Top N Bond before epoxy?

[blackthursday]

I'm a couple weeks away from finally getting my floor epoxied. I've got some locations on the stem walls that have poor transitions and/or divots that I was debating filling with Top n Bond. I tried wire brushing the divots but the paint doesn't seem to come off very easily. Would it be a mistake to apply Top n Bond over whatever "paint" (it might actually be some "paint/epoxy kit" put on by previous owners) is on there? Common sense says yes, but obviously stem walls don't see traffic... so I'm not sure what the risk of it disbonding and causing the epoxy to flake off is. I'm going full flake so I expect the minor divots/inconsistencies to blend in, but there are some real bad spots.

Thanks in advance!

 

[PCustoms]

That's going to look very uneven slapping more epoxy on top of that work.

Can you grind the high spots and some of the "paint" down?

 

[blackthursday]

Yeah you can see in the pics I started grinding some stuff down - I intend to keep going at it which should help, but the divots have me more concerned since they can't be ground down (too deep in most spots).

 

[PCustoms]

Yeah you can see in the pics I started grinding some stuff down - I intend to keep going at it which should help, but the divots have me more concerned since they can't be ground down (too deep in most spots).

Got ya

Not sure, generally not knowing what you're bonding to I think you want a mechanical bond. If you knew what it was you could get a compatible material to chemically bond.

Are you getting flakes broadcast in your new floor?

 

[Nessism]

I'm struggling to understand what those photos represent. That said, a good hard wire wheel prep, followed by IA degrease, should be adequate for whatever filling material you are going to use to fill depressions.

 

[blackthursday]

Yes full flake broadcast.

Sorry - the 1st and 3rd pics shows transitions I've started grinding down, the middle picture shows one of the bigger divots. I'm also only using those wire cups/wheels that go on a drill...wondering if I should get one of those angle grinder wire wheels? I assumed that would be too aggressive/tear up the concrete too much, especially given the side of some of the divots.

I'm starting to lean towards that... do the best I can with wire wheel + clean up. I feel like it would be a mistake NOT to apply the Top n Bond in some spots.

 

[Nessism]

I'd do the angle grinder. The cleaner the substrate, the better the filler will adhere.

 

[PCustoms]

Yeah, wheel on a drill=toy.

What are you grinding with?

Should be able to get a smaller dia cup grinder, or at least a stiff wire cup brush. If you get the brush, eye protection is 100% required, best off with glasses and a face shield. Oh and a heavy long sleeve. Those bristles are moving when they come off....

 

[blackthursday]

Yeah I'll pick up a wire wheel on Monday, this one isn't cutting it.

The grinding is a turbo cup on my angle grinder w/ a dust shroud. The dust shroud makes it real hard to be accurate/see where I'm grinding.

Thanks for the reminder, I should pick up a face shield.

 

[KenC]

Maybe invest in a needle scaler for the divots. May not get all the paint but at least it will be roughed up for a mechanical bond. And paint them with a cement adhesive then let it get tacky before the top and bond. It is only 20-25 bucks a gallon, you'll have a lot left to mix the top and bond instead of water. I've used it that way on plaster over cement ceilings and patio/porch repair.