# painting red cedar white



## Boden Painting (Dec 27, 2007)

Last summer I stripped a house using the paint shaver pro. They were having a huge problem with paint peeling on their 80 year old home. I stripped it, sanded it with 60/80 grit to leave some roughness for adhesion,then primed with 2 coats of SealGrip Alkyd and 2 coats of SW Superpaint. The bleed through was so bad that on some areas of the house I have 4 coats of primer.

I got a call from her last week that believe it or not, it's peeling in spots on the unheated garage. I was flabbergasted, so I went over there and sure enough there were 2 spots about 5' off the ground on opposite sides of the garage (1 side sunny the other shaded by a group of trees) that were peeling. I could put my putty knife under it and pull off 5-6" strips of paint. The cedar underneath looked weathered. There was also a fair amount of bleed-through again.

I took the chips to my paint store and my paint rep sent them to PPG to analyze, however, I doubt that will come to any favorable conclusion on my end.

Any thoughts as to what might be going on? My obvious thought is moisture, but I was really diligent in giving the wood time to dry after rain. It was also a fall job and the weather was really good, in the 80's and low humidity for most of the project. I'm hoping if that's the case it's just a few isolated spots that I can repair.

What makes this even worse is that this is "that customer", the one that you just don't need anything to go wrong with. She's been ok so far as she knows that I really overkilled the prep and priming hoping to solve this problem but I can tell she's getting a little aggravated that for what she paid me to do the job that it's peeling again. 

Any thoughts or suggestions as to what could be going on and how to handle the HO are welcome 









garage after


----------



## NACE (May 16, 2008)

Dear Boden:
There are a few things I would check. First, since you have an 80 year old home the tannins can still be soluable and active if the boards are not back primed. Check to make sure that where the boards over lap under the shadow line, that no residual paint is left in the gap. You may need to take a serated window knife to cut the film and build up so the boards can work in conjunction with each other to respirate evenly and completely. You may need to paint inside the garage, or put a sealer on the concrete to insure that ground level moisture inside the garage is not drawn out by the sun through the cedar siding. It is likely that this space does not have a vapor barrier in the floor. A clear sealer is all that is needed on the inside to prevent the boards from absorbing interior garage moisture. Wedge vent a section if necessary, and see if the moisture level stabilizes at 8-12% Sometimes when cedar is sanded or ground, you leave a profile on the wood that exceeds the mil thickness of the film. If for example you have a wood profile with peaks and valleys of 0-12 mils, the coating system is covering 90% of the wood fibers, however some of the higher peaks are still protruding through the finish and exposed to the elements. Sometimes, although laborish, it is good to prime the wood with oil, then sand it to cut down the wood fibers that the oil raises and hardens, then clean off the dust, reprime, then topcoat. Tannins are always activated by moisture, as they are water soluable extractives that are from the metobolic process or waste of the cedar. Finding the moisture source is the key. Also, when using caulks and sealants, it is important to use a top quality sealant as opposed to caulk. Caulk only has flexibility. Sealant, especially the urethane reinforced acrylics, have elongation and memory. Some of the single component sealants have 600% elongation and 99% memory, so cavities that have a proper bead will move with the sealant and not compromise the seal as it may with caulk. Once the cavity expands greater than the caulks flexibility, the seal is broken and compromised. Any chance the slate roof has issues? Gutter system off for painting? Gable vents should be one cubic inch of vent for each sqaure foot of attic space. Has the house been added to in 80 years without increasing the ventilation space? Ridge and soffit vents? Remember too, that cedar will continue to break down over the years even with an opaque system over it. Cedar naturally grays to form a protective ash, or breakdown of lignin and cellulose to protect itself from the sun and insects. The ash is unstable and happens quickly. Just think of the garden mulch and how quickly it turns gray or fades. Although it seems that this is not an issue here, just an observation from your post. Try to use long oil alkyd based primers on older wood too. They remain more flexible and less brittle, expand and contract more readily with the wood and topcoat. Although they take a long time to dry, you get more of the system IN the wood, not ON the wood. How did you remove sanding debris after stripping? Was there any remaining on the back of the chip you took to the store? Hope that helps with your homeowner. That is a magnificant paint job!


----------



## Mopaint (Oct 17, 2007)

Believe it or not aluminum paint will stop this problem. Spot prime with aluminum paint let cure prime with alkyd primer then finish. Try an area you will be amazed. MOPAINT


----------



## NACE (May 16, 2008)

Wow, that is old school. We use to back prime all clapboards in the winter with Aluminum Paint, and all butt joints, moldings, mulleins, miter joints etc before installation of handmade windows, trim, stairs in the spring. It also works great for sealing knots too. Just need more coats to hide over the aluminum. Platelets of aluminum forming a thin metal, flexible film works great.


