# Removing sanding marks from poly finish



## gb-wood (Dec 13, 2012)

Hi all,

I am in the process of refinishing a wood kitchen table. I have stripped the old finish, sanded the bare wood nicely, and have applied stain and now, three coats of Minwax fast-drying satin oil-based poly. After my second coat, which was applied a bit too heavy (using a sponge applicator) - resulting in some minor pooling, I sanded the finish to prepare for my third coat. When I sanded I started with a 220, followed by 320 and some fine steel wool. Unfortunately, I was a bit aggressive in trying to level some of the pooled areas and although most of the table top was sanded with the grain (difficult with the pattern of veneers), there were spots that had obvious circular sanding patterns. I mistakenly assumed that the final coat of poly (applied with a soft towel pad) would hide those marks. It did not. 

What do I need to do now? Sand back to the prior coat? Even areas where I sanded with the grain seem apparent to me. Should I use a random orbital sander this time? How can I avoid this when I move forward to the final coats? I attached some photos showing the problem spots and the pattern on the table. Any help would be most appreciated.


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## dat (Nov 11, 2010)

try a 600 or 800 grit and mineral spirits wet sanding , I'll finish up with a 3000 "grit" buffing pad with mineral spirits


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## Steve Neul (Sep 2, 2011)

If you are going to put another coat on try using 400 wet and dry sandpaper with water and sand the table again. There shouldn't be anymore scratches when you put the final coat on. If you have enough finish and trying to polish out the scratches then wet sand the table with 1500 to 2000 grit sandpaper and buff the table top with rubbing compound. This may make the table glossier than you wish though.


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## gb-wood (Dec 13, 2012)

Thanks for the replies so far. Just to clarify, I have put another thin coat of poly ON TOP of those scratches in the previous coat. Should I use your suggested methods to get back to that "layer" and clear it up?


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## Steve Neul (Sep 2, 2011)

No you don't have to sand down to a lower level. Sanding it again should level the finish a great deal and another coat of finish should fill the scratches. If the scratches are presistant it may take more sanding and more coats but you can level the finish. If you try sanding down to a lower level you might sand down to the wood which could be a lot harder to fix.


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## gb-wood (Dec 13, 2012)

Thanks for the input guys. I tried the following:

1. Wet sanded with an random orbital sander and 600 grit plus mineral spirits. 

2. Thin coat of 3:2 poly/mineral spirits.

The old scratches had seemingly disappeared, before I applied the poly, but after it began to dry, the scratches are still visible - although, slightly better.

Perhaps I should have used a heavier coat or at least undiluted coat of poly. Or, perhaps I should have been more aggressive with the sanding. I had applied no pressure, just letting the weight of the sander do the work. Perhaps I should use 400 grit.

Anyone have any further thoughts?

Thanks again!


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## Steve Neul (Sep 2, 2011)

gb-wood said:


> Thanks for the input guys. I tried the following:
> 
> 1. Wet sanded with an random orbital sander and 600 grit plus mineral spirits.
> 
> ...


If you are using an electric sander, please stop wetsanding with mineral spirits. Mineral spirits is highly flamable and the motor on the sander can ignite it. Its not good for the finish anyway. It takes the poly a couple of weeks to fully cure and mineral spirits could lift the finish. It's better to wetsand with water. 

I don't recommend thinning polyurethane unless necessary to spray. You can get much better results not thinning it. Just brush it on as thin as possible with a soft natural brush and not overbrush it.


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## dat (Nov 11, 2010)

I hand sand, more like a buffing with as fine of paper I can get let the poly dry well, at least 24 hours, before any sanding, water or mineral spirits, longer dry time is better, at least for me


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## cabinetman (Jul 5, 2007)

You've got quite a bit of poly oin there right now. Each coat you add will slow down the previous coat from curing. I would not use a ROS, but sand with the wet-or-dry and water and a block of wood.

Foremost...what you have now needs to cure. It may take longer than you think. If you start to sand, and the paper gets "grabby" the finish hasn't cured.









 







.


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## gb-wood (Dec 13, 2012)

All,

Thanks for all the advice. I have wet-sanded again with 600 grit sandpaper and applied another coat of undiluted poly. The sanding marks all completely gone!! 

My only remaining issue will be to smooth out some minor variations in luster and there are just a couple of minor stroke marks. 

I understand the need to wait at least 24 hours now to finish things off, but what is the recommended final step? I have read a lot of different suggestions. I am not looking for a high-gloss finish. Some suggest a bit of finish wax and #0000 steel wool, followed by a light rubbing with clean steel wool to remove any wax. Some suggest a grocery bag, etc. Keep in mind there are those minor brush marks in a couple spots.

Thanks to all those who posted for the great input.

GB


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