Glue Blocks

[Mike Minto]

I was turning a block of Osage Orange last evening, about 8x8 inches. I was using a glue block made from a piece of 2x4 to hold it to my chuck, so I'm sure it was pine or fir - softwood, regardless. While turning, the glue block sheared off near the chuck's jaws. Is it self evident that only hardwood should be used for glueblocks, or are there times when softwood is OK - you know, to save money, use what is at hand, whatever? The block was undamaged, and still in the rough turning stage. Thanks for any info, Mike :mad:

[Bruce Pennell]

Mike after my lesson with Wally Dickerman (he always uses glue blocks), I cut up a bunch of hickory I had laying around. I first jointed and then planed the boards before I cut them up. Wally used thick CA and put it on with hand pressure and accelerator, we where turning 5 minutes later. He did say make sure there is squeeze out or your not using enough glue. Wally uses ash, stable and cheap. He had a stack cut up on the bench. Hope this answers your question...Bruce
PS he likes screw chucks to start off with, I like my SN2.

[Malcolm Tibbetts]

Mike, my favorite mounting system is a faceplate, screwed to a piece of 8/4 mesquite. The mesquite is strong and stable and the 8/4 thickness keeps the mounting screws well away from the surface, allowing complete access for any kind of base shape.

[Jim Becker]

I use scrap 8/4 Mahogany, believe it or not, for this purpose. I also had a softwood block "let go" years ago...

[Richard Madison]

Mike,
What size tenon did you have on the glue block? Here's an alternative pine glue block. Eight saw cuts makes a square tenon on a square block of 2x4 or 2x6 (shown below). Make tenon a little shallower than the depth of your chuck jaws. Then bandsaw approx. round. Install on chuck, turn round if desired, face off and sand flat, and mark the #1 jaw position on the tenon. Also easy way to make jam chucks. I make the tenon close to the largest size the chuck will hold.

[curtis rosche]

when i took the maple boards at school to the lathe, i cut off the corners with the bandsaw, i took the corner cut off, turned them round , now when i turn up to 8 inches, i use the 15 minute epoxy and epoxy the blank to the maple block. i also use plywood. if you make a block that is thick enough , you can reuse them, i reuse mine, i part the bowl off right at the glue line taking from the bowl and the block, then i can reuse, and not have to clean the bottom of the bowl to much

[Mike Minto]

richard, the glue block i was using was a stock thickness 2x4 which i had screwed to a faceplate and then rounded to about 3 1/4 inches. it separated near, but not paralled to, the faceplate. mike

[Richard Madison]

Mike, Others are right, of course, in suggesting hardwood, but have used ordinary kiln dried SYP construction lumber many times without problems. That size should have been adequate. Your piece may have had an almost invisible crack or check that ultimately failed.

Edit: P.S. Glad you got your shop floor fixed. Sounds like it will be ok now.

[Mike Minto]

richard, yes, saw your photo, thought it was SYP. i'll never use a 'regular' softwood for a glue block again - SYP, though a softwood, is very hard and i'm sure would work. how avout MDF? i've heard of people using that for glueblocks. btw - are you cat people (re your avatar). we are - have 7. mike :D

[Dean Matthews]

I have a softwood glue block... I am not putting it in a chuck though. I have the beal spindle tap and just made it a big block and then it screws right to the headstock... no problems so far with this method.

[Burt Alcantara]

I have a number of jam chucks made from glued together 2x4s. They have taken serious abuse for over a year and still going strong.

Burt

[Mike Minto]

burt, the jam chucks only experience compression, not tension or unsupported shear, in use, yes? just wondering, mike

[Richard Madison]

Mike,
We're seeing what I would call softwood (fir?) studs in this area now. Cheaper than SYP. Might use it (the fir) for a jam chuck (loaded mainly in compression), but would not use it for glue block or auxiliary face plate. Have no data on the shear strength of mdf, but would not use it with a chuck (like the one in my picture). Might be ok when screwed to a faceplate.

Been a cat person for 35+ years, but not fanatical about it. The avatar is Christine, a stray kitten when found many years ago. My "shop cat" is Missy, abandoned here by the previous owner. Missy has long hair, long tail, short legs, and a bad attitude.

[Malcolm Tibbetts]

how avout MDF? i've heard of people using that for glueblocks. :D

Mike, MDF can be used but only for small stuff that doesn't protrude far. It will facture it weight hangs from it; but for flat stuff, it's great.

[David Walser]

Here are a couple more ideas:

Bonnie Klien, in her book on small turning projects, recommends using 1x pine boards for making glue blocks. Her method is to use a hole saw to cut 2" - 3" rounds from the boards and then use double stick tape to fix the rounds to a face plate. She then faces the rounds off on the lathe before gluing the turning stock to the glue block. For the small stuff she turns, this approach is quick and inexpensive.

Since writing her book, she's changed her method. (I attended one of her seminars, recently.) She found several lock nuts (the kind with the nylon ring at the end of the nut's threads) at her local hardware store. The nuts came in a size and thread that fit her lathe's spindle. Now, she takes a hard maple block (3x3 or 2x2 and about 4" - 5" long) and bores a flat bottomed hole in one end large enough to accept the nut. After epoxying the nut into the hole, she then mounts the block in her lathe's chuck with the nut towards the tail stock and carefully turns away the nylon locking ring. She ends up with a glue block that she can use for several projects. Why did she change approaches? She started using a new lathe that had a different spindle size than her old lathe. This approach was cheaper than buying several new face plates in the new spindle size. Besides, she turns SMALL, and it was hard to find face plates as small as she wanted.

Attached is a picture of one of her glue blocks with a project glued on. The nut that is screwed onto the headstock is towards the top of the picture. Note how she's turned the block round to make it safe to work close to the headstock. To give you an idea of the size of the block, the spindle size of the lathe is 1".

Hope this helps