Ritchie 6 Posted May 4, 2015 Hi, i am currently restoring a chassis that was unfinished and renewing parts where i can, however, whenever i try to screw into the plastic, the screws will not tighten, has anybody got any suggestions please, thanks. Share this post Link to post Share on other sites
WillyChang 1814 Posted May 4, 2015 Coat inside of hole with superglue. Share this post Link to post Share on other sites
Ritchie 6 Posted May 4, 2015 Thanks for that, would the use of threadlock do the same job guys? Share this post Link to post Share on other sites
WillyChang 1814 Posted May 4, 2015 No, anaerobic threadlock is for metal-2-metal bonding. Plastic thread repair is best/easiest/fastest with superglue. If your hole needs more filler material, shave a sliver of wood/toothpick down the hole before applying glue. It's also ok to use machinethread screws into plastic holes. Those selftappers are easy to overtighten until hole strips. 2 Share this post Link to post Share on other sites
GregM 1109 Posted May 4, 2015 I've been using UHU Plast flüssig in the past, which is essentially a glue for plastic model kit building that melts the plastic parts together. I think similar plastic model glues are available from other brands too. I use it by placing some drops on the screw or inside the hole, then tighten the screw into the hole 2 times, and then let the screw inside the hole for at least 24 hours. Worked well for me. 2 Share this post Link to post Share on other sites
Tamiyabigstuff 832 Posted May 4, 2015 My repair method for stripped threads in plastic - 1) Superglue a piece of scrap parts tree into the screw hole, enlarge slightly if required using a drill and allow to set & trim as required. 2) Drill a new hole in the centre of the now filled hole to take the screw and cut a new thread. 2 Share this post Link to post Share on other sites
bromvw 744 Posted May 5, 2015 My repair method for stripped threads in plastic - 1) Superglue a piece of scrap parts tree into the screw hole, enlarge slightly if required using a drill and allow to set & trim as required. 2) Drill a new hole in the centre of the now filled hole to take the screw and cut a new thread. you can also powder up some scrap parts tree and make a paste using Plastic weld solvent . Fill the hole , allow it to set overnight and drill a hole to suit . Works well 3 Share this post Link to post Share on other sites
GregM 1109 Posted May 5, 2015 Great advice, I'll try your suggestions next time I've got to struggle with threads. Many thanks! Share this post Link to post Share on other sites
Yonez 180 Posted May 5, 2015 you can also powder up some scrap parts tree and make a paste using Plastic weld solvent . Fill the hole , allow it to set overnight and drill a hole to suit . Works well Smart! I think I need to start saving my sprues. They've gone from trash to resource :-) 1 Share this post Link to post Share on other sites
bromvw 744 Posted May 5, 2015 Smart! I think I need to start saving my sprues. They've gone from trash to resource :-) the big advantage is that your using the same material so in theory the repair will be as strong as the original part 2 Share this post Link to post Share on other sites
Ritchie 6 Posted May 12, 2015 Thanks for the advice guys, much appreciated Share this post Link to post Share on other sites
steelo 93 Posted May 12, 2015 This probably sounds crazy, but I've actually melted a small portion of a parts tree (with a heat gun) to fill the stripped out hole, let it cool, molded it to be flat and then drilled a new hole to set the screw in. Just don't melt it to the point it is burning Sounds silly, but going on a year and still holding =) 2 Share this post Link to post Share on other sites
XV Pilot 1936 Posted May 12, 2015 That doesn't sound silly at all. Plastic welding is a recognised repair technique, used on everything from car bumpers to domestic appliances. Makes sense to use it on model cars too! 1 Share this post Link to post Share on other sites
Droopy1975 39 Posted May 13, 2015 I have once used heat shrink tube to repair a stripped screw hole. Heat shrink the thread of the screw and superglue it in the stripped hole, after drying remove screw and you have a nice threaded hole. 1 Share this post Link to post Share on other sites
Ritchie 6 Posted May 13, 2015 great advice guys, i will try these at the weekend, work has prevented me doing my hobby for a few days, but we all have to earn a crust don't we LOL Share this post Link to post Share on other sites