latex semi gloss over oil semi gloss - can it be done? - Contractor Talk - Professional Construction and Remodeling Forum

Zeebo · 12-18-2005, 03:11 PM

Can you apply a semi gloss latex over semi gloss oil without using primer??

I have used latex paints over oil based paints in the past, usually applying a flat or eggshell latex over a flat oil base paint. I am comfortable putting latex over flat oil based or peral finish paints without primer. I would usally sand very well and wash with amonia and water (no tsp because of the film). In cases where the oil paint is questionable, I would use a transitionary primer such as zinnser or gripper.

However, I have a client who wants me to paint her doors and window trim (interior). The trim presently has semi gloss oil and is in good shape. She only wants me to put on 1 coat of semi gloss latex without primer.

Am I asking for trouble in this situation?? Have any of your applied semi gloss latex over semi gloss oil with just basic surface preparation such as sanding and washing???

Can you recommend a good semi gloss latex paint that would go over semi gloss oil in one coat---- white paint is what I am applying.

Anything in the ICI, Glidden, Para or BM line??

Thanks for the feedback.

George Z · 12-18-2005, 03:41 PM

Quote:

Originally Posted by Zeebo

Can you apply a semi gloss latex over semi gloss oil without using primer??

I have used latex paints over oil based paints in the past, usually applying a flat or eggshell latex over a flat oil base paint. I am comfortable putting latex over flat oil based or peral finish paints without primer. I would usally sand very well and wash with amonia and water (no tsp because of the film). In cases where the oil paint is questionable, I would use a transitionary primer such as zinnser or gripper.

However, I have a client who wants me to paint her doors and window trim (interior). The trim presently has semi gloss oil and is in good shape. She only wants me to put on 1 coat of semi gloss latex without primer.

Am I asking for trouble in this situation?? Have any of your applied semi gloss latex over semi gloss oil with just basic surface preparation such as sanding and washing???

Can you recommend a good semi gloss latex paint that would go over semi gloss oil in one coat---- white paint is what I am applying.

Anything in the ICI, Glidden, Para or BM line??

Thanks for the feedback.

CIL(ICI) Trim and cabinet paint.
It is available at Home Depot or RONA under different packaging.
We tested on Oil High gloss with a bit of sanding before using it in customer's homes. The best trim paint we ever tried! (latex or oil) This coming out of
an Impervo user. Better leveling and hiding than Impervo, but work it like oil,
it may sag if you think it's going to dry like a latex. In fact it smells suspiciously like the Gripper, they may share some ingredients.

Zeebo · 12-18-2005, 03:56 PM

Hi George. Thanks for the info. I am familiar with this paint since I buy the CIL paint from time to time, but I mostly but from ICI, which produces CIL, colour your world, Dulux, Glidden, etc. etc.

Are you saying that I can apply this directly on top of the semi gloss oil (after proper sanding and cleaning and no primer....this is what I am actually looking for but don't have enough experience with latex over semi gloss oil)?

Zeebo

George Z · 12-18-2005, 04:23 PM

Quote:

Originally Posted by Zeebo

Hi George. Thanks for the info. I am familiar with this paint since I buy the CIL paint from time to time, but I mostly but from ICI, which produces CIL, colour your world, Dulux, Glidden, etc. etc.

Are you saying that I can apply this directly on top of the semi gloss oil (after proper sanding and cleaning and no primer....this is what I am actually looking for but don't have enough experience with latex over semi gloss oil)?

Zeebo

Yes, don't skip the sanding and cleaning

Brian · 12-18-2005, 05:59 PM

As a test I have applied Sherwin Williams' ProClassic Waterborne over high gloss oil without sanding or cleaning. I let the ProClassic dry overnight and could not scrape it off with a key. I finally got it off when I dented the wood.

I have conducted similar experiments a number of times, with similar results. While I don't recommend applying the product without sanding/ deglossing, my experiments have convinced me that the product will perform.

I've had it on my kitchen cabinets for over 5 years and they have worn much like an oil. The only issue I have seen is that they are a little more sensitive to some cleaning solutions.

One thing to check, the gloss level of a waterborn may be lower than an oil. This is the case with ProClassic.

Brian Phillips

George Z · 12-18-2005, 06:16 PM

There are some great products out there, it makes that
latex over oil theory an old wives' tail.

AAPaint · 12-18-2005, 07:40 PM

That's the part I don't get. I've never heard you can't do latex over oil if it's prepped right. I was always taught no oil over latex.....this discussion could go on forever!

