# priming trim in NC



## Xmark (Apr 15, 2012)

I've read quite a few threads about doing NC.most talk about a prime coat after filling.aren't your mdf doors and wood trim already pre-primed? i've never seen a carpenter put up trim that was raw wood.do you guys shoot a coat of primer after filling even if the trim package was pre-primed? i could see the benefits of sealing the filler and evening out everything.after the prime i would sand, caulk then shoot first top-coat,sand,tack, then 2nd finish coat.also,no way I would shoot another coat of primer on pre-primed mdf doors.


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## Oden (Feb 8, 2012)

I don't prime pre-primed wood and doors. Waste of time and material.


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## ExcelPaintingCo (Apr 16, 2011)

I will usually prime pre-primed mdf doors and trim. Although most of the millwork and doors we have been doing lately have been raw unprimed poplar and fir/hemlock. 

I like to prime to build up a nice undercoat that can be knocked down to a super smooth finish without blowing through the primer. Then two top-coats and your sitting pretty.


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## DeanV (Apr 18, 2007)

The factory mdf primer is pretty poor. If you read up,specs on that type of primer, they often say to prime over it becuase it is really designed only to protect the trim during manufacturing and distribution. Also, it often is rough enough that you need to sand it down good in places to bare mdf. Door edges are always junk and need to be primed. Same goes for door jambs and any cut mdf edges. Plenty of reasons to throw down a coat of primer,


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## ExcelPaintingCo (Apr 16, 2011)

How about that, two completely opposite answers at exactly the same time! 

I will agree with Oden, that priming isn't always necessary, especially if it's not in the budget. But if you can sell it, why not? The extra coat and prep will usually result in a superior finish, no?


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## Xmark (Apr 15, 2012)

DeanV said:


> The factory mdf primer is pretty poor. If you read up,specs on that type of primer, they often say to prime over it becuase it is really designed only to protect the trim during manufacturing and distribution. Also, it often is rough enough that you need to sand it down good in places to bare mdf. Door edges are always junk and need to be primed. Same goes for door jambs and any cut mdf edges. Plenty of reasons to throw down a coat of primer,


I did notice one time that the newly primed doors (over lacquer) didn't have as many runs as the factory primed doors..I thought it was just a coincidence.


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## Xmark (Apr 15, 2012)

ExcelPaintingCo said:


> How about that, two completely opposite answers at exactly the same time!
> 
> I will agree with Oden, that priming isn't always necessary, especially if it's not in the budget. But if you can sell it, why not? The extra coat and prep will usually result in a superior finish, no?


It makes sense.you get the filler sealed with primer and the added sanding would make it a smoother finish.


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## jack pauhl (Nov 10, 2008)

Started a job today with all bare poplar trim. Doors and jambs shipped pre-primed. I'm not using primer though.


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## NEPS.US (Feb 6, 2008)

It also depends on the quality of your finishes. We prefer to re-prime everything giving the trim something to sand to give us the desired finish we want. Some primers work well as fillers for small viods and are meant to be sanded for optimum finishes.


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## StripandCaulk (Dec 30, 2011)

jack pauhl said:


> Started a job today with all bare poplar trim. Doors and jambs shipped pre-primed. I'm not using primer though.


Behr is a 2 in 1. But the primer isnt effective at all. I suggest using a primer on anything preprimed. I agree with NEPS and Dean


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## ReNt A PaInTeR (Dec 28, 2008)

Here we re-prime all trim with lacquer undercoater, usually 2 coats and 2 of oil base enamel.


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## NEPS.US (Feb 6, 2008)

StripandCaulk said:


> you would create a weak link.


Around here that is called a mudbone.


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## ReNt A PaInTeR (Dec 28, 2008)

who uses lacquer undercoater ??


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## jack pauhl (Nov 10, 2008)

StripandCaulk said:


> Behr is a 2 in 1. But the primer isnt effective at all. I suggest using a primer on anything preprimed. I agree with NEPS and Dean


Share with me specifically what you would achieve by repriming pre-primed mdf. After all, it is an additional step so I would hope it is to do something.

