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Discussion Starter · #1 ·
I've read about "raising the grain" on cans of various wood finishing products, without really thinking about it. But I think I'm seeing it now, and want to make sure I'm dealing with it appropriately.

I'm making a built-in desktop from bigbox-store red oak plywood. I've applied Varathane Fast Dry Stain (oil-based) and (after thorough drying) applied several coats of Varathane Ultimate Polyurethane (water based). It looks good. But I do notice, even after 4-5 coats of poly, a roughness to the feel, especially in the darker areas of the grain pattern.

Is this "raising the grain" ? From the polyurethane can, it sounds like I should just give it a light sanding (220 ?) and apply one last coat. Does that sound about right ?
 

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Before I apply finish I tend to wet the surface with a mister then a quick rub with steel wool after it dries. I've used 400 grit sand paper previously but I read a post here a while back that said the steel wool lays flat on the surface and doesn't gouge the wood which can lead to more raised grain.

In your case I would re-sand and be sure to clean the surface blow / vacuum / wipe with damp cloth before applying again. Cleaning the room or draping the area with plastic drop cloth also helps control those random motes.

Russ
 

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I am not familiar with Poly finishes but I would think that after the first coat of poly, if you had sanded lightly with 220 or ' higher. the grain would not have risen again because you would have cut the 'tops' off.
Again not being familiar, there are several products called 'sanding sealers'. These products are designed to raise the grain and 'seal' the grain from rising again so one coat takes care of it. Just apply the sanding sealer to the product and lightly sand when dry. Sealers were not designed to fill/seal the pores as many thought. The name was somewhat misleading. At least, that is the way the products worked years ago. may have changed by now.
 

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Discussion Starter · #4 ·
Thanks guys. But unfortunately I have applied the stain and several coats of the WB poly already. I'm not sure I'm feeling raised grain - like I said, it feels "rough" (esp. in the darker parts of the grain pattern) whereas I've read raised grain described as more like peach fuzz - so maybe it's just that the wood wasn't sanded that flat (I didn't really sand it before I started, since the hardwood veneer layer on the bigbox plywood is so thin). But if it IS raised grain, the directions on the poly state "A minimum of 4 coats is recommended. If grain raise occurs, sand smooth before final coat." So I guess that's what I'll do, perhaps using 220 by hand with a rubber sanding block.
 

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Rusty,
Normally when using a water based poly, I do wipe with a damp cloth to raise the grain initially. Let it dry, then lightly sand with 320 to knock the nibs off. Then in between each coat I again use 320 very lightly just to knock any nibs off and also provide some teeth for the next coat to bite into. After the last coat, once its dried for a coûlle days, I'll check for any nibs from dust settling on the finish. If there is, I'll lightly rub it with a brown paper grocery bag. Should be very smooth by then. A white scotchbrite pad works about the same.
Mike Hawkins
 

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Thanks guys. But unfortunately I have applied the stain and several coats of the WB poly already. I'm not sure I'm feeling raised grain - like I said, it feels "rough" (esp. in the darker parts of the grain pattern) whereas I've read raised grain described as more like peach fuzz - so maybe it's just that the wood wasn't sanded that flat (I didn't really sand it before I started, since the hardwood veneer layer on the bigbox plywood is so thin). But if it IS raised grain, the directions on the poly state "A minimum of 4 coats is recommended. If grain raise occurs, sand smooth before final coat." So I guess that's what I'll do, perhaps using 220 by hand with a rubber sanding block.
You are on the right path. Use a sanding block with 220 or 320. You do not want to sand, just buff in the direction of the grain only. You only need to cut off the nibs, or remove what has settled. It does not take much. Blow any dust off, wipe with a dampened lint less cloth, and recoat.
 
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