# Controlliing Tannin Bleed



## DeanV

I have a house that was primed with BM 100 fresh start long oil primer, top coated with BM solid oil stain (white). The siding is cedar and I cannot get the tannin bleed under control. What process would you recommend for repainting? Spot prime? Full Prime? Latex or oil stain? What about XIM's tannin bleed control additive for acrylic paints?


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## johnthepainter

dean, ive had tannin bleed through both oil, and latex primers and topcoats,,,,

the worst tannin bleed through i encountered was oil primer, topcoated with superpaint (this was specd by architect) 

i also had some tannin bleed with coverstain primer with classic 99 oil topcoat,,,

and with 1-2-3,,,,,and a latex topcoat

so,,,, are there both water soluble, and oil soluble tannins???? this is what ive been led to believe, and i think its so.


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## MAK-Deco

I have had problems with tannin bleed on white topcoats as well. I have tried a few different oil primers and top coats and have not been able to solve the problem. We do a bunch of small privacy fences at a town house complex. The get painted on a schedule every 4 yrs. So they get primer and paint every time. I notice the tannins usually in the third year.

I too would like to try the XIM additive to see if it helps...


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## DeanV

There house was built around 2001 (unprimed cedar installed, primed with BM 100 slow dry oil, then top coated with solid oil stain). In 05 I repainted it it, spot priming with coverstain over areas of tannin bleed and repainting everything with solid oil white. I need to look at it again this year since and it sounds like the HO is looking for it to last longer. I wish the siding had been factory primed, that would probably have helped. 

This time around, I might try the XIM additive. I doubt it will help much, but you never know. These white houses make it tough, no forgiveness for tannin bleed at all and a Dutch Colonial really has to be white.


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## MAK-Deco

Yea we do half the fences white the other are a medium gray and the gray holds up a lot better when it comes to the bleed. not as noticeable.


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## painterman

If it is areas that you would normally spot prime with oil then I would spot prime with brown exterior carpenters glue. This method has never failed me ...never :thumbup:


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## DeanV

The problem is that it is not knots bleeding, but larger areas of tannin. I do not think spreading glue over smooth cedar lap siding would work well??


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## painterman

Why?


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## DeanV

It does not sound like spreading glue over a bunch of 3'x3' areas and keeping a smooth, even appearance would be an easy thing to do.


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## NACE

Generally cedar siding will acclimate to an 8-12% moisture content. Since tannins are water soluable extractives that are essential tree waste, they will migrate to the surface in the presence of moisture, especially if there is a constant source for the tannins to dilute in. Have you checked the siding with a moisture meter? Are the gutters clean and working properly? Is there ever any ice dams in the winter? Is there too much paint build-up in the shadow line and overlap of the clabboards? This does not allow proper respiration of the clapboard? Where is the bleed? Is it everywhere or does it show a pattern. Generally a long oil primer is best for tannin bleed becasue it penetrates the furthest into the wood. If the primers are put on too thin, or do not fully cover the mill profile of the siding, some peaks and valleys of the wood will still be exposed to weather. Fast drying primers are good sealers but usually get too brittle and adhesion gets compromised. Was the Tyvek installed properly? Are there any gaps in butt joints or transisitions between the trim and the siding. Is everything properly caulked? Are any nail heads exposed? Check out this link to the US Forestry Service regarding wood siding. This may give some helpful information so that the source of the bleeding can be determined, and then a solution stratedgy prepared to eliminate the bleed.
http://www.extension.iastate.edu/Publications/PM363.pdf
Good luck!!


