Thread Locking in plastic

[Mosey]

Does anyone know of a thread locker that is safe for use in plastics? Ordinary Loctite or equivalents dissolve plastic and cannot be used. The closest product is #425 which is an adhesive cyanacrylate and very expensive. I am locking a small steel screw into plastic and need it to be removable.
I have been using a tiny drop of crazy glue but that is risky.
Mosey

[90LX_Notch]

Mosey-

Not knowing the entire applacation, I wonder how well good old Elmer's white glue would work.

-Bob

[kvom]

Personally I would drill the hole one size smaller for a tight fit and not use any locker at all.  Is there a reason you expect it to back out?

[Mosey]

The holes are for #2 screws in a threaded holes, and are manufactured and cannot be altered. They are motor mount and propeller screws so vibration is inherent. White glue might work. Simple and cheap. I thought of some kind of rubber glue?
I could machine a new aluminum motor mount and then put the steel screws into that with regular threadlocker.
Mosey

[Pete49]

I have found nail polish to work well and a secondry use would make your toes and fingers pretty too. Another method is to use hotmelt glue to the head or underneath if the screw sticks out a little.
Pete

[Jasonb]

I think the 648 is ok in plastic

http://www.loctite.co.uk/loctite-4087.htm?nodeid=8802627682305&msdsLanguage=EN_GB&selectedTab=technical

[Mosey]

#648 is ok but costs $9.00 from China. Domestically it is more like $15.00 to $28.00 for 10ml.
I'm, liking the nail polish better and better.
Or the tiny drop of cyanacrylate.
Mosey

[GailinNM]

Could an internal tooth lock washer under the screw head accomplish what you need?
Gail in NM