Category: woodturning

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Last job on the redwood globe stands

Today I finished the last job on the redwood globe stands. At least, I hope it is the last. The stands still need polishing and assembly of course, but I don’t have to do that.

The stands each have a big mahogany disc resting on heavy stretchers connecting the four legs. In the middle of each disc will rest the pedestal that I made a few days ago, and between the pedestal and each leg is a decorative button. It is these buttons that I made today.

I had saved some small offcuts of the figured redwood from the leg blanks. I cut some 80 mm discs with the bandsaw, then held them in the stepped engineer’s jaws of my old Axminster chuck. I faced off one side, turned a recess for the small dovetail jaws of another chuck, and made a small V at the centre. Rather than finish the job on my spindle lathe, I wanted to stay on the Graduate for better access, so simply held the small chuck in the bigger one. This increased the overhang, and would not do for all jobs, but these pieces were small. I quickly turned the discs to finished thickness with a bowl gouge and formed a shallow dome on the upper surface.

After sanding, I used the drill press to make a blind hole in the lower side. The  button can now be glued to the mahogany disc with a short locating dowel. The figured wood should look great when sealed and waxed.

This whole job has been a lot of work, cutting and gluing up some large blanks and turning big components at the maximum capacity of my lathes. There has been little room for error, as there was only just enough wood. Any extra would have been hard to source, and very costly. I’m looking forward to seeing the finished stands with their globes installed before they are exported to the client.

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More work on the large redwood globe stands

Some time back I posted about making a pair of large globe stands from reclaimed redwood. I made the leg sections, but put the feet on hold because when cut up I found the wood too wet. Cut to length, with exposed end grain for the moisture to escape, they are now dry enough to finish turning them.

Each blank, about 200 mm  long and 180 mm square, was rough turned to a cylinder with a small spigot on one end. I held the spigot in a chuck while drilling a 12 mm hole right through using an auger with a T handle. I then transferred the blank to my homemade chuck with the tapered steel insert (which is proving very useful for this type of work) and turned the foot with tailstock support. Fairly straightforward, but a little nervy, as there is no spare timber – no mistakes allowed! I double checked all measurements and used a spindle gouge for most of the cutting. 8 feet turned and ready for finishing.

The next job was the central pedestals that support the globes. Two are needed, cut from a 600 mm length of 300 mm square redwood beam. The block was only just big enough, I had to cut it in half with a handsaw – it was too big for my bandsaw, and I didn’t think a chainsaw would have cut straight enough even if there was enough length spare for the kerf. Then I used the handsaw to cut off the corners, a total of about 8 feet of sawing. Redwood is quite soft, but seemed to be getting harder as I went on.

The initial sawcut that divided the block left a reasonably flat end grain surface on each piece, on which I could fix a faceplate. On my Graduate lathe, I could drill the axial hole at low speed, then support the block with the tailstock while I shaped the pedestal. I removed some of the surplus wood while still on the faceplate as it gave a very positive drive. Then I switched to my homemade chuck with the tapered insert. When I did so, I found, as expected, that the axial hole was not so axial after all. The auger had wandered a little. On the taper insert, I was able to true it up and continue with the shaping. The redwood is a little soft, and the maximum torque given by the friction was only just enough on a piece this large, so light cuts were essential.

I did not have a pattern for the pedestals, so to some extent I was designing them as I went along. It was very useful  to be able to remove and replace them on the tapers without losing accuracy.

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Hunter Hercules tool

I turn quite a lot of mdf and gritty reclaimed hardwood, both very abrasive and hard on the tools. The mdf turns quite well with HSS or even carbon steel scrapers, but they soon blunt. The gritty timber sometimes strikes sparks from the edge of a steel scraper, and knocks the edge off a gouge after just seconds of cutting. So I have been looking out for a tool that would hold up better. One day I shall try diamond tips – you can get diamond router bits, so perhaps they are available for fitting to woodturning tools, or perhaps a router bit could be adapted. I’ve tried various tungsten carbide scraper tips (though so far not the well-known Easywood tips), but found them to blunt quickly and not cut as well as HSS even when new.

