Flour glue is amazing stuff. It's super sturdy, almost nothing to make and if you let it get really concentrated, it's pretty much wheat paste.
Return to heat and simmer your flour glue until it is a snot-like consistency. Let cool to bathwater temperature and then use. It works best when warm, so store leftover in the fridge and warm it back up in a saucepan when you need it again. Adding cloves or oil of cloves will keep it lasting longer.