On UAVbits website for the strong arm reinforcement plates he mentions using nail polish as thread lock at the bottom of the page right before the video.  Is this a good idea?  Does it work?  If so how much do you apply and how do you apply it.  I have bought some of these for my P3A.  
http://www.uavbits.net/store/p28 ... ith_Motor_Caps.html

Just my 2 cents, I would not put any sort of thread lock on a Phantom 3. The spindles are self tightening so the blades require almost no pressure to seat (spin them on until they stop). Note, I purchased Carbon Fiber props for my P3A and have had zero issues. When the bird lands, the blades are always tight and take a reasonable amount of torque to unscrew. I would leave the system as it is designed, it looks like it works quite well.
Hope this helps

Nathan B Posted at 2016-1-1 21:16
Just my 2 cents, I would not put any sort of thread lock on a Phantom 3. The spindles are self tight ...

I actually meant for adding the reinforcement plates not for the props themselves.  It would be the screws in the body of the P3

So, can anyone verify an answer for this question?

Ryano305 Posted at 2016-1-5 11:04
So, can anyone verify an answer for this question?

Ryan,

I am a motorcycle enthusiast and use many different types of loctite and thread locking products. After much reading and research, I could not confirm that using nail polish was the definitive answer but I was concerned with using traditional thread locking products on DJI's plastic parts. I chose to use nail polish on my strongarm plate screws. I think it should keep the screws in place without tearing up the plastic threads. I have had no issues in doing such and at this point I have not seen any stress cracks or accociated problems.

Jerry

JtrJr-UAV Pilot Posted at 2016-1-5 12:26
Ryan,

I am a motorcycle enthusiast and use many different types of loctite and thread locking pro ...

From the horses mouth, thank you soo much for answering that.  Can you tell me what kind of nail polish you used and how much and how you applied it.  Thanks for all your help

Ryano305 Posted at 2016-1-5 18:33
From the horses mouth, thank you soo much for answering that.  Can you tell me what kind of nail p ...

Ryan,

I just asked my wife for something she no longer uses. I wouldn't be very concerned about the type of polish just that it's consistent and not lumpy or dried out. All you are attempting to do is keep an already tight screw from starting to backing out. The nail polish should prevent that process from ever occurring but with minimal effort you should be able to remove the screw in the future without damage to the shell. I would put very little on the screws, just take the brush and swipe it once across the threads of the screw. Don't blob it on. The screw should just show that you've applied it but the threads should be completely visible. Torque your screws immediately in a staggered manner. Run them all down until they barely touch, then torque each one in a crisis cross manner until they are snug. Do not over tighten them. Once they are torqued, don't check them by trying to tighten them further or you will break the seal you are trying to make. When checking them in the future, don't try to tighten or loosen them, just verify that they have not moved by lightly applying slight pressure in both directions. If they don't move, leave them alone. That's what I did and would advise you to do but others may have a different opinion. Good luck and don't sweat it, it's not a big deal. BTW, make certain you use the correct bits that fit properly or you'll have a different issue to deal with.

Jerry

A tiny dab of super glue is a pretty good threadlocker because it does not really adhere well to plastic.  I use it on my motorcycles when I have no threadlocker blue.

Interesting comments about threadlocking. I am wondering about this because I bought snap-fit propguards for my Phantom 3 A and noticed that the new setscrews have a dab of blue on them which I think is probably a threadlock compound. When I removed the OEM screws they too have a very similar dab of blue on them and the removal process convinced me that it is threadlock because there was that "cracking" feeling when the screw first moved. To those who aren't familiar with threadlock compound the idea is that it creates an additional resistance to release torque over and above the resistance applied by tightening the thread. So when you undo a screw that has threadlock you have to apply a little more torque before it will turn, and if you are sensitive to it you will feel the threadlock "crack".

My engineering experience includes general aviation, marine and railroad work. Threadlock is a great solution to the risk of vibration loosening of screw threads but like everything it has to be done right or it is ineffective. Here are some general rules:
1. You don't want the threadlock to chemically etch or "eat" into the surface of either the screw or the thread it is entering. If it does, when you remove the screw the thread will be damaged. For this reason I think nail varnish or any adhesive of unknown chemical composition is a very bad idea.
2. Once used threadlock can't be re-used. Correct engineering practice is to use the manufacturer's solvent to clean the threadlock off and start again with fresh threadlock - or scrap the fittings on which the threadlock was used. It's like nylock nuts - you should never re-use a nylock nut.

What I want to know is,
1. What threadlock compound do DJI use?
2. The setscrews which secure the original caps under the motors and the replacement setscrews which hold the propguard brackets both appear to be zinc-plated steel but I don't know what material they are screwing in to. In other words, when I screw the propguards on am I screwing into metal (which metal?) or plastic?

