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Can this oil-based poly finish be saved?

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Forum topic by SoCalBonnie posted 11-26-2020 06:50 PM 493 views 0 times favorited 7 replies Add to Favorites Watch
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SoCalBonnie

37 posts in 677 days


11-26-2020 06:50 PM

Topic tags/keywords: watco wipe-on poly oil-based poly watco danish oil finishing

Happy Thanksgiving, everyone… I’m writing this in between cooking and stopping to run back and forth to the garage to lament my ruined finish.

Please note I did not apply the poly in this dusty environment, but in a small, dust-free powder room. I only moved the table here because the light made it possible to show the table surface.

The darker areas in the photo consist of a couple of oily patches as well as a couple of dry areas that are actually shiny.

The lighter areas in this photo show the dry, more dull-looking spots.

Steps I took in my first refinishing job. (The table is over 50 years old.)

  1. Removed old, damaged finish (lots of water marks) and sanded everything all the way up to 400 grit. Wiped everything down with mineral spirits and let dry 12 hours.
  2. Applied two coats of Watco Danish Oil to entire table. Looking nice!
  3. Couple of days later, applied Behr satin oil-based polyurethane (because I had it on hand), a 50-50 mix with mineral spirits, to entire table. 4 coats of this 50-50 mixture. Used clean t-shirt folded into fourths. Applied in dust-free bathroom.
  4. It went on very easy and as you can see, the finish below the table top looks very nice, that’s where I stopped with the rest of the table.
  5. I began to imagine me refinishing all my kitchen cabinets with this stuff.
  6. I then decided two more coats of 50-50 would build up a water-resistant finish on the top, so applied a 5th coat of the 50-50 on the table top ONLY. 12 hours later there were lots of hard shiny areas and several dull areas.
  7. Waited another 12 hours before I tried to even it out with a light sanding and then another application of the 50-50 mix
  8. Dull areas and shiny areas only became more apparent.
  9. I then (stupidly) applied the 50-50 mix to the dull areas only, feathering them out, but this left marks when dried.
  10. I then sanded the top down so finish looked even again, wiped it clean with mineral spirits and let dry.
  11. I then bought Watco’s Wipe-On Poly. The consistency surprised me, it was like honey and would not “wipe” like my home-made 50-50 mix. It kept “catching” and rolling my folded t-shirt in a way the 50-50 mix never did. I could not apply this product smoothly.
  12. About 5 minutes in to this I gave up and wiped off as much as I could with mineral spirits.
  13. 12 hours later, this photo shows what it looks like now. None of these shiny/dull areas match up with the previous shiny/dull areas I had around Step No 5.

I should’ve written for help sooner. Where did I go wrong?

More importantly, how can I save this? How to avoid this again?

Or… maybe it IS saveable? I only need to keep applying poly and then polish? (Wishful thinking!)

And did I get a bad batch of the Watco Wipe-On Poly?


7 replies so far

View Robert's profile

Robert

4292 posts in 2449 days


#1 posted 11-26-2020 06:57 PM

First, off you sanded too high for oil I stop at 180..

Couple things about oil 1) you have to make sure you’ve wiped it off. Lots of people thin it. 2) you’ve got to make sure it’s dry. 48 hrs up to 4 days depending in environment.

I am no expert but I suspect this might be the issue.

Another thing, sanding to 400 is way too much IMO. I sand to 180 prior to oil, 220 or 320 max between poly coats.

Remedy-give it plenty of time to dry and sand with 180 wipe down with mineral spirits and leave it for 3-4 days.

Careful not to sand thru oil layer or you’ll end up sanding the whole thing back down to bare wood. Which might be the best option anyway.

Others more knowledgeable than me will chime in soma I’ll be watching.

-- Everything is a prototype thats why its one of a kind!!

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therealSteveN

6971 posts in 1542 days


#2 posted 11-26-2020 08:06 PM

I like what Flexner says here about leveling, and rubbing a finish, he is suggesting grits between 320, and 600 to finally get rid of the scratches courser grits have made on the wood.

https://www.popularwoodworking.com/article/rub_to_create_a_great_finish/

Wondering if your finish was old? Old oil isn’t in your best interest. Or if drying time wasn’t long enough between coats? Especially Watco products.

But only going to 180 in my experience is a finish I don’t want to introduce to a raking light. It would look like the proverbial scratch and dent sale.

