Posted on 1 Comment

Sanding sealer jar

Lots of turners use a sanding sealer jar with the brush inserted through the lid. This is very handy because the sealer doesn’t evaporate or get full of chips. The brush stays wet and ready to go. Here is an easy way to fit the brush and keep it rigid and with an airtight seal.

A waterproof cable gland from an electricians supply store is intended to make a seal where a cable enters a box, and consists of a flanged screw fitting with rubber sealing washers and a compressible rubber sleeve that will tighten down on a wide range of sizes. They cost very little. The brush must have a cylindrical dowel handle and rust-proof bristle holder. I found some cooks’ pastry brushes that are just the job. You can get them cheaply from Amazon, and the glands too.

The only tricky bit is making a neat hole in the lid  of the jar. If the lid is plastic, you have to go gently with the drill to avoid cracking it. If metal, start with a small drill and then file the hole to size. Don’t attempt to drill the hole with a large drill bit. It will grab the thin metal when it cuts through and damage either the lid or your fingers, or very likely both. It is essential to clamp thin metal when drilling it if you value your fingers. Sandwiching the metal between two bits of board would help prevent grabbing and distortion. This would be the best approach, but the lid flange makes it difficult.

Posted on Leave a comment

Homemade dowel plane

From time to time, I need wooden dowels. I use them to plug holes, join pieces of turning together, and sometimes for general woodwork. Dowels aren’t expensive, but if you buy them in, you don’t have much choice of material or size. My homemade dowel plane can make neat, accurately sized dowels of any length, and from any straight-grained timber. Dowels made from suitable hardwood can make decorative contrasting features on a wooden bowl, or fill a defect with wood that blends in with the item.

These planes work like pencil sharpeners and are quite straightforward to make. They are limited to one diameter, so you may need more than one. This is how to make them.

Components of a homemade dowel plane:

  • a block with a tapered lead-in hole which guides the wooden blank to the cutter. This hole should be about 25 mm deep.
  • the cutter, secured by flat head screws to allow a little adjustment
  • another block with an exit hole, about 25 mm long and the nominal diameter of the dowel. It steadies and guides the plane along the blank, keeping it aligned with the dowel as it forms.

These dimensions aren’t critical, but seem to work for a 6 mm dowel. If you want to make large dowels, scale everything up. The plane may then need a handle to stop it spinning in use.

Making the body

Use a strong, hard-wearing timber such as beech. The plane is in two parts, because this makes it easier to create the seating for the cutter. Take two pieces of beech and turn them to make short cylinders, each about 25 mm long, plus a dovetailed spigot on one end to fit a chuck. The diameter could be about 65 mm. Face off the ends, drill pilot holes, and fit them together with a couple of wood screws. You could insert a couple of dowels too, without glue, to maintain correct alignment. Make sure the screws and dowels will be clear of the tapered hole you will make later. The assembled block can then go back in the chuck while you true up the surface and turn off one of the spigots.

Drill an axial hole right through the two blocks, of the nominal diameter required. Then open up the hole in the outer block to form a taper. This could be done with a small gouge or by scraping with a small skew chisel. Make the sides of the taper straight, and make the taper stop at the junction between the two cylinders. The taper angle is not at all critical, just make the wide end about 10 mm bigger than the small end. You now have a sort of funnel shape within the combined block.

The cutter

Find a bit of steel for the cutter, about 3 x 25 x 25 mm, though the dimensions are not critical. There are lots of possible sources. I used a short section of an industrial hacksaw blade. A piece of sawblade, hand plane blade, planer blade, knife blade, carpenter’s scraper or chisel will do. You need either high speed steel or carbon steel, (which may need heat treatment before it will keep a sharp cutting edge. If you use steel from a cutting blade and take care not to overheat it while grinding, it should work without heat treatment.)

Into one long edge, cut slots for the screws that will secure the cutter. Make them a loose fit on the shank of the fixing screws. Then you can adjust the cutter position. You can make the slots with a narrow grinding wheel, or if it is soft carbon steel, file them. Alternatively, drill fixing holes in the cutter. Grind a single bevel on the other long side to form the sharp cutting edge. Round off one end of the cutting edge where it will be in contact with the dowel as it cuts. If you leave a sharp corner it will score grooves in the dowel. Take care not to overheat the steel when grinding.

The cutter seat

Now make the seat for the cutter. The seat must be positioned so the blade and its cutting edge will be tangential to the tapered hole, inclined to follow the taper. The cutting edge will be at the side of a slot through which the shavings will exit. Have a good look at an ordinary pencil sharpener to get the idea.

Take the two sections apart. Make a saw cut in the block with the taper, so the cut just grazes the taper. Don’t go past that point. This is the only tricky part of the job, so you could saw clear of the taper and work up to the line with a chisel. Saw another cut that will remove a portion of the block (a bit less than a quarter) and leave a slot in the taper to allow shavings to escape. Make the slot about 4 mm wide at the wide end of the taper, perhaps a bit less at the small end. If it’s too wide, the cut will be too heavy and the plane will be grabby.

Clean up the seat with a chisel so the cutter will lie flat. Drill pilot holes and screw the cutter in place with the bevel side out. Reassemble the parts. Grind off any part of the cutter that protrudes, in case the block spins in your hand when using it.

Using the plane

To use the plane, cut a square section blank, a bit over the required length and a little thicker than the finished dowel, and hold one end in a chuck in the lathe. Run the lathe slowly so the blank doesn’t whip, and catch the free end in the taper hole in the plane. Feed the plane along the blank by hand so the rounded dowel enters the guide hole, and stop the lathe when the plane gets to the chuck.

