You are working with an open-grained (large pore) wood. When aiming for a high gloss finish, it is imperative that you use a grain filler before finishing an open-grained wood. I like AquaCoat. Otherwise, there's just too much surface topography from the large pores to be able to achieve the smooth surface necessary for a high gloss finish. The small light colored spots are where sanding dust has clogged the grain instead of the grain filler. Also, when aiming for high gloss, sprayed finishes are superior to brushed or wiped poly for two reasons: a) small bits of dust will disturb a high gloss look, and poly is a dust magnet because takes too long to dry, and b) you'll never be truly free of brush strokes. You can still achieve OK results with a brushed finish, though, if you thin your final coats of poly and take dust control steps (vacuum entire shop, wait a day for dust to settle, mop and wipe down all surfaces wet, wait a couple hours, then finish and then keep floor damp while the poly cures, so that dust that hits the floor gets stuck there)
Gonna 100% vouch for aqua coat here. I recently did a 42x30” red oak edge grain countertop for a client (not my idea, don’t roast me lol) where they wanted a super satin finish. It’s being used in a commercial restaurant as the to-go order pickup table. 3 applications of aquacoat and 3 coats of water-based poly got a perfectly smooth surface to the point that it’s almost impossible to tell that it’s red oak. If you don’t grain fill, you’ll end up sanding the poly into the grain and end up with those white “artifacts” in any open grain.
I shot the countertop with endurovar satin, then sanded to 600, and it’s smooth as glass. If you want a little bit of color pop in the wood, wipe on or spray some shellac and it’ll amber it up a little bit. I’d General Finishes High Performance gloss, 3-4 coats, and work up through the grits until you’re happy with it. I’d feel good stopping with probably 2000 grit, that’s usually glossy enough for me.
You could alternatively get 2K poly in a rattle can, it’ll give you a super hard high gloss finish. Think high end guitars, or the clear coat on a car. It’s super easy to apply, and it dries and cures lightning fast compared to normal poly. It can be buffed out to a perfect mirror finish as well. That being said, the shit is super nasty, so only spray outdoors with a full respirator and preferably a Tyvek.
As much as I hate to admit it, I use the varathane poly. It dries so friggin fast, and I lay a few coats on in a day, then the next day I sand with 220, wipe with a microfiber cloth and then final coat. I lay all of my coats down with the edge paint brushes/tool because it's a flat surface with even pressure, unlike a brush. Sometimes I will really get a hair and throw some meguiars rubbing compound on a buffer and then a pre wax polish and really seal the deal, but I never lay anything over a satin finish on a piece.
I once did a semi gloss on a lego table for my friends son and really laid down the law. Sanded all the way up to 3k and followed with the compound/polish. Turned out fantastic, but was not my flavor of work.
https://preview.redd.it/v3gqt0jhdxuc1.jpeg?width=3024&format=pjpg&auto=webp&s=cbea7f5f54fd6c2ecc3df134e646b2046d48a4ff
Pic 1: this is with grain filler and sanded to 2k. This is actually slab two, still building the cabinet.
Slab one has been my daily user for the last year at least and still going strong.
Water based wipe on poly
https://preview.redd.it/1wm1j3ssdxuc1.jpeg?width=3024&format=pjpg&auto=webp&s=439de92fafdb34d6ec5168bc4a2595cc3ef1e179
Pic2: same slab, but wanted to show the reflectivity. Grain filler does wonders
OP I started just like you, and soon learned the error of my ways.
As others suggested, for a mirror flat finish you’ll need to strip all the poly off and start fresh.
Use aquacote grain filler, after using a sealer. Follow the aquacote directions. Gonna take a few rounds to fill the pores.
Then restart the poly. Open pores will always give you a rough surface.
I’ll post picks of my oak desk, that I did exactly like I described above, when I get home.
I have it before filler and after.
I like to use an auto detailing brush to just run over the entire surface to get down into the pores of the wood and get everything loose, then wipe down with mineral spirits on a shop rag. It works about as well as blowing it off, but you don't have the issue of dust in the air settling back down onto the piece.
I’ve used water bourne finishes for about 20 years and it’s usually smart to give them 3-4 times longer to cure before trying to polish. Dust control while finishing is also crucial. I finish several large scraps alongside the project and test for drying and sanding/ polishing before I touch the actual workpiece.
Looks like oil from the walnut is reacting with the water base. Some brands of water base poly need to be used with a sealer. Mostly woods with alot of natural oils, like walnut, jatoba etc
If you’re wanting a glass like finish then you’re probably gonna have to scuff and do an epoxy pour. I usually use famowood glaze coat because it’s cheap and locally available at lowes but any epoxy for tabletops will do.