The other day I purchased a Hunter Hercules tool. This has a little round cupped carbide tip set at a forward angle on a very robust, heavy steel shaft with a substantial handle. The tips are silvery-bright polished carbide and when new will catch on your thumbnail as sharp tools should. 

It has three modes of operation. Used with the tool shaft horizontal and flat on the rest, perpendicular to the surface and cutting on the very tip, it gives a semi scraping cut that is quite aggressive. If the handle is twisted and the side of the tip used, it shear scrapes and can give a good finish. It can be used for a bevel rubbing slicing cut that also gives a good finish. 

I tried the tool on some edge-grain mdf. In semi scraping mode, it cut freely for a while before the edge lost its initial keenness. But it kept going. The small tip penetrates easily and whether semi scraping or slicing it keeps on taking off the waste. Even on the mdf face-grain, which with normal scrapers produces shavings, the waste was very dusty indeed. The finish produced was not brilliant, but adequate after a little sanding, and I shall normally make the final cuts with HSS tools anyway. I made several complete components with the tip still going strong.

I found the tool quite catchy when going into a spindle cove in semi scraping mode. To avoid problems, the tool has to be swiveled and the cut kept on the front third of the tip’s circumference, say between 10 and 2 o’clock. The  inclined edge at 9 and 3 tends to catch on the sides of the cove and run back. I found it can catch and run in this mode on a flat surface or a hollow on faceplate work too. The best way to prevent runs when semi scraping is to push rather than pull the tool. The small diameter of the tip means that it is not so easy to get a sweeping, regular curve – the tip penetrates easily so any additional pressure makes a dip in the surface.

It is easy to ride the bevel in a straight line or round a curve. This gives a controllable cut and clean surface just like a gouge, but only light cuts can be taken as the tip is small.

Shear scraping with the Hunter is similar to with a normal scraper, but the small diameter tip makes it a little harder to get an even sweep.

Replacement tips are not cheap, though they may last a long time on easy timber. The maker hopes they will be considered disposable, but I hope it will prove possible to sharpen them. Flat carbide tips can be sharpened on their upper surface with a diamond hone, but this would flatten the top of these cupped tips. I intend to try three alternative methods – hone the top and afterwards use the tip as a normal flat tip scraper; mount the tip on the end of a rod like a dop stick (or just pin it on the end of a rod using the tail centre) and hone the bevel while it spins in the lathe; and hone the groove in the top using a very small diamond ball point in a Dremel, also while spinning the tip. I doubt if any of these will equal the original grind, but  shall report the results in due course.

So I am pleased with the tool so far. Quite impressed.

If it cuts mdf, I’m sure it will cut ordinary wood. I tried roughing down a small oak spindle blank in semi scraping mode and it worked well, though it did leave small feathery shavings not completely severed if traversed too fast, due to the small tip diameter. I have not yet tried it on the gritty stuff but shall update in due course. I have however roughed out a number of boxes in some unknown but hard and very abrasive wood. I have not yet changed or sharpened the cutter, though I have turned it through 180 degrees to a fresh edge, and it is still cutting quite well – HSS would have needed many sharpenings in this time.

It will not replace my gouges and scrapers. I shall use it on difficult materials as a roughing tool, and be grateful for the long edge life. When really blunt, the edge becomes badly chipped and eroded, and then will not give a good finish. No doubt others will use it on more tractable timber and get nice polished surfaces straight off the tool, but for me it is too slow-cutting for routine use – I get on better with normal gouges and scrapers that are more free-cutting.

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Homemade chuck

A common problem facing woodturners is how to hold pieces in the lathe. The usual options, such as faceplates, scroll chucks and spur drive centres deal with almost everything perfectly well. But sooner or later there is something different needed. Often in these cases I use my homemade chuck. This is simply a holder, made of steel and mounted on the lathe spindle nose, into which a variety of special purpose inserts can be fitted.

