Woodturning | Syzygy Woodworks

August 26, 2010

Processing a log for bowl blanks

I often hear turners talk about “free wood”. To my mind there is no such thing as “free wood”. Between the time and mileage spent driving to pick up the logs and the time and energy spent processing the logs into blanks, I often feel it would be easier and cheaper to just buy the bowl blanks!

Cutting your own blanks does have some advantages. The primary advantage is that of re-using or recycling wood that would otherwise be destined for the chipper or the burn pile. There is something very satisfying about holding a finished bowl and knowing that you were involved in the complete process from log to bowl, and you created a functional and beautiful object from some timber that could have just ended up in a landfill somewhere.

However, there is a lot of work involved in processing a log for blanks, and it is frustrating when the end results are just a bunch of checked and cracked blanks. Two very important things that will help you avoid this are:

Process the wood as soon as you can. Ideally you will want to process the log the same day as you get it. When this isn’t possible, try and at least get the chainsaw part of the process done as soon as possible, which will remove the pith and then seal the end grain with Anchorseal.
Remove the pith, remove the pith!!

The picture below shows how I plan on cutting this small camphor log to yield both bowl blanks and some spindle stock. If the log were bigger the spindle stock could be used for hollow forms. This layout is just one possible scenario, the most important thing is that the pith, marked with a red x, is going to be removed and discarded.

Make two cuts down the length of the log, either side of the pith. Don’t cut all the way through with the first cut. In the picture below I have made the first cut and then paused towards the end of the second cut to take the picture. Normally I would have just cut all the way through the log with the second cut.

Complete the first cut.

For the most part this is all that I will do with the chainsaw. I then take the three pieces of wood inside to my band saw. However, some of the cuts that I make with my bandsaw can be made with the chainsaw. I just find the bandsaw more accurate, less wasteful and it’s in the shade 🙂

If the log is fairly straight, I set my fence and then cut off about an inch of the live edge. If the log is not very straight then I will just free hand this cut.

Then using the flat section I just created, I will rotate the log 90 degrees and cut it to the desired thickness. If you do not have the capacity to do this on your bandsaw, then this step can easily be done on the lathe when you first start turning the blank.

I have a set of 1/4″ plywood circular discs in 1″ increments which I use to gauge how large a bowl blank I can get out of the log as well as guide me in the cutting of the blank.

From this section of the log I’ll be able to get two small blanks, one 7″ and one 6″. I draw around the discs with some white chalk and mark the circles to be cut out. I could also just nail the disc to the log and leave it in place while making the cuts.

I would then process the other log half in a similar fashion before moving on to the slab I removed from the center of the log. On this slab I cut off about an inch from both live edges.

Then I would set the fence to the same dimension as the thickness of the slab and cut out as many sets of spindle stock as I can, working towards the center of the slab from either side, being mindful of where the pith is. In the picture below, you can set two pieces of spindle stock either side of the pith section which will be discarded.

Here is the yield from the log. Three bowl blanks, two pieces of spindle stock and a section of questionable orientation that I will probably make a sphere from.

This is the reason why the one log half only yielded one blank and the piece of questionable orientation. The chainsaw cut revealed that I had cut through two nails embedded in the log. This illustrates the importance of inspecting the logs carefully before cutting with either the chainsaw or bandsaw. It also confirms my theory about there being no such thing as “free wood”. My chainsaw blade needs to be resharpened now and if I had not noticed these nails they would have trashed my bandsaw blades. I think I may look into buying a metal detector!

The final step is to coat the blanks with Anchorseal. I cut the entire blank, however many people will just coat the end grain and leave the face grain bare. I’ve found the horizontal section of my new log processing platform to be perfect for this.

August 23, 2010

Log Processing Platform

For the longest of time I’ve been working on the ground when processing my logs with a chainsaw. I had a wooden pallet and I would position the logs on it and then cut them. It worked OK. Often I had trouble securing the logs so they didn’t move while I was cutting them, especially when they were still round. However with the use of wedges and such I normally could work around that and get the job done. And each time the job was done my back was killing me!