Everyone has their favorites. I am not into doing a LOT of work on a finish if I can help it, so I gave up on Watco products a long time ago. I’ve become quite the fan of General finishes Arm R Seal, especially the Satin.

-- Think safe, be safe

View Rich's profile

Rich

6390 posts in 1558 days


#3 posted 11-26-2020 08:54 PM

First the grits. You went further than you need to at 400, but it would only be too far if you were applying stain. Danish isn’t heavy on pigments, so it doesn’t matter as much. Whether you stop at 180 or 240 is generally immaterial. With either one, a finish that forms a film like varnish, shellac and lacquer have sufficient solids that those scratches will get filled. Three coats should be sufficient, but when asked how many to use, I just say keep going until you like what you see.

Rubbing out your finish would serve no purpose, since you don’t currently have anything to rub. I don’t bother with rubbing out a finish unless I’m going for absolute perfection. For that I use a 6” orbital polisher and wet sand to whatever sheen I want. Around 1500 grit is a good satin sheen (approximately 35).

Properly applied, any of the film finishes will give you a good result. I prefer lacquer since I have a HVLP turbine and pressure pot, and lacquer dries so quickly, I can get several coats on in a day. Spraying also eliminates any issues with brush marks.

Now, as to your specific issue, I’m concerned that you thinned your varnish with mineral spirits. These days mineral spirits are so dumbed-down in an attempt to be eco-friendly that it’s useless. I assume from your username that you’re in CA, so that might be all you can get. But, if you can find paint thinner, naphtha or turpentine, that’s the solvent to be using, not mineral spirits.

Frankly, if you use a good varnish, you don’t need to thin it anyway. Rather than wiping it on with a cloth, go with a good quality foam brush. It’ll be less likely to leave brush marks.

It’s hard to tell from the photo, but there’s a good chance you can just apply varnish over what you’ve got. Go for at least three coats. Arm-R-Seal is one of the best out there. And when you store it between jobs, you need to deal with the oxygen in the can. Since varnish is reactive, oxygen will shorten its life. I use Bloxygen which is just an inert gas that won’t react with the finish and is heavier than air, so it lays down on the surface to block oxygen from reaching it—hence the name. Don’t be fooled by suggestions to store the can upside down. There’s still oxygen in there and it accomplishes nothing.

-- Half of what we read or hear about finishing is right. We just don’t know which half! — Bob Flexner

View Redoak49's profile

Redoak49

5022 posts in 2957 days


#4 posted 11-27-2020 12:42 AM

I never use Danish Oil when refinishing. I would use a coat of clear shellac, let it dry, a very light sanding and then wipe on poly. I do not try thinning poly because I do not know what is in the mineral spirits. I have had good results with Minwax wipe on product. After the final coat, I will sometimes lightly rub with brown paper bag.

View tomsteve's profile

tomsteve

1129 posts in 2187 days


#5 posted 11-27-2020 01:50 AM

imo, if you want a satin finish, make the satin the last coat- gloss for all previous coats.
and make sure the satin is stirred real good before applying

View drsurfrat's profile

drsurfrat

379 posts in 155 days


#6 posted 11-27-2020 09:33 AM



... # I then bought Watco s Wipe-On Poly. The consistency surprised me, it was like honey and would not “wipe” like my home-made 50-50 mix. It kept “catching” and rolling my folded t-shirt in a way the 50-50 mix never did. I could not apply this product smoothly.
...
And did I get a bad batch of the Watco Wipe-On Poly?

- SoCalBonnie

I really like using Watco Danish Oil, which has part polyurethane. It should NOT be like honey, that happens when it has almost fully cured in the can. Adding mineral spirits will thin it, but will not un-cure it. First get rid of that can. I have had porous woods have blotchy, wet-and-dry looking spots. I usually sand with 220, and after a day apply another coat.

Your problem sounds like you got a poor distribution of finish, so it might be saved. I don’t think it would hurt to sand with about 220 and try again with a new, liquidy bottle. The directions say ‘do not shake’, but it should slop around as you move the container.

Just my opinion.

-- Mike (near Boston) ... Laziness is the mother of invention, necessity is the mother of exhaustion - me

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SoCalBonnie

37 posts in 677 days


#7 posted 11-27-2020 10:48 PM

Thank you, everyone, I really appreciate your input. Lots of information I can use for the future.

I’m so ticked-off at this table I think I’m gonna let it sit for a bit before I figure out what to do. Probably will sand the top down again.

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