'Safe' Grind level?

[Neith]

psupedia isn't loading at all for me, so I have to ask this here.

I'm about to grind some of my C-Grade stuff, but I'm short on cash. I can't really afford to keep buying a new weapon if grinding fails, so I was wondering if there's a level of grind you can go upto safely, with no breakage chance?

Is there a 'safe' level, or would even +1 have a chance of breaking the weapon?

Thanks.

[KazuKun]

Grinding to +1 is 100% success. After that, there's a small chance of failure

[Pengfishh]

I broke going to +4 with a Very High Chance of Success. They were throwaway knuckles, Brassacle, that I was only using to build up Bogga Danga. Makes you feel bad when they break, though.

[Shango]

I have broken a 3star weapon grinding to (3) with a +3 grinder http://www.pso-world.com/images/phpbb/icons/smiles/icon_razz.gif

[Bast]

I've broken a 5* saber w/ a +5 B grinder. Very high chance of success. Going from 1 to 2.