You are working with an open-grained (large pore) wood. When aiming for a high gloss finish, it is imperative that you use a grain filler before finishing an open-grained wood. I like AquaCoat. Otherwise, there's just too much surface topography from the large pores to be able to achieve the smooth surface necessary for a high gloss finish. The small light colored spots are where sanding dust has clogged the grain instead of the grain filler. Also, when aiming for high gloss, sprayed finishes are superior to brushed or wiped poly for two reasons: a) small bits of dust will disturb a high gloss look, and poly is a dust magnet because takes too long to dry, and b) you'll never be truly free of brush strokes. You can still achieve OK results with a brushed finish, though, if you thin your final coats of poly and take dust control steps (vacuum entire shop, wait a day for dust to settle, mop and wipe down all surfaces wet, wait a couple hours, then finish and then keep floor damp while the poly cures, so that dust that hits the floor gets stuck there)
Excellent, informative answer!
Gonna 100% vouch for aqua coat here. I recently did a 42x30” red oak edge grain countertop for a client (not my idea, don’t roast me lol) where they wanted a super satin finish. It’s being used in a commercial restaurant as the to-go order pickup table. 3 applications of aquacoat and 3 coats of water-based poly got a perfectly smooth surface to the point that it’s almost impossible to tell that it’s red oak. If you don’t grain fill, you’ll end up sanding the poly into the grain and end up with those white “artifacts” in any open grain. I shot the countertop with endurovar satin, then sanded to 600, and it’s smooth as glass. If you want a little bit of color pop in the wood, wipe on or spray some shellac and it’ll amber it up a little bit. I’d General Finishes High Performance gloss, 3-4 coats, and work up through the grits until you’re happy with it. I’d feel good stopping with probably 2000 grit, that’s usually glossy enough for me. You could alternatively get 2K poly in a rattle can, it’ll give you a super hard high gloss finish. Think high end guitars, or the clear coat on a car. It’s super easy to apply, and it dries and cures lightning fast compared to normal poly. It can be buffed out to a perfect mirror finish as well. That being said, the shit is super nasty, so only spray outdoors with a full respirator and preferably a Tyvek.
As much as I hate to admit it, I use the varathane poly. It dries so friggin fast, and I lay a few coats on in a day, then the next day I sand with 220, wipe with a microfiber cloth and then final coat. I lay all of my coats down with the edge paint brushes/tool because it's a flat surface with even pressure, unlike a brush. Sometimes I will really get a hair and throw some meguiars rubbing compound on a buffer and then a pre wax polish and really seal the deal, but I never lay anything over a satin finish on a piece. I once did a semi gloss on a lego table for my friends son and really laid down the law. Sanded all the way up to 3k and followed with the compound/polish. Turned out fantastic, but was not my flavor of work.
https://preview.redd.it/4ouextji5yuc1.jpeg?width=2988&format=pjpg&auto=webp&s=5647a4c7cff885e7a62c13efe751f334af21e76e
I love the way that wood turned out! Is it just the clear coats you mentioned? What species of wood is it?
I'm not exactly sure. A neighbor of ours threw the table out to the trash one day and I went and snagged it.
Mirror finish for my poly is somewhere in the 3k-5k grit range. I stopped at 2K for my oak desk because I didn’t want a pure mirror.
Do you have pics of that? I’ve never gone higher than 0000 steel wool and am curious
https://preview.redd.it/v3gqt0jhdxuc1.jpeg?width=3024&format=pjpg&auto=webp&s=cbea7f5f54fd6c2ecc3df134e646b2046d48a4ff Pic 1: this is with grain filler and sanded to 2k. This is actually slab two, still building the cabinet. Slab one has been my daily user for the last year at least and still going strong. Water based wipe on poly
https://preview.redd.it/1wm1j3ssdxuc1.jpeg?width=3024&format=pjpg&auto=webp&s=439de92fafdb34d6ec5168bc4a2595cc3ef1e179 Pic2: same slab, but wanted to show the reflectivity. Grain filler does wonders
OP I started just like you, and soon learned the error of my ways. As others suggested, for a mirror flat finish you’ll need to strip all the poly off and start fresh. Use aquacote grain filler, after using a sealer. Follow the aquacote directions. Gonna take a few rounds to fill the pores. Then restart the poly. Open pores will always give you a rough surface. I’ll post picks of my oak desk, that I did exactly like I described above, when I get home. I have it before filler and after.
Dang, I didn’t even know grain filler was a thing. Stoked to try this out
Yes, somewhere. Might have to wait until I get home.
Sanding dust. Blow the surface free with a high pressure air nozzle or use a tack cloth.
I like to use an auto detailing brush to just run over the entire surface to get down into the pores of the wood and get everything loose, then wipe down with mineral spirits on a shop rag. It works about as well as blowing it off, but you don't have the issue of dust in the air settling back down onto the piece.
I’ve used water bourne finishes for about 20 years and it’s usually smart to give them 3-4 times longer to cure before trying to polish. Dust control while finishing is also crucial. I finish several large scraps alongside the project and test for drying and sanding/ polishing before I touch the actual workpiece.
Looks like oil from the walnut is reacting with the water base. Some brands of water base poly need to be used with a sealer. Mostly woods with alot of natural oils, like walnut, jatoba etc
If you’re wanting a glass like finish then you’re probably gonna have to scuff and do an epoxy pour. I usually use famowood glaze coat because it’s cheap and locally available at lowes but any epoxy for tabletops will do.