So I started looking for ideas as to how I could raise the logs to a more comfortable working high and hold them securely while cutting them. Finally I saw a solution in the June 2010 edition of the American Woodturner, the AAW journal.

The log processing platform was in the “Tips” section of the journal and I’m really pleased with the one I built. It holds the logs secure and steady, has plenty of room for the chainsaw to travel after the cut is complete so the chain doesn’t end up buried in the the dirt, and it raises the logs to a comfortable working height, which my back is really pleased about!

I built mine from pressure treated pine. It took about ten minutes to cut the timber to size, cut some 45 degree angles on the uprights, and then I shot it together using a framing gun and some galvanized nails. The four tall upright pieces are 32″, the two shorter upright pieces are 26″. The gap between the tall pieces is 7″ and the other gap is 4″.

Processing logs with my chainsaw is a far more enjoyable experience. Quicker, safer and less stress on my back. My thanks to the reader who submitted this tip to the AAW Journal.

December 21, 2009

Chuck Reversing Adapter

Every now and then I buy a tool/gadget that takes a time consuming process and just simplifies it. Yesterday I picked up a chuck reversing adapter from my local Woodcraft, and is it going to make life easy!

A chuck reversing adapter is used to take a turning that is mounted in a chuck on the headstock and rotate it and mount it on the tail stock so that you can align or center it correctly while mounting on a vacuum chuck or donut chuck prior to finishing the bottom of the piece. Or to put it more simply, it is a piece of metal with a morse taper on one side and a thread on the other that matches your chuck.

I normally don’t have any problems reversing a vessel with a wide rim, especially when using my donut chuck. However, for pieces with a narrow rim, like hollow forms, I have been struggling with alignment when reversing. The chuck reversing adapter has solved that. The following pictures illustrate how it is used.

Here is a hollow form that I’ve finished hollowing and am now ready to reverse and finish off the bottom. Without removing the piece from the chuck, I unscrew the chuck from the headstock and set it aside.

I then mount the back piece of my donut chuck to the headstock. You can see in the above image that I have attached a piece of scrap wood to the center and have turned it to a cone shape. Then I attached a couple of pieces of self adhesive fun foam. This cone will go into the mouth of the hollow form.

I then mounted the chuck reversing adapter into the tail stock and threaded the chuck onto it. Note, the chuck reversing adapter is not a live center! It does not rotate in the tail stock as it has no bearings. It is a temporary method to hold the chuck in the tail stock in alignment with the headstock. Don’t start the lathe with it in place, you’ll ruin your whole day!

The tail stock was then slid forward till the workpiece was almost touching the donut chuck. Then I locked the tail stock in place and advanced the spindle using the hand wheel until the workpiece was snug against the donut chuck, taking care not to crush it. The front piece of the donut chuck was then secured in place with the bolts.

I then loosened the chuck on the tenon of the hollow form, and withdrew the tail stock. The donut chuck held the piece securely and correctly aligned.

I then put a live center in the tail stock and brought it up to the work piece in order to turn the bulk of the tenon off, leaving just a small nub. It’s a good practice to support the work piece whenever you can using the tail stock.

The last little nub was removed with the tail stock out of the way and then the bottom of the piece was sanded.

December 15, 2009

Spindle and tenon gauge

I was getting tired of reaching for my calipers and setting them to my chuck diameter every time I needed to turn a tenon. The alternative was trying to “guesstimate” the diameter needed and very often I would turn the tenon to small. So I made a spindle and tenon gauge.

I have a set of forstner bits and they go from 1/4″ to 2 1/8″ diameter, in 1/8″ increments. I figured that while I was busy making the gauge, I might as well go ahead and include all these diameters.

