Knowledge You Can Build On — Est. 1998
TURNING PROBLEM
Jim King-Iquitos,Peru
>I have a bunch of these log slices 2 to 4 inches thick and would like to make bowls and platters out of them. The problem being is that most have a crack in them as this one. Any idea how to turn this without getting knocked out by a flying peice ? All I can think of is gluing a peice of plywood to it and bandsawing it round and I am not sure about that. They are about 24 inches across so the hit would be rather painfull if it came apart.
Re: TURNING PROBLEM
Ruth in So. CAl
>Look nice! I would use some thick CA on both sides of the crack. WHile turning I would stop a few times to check the depth of the crack and if the CA didn't penetrate that far I would just keep adding more.........
Re: TURNING PROBLEM
Bill Hale, Woodspinner
>Now that is to die for.
If i was fortunate enough to have that I would fill the crack with a mix of CA and sawdust from the red wood. Cut very thin pieces, break them up and run through a home blender. It may take 3-4 minutes but they will become fine dust.
Turn a little slower than your normal so as not to introduce to much centrifugal force.
Those have to make great platters.
Good turning and be safe
Bill in Casa Grande, AZ.
Re: TURNING PROBLEM
Jim King-Iquitos,Peru
>I agree about the wood and that is why I am looking for advice on how to turn it. I have these slices in this pink with black grain, another in various purples and another in browns and yellows. I makes me sick to just throw them out. I think I will try dowels at angles in a couple and butteryflies in others and sawdust with CA to finish the crack as they have a crack up to 1/4 inch wide on the outside. Plus this I am going to glue on a 1/2 inch plywood backer unless someone comes up with a better idea.
Epoxy
Jorge Castaneda ~ Downeast Maine
>Jim,
Without reading the other posts looks that epoxy can hold that and you may leave the piece whole, just hollow the bowl.
Just an idea
Jorge
Re: TURNING PROBLEM
Barry Irby
>Are you planning to saw them round before you turn them? You could use stainless steel hose clamps around them for safety. You can string together as many as you need. Three eight inch would reach around a 24" bowl. Lowes sells them in the duct department. Turn them so the free ends are pointed away. I put tape over thme in case I brush the screw/buckle while they are turning. I would still turn slow and fill with CA. After you clean them up and and get them balanced, you can very carefully remove the strap marks. Might work on an irregualr shape too.
Barry Irby
Re: TURNING PROBLEM
John Trant (Baltimore/WashDC)
>I would clear out the cracks, slip in wedges of wood and fill the voids with dust and glue. I would thing epoxy would be best but CA or regular wood glue may work. In either case, secure the blank with duct tape or hose clamps. I had a piece of cedar with cracks that were less severe as your come apart on me. Ruined my whole day (to say the least).
By the way, what kind of Peruvian wood is that. It looks just like box elder from my neck of the woods.
John
Re: TURNING PROBLEM
Fog Tanner
>For cracks that wide, I would only use long setting epoxy with some sort of filler. The epoxy can be tinted to give some contrast. I often use coffee which has been ground very fine. You need to let the epoxy cure for about seven days before you turn it. That goes for 15 min to 2 hour set time. It takes about a week for the epoxy to really cure. It may set in a few hours, but full strength is still a week. There are several epoxies or "finish resins" that are fairly thin and would give good penetration. You can also thin them about 10% (no more) with 90% isoprophal alcohol. This doesn't affect set time or strength. But, even with epoxy, a sacrifical backing is a good idea.
I would not use CA for this purpose. You are asking too much of that glue for this application. CA forms a brittle joint and isn't that great for this purpose. It works best when you have perfectly mating joints. The glue itself offers very little in strength, its the bonding action that makes it a good glue. It also doesn't take shearing action very well either, a reason its a poor candidate for gluing on waste blocks. Apahlicresin is much better for that, followed by epoxy.
Re: TURNING PROBLEM
Leo Van Der Loo
>Hi Jim
First of all I would not use plywood for a backer plate, I have used it a few times and and I have had bad experiences with it, it does delaminate and in my opinion it is dangerous to use that, as for the splits in the wood I have used brass and stainless steel screws to keep wood from flying apart, that way the wood has some give when you have hollowed it, I'm sure you know it does change shape after you have turned it, and you can then later fill the splits and cracks up or accentuate them as you please.
Have fun and take care
Leo V
Re: TURNING PROBLEM
GeeSeaWhy
>I agree with Leo - I would be very wary of using a plywood backer on something that big. I would use solid wood instead.
Graeme
Re: TURNING PROBLEM
Jimbo13
>Leo,
Was it a cabinet grade plywood that you had a problem with the delam or one of the construction grade plywoods? Construction grade plywood is softwood. The failure cases I've seen is in the wood, not the glue. Odds are cabinet grade hardwood plywood would be fine as a backer.
Gidday,
Jim
