Reinforce Cheap Components? - Page 1
Forum section: electronics / beginners

author: Ziya
author_rank: Newbie
timestamp: September 09, 2018, 09:35:27 pm
content: I'm putting together a battery charger to go with some 18650 cells that I have. My project was coming together nicely until I broke the USB connector off of the TP4056 Lithium Battery Charging Board. Everything is working fine on the work bench but pulling the usb cable in and out a half dozen times tends to kill those tiny boards. In the past I've used electrical tape to wrap up tabs but that doesn't really help. I have a few other parts that I'd like to reinforce as well. Superglue was a no go because it seeps through the holes in the connector and is far to brittle.So my question is what Hot Glue, Epoxy or other solution do you recommend to reinforce bits that will have a fair bit of push and pull on them? Product links would be helpful, I usually worry if I got the wrong thing.Then my follow up question is can I use that solution to reinforce and insulate any solder joints that I've made?

author: Terry01
author_rank: Frequent Contributor
timestamp: September 09, 2018, 09:40:17 pm
content: I use the stuff from Ebay and it's fine. It sticks good enough, is fine to go over joints and stuff and is very easy to use. I don't know if there is "better" or "worse" stuff.I will also be interested to see if the more experienced guys have a source for "better" hot glue

author: Ziya
author_rank: Newbie
timestamp: September 09, 2018, 11:08:15 pm
content: I've never used hot glue on electronics before. I've seen it all the time when stuff gets taken apart. I was just wondering if it was a different plastic stick I should look for. I got a few glue guns in the tool box. They have what ever cheap stuff Lowes had. I was just looking for somebody to say don't use this, you'll catch things on fire.Also like you, hey newbie, there's a better way is always a possible response in a forum.

author: KL27x
author_rank: Super Contributor
timestamp: September 09, 2018, 11:37:48 pm
content: Hot glue is great stuff. Find a brand that sticks well. Use alcohol to remove it. It's very easy to work with, and very easy to remove in most cases.Sticky side of packing tape can be used to shape it while hot and will easily peel off when cool. You can also trim it, after the fact, with a sharp knife.Sculpting epoxy is sometimes worth the bother for high temp stuff. Kneadatite is my favorite stuff for this kind of thing. It is used by artists and modelers. I have used much cheaper sculpting epoxies in the past, but for this kind of thing, you rarely need buckets. A stick of blue and yellow kneadatite can last decades, and it doesn't leave residue on your hands. Heat it with hot air to make it less viscous and more sticky and to set faster. It is very flexible after it sets, as far as epoxy goes, making it a good match for working with FR4 and plastic housings, and it's very easy to mix up and use in very small quantities.Hot glue and most epoxies are fine as a dielectric. Sometimes I use a squirt of hot glue to fill gaps in splices of wire with thick insulation before putting on the heat shrink or tape.

author: anvoice
author_rank: Frequent Contributor
timestamp: September 10, 2018, 02:25:28 am
content: If removal is not an issue, you could try a two-part epoxy. These are quite strong and will stick well to most clean surfaces. You can find one with a high enough viscosity and working time of 5 minutes pretty easily, so you can mix, apply, and clean off any extra if needed before it starts to set.The issue I had with hot glue is that it likes some surfaces and dislikes others. Vinyl in particular doesn't seem to be one of those it likes too much. Also not as strong as epoxy.

author: Eka
author_rank: Regular Contributor
timestamp: September 10, 2018, 03:00:58 am
content: If I know something is going to get a lot of abuse, I case mount it. I'll pick a connector that physically attaches to the case with screws, or something similar, and has wires going to the PCB. That way it distributes the forces to the case, and not the PCB. It also doesn't damage the PCB by flexing it. For a RPI based device, I fabricated very short USB and HDMI extension cables with ends that had screw mounts for attaching to the case. The other end just plugged into the ports on the RPI. This also allowed me to put all external ports on one side of the case.

author: Ziya
author_rank: Newbie
timestamp: September 10, 2018, 08:26:39 am
content: Quote from: Eka on September 10, 2018, 03:00:58 amThat would be the ideal situation. Not exactly practical this time around. I've found that anything with a mini or micro usb is subject to getting pushed off a board at a moments notice even without human help. The human machine interface is always the worst part on the cheap components. However, building a cord and usb onto every little thing get expensive.Quote from: KL27x on September 09, 2018, 11:37:48 pmIll keep that in mind. I've used that quite a few times.Thanks for the input, it gives me a good point to start trying things without worrying about shorting something out.

author: Pirateguy
author_rank: Regular Contributor
timestamp: September 10, 2018, 06:14:04 pm
content: an old trick from modelers:poor some cyanoacrylate (super glue) where u want it and thendrop some talcum powder or korn starch on it while it is still wet.the glue will instantly be absorbed by it and together it will have some volumeand dry up instantly to form a rock hard substance.that's pretty damn permanent though.

author: CJay
author_rank: Super Contributor
timestamp: September 10, 2018, 06:21:01 pm
content: Quote from: Ziya on September 09, 2018, 09:35:27 pmI tend to reinforce micro usb sockets with a fillet of solder if its got a decent copper land next to it.