Replies

1. 
   mikefm101 | Aug 17, 2020 01:27pm | #1

   Absolutely water based poly.

   Oil based will make the white turn more yellow.

   Water based dries transparent.

   I often do this, especially on painted shelves , to give more protection to keep the paint from wearing.

   One coat is usually sufficient but two won’t hurt. Use whatever gloss you prefer. I’ve used minwax water based poly with no problems.

   Mike

2. 
   _mj_ | Aug 17, 2020 01:54pm | #2

   I've done this many times. I've even mixed the poly and paint together to get a semi-teansparent finish that wears pretty well.

3. 
   fivebirdscustom | Aug 17, 2020 02:16pm | #3

   I also have done this many, many times. Water based poly to go over latex, or as MJ says, to mix wit the paint. Both work quite well.

   If you already had the paint done, mix a little paint in with the poly to add color in the top would be a fine thing to do as well.

4. 
   stantheman | Aug 18, 2020 08:32pm | #4

   Any reason for not mixing poly and paint for painting house trim? It sounds like a great idea to me. I was getting ready to do some, when I saw this thread.

5. 
   _mj_ | Aug 18, 2020 08:59pm | #5

   Never tried it out in the weather, or with exterior-rated materials. Mebbee paint something and leave it outside for a while? Revive this thread in 10 or 12 years to let us know how it went.

6. 
   john_c2 | Aug 19, 2020 04:08am | #6

   Poly over paint outside is a horrible idea.

   The main difference between exterior and interior paint is hardness. Exterior paint holds up because it is soft. It expands and contracts as houses heat up and cool down. Use a good quality paint, and you can still indent it with your fingernail a few years later. A few years after that it dries out, becomes hard, and that's when it cracks and peels.

   Putting a hard shell finish over that defeats the entire purpose.

   Interior paint dries harder, because it takes more daily use, but doesn't have to expand and contract with weather. But It's still too soft to use for bookshelves or table tops. Thats why some put poly over paint in those situations. But you can use regular paint that's harder. Some oil paints are made for those situations, and newer alkyd enamels do well, too.

7. 
   fivebirdscustom | Aug 19, 2020 10:04am | #7

   I would wonder about the UV protection strength of the Poly as well. It might break down/yellow quickly in direct sun, outside? I dunno, though...