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-   -   Primer Questions (http://www.houserepairtalk.com/f107/primer-questions-16819/)

Mel707 03-29-2012 08:40 AM

Primer Questions
 
How important is primer? Is two in one just as good?

I'm also seeing the spray plus primer. Can I use that for lighter jobs and touch ups?

sarahunderw00d 03-29-2012 09:14 AM

So much as changed in technology that it used to be important but not as much now. It helps improve the lifetime of paint and also it's cheaper to get it to a point of being able to paint if you are painting a dark wall with a light color.

Austin 03-30-2012 07:26 AM

I've used the two in one on some things but never the spray.

I like it. It seems to cover better.

imported_Workaholic 04-17-2012 02:13 PM

Depends on the surface. Raw wood should be primed with a true primer and then top coated. Walls for a color change do not typically need primer after a scuff sand. Some glossy surfaces will still require a primer after a scuff.

billhead1 06-09-2012 08:04 PM

Benjamin Moore claims their new Aura alkyd paints can be painted over darker colors in one coat; however, you must wait until the paint dries before you touch up if you miss a spot and it's absolutely critical to keep a wet edge. Practice with this on a piece of scrap substrate before you attempt to paint any interior or exterior surface if you are unfamiliar with the paint's drying characteristics. A stiffer brush is also recommended to reduce the number of brush strokes required to obtain the proper spread & thickness.

Since primers consist primarily of resins and a much lower solids content than paint, they are typically less viscous (thinner) and more spreadable without the requirements of keeping a wet edge. Their lower viscosity helps them penetrate microcracks better, so you will get better protection from a primer's ability to penetrate smaller openings in the substrate. This is a bigger issue with weathered exterior substrates, so a dedicated primer is probably the way to go for repainting exterior surfaces if it is determined that a primer is needed for repairs that penetrate to bare wood, for stain blocking, to improve bonding, or to extend the life of the topcoat(s). Most manufacturers recommend 2 topcoats regardless of whether you use a dedicated primer coat, especially for exterior surfaces exposed to the elements (temperature, humidity, dew point, freeze/thaw conditons) & UV. The exception is interior surfaces, which seldom have surface irregularities, have stable temperature & humidity conditions, and are not exposed to UV.

chrisn 06-10-2012 03:02 AM

http://buildipedia.com/at-home/painting/paint-vs-primer

chrisn 06-10-2012 03:04 AM

Quote:

Originally Posted by Sand&Scrape (Post 1093)
Benjamin Moore claims their new Aura alkyd paints can be painted over darker colors in one coat; however, you must wait until the paint dries before you touch up if you miss a spot and it's absolutely critical to keep a wet edge. Practice with this on a piece of scrap substrate before you attempt to paint any interior or exterior surface if you are unfamiliar with the paint's drying characteristics. A stiffer brush is also recommended to reduce the number of brush strokes required to obtain the proper spread & thickness.

Since primers consist primarily of resins and a much lower solids content than paint, they are typically less viscous (thinner) and more spreadable without the requirements of keeping a wet edge. Their lower viscosity helps them penetrate microcracks better, so you will get better protection from a primer's ability to penetrate smaller openings in the substrate. This is a bigger issue with weathered exterior substrates, so a dedicated primer is probably the way to go for repainting exterior surfaces if it is determined that a primer is needed for repairs that penetrate to bare wood, for stain blocking, to improve bonding, or to extend the life of the topcoat(s). Most manufacturers recommend 2 topcoats regardless of whether you use a dedicated primer coat, especially for exterior surfaces exposed to the elements (temperature, humidity, dew point, freeze/thaw conditons) & UV. The exception is interior surfaces, which seldom have surface irregularities, have stable temperature & humidity conditions, and are not exposed to UV.



say what?:confused:

Schmidt & Co. 06-10-2012 06:48 PM

Quote:

Originally Posted by Workaholic (Post 267)
Depends on the surface. Raw wood should be primed with a true primer and then top coated. Walls for a color change do not typically need primer after a scuff sand. Some glossy surfaces will still require a primer after a scuff.

I have to agree with Work. Also, primers are usually less expensive than paint. Why prime with paint and primer in one?


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