I’ve been painting, and painting, and painting the underside of a wood deck and am getting bleed through. The deck was stained sometime in the past, apparently by pouring on a tanker full of stain (I exaggerate, perhaps). The stain seems to have flowed down between the deck boards and dribbled down the joists. Based on the spots on the concrete floor under the deck, not much care was taken. Prior to painting, I swept off loose dirt and cleaned the underside with a pressure washer. I let things dry for a few days and shot 5 gallons of Kilz2 on with an airless sprayer. Painted area is 8 by 40 feet (320 square feet plus the sides of the joists). I waited a couple of days, applied a second coat of Kilz2. Waited a couple of days. Applied 5 Gallons of white primer (True Value brand, Medallion). The dribbles are still bleeding through. Is there anything that can stop the stain? I’m planning on using a pale yellow latex for a finish coat, but am wondering should I wait a while and keep adding coats of primer before painting.
What the hell could be in the deck stain that allows the color to move through multiple coats of sealant? For something that is so difficult to cover, it didn’t hold up on the deck surface well at all. It might be Penofin stain, there was partial can in the garage when I bougth the house.
Replies
Wow. I didn't think anything went through Kilz.
Not much advance
I contacted the Penofin folks who told me that Penofin is solvent based and after 3 hours won't migrate through a water based sealant (I'm paraphrasing). One of the reasons I picked Kilz2 was the chance, although not certainty, that the deck stain was solvent based, also I'm planning on using latex as the color coat. Well it looks like that was a poor assumption. I'll post a picture of the problem tomorrow. We are having a thunderstorm right now and it is getting dark to photograph.
I'm guessing what you have there is blobs of semi-liquid oil on the bottoms of the joists. I'm afraid you'll have to bite the bullet and scrape the blobs off, then let it dry a few days before attempting to prime again. And you might want to use a shellac primer first.
Picture of bleed through
Attached is a picture of the problem. As can be seen, the bleed through is occuring on the sides of the joists as well as the underside of the deck boards. I have sent the photos to Penofin who have been helpful and I'll be sending them to MasterChem, the makers of Kilz who have not yet responded to my inquiry.
You sure that's bleed-through? Looks more like plain old dirt to me. Note that the areas below the gaps in the decking are clearer, where rainwater has washed away the grime.
The reason I don't think it is dirt is the deck has been covered by acx plywood and polyurethane coating (pretty waterproof) for a couple of months and before spraying the first coat of Kilz2, I swept the underside of the deck and then washed it with a pressure washer. While I may have missed some dirt, I was blasting away for almost an hour. I then let the deck dry for a couple of days. It is warm, dry and windy here. I don't see how dirt could have moved without some source of moisture.
I'm hoping Masterchem, the makers of Kilz will respond to my question, but I'm starting to suspect they are going to blow me off.
Well, I don't know how you account for the pattern. You'd expect the stain to be thicker under the slots, but the wood is cleaner there.
What Penofin has to say
I contacted Penofin regarding my bleed through problem. Since they were nice enough to respond, I don't want to be too harsh in my comments, but I don't think the answer I got makes real good sense. Below are some excerpts from my correspondence with Penofin:
Killz 2 will not block cedar tannin contrary to what the tell you on the label (I know you said you don't have cedar or redwood). I'm not sure it's as good of a stain blocker as Kilz oil based based on my results. I would put a coat of oil based kilz on a stained area on the deck and observe the results for a while. I suspect the problem will go away.
Choose your next product carefully
The original Kilz (oil base) is not rated for exterior use. While I think there is a good chance that an oil based primer will solve the problem, particularly if the True Value primer is also a latex, you do not want any suprises a couple of years from now if the paint starts peeling or some similar failure. Shelac based primers similarly are designated for interior use only.
Kilz Complete and Cover-stain (Zinsser) are rated for exterior use.
Kilz 2 is the second tier latex stain killing primer. Kilz premium is the better product. It is hard to tell from their literature what gets short chenged when they make a cheaper product. It looks to me that it doesn't have the superior adhesion to deal with glossy surfaces (not your problem) but it doesn't say if its stain killing properties are reduced also.
