There's so many different kinds. Which one do I get for the screws in an RC plane? A video said to get the blue one, but there's different kinds of blue ones.
Should I get the thunder tiger one from tower hobbies?

I use Zap Z-42 blue (medium) as it allows the screws to be removed by hand tools if required. I can't think of a modelling situation where that wouln't be sufficient.

http://www.zapglue.com/Thread.html

Good. I'll get that one. Zap products are the best.

Happy to help

ALL OF THEM

not joking. blue red green. gunna need them all at some point.
blue for screws
red for pinions
green because it feels left out

From my understanding, when they are talking about loctite and colors, they are talking about thread locking....one color is for temporary and the other is for permanent thread locking.

I ONLY use Loctite purple. If I have things undoing themselves after that it's the plane's way of telling me I have too much vibration.

Blue used to be the softest hold. But a few years back they came out with the purple intended for even lighter locking and specifically for smaller screws where even the blue was like using red on bigger sizes.

To tell the truth I've only used any sort of locking agent on bolts that are permanently burried such as bellcrank pivot bolts in control line models where the bellcrank is buried in the wing. Even there I degrease the screw and nut and use a small drop of thin CA glue to wick into the threads and lock it as effectively as if it were soldered.

Any other bolt for engines or other uses where it's exposed at most use a lock washer. In over 40 years I've never had any of them come loose.... well... other than the OK Cub .19 engine I had in my teens. I swear that these engines are what they use in paint shakers. It used to SNAP 4-40 engine bolts and would work 6-32's loose despite double lock washers on every flight. I must admit that some threadlocker for that beast would have been welcome. After a summer of dealing with this monster I discovered OS Max engines. The Cub was retired and I never looked back. I traded it for something along the way and was never happier.... I'll bet the chemical engineer that came up with thread lockers is the guy that ended up with it ! ! ! ! !

I've noticed recently that lock nuts (with the nylon inserts) have become available in quite small sizes which provide a good alternative if you are worried about vibration. I would think that the wings would fall off long before those nuts shook loose.

COLOR MEANS NOTHING.

There a multiple products in each color, and different manufacturers use different colors for the different types.

To start with you want some Loctite 242. I prefer actual Loctite brand. I have been using it for 40+ years, and am actually using the original bottle.

242 is a medium strength thread locker. Sort of ageneral purpose material.

YOU will occasionally use 272, which is the "permanent" thread locker. ONLY use this in very specific cases. I use it a few times a year for hoddy use.

Next you want some wicking grade thread locker. This can be applied to a nut that is already assembled on a machine screw. Just a tiny drop at the joint and it will wick in a lock the threads.

And finally, I use a lot of non-threaded cylindrical sassembly locker. This is for non-threaded fastengins, like a drop on a collet adapter on a motor shaft keeps it in place. Also used to lock bearings to shafts. Loctite has several grades, IIRC I mainly use 638.

Finally, DO NOT use thread locker with plastic. IN fact, avoid even getting it on plastic. It can destory certain plastics. For threaded fasteners in plastic, use a drop of CA glue, I use Medium. Loctite does make a plastic thread locking product, but it is basically CA.

I've had a small tube of Loctite blue in the shop for years and this has served me well. You only need a small drop on the area of actual thread engagement (you don't need to saturate the entire threaded area on a bolt or screw) to do the job. Snug the screw or bolt assembly tight and wipe off any excess Loctite with a Q-Tip and you're good to go.

Soft landings,

Joe