[eddiemac]

I am using Varathane Diamond polyurethane, water based, satin finish on six panel oak interior doors. I was intending two coats, but the can recommends three. How necessary is a third coat? I was almost hoping to get by with one, because I want to finish this house up!

The doors are on a bathroom, bedrooms, closets and one between kitchen and laundry room. I thought that might make a differenceregarding protection levels.

 

[MinConst]

eddiemac,
Seeing they are interior doors you can probably get away with 2 coats. I always use at least 3. 4 on exterior. The first two coats are really just sealing. The third one make the job. Light sanding with a scotchbrite between is required.

 

[PlainPainter]

3 coats - sand between coats with 220 - tack cloth with denatured alcohol to get rid of dust. First coat won't even leave a coating - it will soak completely into wood.

-PlainPainter

 

[Mike Finley]

I tend to believe you are going to get results more dependent on the manufacturer of the poly then anything else.

I like to use a product by General Finish for the 'poly' coats. I just buy the gloss version and depending on how many coats I put on depends on the gloss of the final finish.

1 coat will give me a satin finish, a second coat brings it up to semi-gloss and the third brings it to near gloss but nothing I would consider a glossy finish like poly that gives it that plastic look. You are seeking a satin finish, so with the product I use, I would just give it the one coat and be done. I sand between coats with 600 grit, by hand, very, very quickly. A door I would sand between coats in less than 60 seconds a side, just a couple of passes back and forth is all it takes to knock General Finish coatings down to smooth as glass. I also rarely sand initially before stain past 150 grit sand paper, unless I want to lighten the stain a bit by closing the wood pores with finer sand papers.

 

[Teetorbilt]

I'm not a big advocate of poly and work with it very little but the same may hold true. We always prime and coat with gloss saving the final coat for finish. Reason being that gloss is clear, every other finish contains a flattening agent. Too many coats of a flattening agent will make the entire film begin to look 'milky'.