Carl,They use that Cetol stuff all over the place here in SE Alaska. Can't stand the orange color myself and I know they make clear now but having a hard time getting over the ogange that's still in my head. It would help (for me) if they'd say what it's made out of though. The Cetol I see seems to have a strong tendency to keep the wood from turning grey and I consider that very good. Perhaps the stuff they put in it that keeps the grey away is the stuff that makes it look orange??? I just looked in my Peter Culler book and he says kerosene "is often used mixed w linseed oil to drive the oil into the wood". *"some of us still think oil-base paint, usually white, grey, or red lead, sometimes all three in combination, well thinned with turps, is better as a primer on new work than the "undercoaters" often used, which dry quickly, are often hard and drive into the wood not at all". Mixing this w all the other stuff I've read by this man I'd wipe down w kerosene and thin w turpentine. All the above is relative to oil based paints and I haven't actually done the wipe w kero and coat w turp thinned oil based paints. Tung or linseed oil is to turpentine what BS is to politics. Turpentine aids penetration and it's mildew resistant too. I'd use turpentine to thin oil based paints.
Al Ross,
I think one must thin for a reason or not thin at all. Two main reasons to thin is penetrating ability or brush-ability. If you have a very low build coating and the surface is primed and sealed you surely won't want to thin unless you can't handle it w a brush. I'd say thin any oil based coating (heavily at first) when applying it to a porous surface and don't thin at all otherwise unless for brush-ability.
Ken,
I really like what you're doing but I'd use turpentine as the thinner.