Why you should use loctite on polycarb

Hello VEX community, I’m a builder for one of the top teams in California and I would like to share a discovery my team made. We found that using loctite on polycarbonate has numerous benefits and can provide a significant competitive advantage. This advantage helped my team a lot at the recent Mall of America signature event so we would like to share it to everyone. We’ll start by describing what loctite and polycarb are.

Loctite (sometimes also referred to as thread lock) is an adhesive/chemical used in a variety of applications. It can prevent vibration loosening, prevent leaks, protect threaded components from corrosion and increase the reliability of mechanical fasteners. You may have seen screws with loctite on them as they are easily identified by the small patch of red or blue on it. Loctite can also be found in its liquid form in small tubes (preferred for polycarb). Loctite is most commonly used to increase the grip a screw has one something, like a motor or a nut. However, less common but advantageous uses of loctite also exist. Loctite works very well for various applications on polycarbonate.
Loctite 209728 Heavy Duty Threadlocker, 0.2 oz, Blue 242, Single Thread Locking Adhesive, 0.2 Fl. Oz (Pack of 1)

Polycarb (also called polycarbonate) is a nonshattering plastic that is legal for use in VEX with a limitation of a 12x24 sheet. It is very popular with most teams as it is very customizable and also provides a surface that has a lower friction with a lot of game elements, so it is very commonly used in intakes such as trays in tower takeover and intakes in spin up. It is also very commonly used for pieces that need exact measurements such as gussets for x-drives.
1/16" Clear Polycarbonate Sheet 12" x 24" x 0.0625" for VEX Robotics Plastic Sheets - Robosource.net

A lot of teams commonly machine their polycarb so they can get precise sizes with machines such as laser cutters. These leave a lot of burn marks; however, they can be thoroughly and effectively cleaned with loctite applied on the burn marks. Loctite also helps strengthen polycarb due to some various chemical reactions. This is very useful for situations where the loctite is under a lot of stress such as applications where you want to use as little material as possible but want to have it structurally secure.

Thank you all for reading this, I hope this helps your team in future competitions!

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This. Is. GENIUS!!! Thanks for sharing. I will definitely be using this for my next robot.

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I will be using loctite and JB weld on my polycarb thank you kfc321abc

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I can’t believe this hasn’t been found before in the vex community. Thanks for this bit of info and I can’t wait to implement this on my next robot.

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I know that people have already said this, but great bit of work finding this, and thanks especially for sharing this. By the way, welcome to the forums!

Edit: Time to look into specific chemical reactions present here and do some before and after strength testing with some polycarb scraps. Maybe some flexibility too.

Recommended before a mod closes this for “not being correct.” They are trying to stop us from using a superior method.

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don’t actually do any of this.

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Omg!!! So helpful, definitely will use this to clean up the polycarb on my next robot. I heard that it would also give the clear polycarb a holographic finish because of the thermal lens effect.

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Can confirm. I was working on a pepper’s ghost a while back and found that certain types of adhesives will add a holographic effect, but be warned, test this first. Other glues can fog up the plastic.

Good point, we should all consider the use of Loctite carefully before application. While it can be useful, it could also violate rules if used in such a manner. Check the rules first!

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nah, this receives the seal of approval from ryan. loctite gives the poly a very nice texture

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:roll_eyes: y’all really still stuck in the dark ages using loctite, acetone’s where it’s at

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inb4 someone comes here with the “akshually :nerd_face: :nerd_face: :nerd_face: according to R22f in the vrc spin up game manual loctite can only be used on mechanical fasteners :nerd_face:

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Applying solvents to plastics may have varying results (here’s an article that disputes the OP: Myth vs Reality: Does Loctite Blue damage Lexan? - General Discussions - RobotShop Community) . Of course, R9(c) applies if you are attempting to improve the strength of the plastic by chemical treatment.

I remember years ago using some threadlocker on 10-32 machine screws installed into tapped holes on a thicker piece of polycarbonate (this was an FRC bot), and just a few minutes after installing the screws, the polycarbonate started cracking at all the fastener holes.

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