I have been asked to paint a massive cedar pergola on the coast in RI. The owners painted the pergola themselves with a Sikkens solid latex stain. Which is what they'd been told to use. Apart from being covered with a green algic mold, the sikkens appeared to be peeling. So I began taking the sikkens off with 60 grit on an orbital. The tops came off fairly easily and, having broken the edge with the sanding, the Sikkend was "peelable" with my fingers down about a third of the rafter sides....If I pick at it or try to press the 5in1 under a bit to grab, I can peel a shard at a time, maybe a few inches. Sanding off the rafter sides though, even with 60 grit seems like an endless, dispiriting task! I don't dare leave the Sikkens on under a new application, heat-gun doesn't lift it, a wallpaper steamer might even work better than that! If I do go all the way to bare wood ( at least a second week of sanding ) the BM guys shook their heads at the idea of using Sikkens and told me I needed to oil-prime, then 2 coats of SW Duration ( per customer choice ). But now I see in these forums that some say the oil prime did no good and the finish coat bubbled and peeled anyway. Normally I would prime over what won't come off relatively easily, but I'm worried the residual Sikkens might decide to lift someday, with my paint on top of it! I figure the oil prime has at least a chance of soaking into and sealing the cedar in this hot summer, even if I have to pump the Penatrol to it, where any latex product will just dry the minute it touches the wood. I thought it was the oils in cedar that fought back, hence an oil primer. Any help with this would be greatly appreciated! In addition to this beast there are two other gray cedar pergolas ahead as well as 42 fiberglass columns!