No primer, no paint will ever stop the easy to remove factory primers on mdf and finger jointed jamb wood from coming off. Those factory primers are barely on there. The 2nd photo below chipped when the door slammed. Others you brush against the jamb edges and they chip off.

So, if the weakest link is the factory primer, just how exactly is a new coat of primer going to magically make it more "effective"?


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## jack pauhl (Nov 10, 2008)

I'll add, when we re-prime mdf factory primer it is to specifically save time on "filling" nail holes and nothing else using a water base nail putty. 

Other patch fillers do not require re-priming but some mdf is so soft, dull and absorbent that a re-prime is helpful to minimize flashing with certain vinyl fillers typically crucial to a 2 step finish---one prime, one finish. Not an issue with two finish.

There are so many variables with painting mdf its ridiculous. I just named a couple. So in a 3 step process like 1 prime, 2 finish. The prime coat is only to allow for fast filling with a putty. This produces a full flush fill without sanding any holes. So in the time it takes one guy to lay a patch, I can lay a filler and be done. One hour with a gallon of primer saves tons of labor on holes.

Thats the only reason I would re-prime. Gardz won't even make that factory primer stick better.


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## StripandCaulk (Dec 30, 2011)

jack pauhl said:


> Share with me specifically what you would achieve by repriming pre-primed mdf. After all, it is an additional step so I would hope it is to do something.
> 
> No primer, no paint will ever stop the easy to remove factory primers on mdf and finger jointed jamb wood from coming off. Those factory primers are barely on there. The 2nd photo below chipped when the door slammed. Others you brush against the jamb edges and they chip off.
> 
> So, if the weakest link is the factory primer, just how exactly is a new coat of primer going to magically make it more "effective"?


JP mdf needs to be completely sealed off with a prime coat to stop bleed through/flashing in the finish coats. The primer they use is also used more to protect it durring shipping/transport than to actually seal off and give you a lasting finish. It also comes very rough, so for best results you want to sand it down to get a smooth finish. Adding another prime coat gives the assurance that it is compeltey sealed with no bleed through, gives you a surface to sand down and also produces a better looking finish.


Alot of pre primed stuff now is there to actually hide the fingerjoints and give them extra stegnth. On cedar preprimed clapboards if you dont seal the buttjoints after making a cut you can actually void the manufacturers warranty. The pre primed stuff is also notoriously bad for bleed though.


Question for you. How do you handle the nail holes and joints after the trim is installed? that puntures through the factory primer coat? if its done professionaly alot of joints are sanded on installation.


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## robladd (Nov 22, 2010)

Pre-primed MDF is to preserve the materials ( substrates ) during shipping and installation.

That's all it was EVER intended to do!


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## StripandCaulk (Dec 30, 2011)

robladd said:


> Pre-primed MDF is to preserve the materials ( substrates ) during shipping and installation.
> 
> That's all it was EVER intended to do!


Rob, thank you:thumbsup:


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## jack pauhl (Nov 10, 2008)

StripandCaulk said:


> Question for you. How do you handle the nail holes and joints after the trim is installed? that puntures through the factory primer coat? if its done professionaly alot of joints are sanded on installation.


I'm not sure what you are talking about with bleed through. Must be a paint related issue. Certainly never experience any bleed through with either of the BEHR products. Are you talking about some sort of tannin type bleed? 

Are you talking about what the trim looks like when you arrive on the job in regards to joints? If we see any factory joints open up or start to curl up, we sand them smooth and watch them come back later after we stick a beautiful finish on it. Sometimes I honestly feel the nicer the finish, the more imperfections in the mdf are revealed. Some of that mdf is pointless to try to make good. 

What about nails hole puncturing through? Not sure what you mean on that.

We have some with a tight hard and smooth factory primer which almost looks like an eggshell finish and other are like the cheapest flat wall paint you could find. It varies so much around here.


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## Xmark (Apr 15, 2012)

jack pauhl said:


> I'm not sure what you are talking about with bleed through. Must be a paint related issue. Certainly never experience any bleed through with either of the BEHR products. Are you talking about some sort of tannin type bleed?
> 
> Are you talking about what the trim looks like when you arrive on the job in regards to joints? If we see any factory joints open up or start to curl up, we sand them smooth and watch them come back later after we stick a beautiful finish on it. Sometimes I honestly feel the nicer the finish, the more imperfections in the mdf are revealed. Some of that mdf is pointless to try to make good.
> 
> ...


