# Priming MDF



## MIZZOU (Nov 18, 2012)

I've always just sprayed mdf and only back brushed the rough cut ends. New GC says all surfaces of mdf have to be back brushed or rolled. As smooth as it is a really don't see the point and pretty much told the guy off. Am I missing something here? Back brush/roll smooth mdf?


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## DeanV (Apr 18, 2007)

Only reason to do that is if he wants brushmarks or stipple for some reason. No other reason I can think of.


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## ridesarize (Jun 19, 2012)

You are right Mizzou.

MDF does not consist of wood cells that have actual cavities like real wood. MDF consists of glue.


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## journeymanPainter (Feb 26, 2014)

We use trim rollers quite often. Most of the mdf that comes our way is pre-primed anyways


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## ridesarize (Jun 19, 2012)

Btw, if anyone thinks that pre-primed MDF is smooth (paint ready)(like one of our contractors) is wrong. Take a 100W drop light and side light that stuff and you will see TONS of imperfections and orange peel. That does not give you a high end paint job. Pre-primed MDF should be sanded nicely (before or after prep is laid down), and primed again, (then sanded again).


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## journeymanPainter (Feb 26, 2014)

ridesarize said:


> Btw, if anyone thinks that pre-primed MDF is smooth (paint ready)(like one of our contractors) is wrong. Take a 100W drop light and side light that stuff and you will see TONS of imperfections and orange peel. That does not give you a high end paint job. Pre-primed MDF should be sanded nicely (before or after prep is laid down), and primed again, (then sanded again).


We've been giving our mdf a good sand, then re priming them with X-pert primer, then our finish. You'd be surprised how much better the finish is. Doors and trim.


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## ridesarize (Jun 19, 2012)

journeymanPainter said:


> We've been giving our mdf a good sand, then re priming them with X-pert primer, then our finish. You'd be surprised how much better the finish is. Doors and trim.


Well that's good. I'm not surprised it turns out nicer than painting over factory primer. I always put primer down and sand before finish is applied.

Actually I pre sand nail holes in MDF to take the swell spots away and sand primer some, vacuum out holes and trim, fill, sand, clean, caulk, clean house, prime, sand, clean, check imperfections or holes again with spot putty, sand, clean, and finish.


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## MIZZOU (Nov 18, 2012)

New question...

I've always used oil primer with mdf. Long story short, bad flooring contractor butchered the tile floor, was fired, and pushed everything back leaving us only 3 days to finish. Anyone ever used anything other than oil and had decent results? I've heard a latex primer is not a good idea for mdf, but we're in a pitch with the schedule. 

Here's the "contractors" work. 40 years experience lol 😁


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## ridesarize (Jun 19, 2012)

Several water based primers will work. Even though they say wb swells up the mdf, I have used it a limited amount but had great results with very easy sanding. One primer that would be unxepected to work so good, but it works good, is Bullseye all purpose, with the large bulleye covering the side of the can. It sprays very finely, and it almost doesn't need to be sanded what so ever, but sands easy. Very affordable too.


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## slinger58 (Feb 11, 2013)

We've had great results with latex primer on MDF. Lately been using Farrell-Calhoun #699 undercoater. Sands good.


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## MIZZOU (Nov 18, 2012)

ridesarize said:


> Even though they say wb swells up the mdf



That's what I've heard and what has me sketched out. I thought about maybe brushing the cut ends with bin or something and spraying the rest with my go to 123.


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## straight_lines (Oct 17, 2007)

If I were you I would find another contractor. I guarantee there will be a non payment issue if he is producing work like those pics. No way an owner will pay for that crap. 

Frack me that tile work is bad.


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## MIZZOU (Nov 18, 2012)

straight_lines said:


> If I were you I would find another contractor. I guarantee there will be a non payment issue if he is producing work like those pics. No way an owner will pay for that crap.
> 
> Frack me that tile work is bad.



The good and bad news is that the HO is supplying the contractors. Good because I always prefer NC when the HO is writing the checks. Bad because the HO is the reason we're in a bind now due to the tile guy. Tile guy was on a contractors list at menards 😁.


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## stelzerpaintinginc. (May 9, 2012)

Looks like the tile guy prolly used gummy bears for spacers. 


Stelzer Painting Inc.


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## Wildbill7145 (Apr 30, 2014)

No wonder they got fired. That's possibly the worst tile work I've ever seen! I'm just going to assume they pulled that up? What a nightmare that would be.


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## journeymanPainter (Feb 26, 2014)

MIZZOU said:


> That's what I've heard and what has me sketched out. I thought about maybe brushing the cut ends with bin or something and spraying the rest with my go to 123.


Just about any good acrylic primer should work, but If you really want to save some time spray all your trim in Pitt Tech. We've done this on a few jobs now, and It dries so fast. Spray, fine tune, and spray again in one day. 

We're still not 100% sold on It yet, but it's pretty darn good


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## Huntercoatings (Aug 16, 2013)

The bulls eye pimer should work fine, just hit the rough cut ends with kilz in a rattle can.


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## MIZZOU (Nov 18, 2012)

Wildbill7145 said:


> No wonder they got fired. That's possibly the worst tile work I've ever seen! I'm just going to assume they pulled that up? What a nightmare that would be.



Oh yeah, all ripped up and outta there. What an eff story, worst I've ever seen too. Wonder why his bid was 1/3 as much as the next guys?


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