# brick mortar not quite "sticky" enough



## shaftmaster (Mar 30, 2015)

First some background:

I am repointing (tuck pointing) mortar on one hundred year old exterior brick walls. I've done lots of research on brick masonry restoration and have been mixing my own "Type K" brick mortar (1 part white portland cement, 3 parts type S hydrated lime, 10 parts sand) since the brick is very soft and is not structural (it is a 1920's brick veneer added over 1890's clapboard siding). I could probably get away with pre-mixed Type O mortar that is commonly used for repointing in this area, but I'd be worried about the brick faces spalling over time and the pre-mix mortar is too dark anyway.

I'm still learning the techniques used for repointing, but the general problem I have is that my mortar is never quite sticky enough to adhere to the metal repointing tools, which makes filling the vertical head joints rather difficult and messy. I can hold a trowel horizontally and push mortar into the horizontal bed joints but that doesn't work for the vertical joints. Once the mortar is in the joint and compacted with the repointing tools it adheres to the brick nicely, the problem is that it falls off the metal trowels and repointing tools too easily.

Should I consider adding some type of bonding agent to my mortar mix? I've heard about people adding thin set or something called Acryl 60 to improve adhesion of the mortar, but I don't want to affect the strength or color of the mortar.

Any advice is appreciated.


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## stuart45 (Jun 20, 2009)

Using the correct building sand can make pointing easier. Also when using lime it helps when the mortar is mixed up for longer.


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## Colbyt (Jan 27, 2014)

Have you considered using a pointers's bag? Looks like a heavy duty pastry bag if you've never seen one.

Lime works great for sticky but not for angles of approach.


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## jomama45 (Nov 13, 2008)

Mechanical mixing (even a low speed drill with a paddle mixer) helps alot by introducing air into the mix, making it fluffier and easier to work with. You could also try a little more lime, but it could change the color a tad. A grout bag should make the head joints easier as well.......


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## shaftmaster (Mar 30, 2015)

Thanks for the advice. I'll try mixing with a drill and for a longer period of time to see if that will help.

I also read something about letting the mortar sit for 30 minutes (or longer?) after mixing with water and before using it. Does anyone have any knowledge about this? Is that what was meant by "it helps when the mortar is mixed up for longer" or was that only meant to say I should mix the mortar for a longer time?

If none of this helps I can try a grout or pointers bag.


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## Colbyt (Jan 27, 2014)

I was taught that you mix mortar, let it sit for 15 minutes and if needed you can add a bit more water one time, then. After that you can not add more water. Masons work off of a plywood board to allow some of the water to evaporate. All of the things only affect consistency.

Premixed mortar often needs a bit of extra Portland or lime for the sticky factor.


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## jomama45 (Nov 13, 2008)

Generally rule in the trade is to let it sit for 5 minutes before use to allow the water to complete saturate the cementicious material...........


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## stuart45 (Jun 20, 2009)

When using a lime mortar with no cement it's usually in the mixer for 20 minutes, left to sit for 20 minutes to fatten up and then mixed again for a few minutes. After about 10 minutes in the mixer it appears to get wetter as the air works into the mix. If it's only mixed for a few minutes you need a lot more water in the mix to make it workable, which isn't such a good mix.


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