These two questions are definitely for DJI or an accredited repair organisation to answer, everyone else will be guessing and this is a safety-critical issue.

We used to use nail polish on the screws when mounting scopes onto rifles worked well never had them come loose and you you easily undo them with the allen keys .

Nail polish contains Acetone, which is a solvent for many plastics. I would not use it near the body of the aircraft.

You just need the right threadlock for the job.  Loctite 425

Viewfinder Posted at 2016-2-21 21:35
Interesting comments about threadlocking. I am wondering about this because I bought snap-fit propgu ...

If you don't know the material (DJI won't tell you because they want your money), just assume the worst.  If you assume you're screwing into plastic, use a threadlock suitable for plastic.  It'll still prevent the fastener coming loose, especially if it's the type that cures before assembly.

If anyone is interested, there is plenty of good info on their fine products from Henkel in here:
www.useloctite.com
What ever you use, just dip the tip of your screw threads in it,  and then using a towel, wipe most of it off.
You only want it on the inside of the screw threads, not all around them. ;-)

RedHotPoker

nigelw Posted at 2016-2-21 23:40
If you don't know the material (DJI won't tell you because they want your money), just assume the  ...

Well I can't help noticing that nobody from DJI has replied. Poor show.

I have installed those items from UAV Bits and used clear finger nail polish as a thread lock and it seems to work fine.  I was told by the person at UAV Bits that thread locker 425 actually softened the plastic used by DJI.  The blue thread locker used by the manufacturer in China must not be the same as 425 (blue) used in this country.

Rich in Boise Posted at 2016-3-12 19:39
I have installed those items from UAV Bits and used clear finger nail polish as a thread lock and it ...

I think I'd rather trust a company like Loctite than a person at UAV Bits.  BTW, the colour isn't an indicator of the type of Loctite since they produce so many different types.  What many people mean when they refer to blue Loctite is 242 which is completely different & designed for metal on metal threads.

Ryano305 Posted at 2016-1-5 07:04
So, can anyone verify an answer for this question?

Aloha Ryano,

     Geebax post "Nail polish contains Acetone, which is a solvent for many plastics. I would not use it near the body of the aircraft." is an important part of your answer.  Nail polish remover is scented acetone and noted above by Geebax.  Acetone based plastics like nail polish work well with most metals used in manufacturing.  Fiberglass and composites construction with polyurethane based resins use metal reinforcement and holders.  Polyurethane based resins use acetone as a solvent.

     Regarding DJI plastics used in P3 construction, find a discarded piece of DJI plastic; dead battery shell, body shell, landing gear, etc. and put nail polish remover or straight acetone on to it in various concentrations to see the effect it has on surface sheen and solubility (does it melt).  Make your decisions from there.  Hope this helps!

Aloha and Drone On!

nigelw Posted at 2016-3-13 05:55
I think I'd rather trust a company like Loctite than a person at UAV Bits.  BTW, the colour isn't  ...

Agreed. So many people are mis-guided by the different colors and supplies they don't even bother reading the labels....

Why wouldn't you boys use a simple thread tape? Loctite sounds overkill.  
And honestly,
I can get a professional manicure- within 10 days the polish and top coat will chip.
Now, you may opt for a 'gel' coat,
however that will be additional to your regular priced manicure.  

Cheers

You could use witness marks on the screws. Good for a quick inspection
http://www.rotaryforum.com/forum ... 38&d=1109060057

FlyGirl Posted at 2016-3-13 02:29
Why wouldn't you boys use a simple thread tape? Loctite sounds overkill.  
And honestly,
I can get  ...

You mean the PTFE stuff they use on pipe joints?  That's not threadlock, it's just to seal joints in pneumatic pipe & is meant for tapered threads. Loctite threadlock is designed for the job of stopping screws coming loose.

nigelw Posted at 2016-3-13 05:55
I think I'd rather trust a company like Loctite than a person at UAV Bits.  BTW, the colour isn't  ...

You are right about the Loctite 425 and 242.  I had the two confused.  Thanks for catching this.

Rich in Boise Posted at 2016-3-13 15:36
You are right about the Loctite 425 and 242.  I had the two confused.  Thanks for catching this.

No worries, it's a common mistake.  There are so many different types.

I had my bird out for the first time in months the other day and then I seen this thread .. I have the motor plates on mine and I checked my screws after reading this thread ....

the screws were looser than I expected so I redone them using Loctite 2700 .... iv been using Loctite for years on some other hobbies I had/have and its fine as long as you know how much to put on ....

iv had the bird out again and the screws are still tight so it done the job ....  im not fussed on the reports of it harming plastic because I know it doesn't as iv been using it for years around plastic parts with no adverse effects ....