I haven't used Captains in about 5 years. I'm currently on a Interlux and Epifanes kick. I generally buy the recommended thinner.

I had to look back to the MSDS for the ZSpar/Pettit products. 120/T10 brushing thinner is mostly naptha with trimethyl benzene and some xylene and other "petroleum distillates." 121/T8 fast drying thinner is mineral spirits with Ethylbenzene and Xylene.

From the looks of it, buy a quart of the Pettis thinner. Normal paint thinner may not cut it. Why chance it? Besides, a quart is only about $17.
=D

http://www.pettitpaint.com/fileshare/product_msds/11212006.pdf

: I have decided to paint the hull of my Point Bennett (by Duane
: Strosaker) red and the deck with ZSpar Captains Varnish. I got a
: quart of Pettit Easypoxy and it says to use its 12120 brushing
: thinner for clean up. Since I bought a nice Purdy ($$) brush,
: I'd like to be able to clean it properly and use it on other
: projects. Does anyone have any experience using this paint and
: can I use just a normal paint thinner or do I have to go with
: the Pettit product?

: Charles Robinson