Flattening Segmented Pieces

Flatten one side on a disk sander. Make one for your lathe; it's pretty easy to make a 12" disk sander that way. Or, use a flat plate and a sheet of sandpaper. Anyway, get one side of each ring flat this way.

Now, what I do is glue the rings on one at a time. Each ring is trued on the lathe after gluing. I usually keep the piece on the lathe for a day or two at this point; the tailstock holds the ring in place while it dries, then I true it, then the next ring, etc.

To true the ring flat, first use a scraper or gouge to mostly flatten it. Check regularly with a straightedge long enough to span the diameter of the ring. When it's close, switch to a long block of wood (again, long enough to span the ring) with sandpaper wrapped around one end (for small rings, use sandpaper big enough to span the rings also). You should be able to get a light-tight fit this way.

To minimize glue lines, what I do is this: I have a flat board with a small hole in the middle and four blocks bolted on via slots. I use the blocks to align the ring and keep it centered on the hole. The hole is where the tailstock goes as the ring is pressed against the rest of the piece. I apply a little pressure, then start turning the ring relative to the rest; this motion helps the excess glue squeeze out. I tighten the tailstock as the glue is squeezed out, until the glue layer is thin enough resist turning. I think the friction and thin layer helps it set faster; I can usually turn after only an hour this way.

Are you having a problem with the segmented PIECES that fit together to make a ring, Or fitting the RINGS together? The first answer you have would about cover the problem of fitting rings together, but your OP indicates that you seem to be having a problem with segments ?! Phil

Hmmm... ok, I can see how the OP was ambiguous.

For actually gluing the blocks together to make rings, most people glue up half-rings and trim the ends. I use a table saw to make the ends coplanar; others use edge sanders.

Hi Tim

DJ just covered it all, I was going through the steps in my mind just like DJ was explaining it, and learned another simple and neat technique (KISS) with his long block and sand paper to get a straight edge across, Thanks DJ. I have used the straightedge and also the sandpaper around blocks, but never thought about using them in that way, here's another trick up my sleeve I didn't have to invent myself.

I'm sorry I wasn't to clear. I have the segments glued together but now gluing the finished rings is the problem. I have tried to use the table belt sander in the past and found that is the quickest way to ruin a ring. I also tried to sand it smooth on the lathe for each ring but that was not to successful either. Anyone have a jig that works well?

Tim

The only idea I can offer, other then buying a drum sander, is to try really hard to ensure the segments are the same thickness and flat as you glue them. I wouldn't mind someone offering a really great idea.

Me, I ordered a Delta 31-255X belt sander from Amazon, between the coupons at Amazon and the Delta rebate I saved about $300 (plus free shipping)

One has already been offered, but it's upside down to me. I'd take the ring, adhere to a handled board, and rub it over sandpaper stuck to a flat surface. Sort of like leveling the bottoms of warp-and-go turnings.

If you had one of those great low-angle smooth planes, it might work to just slide over the glueup a couple of times. Though it might gum the sole or chip the blade if you were using resorcinol glue.

I hold the ring using Cole jaws the the flatest side down. Using a scraper I flatten then mark all over the ring with a pencil. I then sand off the pencil marks using a 17 x 4 x 3/4 inch plywood board with sandpaper glued to each side. The sandpaper is cut from a 4x20 belt I think 80 grit. I then glue the prior flattened ring or base to it. I start with a glueblock on a faceplate. Hold the faceplate in the tailstock using a tailstock chuck adaptor, add glue and bring the tailstock up and apply pressure. Wait a couple hours and release the Cole jaws, stick the faceplate back on the headstock and flatten the ring using the same process, go to the next ring.

Stuart Johnson Red Oak, Texas

if you have a chuck but no Cole jaws, there are instructions for making a set of large jaws on my web site.

SNIP.......... =====================

If you have a custom cabinet builder nearby, they should have laminate covered plywood cut-outs from sink installations. These make good flat surfaces for making sanding boards or face plate disc sanders. If you use rubber cement, it will release pretty easily from the laminate. The last cut-outs I found were $2.00 each. FWIW.

Ken Moon Webberville, TX.

====================== A post script to my last post:

Those cutoffs also make great face plates. Just use a tap that matches your spindle thread (1X8, 3/4X16, etc.) and add any spacers behind it as required. Mount on spindle, mark circles, and drill screw holes as desired.

Ken

Hi Tim

Not a jig, but a drum sander should make for a very controlled flattening setup.

I have a link to a build it yourself V drum sander, they have all the parts, if you need them.

A good, low cost and easy to do project, have a look.

Thanks to all. There are a lot of good idea's that should help. I especially like the cole chuck idea since I have one but didn't think of using it for flattening.