Zeebo · 12-18-2005, 07:43 PM

thanks guys

It's always funny how these products don't support the latex on oil thing, but I guess trial and error is the best course of action / learning experience.

Have a good one

Zeebo

PlainPainter · 12-21-2005, 12:17 PM

No oil over latex for exterior house painting. The two paints have very different strengths when comparing tensions and compressions. Latex paint is very strong in tension, and oil is very strong in compression. What this means - you'll get severe cracking if you put oil paint over latex on your exterior due to the atrocious amount of expansion and contraction the outside of your home undergoes. Although I could see a house in a climate that hardly changes through-out the year - where this would be less of a problem. But I am up here in the northeast, so I have to worry about these things. Latex over oil is ok for the exterior - but the same cracking still goes on - just happens underneath the layer of latex - and what ends up happening is this strong layer of 100% acrylic exterior house paint will shear the old layers of oil paint right down to the wood! To most homeowners, who are stupid by the way, they think you did a lousy job. I have seen guys spend hours and hours grinding away - only to see the old paint that survived the grinding process - peel the very next year. 100% acrylic latex paint is strong stuff! It will lift old oil paint that your scrapers and grinders couldn't.

Anyways back to original discussion. I find oil resins really stick great! So the inside of your home it's ok to paint oil over latex - with little to no prep.
But the converse isn't true. But I disagree about not using TSP to clean surfaces - natural mined detergents (like TSP) as opposed to synthetic petroleum distilates (like liquid detergents) are great for prepping because they don't leave a film. you just have to rinse the areas well where you cleansed. To be safe - I have always sand trim before painting. nomatter if it's latex or oil. Now the next step is to determine if there were a lot of hand grease from people touching the surface over the years. A rarely visited closet may have very little surface grease - so sanding is adequate. Other places like a main door or kitchen cabinets may have so much grease that sanding merely swirls the grease around. So I will follow with a TSP cleanse and rinse - this has the added advantage of giving the surface a better "profile" for the new paint to cling to.

If it's oil trim, with latex as the next coat. I would sand, prime, then paint.
I would consider sanding, then washing down with TSP (real big believer in TSP) and then paint with latex to see if it works. But only if I felt like experimenting and possibly only do one room - so If I get a callback - it won't be for the whole house.

-PlainPainter

Eco · 09-04-2007, 01:45 AM

PlainPainter, when you say this:

"the same cracking still goes on - just happens underneath the layer of latex - and what ends up happening is this strong layer of 100% acrylic exterior house paint will shear the old layers of oil paint right down to the wood"

Are you saying the latex will STICK, and the oil underneath will crackle and peel off the house? Is latex that strong today? What if the oil was not even sanded... would the latex crackle, and NOT the wood?

gideond · 09-04-2007, 05:53 AM

It's not latex that is the problem so much as the 100% acrylics. They bite HARD. Acrylics now can indeed grab so hard they pull old paint under them loose. It's not a big concern if you prep correctly though.

welovepainting · 09-04-2007, 06:04 PM

I agree interior yes with the proper sanding and cleaning latex over oil... but not outside. On oil exteriors we sand, complete oil prime, and latex satin top coat. We rarely ever spot prime outside unless its in good condition and already has latex on it.

paulbunyan · 09-05-2007, 11:35 AM

It can be done, I've painted latex over oil but only after a number of years. The oil becomes acceptable to latex after it's REALLY dried out over time. Still best to prime. Better safe than sorry!

PlainPainter · 09-05-2007, 05:38 PM

The whole latex over oil thing - is for purposes of what is more acceptable for expansion characteristics of the two paints. You could imagine applying a rubbery compound over something hard like an enamel or shellac. But imagine doing the reverse, an enamel over something gooey - the results would be disasterous. That being said - you definitely should re-prime over a failing chaulky old finish before switching over to latex for purposes of adhesion - but the order is still intact, latex over oil.

That being said further, all homes in New England were oil - and all painters switched over for the most part in the 70's. So what about All those homes - painters weren't priming over the old oil finishes - they just bought and used what was being sold. And they weren't even pressure washing the surfaces clean either - and the latex was mostly vinyl based -eweeeweew. That's why now - we're experiencing rapid failure among finishes - some homes retain more than 50% of the old oil paint, some less - and until it's all gone and scraped away for good - the newer paints will continue to peel. I'd say that's another 10 paint jobs per house before more than 99% of the old lead paint is completely gone.