well mac.. it's essentially black magic if you ask me
(or white going by the color scheme of baking powder)
Anyhow, it acts as a finely granulated filler material, closing tiny gaps much better than just cyanoacrylic glue.
I tested that on a plastic lighter lid.. it broke immediately without baking powder and lasted at least for months with.
why?
I guess you cannot perfectly close all gaps by pressing pieces together so you end up with a solid-glue-glue-solid bond;
and that for some reason is weaker than a solid-glue-solid-glue-solid bond *shrugs*
especially if those solids are literally all over the place
But what exactly happens IDK, I just saw people do it successfully and repeated that myself
(also rather successfully I'd say)
'sid