Acrylic primer didn't bond to Larsen Tile Adhesive - TilersForums.com

[Tiler87]

I had an issue recently that I've never seen before and any help or advice would be greatly appreciated. I used a Larsen acrylic primer on gyspum walls as instructed on product (walls had been skimmed 8+ weeks previous and moisture tested prior to sealing and tiling). 18 months later and it seems the sealer has not bonded to the wall adhesive. Wall was coated with a 12mm trowel and a standard set flexible adhesive used, the tiles are 900mm by 150mm thin porcelain and within weight limit of plaster. Tiles have now come away from the wall with 100% of adhesive on the tiles and 0% left on the wall with sealer still appearing tacky on the walls. Walls are tiled 1.2m high around the room and the issue is only where sealer was applied to gypsum walls,other walls are scratch coated and solid as should be expected. Usually removal of tiles like these should take plaster and all with it, is this is a sealer failure or am I missing something? Apologies for the long post but I'm in the trade a long time and never encountered this.
Thanks

 

[Dave]

Did you dilute the primer ..? As some primers need diluting and not applied neat . Or they form a skin and can fail.

 

[Tiler87]

Did you dilute the primer ..? As some primers need diluting and not applied neat . Or they form a skin and can fail.

Hi Dave, Primer was diluted 1:1 with water first coat and applied neat on 2nd coat as instructed on the drum.

 

[Dave]

Ok , just had a quick read of said primer instructions and it does state as you say but more coasts can be applied if required. Do you have any white residue on tile backs or walls , as in there has been a reaction with the adhesive and the gypsum ?

 

[Tiler87]

Ok , just had a quick read of said primer instructions and it does state as you say but more coasts can be applied if required. Do you have any white residue on tile backs or walls , as in there has been a reaction with the adhesive and the gypsum ?

No residue on either, adhesive stuck to the tile and its as if the sealer broke the bond between adhesive and wall the opposite of what it is supposed to do 🙈 adhesion to tile was excellent, the tile in question is discontinued so I used a concrete grinding disc to remove the adhesive to re-use them. Its left me completely stumped

 

[Dave]

No residue on either, adhesive stuck to the tile and its as if the sealer broke the bond between adhesive and wall the opposite of what it is supposed to do 🙈 adhesion to tile was excellent, the tile in question is discontinued so I used a concrete grinding disc to remove the adhesive to re-use them. Its left me completely stumped

Was the primer fully dry before tiling as tiling to early could wet the primer and weaken the bond.

No residue on either, adhesive stuck to the tile and its as if the sealer broke the bond between adhesive and wall the opposite of what it is supposed to do 🙈 adhesion to tile was excellent, the tile in question is discontinued so I used a concrete grinding disc to remove the adhesive to re-use them. Its left me completely stum

 

[Dave]

Also the plaster shouldn’t be over polished when it was skimmed.. helps the primer to soak in..

 

[Tiler87]

Also the plaster shouldn’t be over polished when it was skimmed.. helps the primer to soak in..

Plaster wasn't over polished as when 1:1 coat was applied it darkened the skim where it was soaking in (which I understood to mean it was bonding into the ppurs) its recommended that the 2nd coat applied should be allowed to dry and become tacky before tiling

 

[Dave]

Plaster wasn't over polished as when 1:1 coat was applied it darkened the skim where it was soaking in (which I understood to mean it was bonding into the ppurs) its recommended that the 2nd coat applied should be allowed to dry and become tacky before tiling

Might be best to ring technical , it’s not a primer i use and not a dilution ratio i use.. just trying to see if it was something simple..

 

[Tiler87]

I Appreciate your reply Dave thank you. I had a local rep out to look at it but I know already they'll try to weasel out of it any way possible 🤷🏻‍♂