# Oil Polyurethane over Latex Paint



## GAF (Nov 4, 2012)

I am restoring and refinishing a 1930s Hoosier cabinet. The exterior is white oak but most of the interior will be painted off white. Can I apply MinWax oil based polyurethane over the oil based stained oak as well as over the latex paint? Do I need to prepare the painted surface to accept the poly?

Small additional question - will oil based poly yellow the latex off white paint?

Thank you.

Gary


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## tcleve4911 (Dec 16, 2006)

My rule of thumb has always been that you can put latex over oils but not oils over latex.....but ......with today's new paints and bonding agents there's always a way to get it done correctly.
Prep is the key to any good finish.


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## Steve Neul (Sep 2, 2011)

I would not put an oil based polyurethane over latex paint or oil based paint for that matter. An oil based poly will yellow over time and make the white paint yellow. You would be better off using a water based polyurethane. The water based poly will remain clear. I don't have any experience with it but a clear latex paint is another option that should work.


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## bradnailer (Nov 11, 2008)

I rub oil based wiping poly over latex all the time with no problems at all. However, it will yellow slightly over time. Unless your base coat is white, then the yellowing would not be an issue.

After I apply the latex, I sand it smooth then rub on the poly.


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## GAF (Nov 4, 2012)

Steve Neul said:


> I would not put an oil based polyurethane over latex paint or oil based paint for that matter. An oil based poly will yellow over time and make the white paint yellow. You would be better off using a water based polyurethane. The water based poly will remain clear. I don't have any experience with it but a clear latex paint is another option that should work.


Thanks, Steve. This is not unexpected but I guess I was hoping that the newer products might address some of these problems.

If I go with the water based approach I will want to apply it to the whole piece including the oil based stained part. How long should I wait for the oil based stain to completely dry?

Gary


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## GAF (Nov 4, 2012)

bradnailer said:


> I rub oil based wiping poly over latex all the time with no problems at all. However, it will yellow slightly over time. Unless your base coat is white, then the yellowing would not be an issue.
> 
> After I apply the latex, I sand it smooth then rub on the poly.


Unfortunately the base coat is (off) white and I was specifically asked not to make the interior look yellow or creamy. Thanks for the feedback.

Gary


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## Hammer1 (Aug 1, 2010)

Most latex paints are too soft for things like shelves, although, there are acrylic enamels that are harder. I can't remember what I used on our Hoosier it was so long ago. Probably an oil in off white. Yellowing isn't a big issue behind closed doors where it's not subject to UV. You would have a hard time seeing any difference over the years. I'd probably go with Rustoleum enamel in satin or a similar brand.


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## Steve Neul (Sep 2, 2011)

GAF said:


> Thanks, Steve. This is not unexpected but I guess I was hoping that the newer products might address some of these problems.
> 
> If I go with the water based approach I will want to apply it to the whole piece including the oil based stained part. How long should I wait for the oil based stain to completely dry?
> 
> Gary


I would be hard to say how long it would take for oil based poly to really yellow but I though you should be warned it will happen. Even innitially you can probably notice a slight yellowing. The finish is yellow enough you can see it in a quart can when you open it.

This time of year I would let oil stain dry overnight before before putting a finish over the top, either oil based or water based. In summer depending on brand a couple of hours might be sufficient. A lot depends on how much linseed oil the stain contains and each brand is different.


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## Bill White 2 (Jun 23, 2012)

Use water born top coat and don't worry about yellowing. Done and done.
Bill


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## GAF (Nov 4, 2012)

Hammer1 said:


> Most latex paints are too soft for things like shelves, although, there are acrylic enamels that are harder. I can't remember what I used on our Hoosier it was so long ago. Probably an oil in off white. Yellowing isn't a big issue behind closed doors where it's not subject to UV. You would have a hard time seeing any difference over the years. I'd probably go with Rustoleum enamel in satin or a similar brand.


Hammer1, thanks for the feedback. That is an awesome Hoosier cabinet. Mine is in extremely bad shape and will never look like yours but it will be much improved when I am finished with it.

Gary


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## GAF (Nov 4, 2012)

Bill White said:


> Use water born top coat and don't worry about yellowing. Done and done.
> Bill


Bill, this is good advice as was your advice a while ago on sealing the insides of drawers with shellac.

I will use water based top coat and surely wait long enough for the oil based stain to dry to ensure there are no issues.

I really like wipe on the top coat and will want to dilute some Varathane or MinWax water based poly. I am not sure what to thin with (simply water?) nor how much (50/50?).

Gary


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## GeorgeC (Jul 30, 2008)

tcleve4911 said:


> My rule of thumb has always been that you can put latex over oils but not oils over latex.....but ......with today's new paints and bonding agents there's always a way to get it done correctly.
> Prep is the key to any good finish.


I think that has been a generally accepted practice.

You say the newer oils will go over latex? If prep is the way to do this please tell us the proper preparation. I have had occasion where I wanted to use oil over latex and would like to know how.

George


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## bradnailer (Nov 11, 2008)

GeorgeC said:


> I think that has been a generally accepted practice.
> 
> You say the newer oils will go over latex? If prep is the way to do this please tell us the proper preparation. I have had occasion where I wanted to use oil over latex and would like to know how.
> 
> George


For me, all that is necessary is to just sand the latex smooth then rub on thin coats of oil based poly allowing it to cure between coats. 

I build a lot of distressed looking furniture where I put a colored base coat of latex, another colored coat of latex over it then sand over the top coat to expose the first color and some of the bare wood. I then rub several coats of oil based wiping poly over the entire piece. Not only does it protect the latex finish but gives it more depth.


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## rrich (Jun 24, 2009)

I have put Polycrylic (Minwax) over Behr latex. The trick is to allow the latex to "cure" for about a month before applying the Polycrylic. The Polycrylic is water based and non yellowing.

I did this more than 10 years ago on a router table cabinet. The finish is holding up well.


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