In Desperate Need Of Help On Polyurethane Mirror Finish!
Hello everyone. I am in desperate need of help with finishing a project of mine. I am trying to get a mirror polyurethane finish, but no matter what I do I continue to have problems. My biggest issue is that once I rub out and polish my project, it becomes very glossy, but I can see what looks like smudges and milky white streaks under the finish. I can even rub my finger across the finish and some of the streaks start to gum up and roll off my project.
I have tried wetsanding the finish down and starting the polishing process over again, yet the same thing continues to happen. For the record I started out with Minwax Oil-Based Brush-On Polyurethane and then decided to go with Minwax Oil-Based Spray-On. I wetsanded the final coat the next day and then I let it sit for 2 weeks before rubbing out/polishing it (it has been humid here the last few weeks if that helps at all). For the wetsand I started with 800 grit and finished at 2000 grit and for the polish I used 3M Rubbing Compound, and Meguires Swirl Mark Remover.
Everything looks good until I begin the polishing process, what the heck am I doing wrong guys? I have also heard of the Behlens Rock Hard Table Top Varnish, but I am unsure of the durability and I also heard that the rubbing out process is brutal (I am unable to use a powerful buffer on my projects). I'm not sure what to do next, so now I am coming to the experts, thanks in advance for any and all advice given!
plastic polishing cream by Novus
I found this thread two years later; however, for those of you looking to polish polyurethane to a mirror finish it can be done. I was searching for something to polish my plain old polyurethane when dry sanding to 2000 was not working. From reading the above thread, I thought it was not possible, and put my project away for the night. Today, I picked up my plastic polishing stuff and gave it a try. It totally works, with not a lot of elbo grease.
It is a plastic polishing system of 3 creams by Novus. I purchased them at Tap Plastics, but have seen them other places. Since I have sanded to 2000, I started with the 2nd cream, for minor scratches. Using this cream and a Viva towel, My sculpture now shines as if it was wet was water or oil! I topped it off with the #1 polish as well, but there was not a noticeable difference from the #2 cream.
To recap: I applied about 6 layers of polyurethane by varathane. I waited 3 days then sanded with 300. Then 600, 1200 and finally 2000. The 300 and 600 was a paper based sandpaper. The 1200 and 2000 are a cloth based and I found them to work better than the 1500 on paper. Last I used #2 scratch cream by Novus. This really made the surface smooth and crystal clear like a mirror; exactly like the wet polyurethane looked, except without brush marks.