I used a piece of 1/4″ hardboard. It was thicker than my parting tool, so I ran it through my drum sander a couple of times until it was just slightly thinner than my parting tool. This is probably not necessary for most applications, but I thought it may be useful occasionally when I wanted to make a parting cut in the middle of a piece and not have to widen it in order to insert the gauge.

Then I drew two lines down each side of the hardboard, just over one inch from each edge. I set my drill fence so the center of the forstner bit was positioned over one of the lines. Then, using a scrap piece of wood as a backer board, I started drilling holes, from big to small, down one side and up the other side.

When all the holes were drilled, I set my table saw fence to the line I had previously drawn, and with two passes, cut all the circles in half.

The gauge now hangs within easy reach of my lathe and is perfect for sizing tenons and checking spindle diameters. A quick, easy and cheap solution that makes my work flow at the lathe easier 🙂

If you have a hint or tip feel free to share in the comments section.

November 30, 2009

Dyeing for Color

A couple of months ago a demonstration at my woodturning club prompted me to start experimenting with dyes. Dyeing and coloring is one of those subjects that can be pretty intimidating. There are so many colors out there where do you start? Well, my first step was to buy myself a color wheel. I also spent some time researching what type of dyes to start with and eventually settle on TransTint Dyes. The next step was to decide which colors to buy. After looking at the number of colors available and the cost of the dyes, I decided that I would just buy the primary colors and black. I figured that with those colors I could mix any other color that I might want.

With that decision behind me I placed my order for a bottle of red, blue, green and black dyes. While waiting for the package to arrive I took a trip to Harbor Freight and got some 8oz squeeze bottles. I also went to Walgreens and got a small syringe for accurately measuring the dyes. If ever you want to feel like a crack addict, going to the drug store and asking for a small syringe will do that for you. Although they very kindly didn’t charge me for it, the kid at the pharmacy looked me over twice and also asked to see my drivers licensee before giving me the syringe!

The package of dyes arrived and, feeling like a mad chemist, I opened it up ready to start mixing. Well, who knew that green is not a primary color!!! I guess if I’d taken the time to really look at the color wheel I brought I might have know. Apparently the laws of physics/chemistry weren’t going to be changed just because I had brought the wrong color dye, so a trip to my local Woodcraft and I had a bottle of yellow dye to add to my collection. (“My local Woodcraft” is a relative term here involving a three hour return trip).

My plan was to mix up a “master” bottle of the three primary colors, red, yellow and blue, and then use those to mix up “master” bottles of the secondary colors, orange, green and violet. From these six colors, along with the black, I figured I could mix up any other color I wanted on a “as needed” basis.

TranTint dyes can be mixed with water or alcohol. They can also be added to common finishes including shellac, water based lacquer and polyurethane and most oil based finishes. I chose to mix the dye with a 50/50 solution of denatured alcohol and lacquer thinners. This would have the advantage of not raising the grain of the workpiece. The one disadvantage of doing this is that the solution dries very quickly after application. As you only get an idea of what the final color will look like when the dye is first applied and wet this does not allow for much time to see if the color is to your liking.

The dyes need to mixed in the following proportion, 1 oz of dye to 1 quart of water or alcohol. If you’re not interested in doing the math, this came to 7.5 ml of dye to be added to my 8 oz solution of alcohol and lacquer thinners.

November 25, 2009

Chatter Tool Results

I finally got a chance to play with the chatter tool I made. My initial experiments were pretty disappointing. The tool was “screeching” as it is supposed to, but I only seemed to be able to put spiral grooves on the test piece. My first thought was that the blade was not thick enough and I was getting too much “deflection” and not enough “chatter”. I had used on old jigsaw blade, so I took an old sawzall blade and cut and shaped that. Even though it was wider, and offer less give, I was still just getting spiral grooves.

So I took the two blades back to the grinder and ground a very slight bevel on the edges. More importantly I rounded over the point of the blade so that instead of coming to a sharp point it came to a blunt, slightly round point. Immediately I started to see improvements! Both the jig saw blade and the sawzall blade worked great, although they did produce different patterns.

