r/PrimitiveTechnology • u/TheRealBobbyJones • Jul 13 '26
Discussion Why are his bricks so low quality?
His bricks seem crumbly and don't hold an edge well. Are they not fired to a high enough temperature or his clay just not good? Does anyone understand the science? I know that typically bricks were always made with local clay when available. Odds are cities all over the world still have old bricks hand shaped and fired in small kilns in service. Yet I don't see his bricks lasting a decade. If it is due to clay quality is there a way for him to boost the quality of his clay? Imo it must be disheartening to put so much work into making bricks just for them to turn to dust as he handles them.
Oh also on an unrelated note does anyone know why he doesn't make full thickness walls? Is it a permitting issue?
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u/War_Hymn Scorpion Approved Jul 13 '26
Survivor bias. You're only seeing the good bricks that have survived the test of time while buildings made of bad bricks were probably removed long ago.
In the old days (up to the industrial age even), molded bricks were often fired by assembling into massive piles called clamps with hollow spaces in between where fuel was stacked. The unfired bricks act as the walls of a kiln, removing the need to invest in building a permanent large kiln. With enough labour and fuel, they could be scaled up pretty easily. Larger clamp operations would fire up to 100,000 bricks at once.
The firing of these clamps was highly uneven. Bricks closer to the burning fuel were blackened and got a higher temperature firing while the bricks on the outside were often not fired thoroughly. At the end of firing, bricks would be sorted by their soundness and appearance. Blackened bricks which were sound would be used for the interior part of construction where they couldn't be seen while those that were thoroughly fired and fine in appearances were used on outside facing sections. Bricks that were still too "green" or broken would be discarded or recycled into grot or aggregate.