What MasterChem, makers of Kilz has to say
I receently got the following response to my inquiry (see bottom of response for original question) regarding stain bleedthrough:
Hello,
Thank you for contacting Masterchem Industries.
We are very sorry to hear you had experienced a difficulty with your most recent deck project. Without knowing more specific details and the size of the project, it is difficult to diagnose the cause of the problem. However, we can offer some suggestions which may work for your project.
While we do very much appreciate that you have chosen to use our product, we must first note that the Kilz 2 Primer is not recommended for flooring and other horizontal applications. Because of this, we would not be able to guarantee that the product will perform to our standards. For these applications, we would recommend our Kilz Premium Primer. This is also a latex primer which provides excellent adhesion, a high resistance to mildew, and is ideal for surfaces that are more prone to moisture.
Based on the fact that the primer is not ideal for the project as well as the explanation of the difficulty you are describing with the stain, we would recommend that the coatings be removed using a conventional stripper and stain remover. You may check your local Home Depot or home improvement store for these products. These would work to penetrate into the substrate foundation to remove the stain that is hindering your project.
If you choose to move forward with the project, it is possible that you may be able to top coat the deck without the stain bleeding through. The primer sealers serve to prevent the stain from leaching from the substrate and do obscure/cover the surface in the manner a top coat of paint would. The stain may be visible on the primer coating, but should not be allowed to leach through the surface when top coated with paint. You may try top coating a small test area with the pale yellow paint to see if the stain continues to bleed through.
It may be necessary to move to an oil based primer, as these are more aggressive and a better block for tough stains. Unfortunately, we do not currently manufacture an oil based primer intended for horizontal applications. In this case, we must again recommend that you check with your local retailer for an oil based product which would be better suited to your project.
For more information regarding our available Kilz and other Masterchem products, please visit the “Projects” and section of the Masterchem website, http://www.masterchem.com.
We at Masterchem appreciate your being a customer and would like to thank you for your past patronage. If you have any further questions do not hesitate to contact myself or any customer care representative, we would be happy to assist you.
Regards,
Jonathan Holt
Web Communications
Original Text
From:
To:
[email protected]
CC:
Sent:
09/14/10 12:47:51
Subject:
Stain bleeding through Kilz2 and everything else
I am attempting to paint the underside of a wood deck. The deck was
stained sometime in the past before I purchased the house. It appears
that stain was either heavily or repeatedly applied on the upper side of
the deck and perhaps thinly on the underside. There are visible spots on
the concrete below the deck. It has been at least 3 years since stain
has been applied. It may have been Penofin brand, since I found a
partial 5 gallon can in the garage after buying the house. However, I do
not know for certain what brand of deck stain was used.
The steps I have taken to prepare the surface for painting are; 1) Sweep
off loose dirt and cobwebs, 2) pressure wash, 3) let dry for two days,
4) apply 5 gallons of Kilz2 with an airless sprayer (area being painted
is 8 by 40 feet, 320 square feet plus sides of joists) 5) wait two days
and apply another 5 gallons of Kilz2, 6) wait two days and apply 5
gallons of white latex primer. After each application of coating the
stain is bleedingthrough. I am planning to paint the surface a pale
yellow. Is there any way of stopping the stain from bleeding through?
How can the stain migrate through multiple layers of sealer primer? I'm
quite willing to wade through a technical explanation of the chemistry
of this problem, since understanding what is going on is certainly the
first step to solving the problem.
Thanks for any help you can provide.
My take on this response is I am underwhelmed. First I wonder what specific details and size information is needed which was not included in my original inquiry. Second I wonder about the relevance of horizonal versus vertical surface. I clearly state this is the underside of a deck, i.e. a ceiling, not a floor. Does it make any sense that a stain blocking product would magically work on the vertical sides of the joists, but not the horizontal underside of the deck. Now I freely admit I should have mentioned that the deck has been covered by ACX plywood and BASF Sonoguard polyurethane coating, however, the bleedthrough happened immeadiately after application and without exposure to anything but atmospheric moisture.
I suspect that Masterchem is brand mining the Kilz name. I'm not trying to set them up for litigation, just trying to find why the stain keeps showing through and how to fix the problem.