Turning bowls and vases, using a waste block. How?

[dirk martin]

Typically, when I turn a bowl, I first screw what will be the bowl opening to a face plate. Then I true up and shape the outside of the vessel, and then create a tenon on the bottom. Next I flip the blank around, and mount that tenon into a chuck.

A fe of things I don't like about this technique are:

1) If the wood is soft, it's easy to crush or break the tenon.
2) Using a tenon, somewhat reduces the overall height of the vessel, when that tenon is finally removed.
3) If the inside of the bowl is gouged out, while only being held by the tenon in the chuck (without the tailstock as support), a tool catch can cause the blowl to break free, and fly off.

I've never used a "waste block" on my turning blanks, and would like to get some experience, doing so.

So, exactly how is this done?

It seems like I could take my bowl blank (assume it's fresh, green wood), and glue an Oak board to what will become the bottom of the bowl. I'd use a 3/4" or 1" Oak board. I'd use either super glue, or Gorilla glue. Since my blank is green, wet wood, I'd think Gorilla glue would work better. After the glue has cured, I can simply screw that oak to my face plate. It would seem to me, that this would be very secure, and I could then gouge the inside of the bowl, and shape the outside, and never need to flip the bowl around, nor even use my chuck. Finally, I guess I'd flip the bowl, use a jam chuck, and turn off the remaining oak waste block....or even shape the oak waste block, to give the bowl a fancy foot. I have a ton of cherry, short, waste boards I could even use. Is cherry strong enough as a waste block for bowl turning?

Am I on track?...or am I missing something?

[Richard Madden]

I'm not going to be any help answering your question because the only time I can remember using a waste block was for the base of staved vessels. Biggest difference was using dry wood. I don't know if I would trust gluing wet wood.

[Dennis Ford]

The process you described will work just fine, I have done many that way. For dry wood, I prefer yellow glue, with wet wood either Gorilla glue or CA (super glue). If you use Gorilla glue, give it several hours to set.

[John Keeton]

Dirk, I use a lot of waste blocks. Typically, I take a piece of scrap maple, poplar, or walnut and cut several 2.25" discs on the bandsaw. I mark the center of each piece with an awl for the tailstock. With the chuck on the lathe, and the jaws closed, I will use a piece of foam drawer liner for friction on the jaws, and jam the piece against the jaws with the tailstock. At that point I will turn a tenon for the jaws. Takes about 10 minutes to make half dozen or so - not counting cutting the disks with the bandsaw.

When I do a piece, I will mark the center of the blank, and using a compass scribe a circle just a little larger than 2.25" to align the waste tenon. Using 5 minute epoxy, I glue on the waste tenon. If I don't intend to turn until the next day, I will use Titebond and use the lathe as a clamp (tailstock pressure against the jaws.) I normally turn dry wood, but if I were using wet wood, then the Gorilla glue or CA would work. I never use a faceplate - only a chuck.

One comment, if you have a catch bad enough to break an integral tenon, it could break the waste block from the blank.

[Fred Perreault]

Dick, I use waste blocks frequently, especially for pieces that are thinner, such as plates and platters. I then turn the waste block off at the end and all is fine. I spend time every once in a while cutting out 3.5" circles for my 3" faceplates. Then I might glue blocks onto a few pieces to turn, using Titebond II successfully for any wood. I have done this for 3 years without any failures on shallower items, but use the tennon process (with tailstock when necessary) for most other items. Since I use mostly log blanks, often times with bark on, I have never figured the tenon depth to be a significant loss of wood. I suppose if one purchases expensive wood, the loss of every 1/4" might be reason to shed a tear or two.

The 3 points you made in your post are valid observations, but those are only some of the issues most every turner has to deal with, and make allowances for. 1) Proper size and pressure on the tenon. 2) Include the loss of tenon height in your design calculations. 3) Sharp tools and practice usually reduces catches to a minimum, or near zero. Last but not least, stay out of the line of fire. I have practiced all these procedures, and I still have to gather bowl parts from the other side of the shop occasionally.

[Steve Kubien]

Contact Lyle Jamieson. He doesn't own a chuck and uses waste blocks for everything.

