And to boot I have seen evidence of some of those primers being so chalky - that unless you had mechanically abraded it totally off the surface to begin with - you'll have problems if you had re-primed or not.
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That is very true. I personally do not care for the pre primed trim. I referr only to interior. There is the chalky factor and most of what I have worked with has a terrible finish...orange peel, globs and runs. So what;s the point if you are required to sand and reprime to get it ready?
Sage

 

Pre-prime = RE-prime for best results...

Factory primed materials are rarely "the best" primers...:whistling2:

The longer some materials sit around, getting dirty/dusty/moved around...the more the primer suffers; starting to chalk, gets too dried-out, & brittle, etc.

Soooo...you do yourself AND your reputation a service, by lightly sanding & de-dusting the "pre-primed" materials, and applying the correct NEW primer for the situation.

NOW you've got the ultimate "Base" for your 2 new topcoats of paint.

I've never understood the logic some people use...that a coat of primer will "magically eliminate" the need for the 2nd coat of paint...WTH...?!!?
Even if you're the world's best painter, 1 coat of paint is still ONLY ONE LAYER.
True "depth of finish" & durability comes from a 2-coat system.

I work at a fairly busy ACE/Ralph-Lauren/C2 Paint/Hardware center.
....we can't afford to give slipshod advice...like you sometimes hear @ "the boxes"...:jester:

Faron

 

There was talk on this here:
http://www.painttalk.com/f6/priming-preprimed-doors-casings-drywall-primer-3879/

Faron... it can be done. Gripper shot generously over pre-primed mdf or finger-jointed pine or poplar then a thick coat of ICI Ultra-Hide Semi-Gloss leaves an amazing 2 coat solution. For reasons unknown to me, I found Ultra-Hide Semi-Gloss as inexpensive as it is leaves a nice solid sheen for what it is - 1 primer, 1 finish.

I have to add this disclaimer: No other combination of primer with no other finish will produce the results I’m talking about. Most any primer will kill anything of sheen you put over it. Other paints I tested over Gripper despite higher costs did not produce near as nice results. I’m not saying this is the best solution but it can fool a trained eye for sure.

Anyway, the focus of a new primer over an old or factory primer is mainly for efficiency related issues in a production environment. The new coat of primer must meet certain objectives such as, better solid sheen on the top coat, better, faster, cleaner filling of nail holes, better easier sanding, better solid fill for the surface to hide minor imperfections etc.

Filling holes over pre-primed trim sucks for lack of a better word. A new fresh light abrasive primer will break-off putty easy and quickly and wont dry out the putty like factory primer does.

Its important to know the capabilities of primer because a primer can backfire on you leaving you with EXACTLY the same result or worse.

 

Faron... it can be done.

CAN be done and doing the right thing are two different subjects.

 

Hmmm...subtlety there!

JP,
I'm a little leery of the "one heavy topcoat" system...
It typically won't "cure through" as well.
If it's all you're gettin' paid to do, that's one thing.

Otherwise, Chrisn's quote hits the right balance here I think..."CAN be done vs. doing the right thing"...:notworthy:

Faron

 

JP,
I'm a little leery of the "one heavy topcoat" system...
It typically won't "cure through" as well.
If it's all you're gettin' paid to do, that's one thing.

Otherwise, Chrisn's quote hits the right balance here I think..."CAN be done vs. doing the right thing"...:notworthy:

Faron

Dont get me wrong, I completely agree, but I think we all know things get done that way more often than the right way. Talking to paint reps always confirm this.

Think about this challenge... Who in their right mind would take brand new pre-primed trim and re-shoot it all with a primer and then shoot two top coats for the same price another painter gets for one coat over pre-primed?

In my situation, I simply can’t do that kind of work and leave it, so re-priming trim had to have some time saving advantages that not only produced a quality finish but got me out of the houses faster.

For example, I can spray 3 coats on the trim in a house in less time than I can fill nail holes on the same house had I not re-primed it. I re-prime mainly because it saves me time filling holes and I get a flush fill vs filling directly over preprimed trim using putty which has challenges of its own. I save time filling, spend more on materials (primer and finish) plus the time it takes to shoot it 3 times and I'm still out of the house faster than the other painter for the same builder. We all know prep is a time killer so for me – prep is the area I focus the most to cut back both with product and process.

Another advantage of re-priming is time saved caulking over a fresh coat of non-absorbent-light abrasion primer vs. super absorbent-smooth-dusty-like factory primer. How many of you have caulked over pre-primed trim only to have the caulk fall out or not stick in areas. You start gunning a line and notice the caulk isn't adhering.

I'm working in my spare time to publish the details of the same house done with two different painters, two different methods and why repriming saves time and what issues and time challenges another painter faces by not repriming. I find it interesting because ultimately the house has to look good finished.

 

Hmmm...subtlety there!

 

Pre Primed wood is done to create dimensional stability of wood that has been dried down to a moisture content of 6% or less. Primers keep moisture out, and keep wood from moving or absorbing moisture. It is not designed to eliminate a preparation or primer step. These coatings are usually poor quality with minimal film build or excessive film build. All pre-primed woods should be re-primed as recommended by the siding or trim company. Primers are designed to be top-coated, and will degrade, chalk, and become brittle within 30 days. This thread has some very good information. Usually I find that most builders and painting contractors are unaware of this, but are very glad to take the extra preparation step to insure quality and reputation.

 

Windsor One

all the cedar dimensional trim and casings I've seen need a proper coat of primer after purchase...I think the metal door primer is good to go if you check for anything rubbed off from contact in transit... pre-primed interior poplar 1/4 round is also good to go, as is MDF...

I don't know if you can get it in your area but google windsor one, I swear by the stuff, it is good to go right out the yard and the straightest stock this side of MDF...

I keep a rattle can of cover stain in my back pocket and go thru all my stock, one or two pieces will have some rub or abrasion from shipping, I touch those up and put them at the end of the pile, and I'm shooting up trim 10 mins after getting to the jobsite

and man that stuff is sooooo straight and square. one time in a pinch I made a T square out of two 1x4s and used it to cut a few sheets of drywall!
fyi, it's finger-jointed pine int. ext. stock, dimensional, crown, plinth, brick & chair etc....

jordan

 

Factory primed material is good because it has been applied and prevented the wood from absorbing and expelling moisture since it left the factory. At the factory the wood has the correct moisture content when primed. I just think of factory primed as a sealer that we do reccomend to our clients and that it will help for the long haul but we will still need to apply another coat onsite. One big problem with factory primed material is that the coating has been put on more than 30 days ago and that alone means reprime. Plus there are all kinds of hand oils and other hard to see stuff that is on there too. So I vote for factory prime on all materials since it is usally not much more in cost for the benifits. Most important we tell clients it does not save any money on the cost of painting and that in some cases(Interior finsihes on casings etc) we may need to do additonal sanding before we can start to prime. This additional time can not be anticipated and is not included in the bid.

 

Hmm interesting, well I hardly reprime doors or casings, sand yes, reprime no. I do prime the beveled edge as most come raw as they are machined after priming, and I touchup the primer where needed. I've never had a paint failure as a result. Also, I disagree about primer being any kind of a moisture barrier... it's not.
Cheers

 

NACE says it all. Just meant to get the wood to where its going to end up, not to aid in paint adhesion or the like