If the dowel is too tight or too loose, adjust the cutter slightly. It will cut rapidly and cleanly if set up correctly. The dowel will be smooth and almost polished. Remove the blank from the chuck, and tap the dowel out of the plane. Saw off the short bit of waste at the end. If your chuck and lathe make it possible, you might find it easier to hold the plane in the chuck and feed the dowel blank through.

homemade dowel plane
Dowel plane
Posted on Leave a comment

homemade pin tool rest

Today I started turning a pedestal disc for another large globe stand. These discs might qualify as fairly extreme turning, being over a metre in diameter and 50 mm thick, made of hard and dense timber. I glue up the blanks with biscuit joints. The cracks in the wood mean that on a piece this size I have to take safety precautions.

To make sure there is adequate support, I use an extra large, specially made steel faceplate, which carries a 30 mm thick mdf disc, one metre in diameter. I screw the blank to this disc, making sure that each component plank has fixing screws.  Just getting the blank on the lathe is difficult. The whole assembly takes two people to lift, and getting it on the lathe is a three person job. I use the outboard side of the Graduate lathe, together with a free-standing tool rest.

To make the job easier, I have recently changed the method of loading. I now start by putting just the faceplate with the mdf extender on the lathe. This is just possible working alone, but still much easier with help. The mdf and the blank both have a central hole. I put a steel pin in the blank and offer it up to the faceplate. The pin centres it and supports the weight while I add a temporary G clamp then put in the screws. Then I remove the pin and the turning begins.

I am using second hand timber, with many grit-filled cracks. It is extremely hard on the cutting tools. It strikes sparks from ordinary scrapers, and makes really hard work of the project. But the customer supplies the timber and it is what he wants to use. I hate the stuff! I am doing a lot of the work with the Hunter Hercules tool. The wood quickly blunts even the Hunter carbide tip. When blunt, the tool starts to bounce and become hard to control. It was physically demanding to keep the blunted tool cutting. To replace the tip as necessary would be expensive, they blunt so fast.

Homemade pin tool rest

The answer was my homemade pin tool rest. This is a toolrest with a row of holes, into which I place a steel pin where required. The Hunter tool can then be stabilized by contact with the pin. It can still slide forward and swivel against the pin to make the cut.

I rarely use this toolrest, but it is invaluable for jobs of this kind. I made it years ago before I started turning these discs, I wish I had remembered it earlier instead of struggling with the tools held freehand.

A pin tool rest is easy to make. You need an ordinary tool rest with a bar that is stout enough to let you drill vertical holes at intervals without weakening it too much. Size and spacing are not critical, but about 8 mm diameter and 15 mm apart is OK. I drilled holes along the full length, but find that I only need three or four, all near the right hand end. Drill the holes using a drill press. The holes must go right through the rest so that chips can fall through.

Making the pin

The pin must be strong, say 10 mm diameter and 25 mm long, with an 8 mm lower section to fit the holes. You want it an easy but not wobbly fit. I turned the reduced diameter section of the pin in the lathe, but it would also be possible to use two bits of rod, one thick and one thin. Drill a hole in the end of the thicker bit and press or perhaps glue the thinner bit into the hole.

You can still use the rest as normal with the pin removed, as long as the hole positions don’t interfere with sliding the tool. Rests like this work for metal spinning too.

Posted on 4 Comments

Grinder platform angle setting jig

Sharpening is one of the essential skills for woodturning. Most turners use a grinder to sharpen tools, and platform sharpening is probably the best method for skews and scrapers. But each type of tool needs a different grinding angle, so a grinder platform setting jig for each angle is very helpful. For example, a skew chisel will usually have a more acute angle at its edge than a spindle roughing gouge, which in turn will have a finer edge than a scraper.

Each of these tools can be ground while flat on either the grinder’s own tool rest or a separate platform rest, which just has to be set to the correct angle. One way to do this is to blacken the existing tool bevel with a marker pen then adjust the platform until the bevel comes into full contact with the wheel, which is inched round by hand so that the ink removed will show the accuracy of contact. Or you can just match the bevel to the wheel by eye, looking from the side. But in either case, any error can be cumulative. It will be repeated and possibly amplified next time the tool is ground. This can lead to a gradual change in the bevel angle.

I use an easy-to-make grinder platform setting jig that gives a consistent, repeatable result very quickly. It consists of a scrap of plywood with two projecting screw heads that align it to the wheel rim, and a straight edge at the bottom to which the platform can be set. The jig is very easy to make and use. A different one is needed for each tool type and thickness (thicker blades contact higher on the wheel rim and because of its curvature will be ground to a sharper angle than thinner ones). Use plywood thick enough to take the screws in its edge without splitting, but no dimensions are critical. All you have to do is set the platform angle as you wish, perhaps copying an existing tool angle, then cut the plywood so it rests on the platform with its edge fairly close to the wheel rim. Insert the two woodscrews (as far apart as the wheel guard and platform will allow, and angled so they are radial to the wheel axis. Drill pilot holes to prevent splitting.) The screws are optional, but if used, they can be turned in or out to fine tune the fit or to compensate for wheel wear. If necessary, the inner edge of the plywood can be cut away to follow the wheel rim more closely.

To use the grinder platform setting jig, loosen the platform, place the two screw heads in contact with the stationary wheel rim, bring the platform into contact with the bottom of the jig and tighten up again. Every time you sharpen the same tool, or another of the same blade thickness, the angle will be just the same, making for quick results and saving tool life.