BEST USE OF A STANDARD SHEET OF SANDPAPER
SMALL BOWL BLANK CUTTING
RED OAK LOGS
Loading-up Black Oak
Unloading Copper Beech
A BIGGER SAW!
Cutting Black Oak
Using painters plastic to slow drying.
ROUGH TURNED BOWL DRYING
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Note to readers: This page is a work in progress and I hope you come back again to see how it’s coming along. If you are looking for indepth professional instruction I highly recommend all of Richard Raffan’s books and CDs.
Note: All tool manufacturers safety guidelines should be adhered to and followed as appropriate for you own personal protection. My own disregard for personal safety should not be an example for you to follow.
Measuring the diameter
This Red Oak log was felled in March of 2008 and about half the log was cut and rough turned into blanks at that time. This bottom half I left sitting up off the ground on a couple of small rounds to keep it from rotting. Red Oak will catch a fungus almost instantly if left on the ground (spalted is a nice look but you will have to cultivate it for a year or so and there is no guarantee on your results).
Length equal to diameter
The length of my cut is approximately the same as the diameter of the log, give-or-take an inch or so. Trees are seldom perfectly symmetrical and you can shorten or extend the length of cut to get the most out of the log.
The chain saw is the Husqvarna 357XP see www.husqvarna.com for a local dealer. This is my third saw (craftsman and smaller Husqvarna) and I highly recommend it. The best selling point is the Decompression button for easy starting.
laying out bowl
Logs are somewhat symmetrical but seldom ideally so. I use a straight edge to find the best orientation for cutting the log in half. Ideally the pith will be an equal distance from both edges of the log. Often you will be presented with choosing between one very nice bowl orientation and one slightly less pleasing. Good bowl orientation choices made at the start will result in a rough turned bowl that warps evenly during the drying process and shows a predictable grain pattern when finished. Obviously, for creative reasons you can orient the bowl many different ways but you run the risk of creating more rough turned firewood that is warped and cracked beyond saving (I have several such pieces of artistic firewood).
Bowl layout, bowl bottom cuts
Deciding on how much to cut off the sides for the bottom of the bowls is again somewhat dictated by how you have decided to orient your center cut. I look to remove all the bark, most if not all of the sap wood and a portion of heart wood. With Red Oak I only cut out the pith if the cracks extend out from the center more than an inch or two. I expect to turn away anything less on the lathe. The proportion of the foot in relation to the bowl width and height is one factor to consider and the other is how much sapwood you would like to leave on the outside of the bowl as a decorative feature. Bark and sap wood might be decoratively pleasing but are weak structurally and will not give the structural support on the bottom of the bowl needed for rechucking the bowl by its foot (I speak from experience on this account)*.
*Experience usually involves the violent release of stored kinetic energy resulting in minor to mildly severe bodily injury. While this kind of learning makes a lasting impression and can be surprising, exciting, and terrifying all in the span of a brief moment, it’s best avoided if at all possible.
cutting sides of log first
I try to make my side cuts (bowl bottoms) parallel to the orientation of the center line (bowl top) of the log and I’m shooting for an even bowl thickness from side to side. Accurate cutting now will allow the bowl to sit flat and square on the band saw.
Center cut, top of bowl
As with the side/bottom cuts, the center/top cut should be straight and parallel to the side/bottom cuts as much as possible. Being accurate now saves time later at the band saw and lathe.
Bowl layout with precut pattern
An afternoon spent cutting bowl templates is well worth the time and effort. One 4X8 sheet of chip board should be adequate or you could use up old leftover scrap pieces that you couldn’t bring yourself to burn, as I did. An awl marks the center and I use a sharpie for the outline.
