# MDF sealer ?



## Blister (25 Jun 2012)

I have in the past tried to paint MDF and as you know it just sucks in the paint 

So what does everyone use as a sealer before priming / painting ?

Thanks


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## mailee (25 Jun 2012)

I use Morrells ac primer for my MDF jobs. I always use MRMDF and give the edges one brush on coat of the primer and then after sanding give them two coats sprayed on when I prime the lot. The drawback is that it is only available in 5 ltr cans at around £35. Someone recommended a product named Zinnser bin for brushing on to seal the edges which is available in smaller amounts but I haven't tried it yet. HTH.


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## Blister (25 Jun 2012)

Thanks for that 

Cheers


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## Phil Pascoe (25 Jun 2012)

Anyone tried using diluted good quality p.v.a.? - I haven't, but it's only just occurred to me.


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## mailee (25 Jun 2012)

yes Phil, I tried it a few years ago. it does work but is a right PITA to sand down. I found the Morrells primer the best so far and I have tried a few I can tell you. Sanding sealer works well but the spirit based one takes longer to dry and doesn't sand as easily. :wink:


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## MattMoore (25 Jun 2012)

what about iron on edging ? I've always used a beech or maple veneer edging for any seen edges. might take a little longer but a much nicer job I think

Sent from my Desire HD using Tapatalk 2


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## deserter (25 Jun 2012)

+1 for edging I use plain white as its cheaper than the timber edgings and it works great.


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## mailee (26 Jun 2012)

That is ok if it's a flat edge but if it's a moulded one?


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## SeanJ (26 Jun 2012)

phil.p":15sxp2dd said:


> Anyone tried using diluted good quality p.v.a.? - I haven't, but it's only just occurred to me.



I'm guessing you maybe mean edges of MDF as the face sides finish pretty good with primer? Choking with primer is Ok but i'm not happy with the extra work and material it can take. i do my'n with pva diluted 2 pva to 1 part water and it's pretty quick if your well organised. I deal with this every week finishing joiners and fitters work and have tried a few methods. 
I find the best way is to cut up a small bit of sponge, (about the size of a block of butter), soak it in your pva/water bath and gently drag down your edges - wiping any runs with a rag, leave to dry for a few hours, gently paper and repeat once more. 2 goes of this means that when you hit it with a primer there are virtually no dry edges and the piece can move along at the same rate as a whole, at most you should only need an extra pass or 2 with the primer down the edges for good measure. I've yet to better this way of doing it and the results are good - and of course it's very cheap.  

Sean


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## Bradshaw Joinery (3 Jul 2012)

+1 for the 2-1 pva, 

tried this today, and the first spray coat after a very quick application of pva and a light rub down, produced a very good finish.


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## Saxwood (3 Jul 2012)

PVA :wink:


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## SeanJ (4 Jul 2012)

Bradshaw Joinery":2hqowuai said:


> +1 for the 2-1 pva,
> 
> tried this today, and the first spray coat after a very quick application of pva and a light rub down, produced a very good finish.




One other worthwhile tip for sealing inside panel edges (eg: shaker style doors) is to put the mix in a squeezy bottle with a narrow squirt tip, then in one go draw a thin line along the inside (pre sanded) edge, keep the line as thin as poss' leaving the final inch into the corner dry, then run your finger along the ledge to ensure its spread evenly, then wipe clean any residue with a rag, the sponge doesn't cut it much with inside angles or is messy at best, the dry corners get fed with any excess when you spread out your mixture. Again 2 coats and a bit of fine paper over it before priming gives me great results and saves time.  

Sean


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