Weird reaction to poly finish

I have a table top that I sanded and put some oil based poly on per my wife's request. The odd thing is while the poly goes on smooth, as it sits there it sort of "separates". Kind of like an oil and water thing. It eventually dries, but sort of dull. It is a Minwax quick drying oil based poly. It did this through 2 coats, I'm going to try a third coat tonight as it will have had time to dry for 24 hours.

Has anybody ever seen this type of thing?

-Jim

Reply to
jtpr
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Sanded it with stearated paper did you? That's the light grey/whitish, soapy feeling stuff.

Reply to
dadiOH

I sanded it with 180 on my RO sander, then handsanded it with 400.

-Jim

Reply to
jtpryan

I sanded it with 180 on my RO sander, then handsanded it with 400.

-Jim

I think what dadiOH is saying is you applied something to the surface that the finish won't adhere to. You could try cleaing it thoroughly with whatever solvent won't damage your finish but will also remove the wax, oil, or whateve is on there. Try a small area near the edge first.

Sometimes it's necessary to apply a couple of coats of shellac between incompatable finishes to prevent ugly messes.

Reply to
Ulysses

OK, here is what I did. This is an old table, as in antique, not valuable, just antique. Anyway, I first tried cleaning it with mineral spirits to see if that would look better. It didn't change it much. So, after it dried (~24 hrs), I sanded it as mentioned above and put a coat of the poly on. Then, ~4 hrs later I sanded again with just the 400 grit, and put the poly on with the aforementioned problem.

Was (were?) the mineral spirits the problem?

-Jim

Reply to
jtpryan

Doubtful. It's more likely that at some point a nasty furniture polish (like Pledge) had been used (perhaps repeatedly?) and worked its way deep into the wood. You don't mention what kind of finish was on the piece before you started... Had it been varnished? Over stain? How much material did you remove when you sanded it? Some of these "furniture polishes" contain crap that should never come *near* a piece of wood (like silicon) and could easily cause problems with a new finish if not completely eradicated, which is something a simple sanding operation may not accomplish.

Reply to
Steve Turner

Well it sounds like you have an existing finish that you did not completly remove, if I follow completly.

Mineral spirits will remove some stuff but it could be wax left behind.

The second possibility is that the original finish is Lacquer. You can't put other finishes over lacquer. It will sort of wrinkle or crackle.

The good th> >

Reply to
SonomaProducts.com

Yes. Your poly was "satin" ? If so then there are gloss breakers that separate. You need to MIX the poly completely for more than a couple minutes.

Reply to
bw

No the poly was gloss. But the third coat seemed to do it. It looks fine now. I have another one to do, so maybe I'll sand it well, then shellac, then poly. If I do this what type/brand of shellac should I use? I have never used this before.

-Jim

Reply to
jtpryan

No the poly was gloss. But the third coat seemed to do it. It looks fine now. I have another one to do, so maybe I'll sand it well, then shellac, then poly. If I do this what type/brand of shellac should I use? I have never used this before.

-Jim

I don't have a favorite brand (I don't think there are a lot of choices) but shellac can be tricky because it dries so quickly. It must be applied all at once so spraying would be my first choice over brushing. Having said that what I would probably do is mist it lightly, several coats, then smooth it out with fine sandpaper or steel wool and achieve the smooth finish on the top finish. This may take a few coats.

Reply to
Ulysses

A note: for the seal coat use a dewaxed shellac such as Zinsser Sealcoat. mahalo, jo4hn

Reply to
jo4hn

Yes, use Zinser Sealcoat. It is a premixed version available at Home Depot, etc. There is alspo Zinser Bulles Eye but it is NOT dewaxed. Other than that you would have to buy flakes and mix your own, big trouble for a one-time deal.

I "think" you can get seal coat in a spray can but maybe not. Regardless, I think the brushing should be OK. Shellac is alcohol based and does drie fast but not so fast you can't get it smooth but try to use enough on the brush to lay down single overlapping strokes. Trying to rebrush a stroke can be a problem it will be partially dry in seconds.

An old trick if you are hav> >

Reply to
SonomaProducts.com

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