Thread: Help with spalted Blackwood bowl

My guess is that you'll be rounding the flat area, also where the cracks are located, once it's ready for final turning. Since it still has a way to go before it's dry, there would be no sense in filling the cracks just yet...in fact they might even be turned away during final turning. If the cracks are still there after turning down, then thick CA or tinted epoxy would do the trick.
The punky area would probably benefit with a good soaking of CA now...it won't hurt the drying process.
Nice looking wood John...the finished product should look aces

Similar thoughts to Ed

Apply some thin CA to run deep into the cracks to inhibit their spread but do not fill until you do the final turning and finishing stage. If you try to fill now you more than likely will have to patch up anyway when you turn down to finished surface. And, they may not be there if turned right away...

As for the porous areas, if it is tearing out or breaking away in chunks then stabilise with CA or whatever will work with your finishing treatment. Otherwise, just leave and treat it carefully (as more prone to denting) and if you are lucky it may also get turned away during the final stage.

Neil

PS - noticed that your foot ring has been left quite thin compared to your bowl rim. The warpage at the larger diameter rim is always greater than at the smaller diameter foot, but if it warps as much as some of the green blackwood I have worked with you may not have a lot left to play with on that foot when dry. Depends a bit on how you complete your feet, but mentioned in case you have more of that blackwood to green turn.

Sorry guys my mistake/bad wording. Bowl has already been roughed/sealed and left to dry. I have now started to finish turn.
Ed, you are quite right the flat will be turned off resulting in a bowl of ~280 mm Dia. The cracks could very well be gone as well when final diameter is reached. Neil the foot ring is purely for turning and will be gone when I rechuck to finish the base. You were quite right there was a fair bit of movement during the drying process, but everything is trued up now.

This is easy to answer John

Its Cracked

Its rotted

ITS FIREWOOD


cheers
























might be a bit controversial

no good putting CA on then turning it off so you need to get to nearly finished size first. Also had no luck filling cracks with CA so i would try araldite when it gets to the finished stage if you can get it in the crack.

Hows that better effort

I'd use thin CA for both, both now and as you turn if it hasn't penetrated far enough. Do not use accellerator, have a cup of tea and what for it to set.

CA tends to soak into spalted areas a bit further than it does into the solid grain, so you may get away with just one coat. But I wouldn't count on it. Coat & turn, coat & turn, until you have a finished product. Especially on the finishing cuts.

I'd also CA the fine cracks, as it really doesn't take much for them to grow. A bit of heat from turning/sanding, a bad catch, or even simple relief of stresses caused by turning the supporting wood away. Sure, they may be turned out of the finished piece, but CA is cheap... and better to lose a dollar's worth of CA than the day's wood & effort.

this is what I do, especially on the fine cracks

Hi John,
I agree with the guys above. I would put some thin CA in the cracks to help hold things together, just in case. I did a similar Blackwood spalted bowl with spongy bits and worm holes.
I kept a lot of the shavings to fill in the holes later on - I poked them in with a bamboo skewer and then drizzled thin CA on top. The Superglue soaked nicely into the spongy stuff and made it hard.
The problem came when I got to final sanding as I pressed a bit too hard and ended up with a rippled bowl.
Nice looking piece of wood, by the way!

Thanks guys , I've started filling the cracks and spongy bits with CA as advised. I'll post pics as the job progresses.

Hello John,

Just a question re the final finish. If you are oiling be careful re the CA. If you don't clean it off the "non spaulted" darker area it will hold keep out the oil and you may get light patches where the CA is on the darker wood. If you are using a clear lacquer it's generally ok. The only prob when lacquering is that the CA, even the thin, tends to fill the grain so if you don't fill the grain with several coats of lacquer it can still be noticable - if you look closly.

Peter