There are no shortage of patterns you can get with the chatter tool. Whether any of them are repeatable is open to debate though! A number of variables affect the pattern.

The amount of the blade sticking out the tool.
The distance from the tool rest to the work piece.
The speed of the lathe.
How hard you push the tool into the work piece.
How quickly you move the cutting edge across the work piece.
How many times you move the cutting edge across the work piece.
The angle the cutting edge is presented.

The image below shows some examples. I colored the patterns with a black permanent marker so they would show better in the image.

A chatter tool is used primarily in end grain, so applications include embellishments on box lids, spinning tops etc. The chatter tool will work better on hardwoods than softwoods.

After spending an hour or so playing with the tool, I feel the most important variables are lathe speed and distance of the tool rest from the work piece. For the most part the tool is presented so that the blade is horizontal and the handle is closer to you than the blade. The tool rest is about 4 to 6″ from the workpiece and lathe speed is around 1000 rpm. The blade is pushed into the wood and then pulled from the center to the edge. Rotating the tool slightly counter clockwise will change the pattern achieved, but it will also cause the tool to move towards the edge of the work piece a lot faster!! I found lathe speeds between 750 and 1800 worked with an optimum range between 1000 and 1200.

November 22, 2009

Al Hockenbery Demo

Last weekend our woodturning club, North Florida Woodturning Association, had the good fortune of hosting Al Hockenbery and his wife Sherry for a demonstration and hands on session. The demonstration was an all day demo on Saturday and the hands on session, with six of the club members was on Sunday.

To see some of Al and Sherry’s work you can visit their website at Hockenbery Woodturnings.

Al was a great demonstrator! He both informed and entertained. Edutainment at it’s best. One of the things I really enjoyed was that he shared many hints and tips as he demonstrated that were not necessarily part of the demo, but an opportunity in the demo arose where he was able to segue and share more of his woodturning experience.

He demonstrated a number of pieces to us, including a natural edge bowl, rough turning a large salad bowl, a natural edge hollow form and his “ball in a ball”.

Shaping the outside of a natural edge hollow form

Holding a wooden ball for hollowing using a Strata Chuck

Hollowing the wooden ball so that a golf ball can be inserted

November 12, 2009August 28, 2019

Homemade Chatter Tool

I’ve been wanting to try some different embellishment techniques, one of which was chatter work. However I kept on balking at the price of a new chatter tool. I decided to make my own. It cost me $3.00 and a hour or two on a Sunday afternoon.

I got a 1/2″ x 10″ nipple from the plumbing department at the home improvement store, along with a 3/4″ long 1/4 20 bolt. The rest of the materials I used were in the shop already including a used jigsaw blade.

I mounted the pipe between centers on the lathe and after a bit of sanding it was nice and shiny. I then cut the threads off one end and drilled and tapped a 1/4 20 thread about 3/4″ back from that end.

The next step was to mount a cherry pen blank in a chuck and turn it down to 1/2″ so that if fit inside the pipe. I only turned down the first couple of inches, and then put it in a vise and cut it lengthwise. This off cut was then glued into the pipe with CA glue, the bolt served as a clamp.

After turning the block of wood to be used as a handle round, I drilled it to fit the the OD of the pipe. Unfortunately, the OD of the pipe was around 13/16″ and the only forstner bits I had were 3/4″ and 7/8″. So I drilled with the 3/4″ and then widened the hole using a square edge scraper until the pipe fit inside. The image below show the handle shaped and sanded, just prior to being parted off.

I’m playing with dyes at the moment, so I applied a red dye to the handle and then a couple of coats of shellac. While I was waiting for the shellac to dry, I ground the teeth off the jigsaw blade, shaped the point of the blade and bent it as in the image below.

The completed tool, ready for testing! Did I mention how nice and shiny it is!

I’ll show some pictures in a future post of the results from the tool. I also have a couple more jig saw blades and some sawzall blades. I plan on experimenting a bit with the different blades and profiles and see what sort of results I get.