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## JTP

NACE said:


> Generally cedar siding will acclimate to an 8-12% moisture content. Since tannins are water soluable extractives that are essential tree waste, they will migrate to the surface in the presence of moisture, especially if there is a constant source for the tannins to dilute in. Have you checked the siding with a moisture meter? Are the gutters clean and working properly? Is there ever any ice dams in the winter? Is there too much paint build-up in the shadow line and overlap of the clabboards? This does not allow proper respiration of the clapboard? Where is the bleed? Is it everywhere or does it show a pattern. Generally a long oil primer is best for tannin bleed becasue it penetrates the furthest into the wood. If the primers are put on too thin, or do not fully cover the mill profile of the siding, some peaks and valleys of the wood will still be exposed to weather. Fast drying primers are good sealers but usually get too brittle and adhesion gets compromised. Was the Tyvek installed properly? Are there any gaps in butt joints or transisitions between the trim and the siding. Is everything properly caulked? Are any nail heads exposed? Check out this link to the US Forestry Service regarding wood siding. This may give some helpful information so that the source of the bleeding can be determined, and then a solution stratedgy prepared to eliminate the bleed.
> http://www.extension.iastate.edu/Publications/PM363.pdf
> Good luck!!


Great Post Nace!!:thumbsup:

JTP


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## Primer Guy

*Bleed Control*

Controlling tannin bleed can be a bit tricky as stated in above posts. Bleed Control is an additive that reacts chemically with tannin and changes it into a paste that can't penetrate the film surface of an acrylic paint. That;s the short story. Obviously if you have a condition which keeps re wetting the tannin paste some might bleed through. Bleed Control is your best bet and it will work in either the topcoat of primer.


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## DeanV

How does it compare to oil primer for blocking tannin bleed?


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## Primer Guy

Dean- Here is the technical scoop on the issue. The difficult part in using an oil based primer is that it will not breathe especially if used on the whole surface. If you have any moisture vapor from inside the oil based primer is susceptible to PREMATURE failure and bubbling. Spot priming is a good practice though with an oil based primer. *B*

*ackground: *Wood species that include redwood, western red cedar and Douglas fir contain natural chemicals known as extractives. These extractives are colored and can vary from colorless to yellow to red and even brown. The concentration of the extractives can vary greatly between tree species, from tree to tree and even within a single tree. As an example, the wood that is close to the bark will contain less colored extractives compared to the inner part of the tree (heartwood). It is not unusual for plywood made from one of these woods to have a wide variation in extractives.
When a wood is exposed to sufficient moisture the water-soluble extractives dissolve and migrate to the surface of the wood. This can lead to discoloration of finishes applied to the surface. This extractive staining can develop during or soon after the application of a water based finish. This staining may also develop months after the finish has been applied. Rain, heavy dew or even water washing may still dissolve the extractives. The moisture can wet and penetrate the permeable latex paint, primer or stain and start the extraction process.

*H*

*ow it works.* The active ingredients in the Bleed Control 100TM soak into wood fibers when the paint is applied and react with the tannin and colored extractives at and just below the surface of the wood preventing them from being extracted. Even though the extractives are “tied up” at and below the surface in the wood fibers, the extractives in the center of the wood are not tied up, and they can be extracted when the wood is heavily soaked for long periods of time. In other words, the paint system (latex primer, paint and tied up extractives) is overwhelmed. Also, there may be an unusually heavy concentration of tannin and extractives in the wood and, therefore more than 4 ounces of Bleed Control 100TM may be required. It is best to test for early bleed-through before starting the job, if this is expected.

*W*

*hat can be expected from using Bleed Control 100TM:* When water based coatings are used a reduction in extractive discoloration is when 4 ounces of Bleed Control 100TM is added per gallon before application. Lab testing, field testing and commercial use indicate reduced extractive bleeding up to 18 months. Although latex films can and do deteriorate with time and exposure to sun and rain, indications are that holding back the effect of extractive bleeding under normal weather conditions can be effective for many years. If, however, the latex paint or primer film breaks down or deteriorates some bleeding and discoloration may be expected. Although the exact length of resistance to bleeding can not be firmly established, as one might guess, the higher the quality of the latex paint, primer or stain – the longer the resistance to discoloration and bleeding caused by the extraction of water soluble extractives. 
Bleed control 100TM does not seal in sap-bleed from knot holes. For example, knot holes in pine should be spot primed with a shellac or solvent based sealer prior to painting with a water based paint or primer.


