Ziricote splitting

[Bob_H]

Howdy - I have been working on a tenor ukulele with Ziricote B&S and a bunya pine soundboard.

The ziricote is causing me grief. The ends of the boards all had some splitting, which I was able to either cut out or stopper with super glue. However, while working with the timber a further small split along the grain appeared in the back, which I super glued and patched. I then went to bending the sides, on a bending iron. Numerous further cracks (7 - appeared, some several inches long. Some where in the middle of the timber, some at the ends. All are with the grain. Many are only apparent when you spray water on one side and then applied some stress and heat - the water would pass through the crack and form a long line on the other side of the timber (similar to how one might bleed from a long scratch, with a line of droplets forming).

I am very much a beginner, having bent the sides for perhaps eight instruments, but I haven't seen this in any of the other woods I have worked with. My feeling is that trying to stabilise the timber would be a never ending game and I should put this down to experience. I have read that zizicote has a tendency to split, but wonder about the viability of trying to deal with the number of splits I have observed. Any advice greatly welcomed. I haven't posted a picture, as most of the cracks are not visible under normal conditions - but now I know they are there!

[nkforster]

Ziricote splits. It's known in the trade as "Mexican crack wood."

The best plan is not to use it. It cracks.

If you do use it, you can do as I do and only use it in veneer form. I then cross laminate it for stability. But as a beginner, this might not be the best way. It just complicates things.



It is common for those who do use the wood in solid form to flood it with thinned epoxy.

My advise is to quit whilst you are behind. Put it to one side and start an instrument using a stable quarter sawn timber. That will give the ziricote time to show you just how much splitting it intends to do. Far better let the wood get on with it instead of trying to fight it.

[kiwigeo]

I agree with Nigel. Put the set to one side and if you really have a passion to do something with it....come back to it after a few more builds.
Taking on challenging woods for an early build can end up killing your passion for building totally.

[Bob_H]

Thanks for taking the time to respond Nigel, Martin. Good advice I feel.

The ziricote was an opportunity purchase, and not too big an investment in pieces that size, but bought without much knowledge of the challenges it might pose a beginner. I have got a good neck and top already complete, and a couple of other sets on hand I could quickly swap in to continue to progress this build.

[Allen]

When using as solid (not laminated) and manage to get the body closed up, most experienced builders will flood the timber with very thin CA that will wick into the cracks you just can't see. I learnt this the hard way the first time using it and applying my first coats of finish that showed them all up.

[Bob_H]

When using as solid (not laminated) and manage to get the body closed up, most experienced builders will flood the timber with very thin CA that will wick into the cracks you just can't see. I learnt this the hard way the first time using it and applying my first coats of finish that showed them all up.

Thanks for the insight - I think I will let these pieces sit for a while before attempting this It is reassuring to know that ziricote is a challenging timber to work with (ie its not just me) but also a good reminder of the benefits of knowing one's (hopefully expanding) limits!

[Steve.Toscano]

I build a lot of ziricote guitars (solid NOT laminated).
A few things:
I leave everything a little thicker ~2.5mm sides, ~3mm backs.
Always flood with thin CA on the outside prior to finishing, and i seal off the insides with around 10 coats of brushed on shellac.
You'll find if its going to split, it will usually do it early on - as soon as sides hit a bending iron, or as soon as back goes into a radius'd dish. I have a had a few sets do this and have abandoned them - chopped up for headstock veneers/rosettes etc etc.

Yet to have any returns or hear about splitting in a finished instrument.

[Bob_H]

I build a lot of ziricote guitars (solid NOT laminated).
A few things:
I leave everything a little thicker ~2.5mm sides, ~3mm backs.
Always flood with thin CA on the outside prior to finishing, and i seal off the insides with around 10 coats of brushed on shellac.
You'll find if its going to split, it will usually do it early on - as soon as sides hit a bending iron, or as soon as back goes into a radius'd dish. I have a had a few sets do this and have abandoned them - chopped up for headstock veneers/rosettes etc etc.

Yet to have any returns or hear about splitting in a finished instrument.

2022-03-22 16.39.07.jpg

Thanks Steve. Sounds like a solid approach.