Bal APD primer not doing its job on Marmox and Impey waterguard

[ahearsum]

My first big tiling job. It's a wet room and I'm at the stage where I have Marmox boards on floor and walls and an Impey former. I'm just about to put down the Impey Waterguard membrane and the instructions specify priming with the supplied Bal APD primer.
I tested the BAL primer inadvertently as I was doing some construction adhesive tests between back painted glass and marmox boards. (The winner incidentally was definitely CT1 by a big factor!). The Marmox primed with the BAL primer was much easier to wrench from the glass than an un primed Marmox board. This led me onto testing the Impey Waterguard membrane on both BAL primed and unprimed Marmox board. Again it was much easier to pull the membrane from the BAL primed Marmox board
I'm now a bit uncertain about the way forward. The nice guy at Impey technical support suggested diluting 1:1 with water rather than using neat (which I'm testing) but does anyone have any views/experience of this sort of issue?

 

[Dave]

My first big tiling job. It's a wet room and I'm at the stage where I have Marmox boards on floor and walls and an Impey former. I'm just about to put down the Impey Waterguard membrane and the instructions specify priming with the supplied Bal APD primer.
I tested the BAL primer inadvertently as I was doing some construction adhesive tests between back painted glass and marmox boards. (The winner incidentally was definitely CT1 by a big factor!). The Marmox primed with the BAL primer was much easier to wrench from the glass than an un primed Marmox board. This led me onto testing the Impey Waterguard membrane on both BAL primed and unprimed Marmox board. Again it was much easier to pull the membrane from the BAL primed Marmox board
I'm now a bit uncertain about the way forward. The nice guy at Impey technical support suggested diluting 1:1 with water rather than using neat (which I'm testing) but does anyone have any views/experience of this sort of issue?

How long are you leaving the primer to dry. ?

 

[ahearsum]

How long are you leaving the primer to dry. ?

Couple of hours at least

 

[Dave]

Couple of hours at least

Was it dry or just tacky

 

[ahearsum]

Was it dry or just tacky

Dry and possibly slightly shiny. The impey support guy said I could leave it for a week to dry.

 

[Dave]

Dry and possibly slightly shiny. The impey support guy said I could leave it for a week to dry.

Because the Marmox is waterproof, it will take a while.

 

[ahearsum]

Because the Marmox is waterproof, it will take a while.

The week time from the Impey guy was only because I pressed him (I'm very slow!) He said it would be ready in 30mim. The mormoz has a very dry , absorbent textured cement surface with soak in the primer quite quickly

 

[benchwarmer]

Sorry if I've read this post wrong?
But you don't prime marmox boards mate

 

[ahearsum]

Sorry if I've read this post wrong?
But you don't prime marmox boards mate

Thanks. I couldn't find anything on the marmox site which said I shouldn't prime them nor on the Bal instructions but my various tests look like suggesting I shouldn't. I had assumed that since it had a dusty, cement surface it would need priming. Thanks for putting me straight.

 

[benchwarmer]

Thanks. I couldn't find anything on the marmox site which said I shouldn't prime them nor on the Bal instructions but my various tests look like suggesting I shouldn't. I had assumed that since it had a dusty, cement surface it would need priming. Thanks for putting me straight.

Marmox shouldn't be dusty and cement like? Are you sure it's marmox?

 

[ahearsum]

Marmox shouldn't be dusty and cement like? Are you sure it's marmox?

Maybe dusty is the wrong word, perhaps dry. Definitely cement though from the marmox website "each side faced with fibreglass mesh embedded into a cement polymer mortar". Yes definitely Marmox.

 

[benchwarmer]

Maybe dusty is the wrong word, perhaps dry. Definitely cement though from the marmox website "each side faced with fibreglass mesh embedded into a cement polymer mortar". Yes definitely Marmox.

100% don't prime
👍🏻

 

[CJ]

Did you dilute APD?

 

[ahearsum]

Did you dilute APD?

Did two tests with neat and diluted. Diluted was better but not as good as unprimed. I phoned Impey and Marmox and they both said priming isn't necessary. Glad I sorted that before priming the whole room and having my tiles fall off a few months later! Being an amateur I just assumed everything supplied in the kit was to be used.