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## DeanV

Bringing this one to the top again. I met with my paint rep today and given that the house is 7 years old and this is the 2nd repaint (last one in 05), I am concerned that the oil primer and stain over smooth cedar now has enough build, especially if I am going to do another coat of primer and top coat it, that it is not functioning as a stain anymore but as a flat paint. My rep suggested a full oil prime and then top coat with a low sheen exterior paint. Do you guys agree? Since the cedar is rough side in and NOT back primed, do you think this is asking for peeling? I am worried that another full round of primer and stain would really seal it up just as tight though. Spot priming is not an option, too much bleed. Bleed is not in a pattern, but more or less all over. It would take longer to spot prime than to full prime. Does not seem to be tied to areas of sprinklers, overhangs are 3' on the lower level so it should be protected from moisture, but it still bleeds.

what would you do?


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## BreatheEasyHP

What I'd do is use an acrylic stain-blocking primer and possibly add the XIM Bleed Control 100.

The only advantage I've read or hear about oil-based primers that is logical is that they penetrate into the wood more. The disadvantages are serious, though - inflexible and impermeable. 

After testing multiple products, I used two coats of Zinnser Smart Prime to successfully block tannin bleed on lattice made of Western Red Cedar (HO painted them first with latex, so I was stuck following suit). One year later they still look good. However, lattice is thin, so it might be a different story...less tannins to bleed, maybe? Just pondering. 



DeanV said:


> Bringing this one to the top again. I met with my paint rep today and given that the house is 7 years old and this is the 2nd repaint (last one in 05), I am concerned that the oil primer and stain over smooth cedar now has enough build, especially if I am going to do another coat of primer and top coat it, that it is not functioning as a stain anymore but as a flat paint. My rep suggested a full oil prime and then top coat with a low sheen exterior paint. Do you guys agree? Since the cedar is rough side in and NOT back primed, do you think this is asking for peeling? I am worried that another full round of primer and stain would really seal it up just as tight though. Spot priming is not an option, too much bleed. Bleed is not in a pattern, but more or less all over. It would take longer to spot prime than to full prime. Does not seem to be tied to areas of sprinklers, overhangs are 3' on the lower level so it should be protected from moisture, but it still bleeds.
> 
> what would you do?


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## jsheridan

I'd try Cabot's Problem Solver
http://www.cabotstain.com/products/product/Problem-Solver-Wood-Primer.html?productTypeName=Exterior


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## plainpainter

DeanV said:


> Do you guys agree? Since the cedar is rough side in and NOT back primed, do you think this is asking for peeling? I am worried that another full round of primer and stain would really seal it up just as tight though. Spot priming is not an option, too much bleed. Bleed is not in a pattern, but more or less all over. It would take longer to spot prime than to full prime. Does not seem to be tied to areas of sprinklers, overhangs are 3' on the lower level so it should be protected from moisture, but it still bleeds.
> 
> what would you do?


That right there is your problem, it isn't back-primed. This to me is the only really tangilble proven reason to backprime, is to control tannins. You see, you are implicitly stating that you believe the bleeding is coming from the front side of the clapboard, by going through all these different systems of coating the front side of the clapboards. But the tannins aren't coming through the paint, they're leaking from above from the uncoated backside of the clapboards.

Nothing you do will fix the problem, because the problem of controlling tannins from the frontside has already been taken care of. Think about it - unless you have a knot, there is no way tannins are gonna get through Moore's 100 series oil primer, unless you seriously thinned it down past it's point of usefulness. Until the homeowner corrects the water ingress issues, the tannins will constantly appear.


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## NCPaint1

I sure hope Dean finished this job already 

Soooo...is it ok now? No callback?


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## DeanV

No callback, but i have not driven by yet either to see. I did a bunch of samples of primer, no primer, bleedcontrol100, no bleed controll, etc. And i put my sample in various areas in the fall. Came back to the house in the summer to check samples and my most important ones where gone. They tore off the back sun room and made it into a porch without telling me. So much for research.

Stop the necro posting madness!!!!!!


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