# Interesting cedar and mill glaze article.



## DeanV (Apr 18, 2007)

http://www.wrcla.org/installation_and_finishing/finishing_other_projects/surface_prep.htm

This challenges some conventional wisdom.


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## kdpaint (Aug 14, 2010)

Great article. I love it when bad science/contractor legends are debunked. Kinda like the guy who says dust on walls enhances adhesion....


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## bikerboy (Sep 16, 2007)

Here's an addendum:

http://www.wolman.com/pdf/reference/R_3_86.pdf


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## DeanV (Apr 18, 2007)

I think bikerboy's link is the original source for my link.


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## JoseyWales (Jan 8, 2011)

Interesting articles but a bit confusing to me.

One article says that "Western Red Cedar does not contain any sap or resins that can migrate to the surface."....The linked article below says to use a stain blocking oil based primer for red cedar...Why do you need a stain blocking primer when "Western Red Cedar does not contain any sap or resins that can migrate to the surface/"....Is it specifcally the "western" red cedar only that does not require a stain blocking primer?

Basically the second article says to prime new wood with an oil based stain blocking primer and topped with 2 coats of an acrylic paint...It says that oil based stains alone are too thin a coating and will eventually fail....It also says that acrylic stains alone shouldn't be used on new wood because they don't block the stains and tannins that will migrate to the surface.

Interesting that you should first wet the smooth cedar to relieve surface tension and thus prevent a raised grain in the future...They say to follow up the wetting with a good scuff sand with 50-80 grit sand paper {when dry}....Even 2 weeks without painting the new wood will degrade the surface because of UV damage...In other words it's always a good idea to scuff sand new wood before painting.

Also how can a painter guarantee his/her work if the other side of the new siding is NOT primed as per recommendation?


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## straight_lines (Oct 17, 2007)

The causes for failure I found most interesting. Earlywood latewood, grain raising and improper film build. Or the use of oil being bad, which I have been saying for years. Its just to brittle, and having acrylic underneath everything is the right way to go even if you must spot prime with oil.


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## jack pauhl (Nov 10, 2008)

If it were me wanting cedar I would use man made. Wouldn't think twice. 



This stuff is by a company called NuCedar Mills. I have trouble selling things I know won't last or require high maintenance. It's one of those things you are best bringing photos of cedar failing etc when meeting with HO so they are aware in advance. Especially if the cedar is already installed. 

I did a NC house back in 91 with BM solid oil straight over the cedar, front, back, all sides. It looked good 12 years later but faded. Houses in same neighborhood looked really bad within 4-5 years with unknown product from other painters. The model home looked the worst and still does today, now sold obviously. Poor people inherited a real problem buying that house. I should grab pics of both houses. You wouldn't believe the difference.

This fake stuff looks real.


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## DeanV (Apr 18, 2007)

straight_lines said:


> The causes for failure I found most interesting. Earlywood latewood, grain raising and improper film build. Or the use of oil being bad, which I have been saying for years. Its just to brittle, and having acrylic underneath everything is the right way to go even if you must spot prime with oil.


They still recommend oil for the first coat followed by acrylic. BM 094 or 366 followed by acrylic stain would be my choice, especially on rough side out. Standard NC process here is 2 coats solid oil.


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## straight_lines (Oct 17, 2007)

That seems backward to me Dean in terms of flex, but I do mostly repaints so there is at least one coat of oil already there in most cases.


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## JoseyWales (Jan 8, 2011)

Often times we painters don't have the opportunity to paint both sides of the boards...How can we guarantee our work in these instances?

I painted some old cedar siding 14 years ago that was in terrible condition..It had stains everywhere with cracks etc.....The woodpeckers created a lot of holes on that house..lol...I caullked them up,sprayed and back rolled a coat of oil based primer and topped it with 2 coats of an acrylic...Looks damn good ,even today!


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## jack pauhl (Nov 10, 2008)

This paint job is only a week old done by another contractor. You should see all the other pics I have from this job over cedar and they haven't moved in yet.

Not going to says whos product but the dull lame look should give it away, solid stain. Cedar on this job was primed all sides prior to install but they used the recommended primer for the product. This cedar went from truck to garage to get primed.


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## DeanV (Apr 18, 2007)

straight_lines said:


> The causes for failure I found most interesting. Earlywood latewood, grain raising and improper film build. Or the use of oil being bad, which I have been saying for years. Its just to brittle, and having acrylic underneath everything is the right way to go even if you must spot prime with oil.


I can see where you are coming from wanting acrylic across board. At this time I am still looking at oils as being better for locking down water soluble tannins, and these are not confined to knots or isolated areas in the cedar. I also think that oils still penetrate the raw wood better. I am hoping some of these new hybrid primers may change the equation, but the water as solvent can still activate the tannins, IMHO.


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