Thread: Exploding Hollow form

Depends on how well the pieces fit back together but I've managed to pull it off a few times - just follow all the golden rules like sharp tools etc and take light cuts for the rest of it

Yep, this has occurred to me heaps of time as I mostly turn burl. I always stabilise and repair with CA glue. Sometimes I add Plastibond to help give it strength or fill.

So, in answer to your question, it depends on how you have repaired it, your tool technique, the timber thickness and strength, the speed you turn at and where your tongue is at the time, hope this helps. A

ll jokes aside, think about what I have said and apply it to your situation

Sincerely
Willy
Jarrahland

I picture also might be helpful.

Going from what you have written so far If you have completed the outside just touch up that again to smooth where the joints are by turning it slow. Once that is completed just as an extra precaution you can wrap some sticky tape around the outside while you work on the inside, when completed just remove and clean any residue from the tape and finish with something that you can either wipe or brush on.

This is how I personally would do it from your description

Originally Posted by mat_au

..... didnt notice a crack in it and it kinda exploded in to 3. ........
any advice would be great

My advice - sit down and have a good think about the - "it kinda exploded" bit and forget about recovering the piece for a little while untill you work out what caused the "kinda exploded."

You say you "didn't notice the crack" so learn from this valuable lesson which fortunately in this instance you appear to be uninjured from. Flying objects with any mass or speed or both comming from the lathe are very dangerous and concerning events that have caused significant life threatening injuries and the deaths of wood turners. You may not be so lucky next time with this glued up blank or another blank.

Often there are multiple contributing factors, unsound blank (the crack), size, mounting method, relatively high turning speed, tool technique (a catch perhaps), failure to monitor turning progress and the condition of the blank, the turned items wall thickness reducing as we turn it away (ie reducing strength), natural stress release and movement in the timber as material is removed, perhaps a change in lathe speed to get a better cut, changed tool presentation angle, or changed tools, operator error/oversight/fatigue, blank mounting failing or loosening, etc.

When you have an idea of what caused the "it kinda exploded" work out ways to prevent it happening again, learn from this event and make sure you keep your self safe so you can make many many more.

+1 For Mobyturn's advise. Look out for yourself.
Regards Rod.

+2 for Mobyturns advise.

If your piece looks pretty well glued put a couple or wraps of tape around it and continue. Below is how I do it.

I turn a fair amount of questionable bowl blanks made from roots, stumps, crotches, etc. Most recently a piece of Locust that I could see some splits. It was a tree that had been dead for years and recently broke off and fell. A friend asked if I wanted it. I took it and cleaned up his yard.

With face mask on and 800 RPM - slowest on the Hegner, and staying at the tail end of the lathe:


It was a half log, so I jammed the flat part against the face plate with a tail center and roughed the outside and made a spigot to grab with the chuck.

I turned it around and put it in the chuck and made the rim round down about an inch and put two wraps of 1 inch masking tape around the rim. I finished the outside with the bowl gouge and ran CA glue in all the cracks. Some wider ones I packed with sanding dust and CA. I hollowed the inside so the bowl was 1 inch thick and ran CA in all the cracks. I let it sit a couple of days and it turned oval as it dried a bit.

I took more out of the inside and put more CA in the cracks, then brought the outside round and put CA in the cracks.

Next day I finished inside and out with scraper, and sandpaper, wet sanded with Tung oil, then Tung oil on a rag, except for where the tape was still on the rim.

Next day removed tape and put it about 2 inches down the outside of the bowl and finished the rim with bowl gouge, scraper, sand paper, and put CA in the cracks. Let dry overnight and wet sanded with Tung oil, and rubbed with Tung oil and rag. I took off the tape, blended the area with wet sanding and Tung oil, then rag & Tung oil and let set overnight.

Next day I took it out of the chuck, put a face plate with plywood on it, cut a groove for the rim and put the bowl on it jammed with the center, turned off the spigot leaving just a nub, used a scraper to make a slight concave on the bottom, sanded, applied Tung oil with a rag, dried it with a hair dryer, removed face plate and bowl from lathe, set on bench and cut off nub with bench chisel, sanded and finished the area of the nub.

I never exceeded 800 RPM and kept the face mask on most of the time.

Photo tomorrow, as I'm too lazy to go down and get the bowl and photograph it tonight.

I tend have a good look at what I'm turning long before it gets on the lathe. Then go from there, up to the discount shop to buy a heap of the cheap CA fill all suspect cracks ie smallish ones. The bigger I use clear epoxy and tip it in till fills the problem. Then leave for a few days, give one look over and onto the lathe.
But I make a conscious effort not to be in the line of fire whilst turning, Its a habit I have formed and it has stood me well.

thanks all i am very careful around the lathe always use my face mask and always stand of of the firing line when turning

but i might try some of those tips. do like the tape around the bowl idea will do that in furture