----------



## Alex PCI (Jul 26, 2007)

My simple solution would be to use Duration instead of Superpaint. I have never been a fan of that stuff and never will.


----------



## Boden Painting (Dec 27, 2007)

WOW thank you NACE, that actually makes perfect sense and I am going to look into the unsealed garage floor and moisture inside the garage as there is a broken window that would allow moisture into that space. There is no peeling or signs of any trouble anywhere else on the house so I think you may have really put me on to something. Now whose responsibility does it lie with? Do I fix it under warranty or charge to fix it? I went above and beyond and did the tannin bleed through repaints out of my pocket in order to keep her happy (it's in my updated contracts to new customers that they get charged for additional coats). I can see this being an issue with her.

I actually did some of the things you were talking about in trying to get the boards to breathe. Over 80 years they had been painted so that the clapboards were all sealed, some of them had even been caulked over the years. One of the problems with the paint shaver pro is that it tends to shred or fuzz cedar, especially if it has had exposure to air/water in it's lifetime so the majority of the house was sanded again after the prime coats in order to try and smooth it out a little more.

thanks again to you and everybody else, your input was appreciated.


----------



## YubaPaintPro (Mar 2, 2008)

Boden,
I did not read all of the above novellas, but as I skimmed it seemed like great info. 1st, the paint job looks great, and nice work w/ the paint shaver. I would also look at an unsealed garage floor. If this is not happening on the house, I guess it's moisture from the floor.

If you don't have a moisture test kit, just mask of all 4 sides of a 2'x2' piece of visqueen 2mil or more in a few places in the floor. 24hrs later if condensation is found, you may have a link.

I would suggest that you "took care of the problem" for your client in about 99.5% of the project. Considering the prep and condition of the project before you got there, I rate it as a success. Unfortunately I am not your client.

Moisture is certainly getting behind the paint. If the lab is not done, have them check for delaminating of the wood on the back side of the primer. Good luck for sure.


----------



## NACE (May 16, 2008)

I like the idea of installing plastic on the concrete to determine if there is moisture. (ASTM-D-4263), 3 mil plastic duct taped tighting to the floor for a 24 hour period will give you a good indication if ground moisture is migrating up through the concrete. Remember, concrete is a ridgid sponge and takes 100 years to fully cure. If there is no vapor barrier, the moisture will accumulate in the garage space, and the interior siding is the easiest place for it to escape as moisture seeks a higher exterior pressure. (Path to least resistance) If you do put a clear sealer on the floor or on the interior siding, it is important to install either gable vents or ridge vents to insure that the moisture has a place to go so the interior can respirate properly and even the pressure cycle. I would not put anything film forming on the concrete, as hydrostatic pressure will lift the film. There are what's called remediation epoxies to hold back up to 15 lbs of hydrostatic pressure, however a less expensive alternative is products that floor installers for vinyl, linoleum, and tile use for problem floors. It is water based and rolls on easily. Not sure what its durability is for car tires. It is my opinion that this is a structual issue that building codes have addressed over the years, and were not in place when the home was built or the concrete poured. It is not related to improper prep, the paint, or application however you are assisting a customer with professional diagnosis of a problem that must be corrected perhaps by a different trade or disipline. You may want to suggest that the client seek a home inspector to verify your diagnosis at their expense, and work up a price on repairing the issue that is fair to all. You have gone to extraordinary lengths to solve an issue that was pre-existing prior to your taking the job. Does that make sense?


----------



## Boden Painting (Dec 27, 2007)

Well, let me tell ya, today was a good day. I got a call this afternoon from the pittsburgh reps asking if we could meet at the house to look at it in person. When we met at the house he said that it looked like moisture, so he asked the HO if she could open the garage so we could look inside. Upon opening the door, all three of us looked like this. The whole interior of the garage was peeling paint. It almost looked like a carpet. 

So, long story short, the HO is going to replace the window and is going to spring for the wedges to drive under the siding to give it maximum air flow. I'll fix up the current peeling spots and check back in the fall to see if the problem has slowed or ceased.

The best part was the rep telling this lady that he hadn't seen a house stripped down so well and come out so nice and that all the work I had done was above and beyond what a normal painting crew would have done.:thumbup: 

Hopefully this is finally settled/solved.


