This page (grouting a floor of pennies) is Part 2 of our sample project using pennies as tile. If you've just landed here from Google or other search engine, make sure you see Part 1 of this project -covering a floor with pennies-
Disclaimer: We do not make any recommendations, expressed or implied, about installation methods, glues/adhesives, grouts, sealers, cleaning, maintenance, etc. We're not responsible for anything related to anyone's project. By continuing with this article you agree with this disclaimer.
We're picking up where we left off in Part 1.
By now (in our case, 2 days later) the adhesive is dry and the pennies are set in place pretty well.
If this was your new floor, this is no time to let everybody walk on the pennies as they are still sensitive and maybe some could be displaced.
The grout (once dried) will likely contribute more to holding the pennies in place than the adhesive alone does before grouting.
Before grouting the pennies we did 2 things:
-one was to trim the plywood as 2 sides were not straight to begin with. We waited to trim it until after the pennies were installed to make sure our 6 sheets will fit perfectly.
-second, we wanted to see how strong (or weak) the pennies are set in place. In other words, how easy/hard would it be to dislodge a penny out of its place.
The challenge here was to actually document/prove the process in pictures. After a quick look-around we put together a 'masterpiece'... a 3 lbs. dumbbell tied up with a string to a hammer which, due to its shape, was able to be used as a hook to hang on the edge of one penny, 'pulling' it downward. Here's the result:
And here is a close-up view:
It's time to grout the pennies. We used black sanded grout.
A good point here to mention is the difference between sanded and non-sanded grout.
Sanded grout has more sand in it versus non-sanded which is more like fine dust.
Sanded grout can be used in 1/8 in. gaps and wider, while non-sanded is best for 1/16 in. gaps.
Non-sanded grout may crack if used in spaces/gaps bigger than 1/16 in. and it'll most likely crack in 1/8 in. or wider spaces.
We mixed the black sanded grout with a special liquid which claims to protect the grout against stains. A mixer attached to a drill (set on lower speed) and a small bucket were used in the process.
After mixing the ingredients for a few minutes, we let it sit in the bucket for 5 min or so. Then went back and mixed again for 2 minutes. These steps are needed for the grout to do its job (chemical stuff).
It'll be hard to describe what consistency the grout had but maybe the picture below will give you an idea. A slightly 'soupier' grout would've been good as well.
Grout spreading from different directions/angles is recommended so the grout goes down between the pennies and as much as possible under the pennies' edges.
After the area was covered with grout really well, we took a sponge and a bucket of water and within 5 min. were down to running the very damp sponge in circles (and other shapes/ways) to kind of get the grout uniform while picking up the extra grout on the sponge.
Rinse and repeat but make sure not to have too much water in the sponge. Squeeze it real tight every time. To start seeing results (clean pennies like the picture below) you have to use one side of the sponge to wipe only once, then the other clean side again only once and STOP. Rinse and repeat. Each side of the sponge gets used only once to remove excess grout, never twice because that will just return the grout back on the area you're trying to clean.
A secret here to know is that with the first couple of runs of the sponge you should press a little more down as you wipe away. The last couple of runs you just place the sponge down easily and basically pull it away with extremely light (or close to no) pressure applied on it. This will ensure you're cleaning the last few marks of grout from the surface of the pennies without pulling up more grout from down below.
See the sponge we're using and the last part of grout to be cleaned from the pennies. The sharpie on the sponge is for size comparison purposes.
TIP: Never let grout sit too long on pennies (same with other tile too). Grout is actually colored cement and dries as hard as concrete.
After running the clean sponge one time on each side on the black area above, the result is shown below.
Another run of the clean sponge once on each side and we get this (pic below).
Some marks can still be seen (not including the very black edge). If these marks are left like this, they will dry and become much more visible.
Final run/pulling of the sponge with very very light pressure, just to remove the last haze from the pennies' surface without bringing up more grout from down below.
That's about it for now. Let's see a few pictures showing different angles and close-ups of how black grout goes with pennies. When ready, click the link below.