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Old 08-14-2008, 11:04 AM   #1
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X-90 Siding leaking oil now??? "HELP!!!"


My painting contractor is having issues with painting the exterior of my house. He spot primed then painted one light coat of paint (acrylic-latex), then needed two more coats to cover. One morning I get up and find oil dripping from the bottoms of the boards! 100% sure it's oil too. What happened here? Too much oil for the surface to handle? Not drying enough in a day? Actually looks like dew until you touch it then it's clean oil.

The hardware store where he got the paint from then said to cover it with a latex stain of the same colour and it will seal the oil in. Didn't work!


...HELP!

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Old 08-16-2008, 01:33 PM   #2
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X-90 Siding leaking oil now??? "HELP!!!"


latex paint doesn't have oil in it so it likely isn't coming from the new paint you had put on. Are you sure it is oil? How old is the siding you painted?

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Old 08-16-2008, 04:57 PM   #3
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X-90 Siding leaking oil now??? "HELP!!!"


Latex paints don't have any "oil" in them, but they do have something quite similar called "surfactants", which are basically like a soap that helps lower the surface tension of the paint so that it "wets" the substrate better to promote better adhesion to it.

"Surfactant exudation" or "surfactant leaching", will typically occur if the paint is applied right before a drop in temperature which causes dew to form on the paint as it dries. The water soluble surfactants in the paint are drawn into the condensation that occurs on the paint film, and as that condensation subsequently dries up, you can be left with the surfactant left behind on the paint film. This can for a small drop, or just make the paint film look artifically "glossy".

My understanding is that surfactant exudation doesn't actually cause any harm, and it's just an aesthetic thing. You can normally just clean it off with water.

http://www.flood.com/Flood/TipsandTo...ching+Fact.htm
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Old 08-16-2008, 05:28 PM   #4
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X-90 Siding leaking oil now??? "HELP!!!"


Although many acrylic/"latex" paints do have "oil" (solvents) in them, it is a very small amount, and they tend not to leak out after application

If it is/was oil on the surface, a coat of stain won't seal it in

x-90/masonite siding, it's probably not the siding itself being the issue

If it wasn't a surface contamination, it may be surfactant leaching
Some paints do use excessive surfactants to get colors to mix
And as explained, environmental issues can cause the problem also

It would help if you posted up some more information, such as the age of the siding, exactly which paint products were used, and how (and when) they were applied

At least that info may rule out some possible causes and lead to a better fix
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Old 08-17-2008, 05:40 PM   #5
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X-90 Siding leaking oil now??? "HELP!!!"


You guys were bang on!

Surfactant leaching is EXACTLY what's happening!

I knew exactly what I was talking about, but didn't have the proper terminology to explain to my painter what I "thought" was happening!

When you said, "Soapy", this is exactly what it's doing! "Oily looking, but when you wash it lightly with a garden hose, it turns soapy!


He washed it with water and dryed it with a rag and then is going to try some high end paint to cover...during a better time of the day!!!

I know for a fact that he finished the shady side of the house last that evening and that particular wall doesn't get enough sun to give the paint enough time to dry!

Our nights have been cool and humid and a ton of dew is present in the mornings.

My question now is...Some of the color (very little) came off with the rinse, so what's a paint that has less/no surfactants in it? (keep in mind that our house is now a granite colour...medium to dark brownish grey)

I can't be sure of the year of the siding since the last owner passed away, but I can tell you that it was in great shape for painting and we got all of the chalk off of it before we began.

I'll keep you posted as to what happens, but in the meantime, please let me know all you can about what to do over top now to get the best results!!!

Thanks!


Jamser

Last edited by jamser; 08-17-2008 at 05:52 PM.
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Old 08-17-2008, 10:14 PM   #6
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X-90 Siding leaking oil now??? "HELP!!!"


Jamser:

So far as I know, EVERY latex paint will have surfactant in it to help wet the surface for better adhesion.

Here, do this: Take a razor and cut a 2 inch square cross hatched pattern (like a checkerboard) through the paint on the area of your house where there was no surfactant leaching and also in the area that have the worst surfactant leaching. Stick some ordinary 2 inch wide yellowish masking tape over each area and pull it off quickly. (This is how they measure paint adhesion in a lab, where the percentage of squares of paint not pulled off with the tape is quoted as a measure of paint adhesion and anything over 75 percent is considered "good adhesion" and over 90 percent is "excellent adhesion".) If you get significantly more squares of paint pulled off in the area that had the surfactant leaching, then it means that film formation and adhesion was compromised by the drying conditions. If you get about the same results in both areas, then it means that the drying conditions weren't adverse enough to interfere with proper film formation and adhesion.

