Can I skim coat concrete over fibreglass pool edge?

[Coolaholigah]

I need to refibreglass a chlorine pool edge. I have cut back the old/broken fibreglass but it seems to have been put on some kind of skim coat which itself was on top of the main concrete structure of the pool. The slim coat, if that’s what it was, was broken and degraded and has mostly come away. But I feel I need to even up the surface so the fibreglass is supported and doesn’t just break under the later weight of the coping stones when they are put back on top. I will need to be able to squeeze/ ‘pour’ the skim cost under the remaining fibreglass edge to support under there too. But on the other side is a drain so obviously I don’t want the skim coat material going into the drain too. Am I on the right track with the idea of a skim coat? Any product suggestions or tool suggestions? I used Watercrete cement patch successfully to patch vertical spots above the drain but the area involved for skim coat is much larger. (When the photos attached were taken I hadn’t started preparing the fibreglass for repair but I know I have to do that!)

thanks in advance

 

[MitchellMc]

Hi @Coolaholigah,

You could use a product like Dunlop 5kg Ardit Rapidset Repair Mortar and pack it in under the existing fibreglass with a putty knife. I'd recommend using the Dunlop 1L Multipurpose Water Based Primer to ensure a sufficient bond to the substrate. The mortar isn't specifically designed for use in or around swimming pools, so you'll need to ensure that you do a good fibreglassing job to encapsulate it. It won't necessarily deteriorate if any moisture gets under the fibreglass, but it's not engineered specifically for this purpose like the Quickset Watercrete.

Please let me know if you have any questions.

Mitchell

[Coolaholigah]

Thank you. I’ve looked the instructions etc for the primer. I understand the drying time. But does it matter if it’s a day or even several days (weather!) between primer and the skim coat?

thanks

[MitchellMc]

Hi @Coolaholigah,

Drying time is 30mins on the primer, so I'd suggest waiting for when the weather clears up for a few days and doing the primer first thing in the morning and skimcoat straight after it's dried. Since the primer is so quick to dry, you should be able to complete the job all in one fine day. It would be different if the primer took 24 hours to dry, as if it rained on the following days, you'd need to wait. If there is rain forecast, I would suggest holding off on the repair. 

Please let me know if you don't think you'll be able to prime directly before skimcoating, and I'd be happy to contact the manufacturer after the weekend to find out the answer.

Mitchell

[Coolaholigah]

Thank you again.

well it wasn’t half an hour after the primer dried but I just got stuck into it and did it all on the same day and now protected from weather by several waterproof layers so fingers crossed.

but if it’s not too much trouble I would like to know whether it’s ok to wait after applying primer for future reference. Obviously if primer is washed away in the meantime by rain one would have to prime again but what about, for example waiting overnight or longer after priming?

Thanks!

[MitchellMc]

It's great to hear you got the job done, @Coolaholigah!

I've had a chance to contact Dunlop, and your finishing product should be applied as soon as the primer is dry. An hour after it dried would likely be fine, but you wouldn't want to wait longer. It might not be an issue if you did, but the product's bonding capabilities perform best immediately after it has dried.

Mitchell