I assume you are talking about the 18 runic spells Odin mentions in the Havamal. If you are, I did not think anyone here is or have actively tried to learn these for a couple reasons. First, as you've stated, the stanzas never give a description of these spells,so therefore it would be very difficult to even begin this study. I mean, you could read the original text in old Icelandic, figuring the original wording and going from there. Second, Odin is very clear that many of them man does not know, and I'm pretty sure he believes men should not know. Third, even if you get a translation, study and examine every rune and every combination for years until you decide on which rune "formula" effects match their descriptions in the Havamal the best, you would never know if they were correct and what he meant. Sure you could divine a conversation, pathwalk, or use seidr to try and convince Odin to tell you the exact translations, but then it would begin to fall into UPG (Unverified Personal Gnosis, there is an excellent article on the topic here at SoM) and although true to you, may have conflicting ideas with others. So all that stated, their is hope. Odin learned these secret spells through intense meditation and study of the runes, literally impaled and hanging by the neck on the world tree. Now you do not need to go so far as to self mutilation, but intensive study and meditation seems to be the key in deciphering any runic secrets. Learn them through them, as if they were living instead of symbols, work with them, and maybe one day these 18 spells you are looking for may be revealed to you, and you will be all the wiser for using this route. I'm sorry if this answer isn't very straight forward, but I hope it will get you through this little area of your practice. Need anything, any qurstioms aboit my answer you can message me. Good luck!
Thanks for a prompt and very well informed response. I agree that personal gnosis will probably be the best possible outcome from any course of study in galdric magick. Ive been reading Cooper, Thorsson, Howard, Peschel and others which corroborate your opinion. Would the community accept reconstructionist rendition of galdr magick? Again, thanks for the response. Anyone else find this of interest?
Here's an example of Galdr that is reconstructionalist in nature. In brevity, a war blot for heathen soldiers (VPG).
"Woden the All Father,
Your children stand before you
Prepared for battle
May Thor and Ziu be our limbs
May the power of the runes be our strength
Victorious, our enemy will fall before our feet
The worthy, carried to your great hall
Hail the Aesen, Hail the fallen
Hail the Folk"
Followed by Galdr incantation (beating on body armor, ammo crates, mogas drums) in groups of low to fast tempo in nine stanzas:
Woden, Ziu, Thor
Woden, Ziu, Thor
Followed by runic incantation in increasing tempo (vocal only)
Ceremony completed with traditional offerings as afforded by circumstance.
If one looks at all of the components of this piece of Galdr, everything is in place. I find this Galdr authentic not by the order or wording of the Galdr but the fact that being present wells up a sense of extreme power and exhuberation in the participants, which drives out fear. This piece works and is in practice with heathen soldiers deployed throughout the world. I think this is pretty close to one of the 18 Galdr incantations that Odin speaks of (destroying enemies). I think any battle blooded heathen will agree but the community in entirety needs to be in agreement so we can reconstruct the magick of Galdr and incorporate it into our practices.
Sources: Heathen armed forces members of various nationalities ( abridged and edited for consensus)