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Ouch, not good!

My guess is that the solvent (mineral spirits) in the poly (which is quite a bit in the wipe-on products) dissolved portions of the spray paint, which also uses mineral spirits as a solvent. The streaks are likely from finger pressure during the wiping…it wouldn't take much too desolve a thin layer of spray paint.

Anytime you wipe on a product over the top of something else that uses the same solvent, well, time to strip it down and start over. This happens all the time with stains. If you wipe on something with the same solvent, it will pick up the pigments in the stain and move it around. This is why spraying is often better for such things, though you could solve that issue in the first place by using wipe-on products over something that does NOT have that same solvent. For example, you could use something like an ebony dye (mixed with water or alcohol) and THEN your poly. Dye is better anyway since it cannot be dissolved (it already was dissolved in the first place). Or, you could have been safe by using a seal coat of dewaxed shellac between the paint and poly layers. Or, you could have mixed some black dye into your poly and wiped that on.

Poly builds upon existing coats…it doesn't work like a lacquer whereby coats melt the coats underneath it. So, putting more poly on will likely make things worse. However, the good news is that if you DO mix some black dye into your poly, then you'll fix your problems. Basically, the tinted poly will cover the streaks underneath. Heck, I've mixed Minwax Ebony stain in poly and got exactly the same look you are describing. I normally coat with a plain coat of poly (or two) over the top.

If you wanted to use spray paint, for your application, you should have used a gloss black enamel spray paint. Enamel paints are designed to be very tough and durable on their own…and putting anything over the top of them will, in fact, cloud up the glossy finish. You wouldn't need the poly.

Hope this helps!
 

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BTW, you can always see what the solvent is by reading the label. If it says you can clean up your brushes with mineral spirits, then you know what the solvent is, right? Most of your typical spray paint cans clean up with mineral spirits…all the ones in my shop are that way.
 

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Get a test board. Put some black spray on it. Let it cure. Wipe on a coat of poly like you did on the table…use a white paper towel. Inspect the towel once finished.

That should let you know the origin of the streaking.

I agree that wipe on poly will show some streaking initially, especially over dark colors, but I thought the pictures looked more atypical of that.
 

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You don't need dye. Any colorant with the same solvent can be mixed in the poly. Like I said, I've used Minwax Ebony oil stain to accomplish the same thing. If I recall, it's actually both a stain AND a dye. Doesn't matter though…any pigment will be suspended in the poly.

3 parts poly: 1 part Ebony stain should do the trick. Wipe on two or three coats to correct the streaks and then apply a couple of more coats of clear poly to finish. It will be black and it will be plasticky.

Just test on another board…which is something you should always do before starting, especially for wipe-on applications.
 
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