Screwed -- what to do? - Page 1
Forum section: electronics / repair

author: blueskull
author_rank: Unknown
timestamp: February 11, 2020, 08:58:35 am
content: Just stripped the thread of my laptop by over tighten the screw, and now it won't retain screws.There are still thread teeth, and screws can still screw in, but won't retain enough force.Be aware that the screw is fine, just the thread is literally screwed.Is there a way to fix it without having to drill it larger, tap it and insert a helix preform?I do not have access to proprietary adhesives like form-a-thread. I only have access to general purpose thread lockers and epoxies plus tapes.Any suggestions?

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 11, 2020, 09:00:53 am
content: Plastic or metal?

author: Muttley Snickers
author_rank: Unknown
timestamp: February 11, 2020, 09:15:08 am
content: As a temporary fix, a slither of teflon tape might be enough for the screw to get a grip, it can't hurt to try it anyway.

author: sokoloff
author_rank: Super Contributor
timestamp: February 11, 2020, 09:35:50 am
content: Try Purple Loctite (222)https://www.henkel-adhesives.com/us/en/insights/all-insights/blog/about-purple-threadlocker.html

author: thinkfat
author_rank: Unknown
timestamp: February 11, 2020, 09:45:19 am
content: Quote from: blueskull on February 11, 2020, 09:24:10 amTeflon won't work. By design, it provides only little friction. Exactly not what you need when you want it to stick to stripped threads.

author: Pinkus
author_rank: Frequent Contributor
timestamp: February 11, 2020, 09:51:26 am
content: a few thin stranded wires shall do.

author: shakalnokturn
author_rank: Super Contributor
timestamp: February 11, 2020, 10:10:01 am
content: I'd try bunging the hole with one form or another of epoxy "repair putty" and re-drilling a small hole in that.

author: thinkfat
author_rank: Unknown
timestamp: February 11, 2020, 10:24:30 am
content: If you have thin solder wire around, might work, too. No-flux core preferred.

author: tunk
author_rank: Super Contributor
timestamp: February 11, 2020, 11:07:44 am
content: Try to fill it with epoxy, drill a 1.5mm holeand see if a 2mm selftapper screw will hold.

author: Ian.M
author_rank: Super Contributor
timestamp: February 11, 2020, 11:57:21 am
content: 1. Start with a brand new screw of the correct diameter and thread. (because the old thread will be scratched and may jam in the epoxy)2. Wax the screw thread by heating it and touching it to a candle, then wipe off all excess wax while its hot and finally reheat for a thin even film of wax on the surface.3. Clean the hole thoroughly with Acetone and a Q tip, or if really small, a narrow strip of paper and a tooth-pick.4. Mix up any metal or ceramic powder loaded epoxy you can get - basically any hardware store epoxy that isn't translucent, according to its instructions. Don't be tempted to try to mix a very small amount as errors in mix ratio are more likely, and will weaken it significantly, so its better to mix too much and discard the excess.5. Work the epoxy into the screw thread, fill the hole and push the screw into it, WITHOUT any board or cover or other part it normally holds.6. Wipe off excess epoxy and make sure the screw is straight and centered7. Wait 24H for the epoxy to fully cure. DO NOT touch it till its set.8. Unscrew the screw from the thread formed in the epoxy. If its difficult to turn, briefly touch the head with a soldering iron to melt the wax.10. File off any remaining excess epoxy with a small diamond rasp.You should now have a reasonably strong formed thread in the hole to fit the original screw.

author: Shock
author_rank: Super Contributor
timestamp: February 11, 2020, 12:12:41 pm
content: If possible insert/poke baking soda into the hole, then put a drop of viscous super glue (cyanoacrylate, an acrylic resin) on top so it sucks inwards. It should set fairly quickly as the baking soda is a partial accelerator. It adds mechanical strength to the dried super glue so will allow you to tap a new thread with the existing screw.Makes sense to practice first just don't overfill the baking soda you don't want to have to chisel it of, super glue is easier to scrape with a blade.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 11, 2020, 02:52:49 pm
content: Probably won't work with very small holes:Simply insert - ghetto style - a wood chip from matchstick.

author: dreamcat4
author_rank: Frequent Contributor
timestamp: February 11, 2020, 03:42:41 pm
content: i would blow compressed air in the hole to clear any existing debris. the if you wrap a brand new screw with a little fine filament 0000 wire wool (the finest) and coat it in loktite 277 thread locker. then that will be the bet you can do without drilling out, re-threading, using the next size up. for example if it was an m2 screw --> m2.5. or for an m2.5 screw then m3. Let us know how you get on. Actually i have a magnesium body dell laptop here and broke a chassis screw clean off. The entire body of the screw is still stuck in the shassis screw hole with no obvious way to get it out again... since its such small diameter. So yeah... not sure what it is with these mangesium chassis

author: MadTux
author_rank: Frequent Contributor
timestamp: February 11, 2020, 03:47:50 pm
content: Get some thread inserts, drill screwed screw holes to size and epoxy inserts into drilled screw holes.That is how I would do it.

author: Gyro
author_rank: Super Contributor
timestamp: February 11, 2020, 08:00:30 pm
content: Wood has been used as a structural gap filler for fixings since time immemorial. It will probably do as a 'permanent' fix.

author: chris_leyson
author_rank: Super Contributor
timestamp: February 11, 2020, 08:22:55 pm
content: Good tip from Ian M. If available for your thread size you could try Helicoil inserts. Might need a bit practice first on some scrap, I know I would. Good luck. Edit: Sorry Blueskull missed your post about the wood splinter, glad it worked, I will remeber that fix if I am ever in the same situation.

author: tkamiya
author_rank: Super Contributor
timestamp: February 12, 2020, 12:37:27 am
content: I do this myself when damage is minor.Use a pin-head hammer and lightly tap the hole. The idea is by thinning THAT area, just around the hole, metal will expand and some of it will migrate to the threaded area. When re-screwing the hole, just go very gingerly. It won't take any torque or it will trash the thread again. But it will hold well enough that the screw won't fall out.

author: BravoV
author_rank: Super Contributor
timestamp: February 12, 2020, 05:49:42 am
content: Quote from: Gyro on February 11, 2020, 08:00:30 pmInstead of wood chips, on metal screw hole, I used solder chips, as they're soft and malleable enough not to destroy the existing screw hole, but as gap filler that will grip strong enough the screw.Its easy to clean as well.

author: Zucca
author_rank: Unknown
timestamp: February 12, 2020, 09:58:37 am
content: Also transparent nail schellac works. One drop on the hole, screw in, let it cure. Done.When you have to remove it, the schellac breaks free.It's nice to know I am not the only one who needs hours/days to repair a 1 second mistake.

author: tkamiya
author_rank: Super Contributor
timestamp: February 12, 2020, 04:51:28 pm
content: Let me just say this, because I ran into this problem and destroyed an equipment.The said equipment didn't have a lose hole but all screw holes are tapped directly into aluminum case itself. That meant, occasionally, metal dust or small shaving may be generated. One of them got on my circuit board which had VERY fine pitch SMD components. Then it proceeded to short out the pins. When one landed on CPU chip (SMD) then it killed the IC. I could see the aluminum dust and tell-tale sign of damage under microscope.Since then, I blow dust very carefully before closing the case. But there is nothing I can do about the dust generated DURING rescrewing of the lid.If you use any conductive material to fix the screws, I'd be careful about this....

author: dreamcat4
author_rank: Frequent Contributor
timestamp: February 12, 2020, 07:11:12 pm
content: So use some loktite thread locker (red or blue liquid) on the screw. This should bind to the particles and keep them in place