Mortar vs Acrylic Repair Sealant to fill in Mortar Joints

[AdrianeS]

The mortar joints in my fireplace are very deep and I'd like to bring them more level with the surface of the brick. The fireplace is no longer in use so heat is not a concern. I'm wondering if I should use real mortar or if I can get away with using Acrylic Mortar Repair Sealant that comes in a tube, like caulk. The tube would be much easier to apply but I have concerns it would crack over time and I intend to paint over it so that would be no good. Any opinions or has anyone had experience using the acrylic stuff?

Also, I was going to prime the bricks with Zinsser BIN Shellac Primer but if I use the acrylic stuff it says it can only be painted with latex. Any ideas about why only latex and would shellac be able to be used instead?

 

[Snoonyb]

SURPRISE, IT'S ME AGAIN.

I've used both the, "paint with water-based" and this, extensively;
https://www.homedepot.com/p/Sika-10...ethane-Sealant-in-Limestone-7116090/300934529
And prefer the 2nd, because; "We only recommend painting Sikaflex Mortar Fix with water-based, oil-based or rubber-based paints, and we always recommend doing a mockup first to test for compatibility and adhesion, before painting over the entire repair area."

 

[AdrianeS]

You, sir, are quite the jack-of-all trades! I ended up emailing Quikrete and they recommended I use regular mortar instead. The joints are really solid already with no cracking in the mortar. If I used the Sikaflex product how do you think it fares as far as crack resistance? If there's the slightest chance of cracking I'd probably rather get messy with the real mortar so I don't have to constantly deal with touching up the paint job. What do you think?

 

[Snoonyb]

I will use the SIKA because the PLOYURETHANE makes it elastomeric, in that, over duration, it doesn't split as it eventually dries.

QUICKRETE is the other product that I routinely use, for tucking & pointing, where there isn't likely any chance the product will be painted, by that owner.

However I've used SIKA for all walkable surfaces, projected paintable, and deck too structure flashing intersections.

While there are additional products, which may suffice, and with similar knowledge of tooling, time is a value.

You see, I warranty anything I do, for as long as that homeowner, occupies that dwelling, Which, my seem self-serving because the average dwelling turnover, in the U.S., is seven yrs.

 

[lucyonfire]

SURPRISE, IT'S ME AGAIN.

I've used both the, "paint with water-based" and this, extensively;
https://www.homedepot.com/p/Sika-10...ethane-Sealant-in-Limestone-7116090/300934529
And prefer the 2nd, because; "We only recommend painting Sikaflex Mortar Fix with water-based, oil-based or rubber-based paints, and we always recommend doing a mockup first to test for compatibility and adhesion, before painting over the entire repair area."

Also help me a lot!

 

[AdrianeS]

I will use the SIKA because the PLOYURETHANE makes it elastomeric, in that, over duration, it doesn't split as it eventually dries.

QUICKRETE is the other product that I routinely use, for tucking & pointing, where there isn't likely any chance the product will be painted, by that owner.

However I've used SIKA for all walkable surfaces, projected paintable, and deck too structure flashing intersections.

While there are additional products, which may suffice, and with similar knowledge of tooling, time is a value.

You see, I warranty anything I do, for as long as that homeowner, occupies that dwelling, Which, my seem self-serving because the average dwelling turnover, in the U.S., is seven yrs

Sika it is then. Thank you again for your help!

 

[Snoonyb]

Sika it is then. Thank you again for your help!

Just, as an expansion of the discussion, could you post some follow-up comments of both the plus and neg. of your experiences, with all the products used.

Another product I've used, in a pinch, is sanded grout, and I say in a pinch, because the aggregate in the sanded grout in fine in texture, and even though modified, at width, is prone to fracturing.

Tooling and knowing you product.

 

[AdrianeS]

Absolutely! I'll probably start the project next week and will update this thread with the results.

 

[PJB12]

If it's helpful to you, PPG Seal Grip Gripper primer works very well over Sikaflex. It is very low VOC water based. It'll flex with the polyurethane caulk.

Sometimes people will use a polyurethane, like Sikaflex and lightly rub mortar or sand on the surface so the texture matches the surrounding mortar.

Paul