[Wally Dickerman]

The use of wasteblocks or glue blocks goes way back to the days when everyone used faceplates. (The modern 4-jaw chuck came on the market around 1990) Then, some folks used paper in the joint. I don't recommend it.

I started using wasteblocks at least 30 years ago. I usually used a screw chuck which is a form of faceplate using a single center screw. I now usually cut a tenon on the wasteblock and use a chuck.

You've had some good advice so far. I'll add a few things of my own. Do yourself a favor and use a soft wood for the wasteblock. Easier to part off. I use alder. Poplar is good. Never use plywood or MDF. Could separate. You're making a glue joint, so both surfaces must be true and flat. I only use med. CA glue. The new flexible glue is probably best. If you have a joint failure it nearly always is because not enough glue is used. I want to see squeezout of the glue. I only use hand pressure when applying the block. With CA there is no curing time. The block an be installed and few minutes later it's on the lathe.

I part the piece off after it's finished, using a parting tool right on the glue line. With a fairly small bowl, part it down to a joint about the size of a dime. Then, holding the piece with one hand, pop it off the with the heel of the other hand. Looks kind of scary but I've done it many hundreds of time and haven't lost a piece yet....

Wally

[dirk martin]

Thanks for all the great replies, guys. Ok, now a twist to this question.

I'm turning green, wet wood here. Raw bowl blanks. I turn them down to about 1" thick walls (I use the 10% rule most of the time). Then I use the alcohol soaking method, for drying. After being dried, I will finish turning some, and sell others. So....I think you see my coming question....

Sounds like I can use either TightBond, CA Glue, or Gorilla Glue on my waste block. How well do you think those 3 will hold up, soaking in alcohol for a day or two?
Of, if you all feel those may indeed fail after soaking in alcohol, I'll just part the bowl off the waste block, while green...and then dry it. After dry, I'd then re-glue a new waste block on, and finish turning.

[John Keeton]

Dirk, I would be afraid of a glue joint after soaking in alcohol. For sure, it will dissolve an epoxy joint - not sure about the others, but wouldn't do it!

[Dennis Ford]

Not sure about the alcohol soak but the warping that occurs when the wood dries will often cause a glue joint to fail.

[Dan Forman]

Not sure about the alcohol soak but the warping that occurs when the wood dries will often cause a glue joint to fail.

If this is true, what do you do to return the now dried bowl? I'm thinking mainly of using using this for bowls or platters turned from crotches, where you want to preserve as much of the feather as possible.

Dan

[John E Wallace]

I use Hot Melt glue and scrap 2X6's, 8's for the waste blocks. I true the blocks using a metal straight edge before gluing the tenon and haven't had a failure yet. I don't think alcohol will effect the glue. The Hot Melt glue is a bit thicker than CA and seems to work well with end grain.

[Joe Herrmann]

Pick p a copy of Ernie Conover's new book, the Frugal Woodturner. He discusses waste blocks at length.

[Art Kelly]

This thread went around a while ago.

http://www.sawmillcreek.org/showthre...50258-hot-glue

I've abused a lot of hot melt used for waste blocks, but never after an alcohol soak. I'll test it in a couple of days. I don't think it would have much effect and may depend more on the wood being glued than anything. I also don't think I'd bet that it was completely safe to rely on the glue joint after the DNA soak.

What would Grumbine do?

[Art Kelly]

I've never used a "waste block" on my turning blanks, and would like to get some experience, doing so.

So, exactly how is this done?

There are a bunch of ways. I like to used "waste blocks" that have been drilled and tapped to fit the lathe spindle. This means I can keep a piece ready to go back on the lathe without needing a chuck. Rechucking often results in a little runout, but then so does sitting around and gaining or losing moisture. Here's one I posted a while back.

This little one has a lot of miles on it--notice the two extra glue lines. I was using it to do Christmas ornaments, and when I parted one off, I just faced up the little bit of waste left and used it again. I have some that are probably 5" in diameter. I'm still anxiously awaiting my first failure, but keep thinking that the glue is so pliable and gummy that it will probably not just instantaneously "snap" off. It'll still ding up the piece of course.