# Polyurethane over paint?



## panhandlion

I built a wooden coffee table for my daughter for Christmas. She wants it painted to match her decor. 

I applied one coat of primer and plan on putting one or two coats of latec semi-gloss paint.

Question... Can I add a coat (or two or three coats) of clear water-based polyurethane over the paint?


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## slickshift

It's not a good idea...on a couple of levels
Why would you want to this?
Are you looking for longevity? durabilty? protection?
In that case my suggestion would be to use a waterborne enamel (or even an oil-based/alkyd enamel for a little more) rather than a latex semi-gloss paint
There will be no need for any further finishing


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## End Grain

panhandlion said:


> I built a wooden coffee table for my daughter for Christmas. She wants it painted to match her decor.
> 
> I applied one coat of primer and plan on putting one or two coats of latec semi-gloss paint.
> 
> Question... Can I add a coat (or two or three coats) of clear water-based polyurethane over the paint?


*Slickshift* said it. Why not use a hi-gloss alkyd (oil based) enamel instead? It will have a good shine to it and be rock-hard durable and washable as well.


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## jimc48

Maybe Panhandlion lives in a state, such as Maine where I live, where you are unable to purchase Alkyd/Oil-Based paint. I imagine that this is in response to the VOC/environment concerns, but it sure sucks! I talked with my hardware store and they say they had to pull all Alkyd/Oil paint off the shelves. I've heard of some low-voc paints, but haven't seen any such on the shelves at any of the hardware/bigbox stores. 

Jim


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## joewho

Theoretcially, there really is no reason you can't use waterbase poly.

It's another miracle product that is very durable, but still not as durable as oil based products.

The problems arise in the application. Water base poly is thin, like water. It takes 4 or 5 coats to get a nice buildup. It does dry absolutely clear and it won't yellow like oil based poly. I don't like to see it used on floors. It looks great at first, and yes, it will hold up.

But, I've yet to see a floor finisher lay it down bubble free. You can't see the bubbles until they get walked on or scraped. At that point it's a breach of the finish as well as looking bad.

It bubbles like crazy, though. The bubbles have to be brushed out. On a coffee table, you might as well just brush the whole thing. 

It's very common to lay a coat or 2 of wb poly over a faux finish to give it some extra protection.

For a diy coffee table project, it will work just fine.


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## slickshift

You could use a water-based poly over wall paint
But it will not offer better protection and durability than a waterborne enamel

The labor and material cost would be more to do two coats of wall paint, then 3 or four coats of waterbased poly

I'd suggest doing two coats of waterborne enamel and being done with it


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## sirwired

panhandlion said:


> I built a wooden coffee table for my daughter for Christmas. She wants it painted to match her decor.
> 
> I applied one coat of primer and plan on putting one or two coats of latec semi-gloss paint.
> 
> Question... Can I add a coat (or two or three coats) of clear water-based polyurethane over the paint?


Like Slick said, the Waterbourne enamels are the way to go here. SW ProClassic or BM Impervo will both work just great for this application. Just make sure you practice on scrap wood first, as they don't go on exactly like paint. (Just search this forum for ProClassic and SirWired, and you will find my advice on this product.)

SirWired


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## carlabunga

*poly over exterior latex paint on basement stairs?*

Hi,
I was told (by the HD paint dude) to use an exterior latex enamel paint on my basement stairs after the first paint I used didn't stay (wiped off with a wet rag after the cat burped up a hair ball.) so, I painted the stairs again with the new paint last weekend. Yesterday the Cat did his burping again and this morning when I wiped it came up again. 

Can I poly over the paint instead of buying my 3rd can of paint? I like the color and would really like to minimize the work. I called the HD store again and the next guy told me they told me wrong, that I should have used floor paint and that I will have to wipe it all off and sand it because the floor paint wont stick over the exterior paint. 

Anyone know if I can poly over the exterior latex enamel paint or if I can just paint over the existing paint?


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## bradnailer

I make a lot of furniture pieces that are painted and distressed. For the paint treatment, I normally use Rustoleum's American Accents acrylic latex then rub on several coats of oil based wiping polyurethane. The poly gives the paint treatment more depth, especially on a piece I've distressed. I've never had a problem with this process.


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## jimc48

Sounds like your paint isn't curing properly. Is your basement cold or damp? If the paint isn't drying, then the polyurethane certainly won't - it is more temperature and humidity dependent than latex paint.

And if it were me, I'd get rid of the cat!

Jim


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## carlabunga

I live in upstate NY and the average temp has been around 25 degrees, so yes the basement is cold and damp. Should I wait for a 50 degree day to do the poly?


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## Bubbagump

Why poly? You have bigger problems. First off, what are the steps made of? I assume regular old pine. You did prime, correct? Assuming you did, you may have problems with tannin bleed or the like and a primer like BIN is the ticket. Past that, get a good quality floor paint like SW Floor and Porch (quit using that Behr junk...) and apply it during proper temperature and humidity conditions. There is no way you are at 25 degrees all year. Mid-July and a dehumidifier will likely be the ticket.

