[hellosailor]

Pretty much any "mineral spirit" will dissolve wax to some extent, but different ones work better/faster. And these days "wax" or "polish" is often not wax but a silicone or other synthetic that the cheap spirits won't really lift, which is why it pays to use a more expensive "prep wash" from 3M or any of the other big brands, if you want to make sure that any contamination is gone, and you don't know what the contaminants might really have been.

If you mix your own, using the same solvents, odds are it will cost just as much. "Thinner" is damned expensive these days!

 

[hellosailor]

Speaking of products, Liquid Tide (laundry detergent) is also a fine one, it even removes Cosmoline, which is a bear to clean. Still, I'd finish with a commercial prep solv.

 

[hellosailor]

For all you know "mineral spirits" could be diesel fuel. That's the generic name for "cheap stuff that probably will clean your paint brush". If saving ten bucks is worth gambling that your new expensive paint job may come off in six months, use the cheap stuff. Using a "prepsolv" that is designed to remove wax and other problems can be cheap insurnace. Ditto for using lots of clean paper towels, not rags that may have detergent residue or laundry softeners (wax) in them.

The bilge? Probably will have oil residues in it as well. Prep is 90% of any paint job, if it isn't clean enough to eat off, it needs more prep.