Plastic safe threadlocker?

zoltan · Oct 30, 2014

I'm working on a project where I have small metal screws going into nuts embedded in a plastic body. I don't want to use a normal threadlocker like the blue Loctite since I won't be able to keep it off the plastic as I assemble the two parts. I've done some research into plastic safe options for threadlockers, and the best recommendation I've found thus far is Krazy Glue. However, in my own tests, it doesn't seem to provide much threadlocking strength.

So, what are my other options here? I have access to the heads of the screws, so I was considering just putting some hot glue on each to keep them from turning or vibrating loose.

canadianhorsepower · Oct 30, 2014

depending what kind of plastic you are talking about their is mamany answer
usualy I drill one size smaller drill."not 1/32" and tap that will end out pretty solid
or I will put a small drop of acetone when I'm almost done threading, acetone will
melt your plastic
good luck

mcostello · Oct 30, 2014

Maybe RTV, much experimenting required.

gmac · Oct 30, 2014

Zoltan;
Loctite list a threadlocker specifically for use on plastics and metals. Loctite 425 Assure, blue strength. Since the screws are small blue grade may provide sufficient strength.

http://www.henkelna.com/product-search-1554.htm?nodeid=8797887234049

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/F3315286A80C8A55882571870000D782/$File/425-EN.pdf

Cheers Garry

zoltan · Oct 30, 2014

gmac said:
Zoltan;
Loctite list a threadlocker specifically for use on plastics and metals. Loctite 425 Assure, blue strength. Since the screws are small blue grade may provide sufficient strength.

http://www.henkelna.com/product-search-1554.htm?nodeid=8797887234049

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/F3315286A80C8A55882571870000D782/$File/425-EN.pdf

Cheers Garry

If you check the MSDS sheet it's basically just blue colored Krazy Glue.