That will conclusively tell you how much the paint film was affected by the surfactant leaching.

Because of the way latex paints (and floor finishes and just about anything that's milky white in the can and dries clear) form films, the fact that you haven't said anything about the affected paint being "whitish" in colour would suggest to me that you still got proper film formation and adhesion everywhere.

You don't need to know this, but it helps to know how latex paint works:
Latex paint consists of a slurry of clear hard plastic particles and pigments of various kinds suspended in a solution of water and a low volatility water soluble solvent called a "coalescing solvent". After you apply the paint to a wall, the water evaporates and the hard plastic resins find themselves surrounded by the coalescing solvent at an ever increasing concentration. The coalescing solvent penetrates into and softens the plastic resins sufficiently that capillary pressure and surface tension cause the soft resins to pull on one another (just like rain drops coalesce in a clowd to form bigger drops) hard enough that they distort in shape to form a continuous very soft plastic film with no air spaces in it. The coalescing solvent then evaporates from the paint film over the next few days giving you that "freshly painted smell" in the air, and the plastic then hardens up to it's original hardness with the pigments suspended in the plastic film very much like raisins in raisin bread.

If there were a problem with proper film formation, then the resins would not have softened enough nor been distorted enough to form a continuous plastic film, and there would be tiny voids or spaces inside your paint film. (Remember, a paint film is made of a clear plastic binder which only has colour and opacity because of the various pigments in it). Those tiny voids in the plastic would reflect and refract incident light in all directions, and the scattering of the light would give the paint film a whitish appearance. That is, the tiny voids in the paint film would make the paint whitish for exactly the same reason that tiny air bubbles in and ice cube make the ice cube white instead of clear. There is nothing white inside the ice cube or the paint, it's just that your eye sees all the different frequencies of light that get scattered in slightly different directions at every refraction as the colour "white".

Since you haven't mentioned anything about a white discolouration in the affected area, that tells me that the paint film formed a film properly, even in the worst affected areas.

Maybe do the masking tape test in several areas to ensure that the results you get aren't just anomolies.

Last edited by Nestor_Kelebay; 08-17-2008 at 10:40 PM.
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Old 08-17-2008, 10:43 PM   #7
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X-90 Siding leaking oil now??? "HELP!!!"


I just re-read your post and remembered this statement:

Quote:
Originally Posted by jamser View Post
My question now is...Some of the color (very little) came off with the rinse, so what's a paint that has less/no surfactants in it?
That area where the colour came off with the rinse, does it have a whitish appearance? Hold a light near that area of the paint and see if the gloss of the paint film is lower in the area where some colour came off.

Also, if you scratch at it with your finger nail, can you scratch what appears to be a whitish plastic (or lighter colour plastic than the rest of the wall) off?

If so, do your tape test in those areas for sure.

Last edited by Nestor_Kelebay; 08-17-2008 at 10:46 PM.
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Old 08-18-2008, 12:40 PM   #8
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X-90 Siding leaking oil now??? "HELP!!!"


Holy moly, you know your stuff! Thanks for the quick reply, I sure appreciate it!

The paint actually dried well after the rinse and hand wipe-down...but now it's just a bit duller looking than the rest of the house, and those "stains" remained slightly visible.

So now I'm getting my painter to go over the area again (in the early part of lunch-hour!) and go behind with a heat gun from a bit of a distance to help it dry.

Hopefully this will resolve any issues we still have with that one wall and I can move on to the rest of the house!


Thanks again for all of your help and it's great to know there's people who still give a damn!!!


Jamser
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Old 08-18-2008, 05:16 PM   #9
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X-90 Siding leaking oil now??? "HELP!!!"


Lose the heat gun. It really isn't necessary if you're painting during the daytime. The paint should have plenty of time to dry normally on a decently warm day without wasting electricity on a heat gun, even in the shade.

OK, G'Luck on the rest of the painting.


Last edited by Nestor_Kelebay; 08-19-2008 at 01:41 AM.
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