A Major (And Much Improved) Design Change To My Silicone Faux Stone Molds (Plus, A Progress Status Update)

At the moment is the day, y’all. It’s the day that I’ll lastly have the ability to begin attaching my fake Austin stones to the skirting space of the entrance porch. We’ll be having an attractive day right here in central Texas (scorching, however at the very least no rain within the forecast), and I’ve all the massive stones prepared and ready, and about half of the small stones able to go.

Once I initially made the mould types for the textured silicone mats, I wanted one thing to position underneath the silicone mats to carry the perimeters straight and provides the mats assist beneath. In any other case, I’d find yourself with wavy edges on my stones…

I ended up utilizing the kind of sand that you’d use beneath paver stones. I already had the sand readily available, and it appeared straightforward sufficient to elevate the perimeters of the silicone mat, drop some sand beneath, after which regulate the silicone mat in order that the perimeters had been straight.

As soon as I had the mat on the proper top all the best way round, and fully supported beneath, I vacuumed away the surplus sand after which caulked across the edges of the silicone mat the place it met the PVC boards that I used to make the molds.

I believed that may be principally a one-and-done course of. I knew that to be able to demold every stone, I must take away one facet of the mould, so I believed that meant I’d simply need to re-caulk one facet of every mould earlier than pouring the subsequent stone. That turned out to not be the case. As I eliminated every stone, it pulled the silicone mat up a bit together with the stone. And that dislodged different areas of the mat. As soon as these different areas of the silicone mat had been pulled away from the caulk, sand would come out. And since I used to be utilizing silicone caulk between the silicone mat and the PVC boards, which continuously remained sticky, the sand would get caught within the caulk and create an enormous mess.

So I used to be principally having to undergo half of the mold-building course of earlier than every new pour — including extra sand, shifting the sand round, getting the silicone mat good, clear up the surplus sand, after which re-caulk the entire thing. That was so time-consuming!

I lastly determined that the proper product for that’s Nice Stuff increasing spray foam. It will fill in these areas, and as soon as it cured, it might maintain its form. I particularly selected this model as a result of, after a fast google search to seek out the quickest curing spray foam obtainable at massive field shops, this was the one. It units inside about quarter-hour and cures in an hour.

So I took one facet of every mould off, emptied the sand, and acquired every mould cleaned up by eradicating all the remaining sticky caulk with sand caught in it. After which I lined up the silicone mat alongside the straight guideline that I had drawn on each indicating the place the perimeters of the silicone mat wanted to be. I held it in place with one hand as finest as I might, after which I sprayed the spray foam between it and the underside of the mould field. It did its factor and expanded and got here out of the open facet. Whereas it expanded, I simply stored pushing the silicone mat into place to ensure it stayed lined up on the mould field.

After it stopped increasing, I scraped off the surplus that had come out the facet…

After which I screwed that facet of the field again on and made positive the mat was nonetheless lined up on it’s guideline. I needed to push it down extra in some areas, and that brought about the spray foam to return out between the field and the mat. However I simply left it and let the froth dry fully. As soon as it was absolutely dry, I reduce away the surplus foam, re-caulked, and was able to pour the subsequent stone.

This made the entire course of a lot simpler and cleaner. I not needed to cope with shifting sand. I not needed to cope with principally remaking the mould once more between pours. The froth held its form, and since it’s very sticky when it’s moist and had grabbed onto the silicone mould, it additionally held the silicone mat in place as I demolded the stones.

I used to be in a position to elevate the stones off of the mat whereas the mat stayed in place on the opposite three sides.

The stone got here out very cleanly and three sides of the mould remained fully intact.

Then I simply needed to put the facet of the mould again on, re-caulk one facet and two corners, and I used to be prepared for the subsequent pour.

So whereas I’m not fairly completed pouring stones, I’m able to get began attaching them to the skirting space of the entrance porch. I hope to have some progress to indicate you tomorrow!