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Preface - I'm a woodworking novice.

I applied a polycrylic finish to an Ikea Gerton (solid beech wood) table top. I only lightly sanded with 220 by hand before applying the finish. I wasn't aiming to smooth the wood as I was under the impression the finish would smooth things out based on the following:

The whole idea with sanding the wood is not necessarily to get it as smmoth [sic] as glass. Rather, its to give the wood a clean, even, and scratch-free appearance. [...] Sanding up to 400 really isn’t going to give you a smoother finish in the end. Because after the first coat of finish is applied, you are no longer dealing with the raw wood. You are dealing with the finish.

Source

However after applying 3 coats, with a light 220 hand sanding between coats, the wood feels pretty much the same as before applying the finish. Should I have sanded more before applying the finish or did I do something wrong in the application?

Would sanding the finish help achieve a smoother feel to the surface? If so any tips would be appreciated.

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  • Good point, I ran over it once with 220 very lightly by hand, I'll add that to the post
    – kfoley
    Jun 30, 2019 at 15:28
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    Hi, welcome to SE. We need some more detail before you can get on-point Answers. Just saying "didn't sand much" doesn't really tell us anything (some people don't sand certain surfaces *at all, although this is less common in this era of ubiquitous power sanders). Anyway, because this is a Gerton top it probably didn't need much in the way of sanding. So, how much did you sand and with what grit(s)? Presumably you didn't raise the grain as you'd have mentioned it if you had, so did you sand after the 1st coat of finish? 1st coat would have raised the grain if not done previously.
    – Graphus
    Jun 30, 2019 at 15:34
  • OK got that now, that's a good detail to include (and this is fine for final sanding, there's little to no point in sanding finer than this when using varnish or another clear coat). Problem is likely the first coat of the finish raising the grain, something that all finishes do to some degree but waterbased finishes are most guilty of.
    – Graphus
    Jun 30, 2019 at 15:36
  • I also added that I sanded between coats. I'm concerned that any sanding I did was too light as I was afraid to sand too much given my inexperience so I'm not sure if that would have helped with the finish raising the grain. I'm planning on sanding with 400 grit by hand, do you think that's the right approach to smooth things out?
    – kfoley
    Jun 30, 2019 at 15:46

4 Answers 4

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I only lightly sanded with 220 by hand before applying the finish.
Should I have sanded more before applying the finish

With wood that is already well prepped like on a Gerton worktop from Ikea (already finish sanded in the factory) this would normally be the right amount of sanding.

You can sand more, and many people do (there's a lot of over-sanding these days), but just a light hand sand should be all that's needed to refresh a previously prepared surface and make it amenable to a waterbased finish (i.e. to help prevent beading).

However after applying 3 coats, with a light 220 hand sanding between coats, the wood feels pretty much the same as before applying the finish.

Given that a flat/smooth wood surface sanded to 220 is pretty smooth that may be what you should expect.

You can't achieve a surface like a sheet of glass until you've built up a thick film finish and sanded and buffed it smooth1. One other point possibly worth noting is the sort of "silky" surface that well-sanded wood has isn't quite like the glossy surface of a varnish or other film finish, and consequently they don't feel exactly the same.

did I do something wrong in the application?

Can't be sure but I don't think so. As my previous Comment indicated I was initially concerned that the finish had raised the grain2 and you were now dealing with a rougher surface, but your comments seem to indicate you have a surface as smooth as it was prior to the finish going on which is fine.

The above is based on the updated Question with the added details requested (thanks for that BTW, often we don't get those!) so it's just the title has me wondering, it shouldn't still be rough since it shouldn't have previously been rough......

1 See Evening reflectivity of a finish after "finishing the finish" and Leveling a finish/finishing the finish

2 Some sources state that all finishes raise the grain to some degree, but waterbased finishes do this much more than others because of the water they contain (although even with these it varies somewhat product to product).

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One thing I haven't seen mentioned yet is to make sure no tiny dust particles settle onto the finish while it's drying. I've overlooked this in the past when trying to diagnose this same problem.

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In my experience, the key to a smooth-feeling finish is to sand lightly with a high-grit (I've used 320) paper between coats of poly, as well as lightly sanding at the end with the same grit. I don't blame you for not sanding the factory surface on the Ikea top, I'm not sure what materials they're using and if it's any kind of plywood you could go right through the veneer and ruin the table top- so good call there.

For your situation, I would recommend lightly sanding with a high grit paper, somewhere around 320, and see if that smooths out the feel of the table. For next time, try sanding in the same way in between coats of poly (making sure to wipe away any dust with a tack cloth or similar), and you should have a smoother feel.

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  • I've edited the post to clarify it's a solid wood table top, given that would it have been better to smooth things out before finishing? I did sand lightly (probably too lightly) with 220 between coats. I think I'll try 400 (the only other paper I have right now) on the finish and see how it feels.
    – kfoley
    Jun 30, 2019 at 15:02
  • I think the 400 is a good bet, I would do that a little less lightly and see how it feels. I had to google what the actual purpose of sanding before finishing, as I'd always just done it because I was the thing I'd heard to do. Turns out the main purpose of sanding before poly is to give the wood a clean, scratch-free appearance, in which case if the top from ikea already looks nice and un-scratched, you're totally cleared to go for poly. Good luck!
    – Daniel Grimes
    Jun 30, 2019 at 15:12
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Unless the finish applied is one with a very thick film, it will not make the wood smother, in most cases the surface should be sanded smooth 150 to 220 (some will differ on how fine to sand). Water born finishes tend to raise the grain much more than solvent based finishes, though most do to some extent, sanding or using steel wool, or abrasive pads between coats will provide a smoother coat.

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  • Yeah polycrylic is water based and is very thin. I added the detail that I lightly sanded with 220 by hand between coats.
    – kfoley
    Jun 30, 2019 at 15:49

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