OK, sorry it took a while to get back to this. Caught a nasty bug in the meantime.
Anyway, I think the following will be useful to some folks in the future.
The 18G needles seemed large enough to accommodate something like Titebond without even having to thin it in any way. Full discolsure: I judged this by sight without actually trying it, since 18G was too big for some of the tighter splits I was dealing with.
The 22G needles would accommodate only a VERY low viscosity glue, and glues with such low viscosity tend to have very brief working times. I needed working time so did not even try these.
The 20G needles turned out to be perfect for my needs. A bit large for the narrowest splits, but because these are actual syringes with a sharp point I could use that point to work my way in. I used hide glue and warmed it to make it as runny as possible. Even then the glue squeezed through the needle only slowly. It took patience, but I did have plenty of working time. Cold hide glue would never work with this size.
A bonus of working with hide glue is that it cleans up easily with hot tap water. I was able the reuse the syringe and needle several times. I still have the originals, cleaned up and ready to go again.
The bad news is that once the drum was fixed the owner rushed to retrieve it. Between fighting off the bug and work, I didn't get a chance to take the usual AFTER pictures. Sorry about that.
@Coop I'm surprised you could make even a bad cut with the blade tension off. When I turn on the saw with the tension off, the blade just falls off the wheels.
@Beechwood Chip, I do something similar with a red shop towel attached to my saw behind the switch. When I detension the blade, I drape it across the switch. That works well when you remember to do it.
Recently, when I cut the veneer for the back support of my chair, I set the fence up and attempted to cut some 1/16” strips and the blade veered off of the line immediately. Thinking it might be the grain, I chose another board and got the same results. So thinking it’s a dull blade and am lucky to have a new one, I take the table off of the bs and go to detension the blade only to find the tension bar in the upright position. I went ahead and changed the blade, blaming it and not myself!