# Help- General Finishes Polyacrylic Matte



## goose (Jan 15, 2010)

Hello, 

I am applying the top coat to a set of dining room chairs. The first coat of General Finishes Polyacrylic Matte goes on great. Then after sanding with #320 and an even finer 3M pad, the darker sections of the wood seem to be turning grayish (just thought it was residue from sanding at first but now I'm not sure... it won't come off completely). I am using water based over oil based stain, but they have dried for for at least 2-3 weeks. Anyway, after 3 coats of General Finishes Polyacrylic Matte it seems like the problem stays the same (it doesn't get any worse- but doesn't go away either). Can anyone explain what is happening? Also, since I haven't put a top coat on the table- should I use a different finish on the table top? Just not sure what to expect and would hate to have grayish spots on the 96" table. 











Any help or comments are appreciated.

Thanks


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## JW_in_Indy (Mar 20, 2009)

Hmmm.... weird. I'm using the General Finishes PolyAcrylic satin myself right now on a project. I love the stuff. I am also using it over an oil based stain with at least several days drying time. However, I almost always (as I did on this project) use a coat or two of a *de-waxed*, shellac based sanding sealer between the stain and finish coats. The sanding sealer (shellac and denatured alcohol in a 2" cut) helps completely seal any remaining open pores and eliminates any grain raising that you often times get with a water based finish. However, your issue doesn't sound like that kind of issue at all.

Sorry, I haven't been much help. If you happened to get your General Finishes product from a Rockler or Woodcraft retail store.... you could give them a call or take one of your chairs by and let them take a look. Kind of a PITA, but maybe another set of eyes might help way more than I did.

Sorry....


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## JW_in_Indy (Mar 20, 2009)

Follow up.... did you happen to wipe your piece down after sanding? I always use a rag soaked in mineral spirits. If using a water based finish like the PA.... you need to let the mineral spirits flash off and dry, then go over it with a wet cloth and let that dry before applying the next coat. I usually sand ever so lightly with #320 after the first coat, then #400 after the second, then a synthetic scrubber after any subsiquent coats. I usually end up with a bit of "grayish" sanding residue when using sand paper.... but it all comes off with the wipe down with mineral spirits.


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## goose (Jan 15, 2010)

Thanks for your comments JW. I have been wiping b/w sandings with a non-sticky tack cloth- it's actually more like a microfiber cloth then anything else- followed by damp rag. It's OK to use mineral spirits with the water based product? I'll try that instead. Thanks!


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## cabinetman (Jul 5, 2007)

goose said:


> Thanks for your comments JW. I have been wiping b/w sandings with a non-sticky tack cloth- it's actually more like a microfiber cloth then anything else- followed by damp rag. It's OK to use mineral spirits with the water based product? I'll try that instead. Thanks!



I would not use mineral spirits on WB poly. I'm taking a guess at your problem. Sanding with 320X is OK. If your pad is too smooth it may be burnishing the finish instead of abrading it. I would just stick with sanding. I like an "open coat" silicone carbide sandpaper for dry sanding it's not the wet-or-dry stuff, but rather a very light gray color. It could be called "Free-Cut", or "No-Fil" (Norton). You can find it in the box stores.

I don't have a problem applying the WB poly over cured oil base stain.


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## JW_in_Indy (Mar 20, 2009)

goose said:


> Thanks for your comments JW. I have been wiping b/w sandings with a non-sticky tack cloth- it's actually more like a microfiber cloth then anything else- followed by damp rag. It's OK to use mineral spirits with the water based product? I'll try that instead. Thanks!


Sure.... you can use mineral spirits anytime. Your WB product is dry when you sand it so the mineral spirits will not affect the finish at all. What you _DO_ need to do.... is allow the mineral spirits to dry throroughly and _THEN_ wipe it down again with plain water and allow that to dry.

