# Mdf primer



## DeanV (Apr 18, 2007)

We have always used a wb primer for mdf. It works fine on regular trim.

On doors and unprimed sheets used for cabinet part, pillars, etc it often swells up texture on the face of the mdf.

Is there a wb primer that absolutely will not do this?

Otherwise I am thinking shellac or cover stain will be the way to go. I do not want to go back to solvent,but am considering it at this point.


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## CliffK (Dec 21, 2010)

DeanV said:


> We have always used a wb primer for mdf. It works fine on regular trim.
> 
> On doors and unprimed sheets used for cabinet part, pillars, etc it often swells up texture on the face of the mdf.
> 
> ...


 I think you answered your own question Dean. I've tried the wbs as well and always end up back to the "'ol faithfuls", shellac and solvent based when it really matters.


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## Precision-TBay (Jun 1, 2011)

I always use coverstain or BIN on mdf, everything else seems to cause problems


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## JoseyWales (Jan 8, 2011)

Insl-x STIX..It's urethane enhanced,sands easily and sticks to anything.

That said,I can't guarantee you that your problem will be solved as I just haven't sprayed enough un-primed mdf to give you a definitive answer...But that would be my first choice...In fact I have some MDF shelves and base to do next week in a bathroom that is not primed.


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## BreatheEasyHP (Apr 24, 2011)

I'm planning on testing Zinnser Smart Prime for this when I have the chance. It acts different than other WB in other ways, so it's worth a shot.


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## billy the kid (Jan 22, 2011)

xim makes a bonding agent the sands down smooth and drys quick,it wb and is really good for adhesion


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## Workaholic (Apr 17, 2007)

For preprimed WB works well for raw mdf an oil based is best.


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## Schmidt & Co. (Nov 6, 2008)

I go the same route as Sean. Preprimed gets WB and raw gets oil. But if I remember correctly, JP likes Guards on MDF. Going to test some on the next raw MDF I come across.


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## Bender (Aug 10, 2008)

Lacquer undercoater.


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## straight_lines (Oct 17, 2007)

Don't flame me until you have tried it please. Do an adhesion test and you will see for yourself. 

WB impervo applied directly to these MDF built ins, bare popular, and birch bead board. It will save you a coat, and the primer cost.


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## BC_Painter (Feb 14, 2010)

I've always used Cover stain.

An old dealer also told me if there was any kind of damage a WB would simply make it swell more and more, and need to be sanded and sanded, while oil always did the trick MUCH faster.

Not even a question for me anymore....


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## Ultimate (Mar 20, 2011)

Bender said:


> Lacquer undercoater.


I haven't done laquer primer on trim in a long long time. Love the way it sands. LOVE IT.... Why did I stop doing that? Next chance I get.


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## Rcon (Nov 19, 2009)

Lacquer undercoater brother. Sands to a powder and won't swell the substrate. Stinky - yes. More expensive - depends on how you look at it. Does a better job - you bet.


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## Rcon (Nov 19, 2009)

Bender said:


> Lacquer undercoater.


Sh!t you beat me to it


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## jaz (Jun 20, 2009)

so does that mean laquer undercoat is ok for use under oil enamel. does is have to be a certain type. ??


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## DeanV (Apr 18, 2007)

I have worked with painters who used solvent lacquer undercoat as their primer but they were noticing health effects on the lungs even using respirators, seemed even worse than clear lacquer on the body. Not a fan of the way lacquer solvent gets absorbed through the skin either.

Lacquer solvent based stuff is out for me.


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## Rcon (Nov 19, 2009)

DeanV said:


> I have worked with painters who used solvent lacquer undercoat as their primer but they were noticing health effects on the lungs even using respirators, seemed even worse than clear lacquer on the body. Not a fan of the way lacquer solvent gets absorbed through the skin either.
> 
> Lacquer solvent based stuff is out for me.


Use fresh filters on your respirators and blue nitrile gloves when using the stuff. You could always use shellac as well, but it's still a solvent based material (alcohol).


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## straight_lines (Oct 17, 2007)

Do the WB lacquers perform well? I know Gabe mentioned them in that thread I linked above. 

I agree with Dean about solvent based coatings. I don't want the health problems that will come from using them for years. Not to mention the other dangers.


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## Rcon (Nov 19, 2009)

straight_lines said:


> Do the WB lacquers perform well? .


I was just about to suggest that acutually. Try MLC waterborne lacquer primer. Might be just the ticket you're looking for.


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