Is Primer necessary before Paint or Wallpaper on MDF?

[Silvergirlsails]

I plan to use wallpaper on the walls and floors of Victoria’s Farmhouse. 

Do I need to use primer, or is one coat of flat white latex paint on the MDF enough before wallpapering?

This tutorial states no need for primer https://www.dollhouseworkshop.net/RGT/1065/Painting.html but I see that many do indeed use a primer. 

If I used primer, about how much primer would I need for the exterior as well as the interior walls, ceilings and floors?

In your opinion, which primer works well for  RGT dollhouses?
 

Thanks!

[havanaholly]

Any wood product that contains acids among the chemicals used to treat/ manufacture it needs primer, IMHO.  I prime with flat white interior latex paint; I have also primed with gesso. One coat of primer throughout you could probably get away with a pint.

[Silvergirlsails]

1 hour ago, havanaholly said:

Any wood product that contains acids among the chemicals used to treat/ manufacture it needs primer, IMHO.  I prime with flat white interior latex paint; I have also primed with gesso. One coat of primer throughout you could probably get away with a pint.

Good to know I can indeed use a coat of paint as my primer. He does use interior latex paint as a primer in the tutorial, (but he uses semi-gloss which I didn't think would be the best option under wallpaper). I just wanted to make sure it was fine to use paint instead of having to purchase an additional can of primer. Thank you!

[Medieval]

I do one coat of primer and sand it. I forget the grit. But it's medium. Then I do a second coat and sand it with finer grit. Then I add color or paper. Depending on how it dries I might put a second coat of color. I used 1.5 sample jars of semi gloss primer/paint in ultra white for exterior and same amount for interior in an eggshell white. I used it on the pierce dollhouse.

[jbnmini]

And I don't use a real heavy-handed coat of primer- enough to coat and seal.  You do not want to primer any surface that you want to eventually stain.

[Silvergirlsails]

Thank you all who replied--much appreciated!

[Silvergirlsails]

I contacted RGT for clarification and they do NOT recommend painting or priming before wallpapering.

“If you do paint, it will be necessary to sand off the paint for any glues to adhere.“

They recommend only priming/painting the surfaces that will ultimately be painted and not those which will be glued with wallpaper or veneer.

 

[havanaholly]

Wall[paper paste sticks wallpaper to primed walls, in my experience; I do use a flat-finish primer.  Papering unprimed walls allows the acids present in the wood to discolor the paper over time.

Edited July 13, 2020 by havanaholly

[Silvergirlsails]

32 minutes ago, havanaholly said:

Wall[paper paste sticks wallpaper to primed walls, in my experience; I do use a flat-finish primer.  Papering unprimed walls allows the acids present in the wood to discolor the paper over time.

I do value yours and everyone else's experiences here--it sounds like it may just be a matter of preference. I'm just pleased I don't have more sanding to do with the MDF.