How To Deal With Split Blanks?

[custard]

How do you deal with split turning blanks?

Here's a 10" Maple blank that's on my lathe right now. It doesn't show too well on the photo, but it's quite dramatically figured, I'd really like to save it. But is that possible, and if so how? At what point do you judge a split too dangerous, or too damaging, to proceed?

Sorry, it's been a while since I've posted and they've changed the process for posting photos! If anyone can give me a simplified method I'll happily add an illustrative photo.

 

[custard]

Durrr! I just needed to log in to enable photos!

 

[HOJ]

Can't help to be honest, just very pleased to see you posting.

 

[okeydokey]

IMO and if you were turning a bowl gently remove the part with the split first (thats the outside of the bowl) and you may turn the split away

 

[custard]

Let's assume the split persists. How would you deal with it?

Thanks

 

[Duncan A]

I would turn the blank around on the lathe so the split is on the lower part of the bowl and then proceed to shape the outside of the bowl. This will normally be a lesser diameter than the upper part of the bowl which will remove some of the split and give you an idea of it's extent.
You can then run thin CA glue into the crack and give it plenty of time to set. Best not to use an accelerator as it tends to turn the CA white and make it more brittle. If the crack seems too large for this, but the wood is still looking safe to turn, put sawdust (or coffee grounds, brass dust, anything you fancy) in the crack and then add the CA, giving it plenty of time to percolate into the crack and dry before, if necessary, adding more glue.
If it looks reasonably sound, reverse it on the lathe and hollow it out. Treat the crack on the internal side in a similar way to the external.
If in doubt about the wood's integrity, keep the speed down, listen for any out-of-place sounds and stop for a visual check frequently.
And wear a good facemask!
Duncan

 

[custard]

That's a great summary, thank you! I'm going to follow your advice tomorrow with this bowl.

 

[MARK.B.]

Have a spare pair of underkrackers handy - just in case

 

[Stigmorgan]

If it really worries you, fill with CA/superglue, turn it until the open crack shows again, fill with superglue again and keep repeating until the crack has gone or you've reached the desired shape then turn around and hollow out, if the crack then shows up on the inside repeat the same process.

 

[Orraloon]

Its a bit hard to judge how far the split goes with a solid blank and I usually only worry about them when the bowl is nearing its completed shape and wall thickness. With luck it may be turned away by then. As said above ca glue is the turners friend. On the safety side keep a lookout for cracks near the base where it mounts in the chuck. Sometimes you may have to rethink the overall bowl shape and work with the wood you have. Duncan has summed it up very well.
Regards
John

 

[Lefley]

If it really worries you, fill with CA/superglue, turn it until the open crack shows again, fill with superglue again and keep repeating until the crack has gone or you've reached the desired shape then turn around and hollow out, if the crack then shows up on the inside repeat the same process.

But make sure you are wearing your ppe! Lol. I seen a guy recently that wasn't wearing it for a split second!

 

[Jameshow]

How about warmed epoxy?

Stronger than ca?

 

[kinverkid]

How about warmed epoxy?

Stronger than ca?

Warm epoxy would be my choice too. It soaks down through any cracks and will often find an exit crack too which is sometimes a bonus or a hindrance when it drips onto your lathe/work surface. A hairdryer on low will do the trick but you will really need to give it a day to be sure it has cured.

 

[--Tom--]

To my eye the crack isn’t big enough to get warm epoxy into, will need thin CA to wick its way in

 

[Phil Pascoe]

From my experience of cracks like that it should have a little arrowhead on one end along with "this way to the wood stove". You won't hide it and it'll irritate you every time you look at it.

 

[David Lloyd]

I use CA for thin cracks, epoxy on the wider ones - usually with some glitter, dye or brass filings in it.

If the crack looks bad and likely to explode, I turn the outside to shape then wrap the piece in Duck Tape while I turn the inside. If it does explode the debris field is smaller and less likely to cause injury.

 

[Stigmorgan]

I use CA for thin cracks, epoxy on the wider ones - usually with some glitter, dye or brass filings in it.

If the crack looks bad and likely to explode, I turn the outside to shape then wrap the piece in Duck Tape while I turn the inside. If it does explode the debris field is smaller and less likely to cause injury.

I've used this method a couple of times, works great

 

[dennisk]

I’ll use stretch wrap like thre stuff they use for tying up bunches of miscellany
It’s about 4” wide , no residue. Super strong and way cheaper than duct tape, not sure if that’s the same as Duck tape

 

[Inspector]

You can inlay butterflies along the crack to repair it and add a decorative touch too. Make your own templates etc or buy a ready made system.

https://bigislandengraving.com/butterfly-inlay-repair-system/
Some of the local club members have been using them with success.

Pete

 

[custard]

Some great suggestions here, thank you all very much!