Cutting out blank on the band saw
I started out with a 14” Delta band saw, but became so frustrated with its lack of power and cutting capacity (only 6” and ¾ hp) that I bought a bigger saw as soon as I could afford it. The Grizzly G514X saw (www.grizzly.com ) with a 12” depth of cut and at 2hp is fantastic. On sale this was a great bargain at about $900 which included shipping w/lift gate. It has all the bells and whistles the more expensive saws have, at a better price and Fine Woodworking Magazine gave it a best buy pick. I received my saw with shipping damaged doors and Grizzly customer service shipped out new doors within the week, no hassles, they were great.
Completing the cut
Timber Wolf Band Saw Blades www.suffolkmachinery.com are the best for cutting green wood. I’m running their ½” X 3AS .032” blades. Suffolk sells blades direct and they're cheaper than the retail stores and you have access to their entire line of blades. Suffolk also has a great on-line tutorial on everything you ever wanted to know and more about band saw blades and their proper use. Using Pam to lubricate the blade is recommended and I’ve found it does improve ease of cutting and blade life. Their blades will cut through a 8” thick block of wood with ease. Timber Wolf blades are a bit pricy at about $27.00 each but I think it’s well worth the money.
Bowl blank and firewood
Working from whole logs gives me the advantage of using the byproducts for firewood and mulch. The cost of the wood is a write-off at the end of the year and you save money on heating costs (life is good)
A nice stack of bowl blanks gives me a sense of accomplishment after a mornings work. I’ll feel even better when I’ve finished roughing these blanks out and I can add them to my bowl bank (rough turned bowls are like money in the bank for a production turner). Also be aware that Red Oak tannin will oxidize bare steel almost instantly upone contact, clean off dust and shavings right away and apply WD40.
Drilling for screw chuck mounting
A good quality cordless drill (½” 18V) is a must have and it's one of the most useful tools I’ve ever bought. On sale you can get a quality drill for about $150.00 and it's worth every penny.
Screw chuck setup
Every lathe comes with a face plate but I’m not sure why, I’ve never used one and don’t plan on ever using one. Maybe I could use it as a paper weight to keep my sandpaper from curling due to summer humidity? When I bought my fist lathe, a Nova 1624/44 (www.teknatool.com ), I also bought a SuperNova2 Chuck to go along with the lathe as a matter of course. The advantages of using a chuck over a face plate are abundantly clear once you have seen it in action. Richard Raffan expertly demonstrates the versatility of a scroll chuck in his books and CDs. The SuperNova2 has served me well (I have two) and at $149.00 on sale it’s a good buy. You will also have to shell out another $25.00 for the insert to match your lathe. The jaws that come with the chuck are fine to get you started but you really need to buy 100mm and 130mm jaws to add more versatility. I just bought a Vicmarc VM120 chuck (www.vicmarc.com ) with step jaws. Vicmarc is the gold standard in lathes and chucks but the price reflects the high quality. Woodturners Catalog (www.woodturnerscatalog.com ) currently offers the best price at $269.99 w/insert.
Mounting blank on chuck
The worm-wood screw that comes with the chuck has been adequate for almost everything. I’ve put on it so far, even up to 16”W X 6”H Red Oak blanks. On something this big I started out also backing it up with the tail stock for the outside rough turning but now I don't even bother. I've recently turned 22"w x 8"h ash without the tailstock.
Rough turning outside of bowl
Rough turning the outside of the bowl consists mostly of removing all the bark and most if not all of the sap wood. Leaving sapwood can add an attractive contrast to the outside of your bowl but you run the risk of this wood cracking and splitting because sapwood dries much quicker than heartwood. When rough turning bowl blanks, your final bowl shape design decisions need to be made at this time. If you leave your wall thickness a bit on the fat side you will leave yourself a bit more latitude on your final shape and any embellishments you might like to add. Leaving as little as 1/4 inch extra wall thickness now can yield a wide range of design options later on when you finish turning the bowl. The trade off is you run the risk of having a higher percentage of split bowls down the line as they dry.