Tangent: I learned the very hard way on Behr exterior paint. Painted my entire house with their 436 primer and paint 5 or 6 years back and in the course of 1 winter it started falling off. Talk about frustrating after spending hours and hours and hours doing initial scraping, sanding, priming and painting dangling off of ladders 35 feet in the air for the whole summer... no to mention money lost. No surprise redoing the whole thing the next summer (never have more 4 letter words been uttered) with SuperPaint and A100 primer has lasted to this day. Man, I need to go cool down. This Behr thing brought back all sorts of bad emotions....


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## bradnailer

Carla, is there any way you can put a fan on your paint. It might help speed curing. I had a curing problem on some pieces I'd made that were in my unheated woodshop and the fan helped.


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## carlabunga

*poly for a shiny finish*

The steps are made of I guess pine. They were already painted so I just cleaned them really well with vinegar and water and painted them. I can use a fan to dry them. We are putting the house on the market March 1st, so time is of the essence. I want to get it taken care of by the end of this coming weekend.

Should I binz over the paint and then use the floor paint or just poly? My husband wants to poly, he thinks it will look better for selling. Personally I think a nice paint job will do just fine. 

And thanks everyone for your input, it is much appreciated.


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## slickshift

carlabunga said:


> Hi,
> I was told (by the HD paint dude)....


If you only new how many disasters I have been introduced to with those words...

A Porch & Floor paint was the correct answer
Adding poly now won't seal in and keep an ill-adhering paint from lifting under any poly applied, thus lifting the poly and making a larger mess

Wash, scrape, and sand any loose or ill-adhering paint, apply an oil-based primer rated for foot traffic (floors), and top coat (you should do 2 coats) with a quality floor paint from a real paint store (alkyd or water-based)


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## Nestor_Kelebay

panhandlion said:


> I built a wooden coffee table for my daughter for Christmas. She wants it painted to match her decor.
> 
> I applied one coat of primer and plan on putting one or two coats of latec semi-gloss paint.
> 
> Question... Can I add a coat (or two or three coats) of clear water-based polyurethane over the paint?


 
Panhandlion:
Yes, you can put a water based clear coat (like Flecto's Diamond water based finish)
http://www.rona.ca/product/varathan...yurethanes_paints-varnishes-stains_paint_shop

The problem is that it's never a good idea to put a hard coating over a soft one. This is an important point when it comes to applying floor finishes, but it's not even considered in painting circles. When you put a hard coating over a soft one, then impacts and stresses are going to cause the soft coating to break, and the result is that the hard coating will seem to "chip" easily. The problem is that it's not supported by an equally strong substrate.

You say you applied a "primer" then two coats of a latex semigloss paint.

You may as well apply a hard water based clear coat over what you have now, and maybe plan on stripping and repainting in future.

It would have been better to have applied a much stronger and harder primer (an Interior Alkyd Primer) and then top coated with either an interior alkyd wall paint, or a tintable polyurethane fortified paint.

The other option is to strip off the paint you have now, and start over with an alkyd primer and paint.


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## carlabunga

*thanks*

thanks, I am on my way to get the oil base and floor paint.


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## Clare Eckert

*water-based urethane over acrylic paint*

I was reading this thread and it makes sense, for furniture. I work at a nature center with live animal exhibits and MANY interactives for kids to play with. We have 30-40,000 visitors per year in the 6 months we are open. Some of our interactives are painted murals with doors in them; kids pick up the doors and see a picture or some text underneath. People apparently like to spin their fingers around the knobs, and the paint wears off and needs touching up every year. If we try use oil-based paint on the murals, it still wears off and is VERY difficult to touch-up. We prefer to use acrylic paint for the murals but would love to be able to protect it. I've had good luck with a water-based urethane on a pine kitchen counter at home. Our question is, will the urethane adhere as well over acrylic paint as it does to clean bare wood?

Thanks! Clare


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## annie68164

I just want to say I have done several home improv. project using water-based poly over paint and have been pleased with the results. Here's what I've used it on: 
desk top surface that was decopauged (sp?) with vintage airplane printouts glued on then 5 coats poly over it. 
Basement stairs painted red then about 3 coats poly. Holding up excellent
coffee table in living room that was painted antique white and about 4 coats poly. 
bedroom dresser top got from goodwill, painted and about 3 coats poly. has held up for several years but has yellowed because I used oil based poly 
various other things like TV stand, kitchen table refinish, kitchen cabinets and it's always held up well. I mean every surface needs refinishing after so many years that's just how it goes. i do have 2 little sons who beat everything up with metal tractor toys, "swords" and about anything they can play warrior with, so I get plenty of chips and dings but if you don't have rough people in your home your poly surface could last close to forever.

Overall I haven't had any problems-yes, there are bubbles but you lightly sand those between coats. I will say it's pretty difficult to get the surface smooth as silk because of these bubbles but it isn't noticeable unless your trying to feel it. I just don't recommend ever using oil based on lightly painted surfaces due to yellowing. probably be ok on stained wood though.


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