I have to agree with that point.i just finished a job that had very high quality primer on it and it sanded nicely without rubbing off.other primers are soft and can be rubbed off with a rag seemingly.


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## StripandCaulk (Dec 30, 2011)

jack pauhl said:


> I'm not sure what you are talking about with bleed through. Must be a paint related issue. Certainly never experience any bleed through with either of the BEHR products. Are you talking about some sort of tannin type bleed?
> 
> Are you talking about what the trim looks like when you arrive on the job in regards to joints? If we see any factory joints open up or start to curl up, we sand them smooth and watch them come back later after we stick a beautiful finish on it. Sometimes I honestly feel the nicer the finish, the more imperfections in the mdf are revealed. Some of that mdf is pointless to try to make good.
> 
> ...


JP what is your current BEHR finishing system? ULTRA? How do you like killz2? 

Nail holes punturing through, when they do the install it will break through the primer coat as the nail penetrates through the surface. Even if they they are using pin nails, there will still be a bit exposed. 

Have you ever tried to paint raw mdf with latex finish paint? 

Btw, who is your behr rep right now?


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## Xmark (Apr 15, 2012)

StripandCaulk said:


> JP what is your current BEHR finishing system? ULTRA? How do you like killz2?
> 
> Nail holes punturing through, when they do the install it will break through the primer coat as the nail penetrates through the surface. Even if they they are using pin nails, there will still be a bit exposed.
> 
> ...


no need to get a behr rep.the little old lady down the street pays the same as painting contractors.:yes:


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## jack pauhl (Nov 10, 2008)

I need to stop getting involved on these never ending mdf threads. The variables are too great and so many things affect the outcome. 

Nail holes can be a HUGE production killer when using patch fillers over factory MDF. They can be difficult to sand, they can require additional filling after sanding, they can flash, they can be slow to apply, they can take too long to dry hard enough to sand fast.

Here is how I came up with a solution to allow for filling with my favorite water base putty.... I found that the putty (specifically one brand) not any other brand snaps off flush over a certain type of surface similar to flat wall paint if you sprayed it on something smooth. It takes no more than 2 seconds on a hole. Time yourself next time you guys use patch fillers. Time the fill, time the sand, time the re-prime if any, time the 2nd coat you need to hide the flash and come up with a total. It's far greater than putty.

I will selectively use patch fillers under BEHR on select areas. For example, the job I am on today has all bare poplar so I filled all nail holes on baseboard with a patch filler because I already plan on sanding the poplar with the RO before painting it. Again, applying patch takes 2 seconds per hole. No time lost.

If I choose to re-prime factory primer it would be to apply a "desired" surface over the factory primer I know the putty works great over. That being the extreme opposite of trying to fill PVC with putty.

The primer in that case would be applied first before filling, then fill, then spray one coat of ULTRA or Premium Plus, then sand the finish tight and smooth with 240 abranet, then spray a final coat of paint. I do not pre-sand MDF unless an area needs addressed. I do shop vac it first to remove dust and glue strands. Glue strands will not allow 1 or 2 second filling.

The down and dirty method is to know which patch fillers won't flash under one coat of your preferred paint. This would be patch, sand, paint, done. Typically lightweights works best in that scenario such as Fast n Final, Sherwin Williams Shrinkfree, Zinsser Ready patch lite. If the patch flashes, you're screwed so its good to sample the patch filler first especially when knifing it.


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## jack pauhl (Nov 10, 2008)

StripandCaulk said:


> JP what is your current BEHR finishing system? ULTRA? How do you like killz2?
> 
> Nail holes punturing through, when they do the install it will break through the primer coat as the nail penetrates through the surface. Even if they they are using pin nails, there will still be a bit exposed.
> 
> ...


Big D out of Elyria. Denando posts on my google+

The job I am on this week is all flat stock poplar trim. I'll have pics later, I am applying Premium Plus direct to wood and doing a fine finish on it. KILZ2 is not in the current product line-up but KILZ PRO-X 110 is. 

Still not following you on the protruding nail holes.