Truing up the face
On the face I only cut in towards the center about half way. If my blank wasn’t cut right down the center of the log, I’ll turn away wood until the pith is removed and then a bit more. Turning away the pith can also be done when the bowl is re-chucked for hollowing.
Turned foot for remounting in the chuck
I like to turn the foot just shy of the max diameter of the jaws but not so wide that the foot won’t fit into the jaws after the foot warps a bit oval during drying. Adjusting a set of calipers to this width takes the guess work out of the process. I’ve also made my own fixed caliper out of shop scraps (see sidebar) to save the cost of having a half dozen calipers dedicated to one measurement.
Hollowing out inside of the bowl
Using a McNaughton system to core out two or three additional bowls from one blank is ideal but that’s a process best learned from a master turner. Mike Mahoney is the best authority on coring out bowls and Richard Raffan also gives a good account of how it’s done. The $285 you’ll need to spend is worth it but, you can live without it when you are just starting out. Drilling a center hole to gauge how deep you want to hollow is a good idea and it makes getting started a bit easier. Always cut from larger to smaller as you hollow the bowl. As the bowl dries the rim will distort more than the base. Leaving the rim thicker than the base will give you the necessary wall thickness to preserve the depth of the bowl you originally planned on. If you find the bowl has warped beyond your available rim thickness all is not lost, you just cut the rim down until you have enough wall thickness to work with. A wall thickness 10% of the bowl width is the rule of thumb.
It doesn’t hurt to knock off the sharp edges on the inside and outside of the rim and I’ve heard it helps prevent the rim from splitting. I also turn a rabbit in the bottom of the bowl for reverse chucking. Again, I eyeball how wide to cut the rabbit in the pursuit of my motto, “less time measuring is more time for turning”, and if I’ve made a good guess I can remind myself of how wonderful I am (self congratulation is balanced by the dejection that comes after you turn through the bottom of a bowl or when the bowl explodes in your face as your finishing off the rim).
Basic salad bowl
Drying bowls is a process of Natural Selection. It’s like the mother turtle laying her eggs on the beach. She lays hundreds of eggs and then just swims away not knowing or caring how many of her babies will grow to adulthood. Roughed out bowls must be like those eggs to the turner. Pile them up in a corner and just turn your back on them not knowing or caring if they will ever become finished bowls. Like the baby turtles who will get devoured only moments after they hatch or later as they struggle to reach the water, some bowls will split and crack beyond salvaging. Not many will be lost, but it’s foolish to get attached to your rough bowls because they may ultimately be lost to the whims of chance or a moment of lost concentration. This is a good thing because bowls that split in the drying process, of their own accord, are best used as firewood. Bowls that come through the ordeal of having their guts carved out and left to dry can be expected to endure the ensuing torture of finish turning and the ultimate test of daily use. I must admit to becoming attached to a few bowls when they came off the lathe and to anticipating the final turning knowing that I may be disappointed in the end.
Date and set aside to dry
I date the rim with a black sharpie; month, day, year and the wood type. If you only have a few roughs wood type is not crittical but, if you have several hundred at any given time it will help you keep track of what you have (after sitting and collecting dust for a year or two they tend to all look the same). I then stack the bowls on the floor under a bench for a few weeks or months where it’s cooler and damper. In the humid summer months it’s good to give the roughs a few extra months to stabilize. In the dry winter months as little as a month may be adequate. If the wood is very wet I'll drape the pile of bowls with a sheet of clear plastic and flip the plastic over every day until the condensation no longer collects on the underside.
4' DIAMETER COPPER BEECH LOG BUTT. Tree was cut 2-9-2010
SCRIBE A LINE FOR THE CROSS CUT
CUT AND SEPARATE THE SLICE
BOWL BLANK CUT PLAN
MARK FOR FINAL CUTS
BAND-SAW READY BLOCKS
BLANKS READY FOR ROUGH TURNING
SELLING YOUR BOWLS
David Pye: THE NATURE AND ART OF WORKMANSHIP