So let me ask another somewhat related question.

The current house I'm doing is the same situation, red cedar but this time painted a beige color so the bleeding issue shouldn't be as much of a problem. This HO wants to use BM as her topcoat so I figure I would try BM's primer as well. The pittsburgh rep thought that one of the possibilities was an incompatibility between PPG Sealgrip Alkyd and SW Superpaint. I'm not sure how often or important that is but thought I'd try BM primer anyway. MY discount makes it about the same price as sealgrip/manor hall. 
Here's the question. The kid working the counter said that I need to use the BM fast drying oil primer as it was the only one that would block the tannins, I responded with NACE's info about using something that dried slower so that it permeated the wood more. Who's right and is Moorgauard as good or better then Manor Hall?

And just wanted to say thanks again for all the help, I learned something new for sure about red cedar.:yes:


----------



## MAK-Deco (Apr 17, 2007)

I don't care for Moorgard (not bad but there's better out there) never used Manor Hall do they have BM Aura there? if so worth a try. Yes the slow dry oil would be better for tannins, we do a lot of cedar. BM has a slow dry oil available.


----------



## NACE (May 16, 2008)

It is important to always use manufacturers systems when painting. All coating manufacturers make their products to work in conjuction with one another and have compatability. In addition, a manufacturer or rep will always fault the other manufacturer in any given failure. Long oil primers are becoming a thing of the past but they are better at locking down tannins and blocking their migration if the moisture level does not exceed the film or systems ability to hold it back. Fast dry primers are always more brittle, are usually thinner, and have less or no long term flexibility. The BM premium primers all have mildewcides in them, which is rare and expensive for primers. (The green stuff on the top of the can when you open it.) If you have the time to allow a long oil primer to dry for a few days on bare wood, you will get much better penetration and film build. Fast dry primers do not penetrate very far into a surface. Long oils can penetrate as far as 3 mils. I like primers *IN* the wood, not *ON* the wood. MoorGard is a great product in my opinion. It has a slight sheen so it sheds dirt accumulation therefore better mildew resistance, but hides minor surface imperfections and scarring on siding. It has excellent color retention and because it is a lower sheen, has better flexibility and breathability. The N103 formula is an all acrylic, so it does not have the same application and handling characteristics that it use to, but it has much better adhesion, sheen, and color retention since BM dropped the vinyl acrylic alkdy modification formula.


----------



## DeanV (Apr 18, 2007)

I have always like BM primer selection, but for the exterior primers I have never been entirely clear on when to use which one. Hopefully NACE can help here

1. Fresh Start 100: This is the loooong dry exterior oil primer. I have been told this one was formulated for use under paint specifically. It is not specifically formulated to block tannins.

2. Fresh Start 094 Fast Dry: 4 hour dry time, not on website any more. Specifically design to block tannins and for use under solid stains. Can be used under paint as well, but 100 better choice. 094 is no longer on the website.

3. stain primer 366; This seems to be replacement for 094???? 

Can you shed more light on these primers? Is the 094/366 still a long oil primer? Since fast dry is often associated with things like coverstain, it may not be fair to lump these in as a "fast dry" primer.


----------



## NACE (May 16, 2008)

*100-00 Fresh Start Moorwhite Primer:* Long oil, slow dry, more like a bonding and filling primer. Long deep penetration into a wood surface, excellent film build, remains flexible under paint systems. Ties down moderate chalk and unstable wood and creates a uniformly sealed surface. Mildewcides included. 500-550 sq ft per gallon at 3.1 mils WFT, 2.1 mils DFT. Excellent for tannin bleed. 66% volume solids. Best used on siding and can be used on trim.

*094/366 Fresh Start Alkyd Fast Dry Primer/Benjamin Moore Alkyd Primer:* Same product. One is a foundation to support solid latex siding and decking stains on bare wood and weathered but clean surfaces (366).
One is for supporting paint systems. (94) Fast Dry, short oil, 4 hour recoat. Less film build, tighter less flexible film, less DFT and volume solids. 3.7 WFT @ 500 sq ft per gallon, 1.7 DFT, 56% Volume Solids. A sealing primer as opposed to a bonding primer. Great for tannin bleed and other water soluable extractives. Goes under thinner film systems. Can be used under paint too, but has less film build and pentration. Does contain mildewcides. In some markets, the OTC/VOC laws have eliminated these products, or are only available in quarts. Great for siding or trim.

Let me know if that helps or if you need explanation for any other primers.


----------

