I recently received a request if it was possible to make a boulder with house numbers. Of course that's possible! So I went to a garden materials center and bought a heavy boulder of about a meter wide. It could just fit in the back of my little van, because it weighs over 400 kilos. Having a collision would become a problem at that weight. Had it been any heavier, I would have transported it by truck.

I would carve the house numbers 1-3-5 in it, for a group home for young people with a minor intellectual disability. Therefore, I chose a lively font. The boulder consists of red granite, probably a kind of Multicolour Red. But a boulder is not the same quality as found in the natural stone trade. You always need to find out if there aren't any cracks deeper inside.

Polishing

I started polishing the place where the numbers will will come. Once I'll lower the surface of the stone surrounding them, I will end up with raised letters or numbers. If I just carve the house numbers into the stone, then they will become recessed letters/numbers.

The tricky part here is the surface of the stone. It was formed by nature, so it's irregular. If it's wet, then it will be darker and when the weather is dry lighter. That means that in wet weather the polished surface of the figures disappears against the background. In dry weather it's easily readable.

Pasting and carving

The group home has the house numbers 1, 3 and 5. They share one common entrance. The stone will be located at the entrance and so will have all three house numbers. Now the house numbers are still on a sheet of paper behind a window, but because the group home is situated in boulder puller's town Amersfoort, it's a much better idea represent them on a boulder.

I had printed out the figures at 21 cm tall on paper and pasted them onto the stone. Now I could carve the numbers right through the paper into the stone . After that I just had to bring the surrounding stone down until the numbers protruded almost 2 cm above it. Red granite is quite hard, but it all went pretty easily; the stone had almost no faults.

Lowering the background

When all the contours were carved, the stone in between them had to be lowered still. That's easily done with a bush hammer, a kind of blocky chisel with pyramid-shaped points. This crushes the stone surface, leaving behind a rough skin.

After several years of weathering you will notice that the stone has become one a single entity, with its letters clearly contrasting. Now the bush hammered spots are still a bit lighter, but that will, over time, merge into one another seamlessly.

To finish it closer to the original surface of the stone I then followed with a rotating wire brush and brushed off all sharp bits.

Gilding or not?

Unfortunately, it appears that in wet weather everything gets the same color. So was thinking of a solution for this. I thought of painting or gilding. Once the polished surface of the figures is gold plated, even during rain or dusk they will clearly stand out. But we are not yet certain whether that fits in with the informal nature of the group home. I will soon install the boulder and then we'll see whether one day an alteration should be made.

This was a small (pro Deo-) job in between other things. Now I've learnt something new: how to make a boulder with house numbers. It's not a sculpture and letter carving's not something I do very often, but this was certainly just fun to do. I like working in granite, it's a robust material. I'll post pictures of installing it next week, and an update about the final finish and, still, painting.