Trade paint supplier - given right/wrong advice????

[finishthehouse1day]

So confused. Trade paint supplier was horrified today when I wanted to buy oil based primer for project in mix of MDF and pine. She said I MUST use a water based acrylic primer as the oil based would make the MDF 'blow'.

But I'd read on kitchen maker forums that they recommend oil primers for MDF and MDF/timber mix, esp when hand painting!

Who's right?

I've used aluminium primer before on a timber/MDF project autumn 2014 as it sealed the knots on the pine and ensured a nice consistent finish across the two substrates. It hasn't 'blown' yet - does that mean it's OK after this amount of time?

My top coat will be traditional oil based eggshell (I bought up discontinued F&B - old formula) and it's in an area of high wear, needs to be tough.

 

[Robbie uk]

Utter Tosh !! Nothing wrong with oil based primer, I prefer it over water based paint any day.
Most of the people in trade shops have never worked in the trade !!

 

[finishthehouse1day]

Thanks Robbie. I thought it seemed odd but paint finishes seem to change every year and I'm a traditionalist - so wondered if I was missing something.

 

[finishthehouse1day]

So I went back to swap the water based primer for solvent based - supplier clearly thinks I'm barking - made a point of calling out to other customers, "anyone ever heard of using oil based paints on MDF?" She still insisted I should use acrylic primer and only then was it 'safe' to put an oil paint on top.

MDF and pine now all primed with aluminium primer and guess what? MDF hasn't blown! (And the cupboard I made in MDF and pine and painted the same way three years ago is still looking good.)

Since all these changes to paint formulae there seems to be a load of dodgy advice around.

 

[misterhelpful]

There is nothing wrong with using either type of primer. MDF isn't really that absorbent through it's surface when it comes to painting but more so on it's endgrain, unless subjected to excess moisture for a longer period. I'm not sure AWP would be my first choice to use, but if you have a combination of wood products to prime I suppose it would work.

The supplier is probably just used to selling water-based products for MDF, because they are much quicker and easier to use and most specific MDF primers are water-based. That said, there is no need for her to be rude to a customer, even if you had been making a mistake, although I suspect she was also trying to cover herself for any issues you did get. I'd either write a letter of complaint to the Queen...or just go back and show the supplier that the completed task that has turned out well.