1.8 Guild Thread is a guild only thread for members who have The Arc as a way of fast leveling their Great Buildings, requiring at least a level 60 Arc to participate as some one who can level GBs. This is a form of Powerlifting.
How it works
People post their Great Buildings to the designated 1.8 Guild Thread, with the goal of power leveling their Great Building. People with 60+ Level Arcs then dump Forge Points on to the Great Building to lock first, second or third place. Unlike 1.9 Guild Thread, there is smaller compensation for 1.8 threads in terms of FP, BP, and added risk that the person lifting may be poached by another person with a higher level arc.
People who put their GBs in the thread are expected to quickly finish self-leveling their GB when all 5 spots have been locked so the people who put the FP down can get them returned to assist in leveling another person's FP. People donating do not want their FP locked up for days or weeks because a person will not top off their GB, or the donator needs to top it off at a loss in order to get back a return.
As 1.8 Guild Threads may be open to all guild members to rapid level their Great Buildings, participating by putting a self-leveled GB into the thread means you can often level a GB in a matter of days instead of a week or two if you participated via Guild Swaps.
For people with higher level arcs, it is an opportunity to earn more FP, medals and Blue Prints at a much cheaper rate than guild rates. It can also be much easier to do this than traditional poaching on Hoodies, Guildies or Friends as you do not need to constantly check them to see if there are opportunities to poach.
There are often two variants of this type of thread. One is a friends only 1.8 thread, where only 60+ level arc people are invited to participate and everyone must be friends with everyone else. People drop their GB in and people donate.
More informally, a group of higher level players with level 60+ Arcs can have a social, game discussion thread where people post their GBs in and tell people spots are available. There is not fixed expectation of a 1.8 or 1.9 profit return, just opportunities for people to potentially profit, snag prints or get medals.