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I was wondering if you guys have had any luck rubbing out polyurethane finish? The project is a box with satin gloss does using wet/dry sand paper with a grit 2000 or so with soapy water smooth and leave the coat still a satin or semi gloss sheen?
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I'm not sure what you're trying to achieve? My understanding of satin and semi gloss poly is that they are satin and semi-gloss because particles have been added to refract the light, essentially dulling the finish to the desired look. I don't see how rubbing out could get you to a higher gloss, simply because the dulling particles will still be there; OTOH, you could certainly dull them further with sandpaper.
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Just a couple of things: urethane resins are scratch resistant (that's their real calling in the finishing world, plus they are less expensive) so by nature they are a little harder to sand than most finishes. They need to be pretty close to fully cured to do this sanding, more like weeks than days. Lastly, what you want to do will leave the coat smooth and with a dull sheen, probably more so than what you have currently. We have a member named Howard Acheson ( a finishing guru) who used to explain that the sheen will get more dull over time. This is because the finish itself will shrink a little as it cures. Doing so lets some of the flatting agents (silica) become more exposed and increasing the light refraction. I'm aso not sure what your goal is, but if smoothness is what you are after, you might try rubbing it with wadded up kraft paper (after it cures). This can smooth out tiny imperfections.
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When I have rubbed out oil based poly in SG sheen, I've had good luck using 0000 steel wool and Johnson's paste wax. The paste wax can be bought at most big box stores. I did this with the crib I built my son 12 years ago. The SG sheen was nicely knocked down to a wonderful satin and baby butt smooth when I finished. I don't use wipe on oil based poly anymore but when I did I always rubbed it out this way. I have never tried 2000 grits and water as the steel wool and paste wax method has worked very well for me. You will want to buff the wax off with a clean cotton rag.
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What I am trying to achieve is a smoother finish. I have my final coat of poly on but the finish is a little bit rougher then I would like so I really am just looking to level and smooth the finish but want to end with at least a satin sheen when done. I am not trying to raise the sheen just want the finish to be about where I am at just a little smoother. The finish is not super rough just not quite where I want it to be as far a smoothness.
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Try Wol Wax. A search of my username will reveal the method.
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(01-09-2017, 09:31 AM)tuneswoodshop Wrote: I have my final coat of poly on
No, you don't.
Sand and apply another coat.
Mark
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If it's well cured you should have no trouble rubbing out a polyurethane finish. Ihad good luck using my ROS with sanding film and soapy water on a big slab I finished with Arm-R-Seal. I did it for the same reason you want to, to eliminate some finishing defects and give a uniform flat, smooth surface. I let the Arm-R-Seal cure 12 days before I did it and the sanding made nice dust with no sticking to the sanding media. I took the sheen back up to gloss after I was done with the sanding film by using auto body polishing compound, but you can get a nice satin sheen at around 2000 grit if that's what you're after. If you want a higher sheen you can use Micromesh sanding pads or autobody polishing compound like I used.
John
