There are different sorts of Loctite, some more easily undoable than others. The purple, I think, is the eminently undoable kind, as I recall, but that should be easy to research. I got it originally for a Husqvarna with plastic bits in the bobbin race such that properly tightening the part deformed the part and the machine (a 19e?, 220v version) would not sew. I put the Loctite on it, snugged the screws up gently, and it's been sewing merrily for three years. (I also had to brass shim the whole mess due to plastic shrinkage: not a big plastic fan. Phooey on progress.)