Stripping the Panels from the Forms
The next day I removed the form sides, and ends, and these castings came out fairly easily. I first stripped the 48″ panels. Removing the screws and gently wiggling the sides, then rocking the ends. Then tipping the panel up and prying off the base with the help of a paint scraper.
Both 48″ forms looked identical and time would tell if the addition of the glass fibre would make any difference.
Next, I stripped the 36″ red coloured panel. It too looked good and I didn’t see any issues. Right out of the form it kinda looks like red clay brick.
And finally ,I stripped the black dyed CSA concrete panel. It felt harder and that’s to be expected as it cures quicker than portland.
Submerging the Concrete Panels to cure
To help all the panels cure to their maximum strength, I completely submerged them in water in an old bathtub. After a few weeks I removed them to dry slowly in my shop before weighing.
Then I could test them for durability. As in Part 3 of this series I lined up panels on the lawn and ran an edge trimmer against them.
The line trimmer didn’t damage the perlite concrete at all.
Like the vermiculite, the perlite-based concrete mixed easily and was noticeably lighter. And this made it easy to fill the forms.
It settled well with vibration and has a smooth texture while troweling and edging. It came out of the forms easily and has a nice smooth finish.
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It passed the weed eater test so I think, all in all, perlite concrete in these proportions makes a good lightweight alternative for these garden panels.
The panels weighed, on average, 34 percent lighter than regular concrete. And this was a bit lighter than the similar vermiculite panels from part three.
Significant Weight Reduction
The CSA perlite panel was 45 percent lighter. Since CSA concrete is stronger than Portland I was able to use more perlite in the mix.
The drawback is the CSA cement is more expensive and sometimes harder to find. And, the portland ones appear to be strong enough, and light enough.
The colours worked well and blended evenly. I think I could have used less of the red as it came out deeper than I expected. The black looks pretty good though and I’d use that again. And maybe even more.
I’m happy with perlite and it makes a light, strong, and durable panel for these garden boxes. I wouldn’t hesitate putting them in my garden if weight was an issue for me.
In the next episode I’m going back to look at aircrete. I’ve worked on some new blends and got really good results. So that’s coming right up.
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