I've found that this process will get everything squeeky clean prior to your next coat. I have not found a commercial "tack cloth" that I like. They often times contain wax (one of the things that make them sticky) which if you leave any behind, can affect the next coat of finish.

Interesting comment by Cabinetman on burnishing instead of abraiding. I hadn't thought of that. But, then again.... if you're using the correct 3M synthetic pad.... it won't be too smooth and I wouldn't think.... cause you a problem. I really like using the pads with the WB PolyAcrylic on the final coats because I can get an almost hand rubbed effect. It just works for me.... YMMV of course.


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## cabinetman (Jul 5, 2007)

JW_in_Indy said:


> Sure.... you can use mineral spirits anytime. Your WB product is dry when you sand it so the mineral spirits will not affect the finish at all. What you _DO_ need to do.... is allow the mineral spirits to dry throroughly and _THEN_ wipe it down again with plain water and allow that to dry.
> 
> I've found that this process will get everything squeeky clean prior to your next coat. I have not found a commercial "tack cloth" that I like. They often times contain wax (one of the things that make them sticky) which if you leave any behind, can affect the next coat of finish.
> 
> Interesting comment by Cabinetman on burnishing instead of abraiding. I hadn't thought of that. But, then again.... if you're using the correct 3M synthetic pad.... it won't be too smooth and I wouldn't think.... cause you a problem. I really like using the pads with the WB PolyAcrylic on the final coats because I can get an almost hand rubbed effect. It just works for me.... YMMV of course.



I should have qualified my opinion on not using mineral spirits on cured WB poly. Mineral spirits (paint thinner) is petroleum based. Once the solvent evaporates, a residue can remain and contaminate the finish. 

I like simple finishes. Keeping like chemicals in the finish schedule will yield less problems. For this particular project, I would just apply the WB poly over the cured stain. I wouldn't use shellac as an intermediary application. Cured finishes that can be stand alone finishes have different physical properties, that may react if combined, and may not show up immediately.

I'm not a big fan of tack cloths, but a dry cloth like this one works pretty good and leaves no residue.


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## JW_in_Indy (Mar 20, 2009)

And.... as usual, CM makes some intelligent points. Quite possibly, I make things harder on myself than I should or they need to be. As an older fart :wheelchair: .... I find that old habits are hard to break. 

Like always using a sanding sealer between stain and finish coats. Hell, that "necessity" died with the dinosaur's. And shellac?.... my gosh, I'll bet there are only a handfull of us old geezers left that still even remember the stuff, let alone love using it. And even something simple like a cotton rag dampened with mineral spirits to wipe off my sanding dust, well.... another old timer showed me that years and YEARS ago and I've never found a thing that works as well since. However, I've got to admit, that new fangled high tech cloth in CM's post looks tempting to try on my next project. Thanks CM I'm gonna have to pick one of those up. :yes:


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## goose (Jan 15, 2010)

thanks for all of your comments. I decided to put a coat of shellac on between the stain and the top coat. After allowing the shellac to dry overnight, i have noticed streaking. I tried lightly sanding, but that doesn't do much...will these streaks be visible through the PA matte finish? 

Thanks


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## JW_in_Indy (Mar 20, 2009)

goose said:


> thanks for all of your comments. I decided to put a coat of shellac on between the stain and the top coat. After allowing the shellac to dry overnight, i have noticed streaking. I tried lightly sanding, but that doesn't do much...will these streaks be visible through the PA matte finish?
> 
> Thanks


If you are going to use shellac as a sanding sealer between your stain and finish coats, it must be de-waxed shellac. Otherwise the wax that's present naturally in the shellac flakes will interfere with your finish coat. Much like the wax present in a lot of tack cloths. PM me a picture of these "streaks" if you will and I'll take a look at them for you. I don't understand exactly what you are describing.


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## lghilton (Jan 29, 2010)

I was told from General finishes not to use a tac cloth, it has linseed oil in it. and that will cause alot of issues.
vacum the dust off and use a damp cloth.


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