I often have to turn items with a half inch diameter axial hole. In these cases it is usually best to drill the hole in the blank before the turning is done. If the hole is used as the location for turning, it remains true in the finished item. How to hold it in the lathe so the hole is central? Till now, for larger holes, I have either used a conical tail centre in the headstock to drive by friction, or a counterbore with a pin to locate in the hole. Both are liable to slip on larger pieces.

So I made a taper pin for the insert chuck. I cut a piece of mild steel rod about 2.5 inches long and 5/8 inch in diameter and used my old Atlas metal turning lathe to reduce the diameter to 1/2 inch over part of the length, to fit my insert chuck. Then I reversed it in the lathe and turned a gentle taper, leaving it just under 1/2 inch at the end, so it would slip about 1/4 inch into a 1/2 inch hole.  Then I filed a flat on the shank where the locking screw bites, and the job was done. An insert like this could also be made from a soft steel morse taper with enough length to turn the taper on its nose, a job that could be done by hand in the wood lathe. For light work, it could be made from hardwood.

The taper has to be right, though I haven’t measured it. It’s not really critical, but too steep and it will not grip well enough, too gentle and it can split the wood. A little steeper than a morse taper but not as steep as a tailstock dead centre is about right. If the drive does slip, I can just tighten the tail centre a little more.

I used the chuck to make some wooden cylinders about 4 inches in diameter. Mounted on the taper, with the tail centre to keep them in place, they turned easily and accurately.

Taper insert for homemade chuck

 

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Tungsten carbide woodturning tools

Tungsten carbide is a very hard but brittle material used for cutting tips in metalworking. It is now used in woodturning too. I first made some tungsten carbide woodturning tools many years ago. They had a use, but I had to use them fairly forcefully to make them cut. I could not make them sharp enough to cut wood at the lathe, even though carbide has long been used for saw teeth. Recently there has been a lot of publicity given to tungsten carbide woodturning tools. They normally have replaceable carbide tips. They are supposedly formulated to be sharper. However, they are apparently less robust than other grades.

Several companies are now selling tipped tools, and users report very favourably. The tools are expensive, and without information about the carbide grade, you have to take the quality on trust. I would like to make some tipped tools with this woodturning grade carbide. I’ve bought some tips from various sources but the ones I have tried so far don’t keep their edge very long when cutting MDF. MDF is very abrasive and hard on sharp edges. A long-lasting edge is the main reason for using carbide. After a bit of use, the carbide edge feels rough to the touch, and like a sawblade when tried with a fingernail,

Yesterday, I bought a micrograin carbide tip from Robert Sorby. I fitted it to one of my homemade tools to try. First impressions are not good. It didn’t do well on MDF, which I turn a lot. Very likely it would work well on ordinary wood though. And at least the tip has a very generous thickness to allow sharpening with a diamond hone.

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Burr acacia

The batch of decorative wooden cones that I started a few days ago is nearly finished. I used pear, spalted hornbeam and burr acacia. They just need one more coat of finishing oil, and already they are looking pretty good. The burr acacia is from my rapidly diminishing stock that I got from a tree surgeon many years ago, and is one of my favorite timbers. It has a dark gold colour and very highly figured grain, and is nice to turn – crisp, but not too hard. It is almost free of the cracks and fissures that are very common in most burr timber. Over the years I have made numerous turnings from it, including small bowls and wooden mice. There are still scraps of it scattered through my wood pile, but I wish I had more! 

 

Also today, I started the final turning of some pearwood bowls. This is the pearwood that a customer brought to me for this purpose months ago. It came from a tree that had to be taken down in his garden. He has already bought some bowls and wooden pears made from the tree, and now wants more bowls to give as gifts. Pear wood, like other fruit woods, normally turns very well with the gouge, though it does distort and sometimes crack while drying. These new bowls were roughed out last winter and are now properly seasoned.

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Buffing cord pulls

Today I buffed the latest batch of cord pulls. I turned them a few days ago and  they have been oiled and given enough time for the oil to harden properly in the wood. I use the Beall buffing system. Tripoli first followed by wax. I don’t use the carnauba wax but apply microcrystalline wax from a block as it is more durable, particularly for something like a bathroom light pull that will frequently be wet. I made some in teak, some in oak, and some in plum wood, which have come out very well – the plum has a very rich colour.

