Priming Slurry for Outdoor Porcelain

[tododo]

Hi - my neighbour mentioned that I need to prime the back of my 900x600 porcelain tile before I lay them

To be honest - I didnt know I had to do that....although I have done that on our slate patio in the past

Now Ive googled a bit - this looks like its essential step

I see some are making cement and SBR mix - is that sufficient or should I go and buy the bagged primer

Thanks

 

[Wayners]

Either will do
I'm buying a slurry bag for £20 and I mix what I need in small batches as I go.
I find a 2 inch paint brush works although I started with a mini roller

 

[matlob]

I've done SBR and Cement and all good. Just don't get ay of the tile face as it won't come off easily. And as above small batches as it goes off quick