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## robladd (Nov 22, 2010)

The only addressing is those BS pics you put up.

JP get REAL. No professional painter on this forum is going to take your advice and purchase
BEHR!


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## jack pauhl (Nov 10, 2008)

StripandCaulk, thats cool you post on paint talk. I think you are the first paint rep i've seen do that. :thumbsup: I talk with Denando every day, he's been great and his expertise in dealing with mold is top notch. Its great to have access to his knowledge and I don't let him get too bored.


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## jack pauhl (Nov 10, 2008)

robladd said:


> The only addressing is those BS pics you put up.
> 
> JP get REAL. No professional painter on this forum is going to take your advice and purchase
> BEHR!


What's BS about the pics? Not clear enough, videos not good enough? 

Sound exactly like another paint contractor today who put 4 coats on a bath with another product. I told him, "never more than two". He had to eat that extra paint and extra labor. 

Which paints would a professional painter use?


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## robladd (Nov 22, 2010)

What JP ? Have I been Shuned? Are really calling S&P a rep?

Your the only rep HERE.


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## jack pauhl (Nov 10, 2008)

robladd said:


> What JP ? Have I been Shuned? Are really calling S&P a rep?
> 
> Your the only rep HERE.


I want to know which paints a pro uses


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## robladd (Nov 22, 2010)

jack pauhl said:


> What's BS about the pics? Not clear enough, videos not good enough?
> 
> Sound exactly like another paint contractor today who put 4 coats on a bath with another product. I told him, "never more than two". He had to eat that extra paint and extra labor.
> 
> Which paints would a professional painter use?


You showed total failure in what you think is your advantage. Trust me pal showing all the crap that you put here on PT promoting your product is total BS!


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## robladd (Nov 22, 2010)

jack pauhl said:


> I want to know which paints a pro uses


BM, SW and Glidden.


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## jack pauhl (Nov 10, 2008)

robladd said:


> BM, SW and Glidden.


BM, SW and Glidden. I see.


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## Workaholic (Apr 17, 2007)

I see a mix of pre-primed and raw wood and mdf. I reprime the pre-primed stuff.


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## StripandCaulk (Dec 30, 2011)

Workaholic said:


> I see a mix of pre-primed and raw wood and mdf. I reprime the pre-primed stuff.


That looks like a nice project sean. What are you using to prime? coverstain?


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## Workaholic (Apr 17, 2007)

I use a lot of Seal Grip by PPG and I use Cover Stain.

That job is done and done, I will see if I can find the after pics they must be on another comp. I just used it as an example of what I see around here.


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## PatsPainting (Mar 4, 2010)

Personally I think JP does some great work and I enjoy seeing his pictures. He uses behr, so what... I don't use it, mainly because of the Home Depot factor. I do know it blows Dunn Edwards away. Had a chance to test the two - DE on one room and Behr on another and it was no contest. Behr was way better in coverage and the finish looked nicer. Dunn Edwards is mostly used by the pros. I guess cuz it cheap and chit.

Pat


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## Oden (Feb 8, 2012)

robladd said:


> What JP ? Have I been Shuned? Are really calling S&P a rep?
> 
> Your the only rep HERE.


Are you implying corporate influence?
No way! I don't believe it!

"Say it ain't so, Jack." "Say it ain't so."


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## Builtmany (Dec 5, 2009)

DeanV said:


> The factory mdf primer is pretty poor. If you read up,specs on that type of primer, they often say to prime over it becuase it is really designed only to protect the trim during manufacturing and distribution. Also, it often is rough enough that you need to sand it down good in places to bare mdf. Door edges are always junk and need to be primed. Same goes for door jambs and any cut mdf edges. Plenty of reasons to throw down a coat of primer,


We always apply a fresh coat of primer. IMO the primer they use is almost worthless.


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## jack pauhl (Nov 10, 2008)

Xmark said:


> I have to agree with that point.i just finished a job that had very high quality primer on it and it sanded nicely without rubbing off.other primers are soft and can be rubbed off with a rag seemingly.


Dulux Diamond 350 flat wall paint dripped on this factory pre-primed mdf and dissolved it almost instantly. The exact same thing occurs when you apply trim paint over it. This creates the extra drag.


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