I talked to a painter about repainting the white interior trim of my house. Long story, but half of the trim is BM oil-based satin Impervo, and the other half is BM water-based satin Impervo. I want to minimize labor costs and time, but still want to do this properly. The painter recommended using oil based trim paint for the whole house. He says that he could just apply a coat (or two) of new oil based paint on the oil Impervo. But he also says that, to minimize labor and time, he can just apply new oil based paint over the water Impervo, without primer. (I presume he would use a deglosser before applying the new oil paint). I thought that was incorrect -- i.e. skipping the primer. But I checked with a paint store employee and he also said that, if the surface is in good shape, you can apply oil over acrylic without primer. (Of course, you cannot apply acrylic over oil without primer).

Is this correct?

As an alternative, I thought about a urethane acrylic (like Cabinet Coat, self-priming). I would imagine that you can apply CC over the (deglossed) oil Impervo. Would this be superior or inferior to the painter's idea of using oil in the whole house?

 

Oil over latex without primer is ok - it's the other way you need to be concerned about.

My concern here is that oil based paint tends to yellow with time so I would never use white oil based paint.

 

Thanks, stickshift.
Quick follow-up question: does the same apply for exterior paint? I might have the same painter do exterior re-paint of some windows and couple of doors, including frames -- most of them currently have oil, but some have acrylic. He again argues that, to save time and labor, he can apply new oil based paint to all.

 

Yep, same concept.

That said, oil based paint is not what it used to be and latex has gotten much better, I have latex only inside and outside my home. Not trying to sway you, just sayin'.

 

Thanks. One last question about interior trim. I now understand that I can use something like BM oil satin Impervo. Can I also use a water-borne alkyd, like BM Advance? Would it work the same -- applicable over both existing oil and latex without a primer?

 

That waterborne alkyd came up recently and we just don't know much about it. It seems to be oil based in that it does talk about yellowing over time but I don't know whether it covers oil based paint like regular oil based paint.

 

They say the waterborne is ok going over sanded oil base but I don't trust it, I'd rather oil prime first and KNOW there won't be any issues. As noted above there is no issue with applying oil base over latex. It's never a good idea to use liquid deglosser over latex paint!

Exterior paints are a little different. Generally it's ok to apply latex over weathered oil base but you really need to evaluate each job separately.

 

Thanks, guys. So it looks like:

a. Applying an oil based paint over both oil and latex, without primer,
will work -- and it would be most cost effective, since something like oil BM Impervo can cover with only one coat

b. Applying a water-borne alkyd *might* work like a regular alkyd, but we're not sure, right?

c. Applying a urethane acrylic self-priming enamel like Cabinet Coat would call for a primer coat for precaution.

The winner, in terms of labor and material costs, is then option a, right?

Thanks

 

A and B are both Yes. I have no idea what product that is in C so I cannot respond to that one.

 

Applying oil enamel over all the woodwork might be the most cost effective for now but would increase the cost if you want to switch to waterborne or latex later. Another thing to consider is the odor. If you switch now, you only have to oil prime half of the woodwork.

 

Thanks. I will either paint all the woodwork will oil based paint (like satin Impervo) without primer -- or will again recoat new oil over old oil (no primer), and new acrylic over old acrylic (no primer), and just "kick the can" down the road.

 

I'm all for keeping all the woodwork the same and if converting to waterborne isn't a consideration, I'd repaint it all with oil base enamel .... unless the 2 different paints are different colors or on different floors.

 

Thanks, marksr. Actually, the acrylic is in the first floor and the oil is in the second. They meet at the bottom of the stair baseboard. After almost eight years, the oil is noticeably yellower than the acrylic. One main reason for repainting is potential house resale in the near term (so I am fine if the new oil stays white for a few years).

 

Someone else, as I mentioned, brought up that waterborne alkyd paint recently and BM claims to have done something about the yellowing - minimized or delayed it or something.

Yeah, it'll probably stay white a few years and who knows what the next owner will want anyway. In the interest of being a good citizen, though, I would tell them it's oil based paint (after the closing is over is fine ) so they know they'll need an oil based primer down the road if they want to switch to latex. That or just leave them the rest of the can once you're done. I know I'd appreciate having that information.

 

Thanks. Yes, I am planning to leave paint cans if/when I sell.

I'll stop by my local BM store and ask if Advance behaves like oil Impervo -- ie no primer needed. All that said, I do like the porcelain-like texture of the oil Impervo -- nicer than the water based Impervo, imo.