Hairline Cracks

[Armageddon]

Yep, i read the thread Shinai hairline cracks already. But it didn't really explain how the cracks came about.

I recently bought a BRAND NEW Shinai (Top Mu Kon)
http://www.onlinekendo.com/htm/products.php?pid=19&typeid=29&sorting=3&display=12
When i pulled it out of the box i was quite happy with the quality, its a really good shinai (so i thought?). I pulled it apart, filed, sanded the sharp edges & wiped it down. As you know when you are sanding it you pay alot of attention to what you are doing & there were no visible cracks anywhere on the slats. I then started to oil the slats with a light vegetable oil (olive). After 12 hours i noticed that some hairline cracks had developed on the inside part of the slats, just above and below where the tsuba would go. I have attached a photo of the cracks.

What has created the cracks?
Will the shinai be ok?
What is the most common place that you have broken your shinai?

I think the cracks may have come about due to the expansion of the bamboo as it has absorbed the oil. But i'm not too sure. Any help would be great.

[ukenagashi]

speaking as a joiner, the oil wont do anything like that, thats why most peole put things like teak oil and linseed oil on thier bokkens,
one theory why this may of happened

the shinai may not have had suficient oil rubed into it and moisture may of got into it and expanded when being stored in the shop or transport, as the expanded shinai has been transported it has dried up and a shrunk, which has caused these cracks,

[billyboy]

if you ask me the cracks on the shinai are just on the varnish type finish put on the bamboo and not actually damage to the bamboo. i wouldnt have a problem using that shinai and would say it isnt going to break.

[taganahan]

you can try and peel it off. my shinai had those stuff but i didn't mind. after some months, i saw it again but this time i could peel it off cause the skin was sticking out a bit.


~taganahan

[elssha]

if you ask me the cracks on the shinai are just on the varnish type finish put on the bamboo and not actually damage to the bamboo. i wouldnt have a problem using that shinai and would say it isnt going to break.
Um... but if he sanded it, wouldn't that have taken off whatever varnish was on the bamboo?

[Armageddon]

It's definately not the varnish because the cracks are on the inside of the slats, and i did sand the edges and inside surfaces down.

[Girlinpigtails]

You know what? I noticed the same thing too w/ my brand new shinai! I was wondering the same thing too. I had pour copious amounts of oil on and let it soak for a long time (overnight). I thought it was weird since in the morning, I had to wipe the excess oil off and that's when I noticed the small cracks b/c if it was to have dried, I wouldn't have to wipe off all that oil.

[billyboy]

i have never noticed any cracks like yours on any of my shinai but i have seen a shinai break during practise and that one split length ways down the shinai. it split because it had never been oiled or sanded and the unsanded edges grated against each other causing the break (and a face full of splinters for his unlucky opponent).