If you’ve made a chatter tool let me know what type of blade and profile you got the best results with by posting a comment. Thanks.

November 8, 2009

Uphill and downhill – cutting with the grain on a lathe

Uphill or downhill. Cutting with the grain or against the grain. Understanding how the grain is orientated on the lathe and which direction to cut in order to get the smoothest cuts possible can be confusing.

Brian Clifford has a great article on his site The Woodturners Workshop which illustrates these concepts very clearly. Here is an brief extract from the article. To read the full article please visit Brian’s site here.

7.1 Introduction

In the previous chapter, in thinking about the way the tool cuts, three important factors were temporarily ignored. These are :

the question of grain and its direction

the rotation of the work-piece

the fact that the cutting edge is often held at an angle to the direction in which the wood is moving (the slicing cut)

7.2 The concept of grain

The cells of the wood, which take the form of hollow cylinders, join together to form strands of fibres which lie in a uniform direction which is more or less axial either to the trunk or to its offshoots. The lay of the fibres is commonly referred to as the ‘grain’.

Diagram 7.1 Primary forms of cutDiagram 7.1 shows a block of wood in which the grain is running longitudinally. Three tools are shown as if about to make cuts in the directions indicated by the arrows. These illustrate the three primary forms of cut; as defined in the common expressions of:

cutting along the grain (A);

cutting across the grain (B);

cutting end grain (C).

In practice of course, particularly in woodturning, there is an infinite range of variations on these cuts. Not only can any number of intermediate positions between those shown be taken up but the edge of the tool does not necessarily have to be held at 90 degrees to the direction in which the wood is moving. It should be noted that in Diagram 7.1 the wood is assumed to be stationary and the tool to be moving. Often, in woodturning both the wood and the tool are moving, but with the wood moving faster than the tool. For the purposes of analysis, in this particular context, this does not matter; all that we are concerned with here is the movement of the wood and the cutting edge in relation to each other.

7.3 Cutting along the grain

Anybody who has worked wood with a hand plane will know that it is desirable to plane with the grain. Diagram 7.2 illustrates the common situation in which the fibres of the wood lie at an angle to the edges of the wood block.

Diagram 7.2 Planing with and against the grainWhen the wood is planed with the grain any splitting between the fibres takes place above and in front of the cutting edge, which subsequently severs the fibres neatly, so leaving a clean surface, as shown in Diagram 7.3.

Diagram 7.3 Cutting with the grain
Based on: Bruce Hoadley, Understanding Wood, The Taunton Press (1980) – p150

If an attempt is made to plane against the grain the cutting edge picks up the ends of the fibres, lifting them out of the wood, so that they break off in an irregular manner leaving a rough finish. This is illustrated in Diagram 7.4.

Diagram 7.4 Cutting against the grain
Based on: Bruce Hoadley, Understanding Wood, The Taunton Press (1980) – p150

September 15, 2009

If the only tool you have is a hammer …

.. . then all your problems start to look like nails.

Yesterday evening I gave a demonstration at my woodturning club on turning a wooden mallet with an oval handle. I spent time over the weekend preparing for the demo. While I was turning a mallet in my shop, a friend of mine came round to visit. As he watched me we got to talking about hammers and he told me of a big carnival hammer he once had.

Boys will be boys, and not long after that we had this big log on the lathe and were busy making a monster size mallet 🙂

The head is 7 1/2″ x 9 1/2″ and the oval handle is 2′ long turned from poplar.

I took it to my demo and used it as an icebreaker at the beginning of the demo. It got a good laugh and helped to relax me as well as add some entertainment to the evening. Things came full circle at the end of the demo. I had turned the tenon on the handle ever so slightly oversize and was having difficulty pushing it into the hole of the mallet head. So I grabbed the “mother of all mallets” and with a sharp tap the handle slid snugly into the head, ending the demo nicely.

Category: Woodturning