstones! Take three-four stroke strokes on your tool. Rotate just a tad. Keep bevel absoultely flat on the stone. It is a pain, I know. Oh how I know It is very tedious. If you keep up with your edge is is a lot less tedious. Be sure to remove any burrs at the end; use a round stone for this, also easy to find.

If you have an inside bevel, I see no alternative to purchasing several slipstones. Not for me to advise you; no idea on what you have... but do try to match the curvature of the stone(s) to the gouge. Less work that way.
ToneWood
Regular
 
Posts: 1846
Joined: Mon Jan 30, 2012 2:21 pm

Re: Sharpening a curved adze

Postby jrccaim » Fri Mar 22, 2013 4:55 am

ToneWood wrote:Excellent - I'd never come across drum sanders for drills before.

BTW I think jrccaim meant to post this post to this thread (rather than Sundqvist Schliefstock - Sharpening/Grinding stick?):
jrccaim wrote:Sharpening curved edges is always a bear. My experience is with big gouges. But ideally what would you do? Well, you would find a "stone" that exactly matched the edge you would like to have. Further, you would have this stone in varous grits, so that you could refine the edges. Alas, we live in a non-ideal world. So we have to find substitutes.
...



Well., actually, I meant to post it in the Schliefstock thread, because I had not read the curved adze thread but read this one first. It does not matter because what I have to say applies equally to both threads. Sharpening curved edges is a bear (gouges or carving axes). The problem is to find a sharpening tool that has the right shape. It should exactly match the curvature of the adze or gouge. For gouges you can usually find sliptones that will fit. But not for something as big as an adze. So I had a thought. Make your own.

Suppose you have an inside bevel. Then the proper tool is a cylinder. It is very easy to make a cylinder on your pole lathe. Make it exactly the same diameter as the radius of the adze or gouge, using the tool as a template. Then turn off one skosh. For the purposes of this post a skosh is the with of a sheet of sanpaper, not much. While you are at it, make the longest cyliner you can, part off ohh some 15 cm pieces. Now take faithful wet and dry sandpaper in various grits. Cut it carefully to the right length and wrap it around the cylinder. When it fits exactly, glue it on. Then make a handle. Behold, a DYI Schliefstock. A Selbstgemachtzylinderschliefstock, which I just made up. You can do that sort of thing in German :). If you want power sharpening, then instead of a handle drill a hole in the exact center of the cylinder and put in say a 6mm rod, with some epoxy to keep it there. You will of course make these things up in a variety of grits.

If you have an outside bevel, your problem is the negative of the above. You need a trough. Alas it is more difficult to make a trough than it is a a cylinder. I need to make a hole the same radius as the adze. For a gouge it is not a problem, because we can drill the holes and then cut our holes in half. For an adze... oh dear. Our forefathers had more time on their hands, and proabably would have carved troughs by hand. If you have a continous motion lathe and a chuck it is not a big problem to bore a say 80mm hole. You need some equipment but it can be done. If you have a hole saw (found at DYI stores) that is big enough then maybe you can do it that way. All you need is a few centimeters. Myself, at this point would resort to my trusty Taig (Peatol) lathe and bore the hole with (of course) a boring bar :) If I can chuck it I can bore it. How boring :). Cut the piece in half; then you have a custom slipstone. Cover it in wet & dry, of course.

In my previous post I thought of all sorts of clever ways to bore holes in shortish pieces of wood, but they are untried and I will save them until I actually try them.
User avatar
jrccaim
Regular
 
Posts: 1082
Joined: Sun Nov 02, 2008 3:53 am
Location: Willow, Alaska USA

Re: Sharpening a curved adze

Postby nic » Fri Mar 22, 2013 11:35 am

inside or outside bevel you need to be able to get at both faces. Wet or dry wears down very quickly so I wouldn't glue it on permanently.
A rod will do for the inside, regardless of bevel. But if you have an inside bevel then the bevel is conical. If you have an outside bevel the the flat face you are polishing is tubular.
For the outside face - if you have an inside bevel then the flat face on the outside is tubular, if the bevel is on the outside then it is again a cone so I don't see how you bore a hole to fit that perfectly. With practice you can sharpen outside faces with a flat stone. However an intriguing option is to use the gouge/ adze to cut its own sharpening tool . If you do this in MDF it is abrasive enough to act as a strop, when it glazes you can add compound. If you cut it oversize you could put some paper in for a more aggressive cut.
Obviously you need the tool to be sharp to sharpen it with this method but as I say you can get close with a flat stone. You don't need to cut a very big depression as you can rotate the tool.
nic
Regular
 
Posts: 265
Joined: Thu Jun 16, 2011 10:33 am


Return to Tools

Who is online

Users browsing this forum: No registered users and 4 guests

cron