Some time ago I bought some UNI size B thread at a close sale for about a dime a spool. Didn't know what I would do with it so I used some as ribbing. Then I decided to tie some large flies for crappie or bass. I found that when tying the finishing knot there was a tendency for the knot to come loose. I have not had that problem with 3/0 or 6/0. Some time ago a member, I believe it was Rick Z. suggested using super glue when tying Boa flies. I took this suggestion and my problem was solved.
Thanks to Rick Z or whomever suggested supper glue.