I also made some more decorative wooden cones. Some are now ready to finish, but others will need time for the wood to dry before final turning. I removed the centre mark with a dremal cutter and sanding disc, and shaped the point with a chisel by hand.

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Turning wooden cones

A discerning person has bought my remaining stock of wooden cones, leaving me sold out. These cones are decorative items, non functional except perhaps as paperweights, but I think they look good. A while back I took one to the woodturning club show and tell, and other members made some for the following meeting, so they must have something to recommend them!

Now I have to replenish stock. The difficulty is finding suitable blanks, they need to be well figured and of suitable size. I found several nice bits of pear wood with some ripple grain and darker patches. I’ve used this for making bowls previously and know it finishes well. I also sorted out some spalted sycamore and horse chestnut, but this is too wet to use at present. I spalted it myself, simply by wrapping it up in plastic bags for about a year. It certainly is heavily spalted, some of it too much so, but I won’t really know till it’s dry. I roughed out some cones from the spalted wood and put them aside to dry. The pear is good to go now, so I made a couple of cones with that. More tomorrow I expect.

Turning wooden cones is fairly simple. The blank goes between centres and I turn a tenon at one end for the chuck. Then I can turn and finish the taper, with the point on the end. The problem comes when the tenon has to be removed. How to hold the cone? I put a rubber bung in the morse taper. The bungs are sold for use by wine makers. The cone’s point goes in the hole in the bung and the tail stock supports the other end. Friction provides enough drive force for the tenon to be turned away. The bottom is undercut a little with a small gouge so the cone stands straight, and then sanded.

 

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Condiment tray

My pal Tony visited today for the first time in many months. He has been unwell for some time, but I’m glad to say he’s improved a lot now. He goes to the same turning club as I do and has become a friend. In the workshop, we made a condiment tray. The design was very simple, just a small flat-bottomed dish with vertical sides that will hold bottles etc on the table. We considered using oak or mahogany as I had some blanks handy, but he wanted pine to match the table. I found an offcut the right size to make a tray about eight inches in diameter.

Tony did all the turning and was pleased with the result. With the blank sawn to a disc and mounted on a small faceplate, he faced off the bottom, making it slightly dished so it would sit flat on the table, and cleaned up the edge with a gouge, making a clean cut that brought out the grain nicely. A small chucking recess on the underside enabled reverse mounting in a chuck. Then the tray just needed hollowing and sanding. He did most of the turning with a tungsten carbide tipped tool that we made a while back. It cut fast and the tray was soon completed. The only tricky part was getting the inner surface flat for the bottles to stand on.

There was time to put on one coat of finishing oil. Two or three more coats followed by buffing in a few days time and the tray will be done.

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Making more cord pulls

Today I started building up my stock of cord pulls a bit. I picked out some teak, some oak and some plumwood and sawed the wood into small rectangular blocks on the bandsaw, about a dozen of each. I marked the centre of one end on each block, drilled most of the way through with a 6 mm twist bit, then the rest of the way with a 3 mm extra-long twist bit.

Then I put them in the lathe and roughed each one to a cylinder before completing any of them. I don’t really know why I do it this way, lots of turners would do them one by one. I like the speed of roughing down, with shavings flying and no accuracy required.

I looked through a bag of pulls that I made some time back, all different, to pick out the shape I wanted, this time a tear drop. This became the sample to copy.

Then back in the lathe one more time to form the shape using a medium size spindle gouge. They have some small coves on the shoulder that I made with one of my miniature homemade gouges. They are normally easy to use, but I found this time that the coves on the sloping surface wanted to over-cut, becoming too big. Several pulls had to be reshaped to remove the defective details and start again. But it was quick work once I got my hand in properly.

I had time to complete the teak ones and start the plum, which is slightly spalted and dark in colour. I think they will finish nicely.