Groovy.Thanks very much guys, I've got all the info I need to go on with it now.
It depends on how thick the liquid shellac is when you apply it. I mix it thicker than Micro. It doesn't seem to soak into the felt too far and if anything sometimes it sets up too quick.The time it takes for the micro liquid shellac to dry and "set" is quite a while---especially when it has soaked into a felt piece. I'm not sure I would use that on a quick repair where the instrument needs to be played right away. With properly thinned contact cement, wait 5 minutes, put the parts together and it is solidly in place.
You'd have to take several keys off starting with the LH3 (or 'G') key, the high E key, the high F# key and then remove the screw that holds the LH main action in place until the LH2 key is loose enough to remove. Sometimes you may need to remove all the LH main action keys (the C# vent, the front F key, LH1 and LH2) and also might need to undo the Bb bis key to get the LH2 key off depending on the make. You do run the risk of altering the spring tension if you don't disengage them beforehand. If you're a novice and unsure what does what or what goes where, don't do it as you could make things worse.I didn't really want to get into removing the key itself - I didn't have the confidence for that. On that subject, is it easy to remove the key itself and then how hard is it to re-attach?