Woden said:
I should clarify, one of the reasons I do it like this is also because in my experience, it feels better to work with power numbers rather than a multiple of the Runic number.
Bjarkan for example, one could go for 54, 72, 90 or 108 vibrations (18x5), or use 88 instead as a power number which seems in my experience very effective for protection.
108 may be good as well, however I have always cautioned against it ever since Maxine had written that Azazel told her never to use the number 108 for personal workings on herself.
Even though HP HoodedCobra explained in more detail later about the number 108, I still avoid using it for personal workings or things like chakra work, favoring other power numbers instead.
Between the other options and 88 I do not know for certain which would be better, but since I am under the impression that the number 9 has to do with endings rather than protection using the number 90, or another multiple of 9 seems a little unintuitive in the case of a Bjarkan working.
I do know that the number 18, despite being a multiple of 9, is quite different from the number 9, being a power number of its own that has strong properties of completeness, but I don't get the same feeling from other multiples of 9 such as 36, 54, 72, etc, so I prefer settling with 88 in this case.
I tend to match the number of vibrations I use with the purpose of the working, which sometimes does line up well with the runic number (a curse working with Thurisaz and Hagl is very effective with multiples of 9 as the base number. 108 especially effective in my experience, which is a multiple of 12 times Hago's number and 36 times Thurisaz's number, all lining up very strong for a curse or death spell).
Adhering to runic numbers can cause difficulties when doing a working with multiple runes, for example with a protection working that uses Algiz and Sowilo.
15 and 16 don't match up until 240, so you can't easily use a unified number that matches both Runic numbers, and the number 16 on its own isn't nice as a power number either being rooted in 7 (1+6). 15x16 is 240, so you'd be using a multiple of 16 for Algiz which doesn't feel right to me.
Not to mention that 240 vibrations for two runes is a total of 480 vibrations, which is just not necessary for a daily protection working, and probably not sustainable for most people either.
One could use two separate numbers, but I've avoided that since it makes sense to me to use the same power number for the whole working, however it may be correct to do.
It's part of a hypothesis I have on how to get the most out of runic workings, however I do not know enough about this yet to further comment on this, since I want to avoid giving misinformation or personal conjectures that may not be true.
Hail Satan!