Repair Broken Plastic Parts with Epoxy

hi thanks for checking out next-level carpentry I'm doing a short video to answer the simple question can this be fixed I use these little pump up spray bottles for different things and it's just got a little plastic knob and as you can see this one's busted it fell out of my cabinet tipped over on the floor and snapped the little knob off the top and my answer to the question can it be fixed is yes and in my experience there's no glue that you can just use to stick this on and have it be strong enough to be functional but I'll show you a process that I use for fixing things like this and often the question is not whether can it be fixed this should it be fixed and in this case this sprayer is 10 or 12 bucks it shouldn't be fixed it's going to take me longer to fix it than it's worth but the process I use for fixing stuff like this I think is worth sharing to the audience so I'm going to go through it now so you'll know how to fix plastic things that break but the decision of whether or not it's worth it or you're going to bother is up to you but at least you'll have the tools and a process to get the job done so I'm going to go over to the bench and run you through the process so here's a close-up of what I'm working with it's the knob that's attached to this plunger rod and it just made as one plastic molded part when it fell off it just snapped right at the weak point right under this washer and that's what it needs to look like and it only has to be strong enough to run this plunger rod up and down and resist a little bit of pushing but you can see on the broken one here how it sheared off right below that little plastic washer looking thing and I hope you can see the contour at the bottom of the knob matches this little profile of this top where it broke off exactly but it only goes in one position this is kind of tricky with the camera but I don't know if you can see this there's a little rib on the bottom the way this bloke broke off and there's a corresponding little dent in the top of this shaft and by lining up those two features I can tell that this is the exact orientation that the knob needs to be reattached to the shaft every break is different but every break has some characteristic that will align the two broken parts for the optimum fit when they're put back together probably the first most important thing for a repair like this is you get one chance to fix it right if you're the second person trying to fix it there's little hope of getting a good repair and somehow I want to index the part for the proper orientation when I put it back together if this part was white I could just use a sharpie marker to line it up but as it is I just put a piece of tape on both parts and then I'll use a sharpie marker to make an alignment mark it gives me a real good idea of how this needs to go together after I do the next few steps and with those alignment marks I can easily put the knob back in place and wiggle it and get a feel for the exact alignment that it'll take for a good repair my go-to glue for this sort of repair is jb weld there now making it in this handy plunger pack they used to come in two separate tubes like toothpaste now they're put in this double dispenser pack for getting equal quantities of Part A and B and like it says on the back it's used for plastics and PVC other epoxies can tend to melt or softened plastic and won't hold but I find jb weld to have pretty universal applications but like I said earlier in the video there's really no glue that works by just putting glue and sticking the two pieces together jb welded have a good chance of doing that but the repair would probably be not worth the time for doing it so that's why i'm going to show you the next few steps that i use and a repair like this to assure that the repair is stronger than the original and the secret for making quick durable repairs in marginal materials is to use rebar just like rebar strengthens concrete rebar will reinforce a joint between two parts and in this case I'm going to use a piece of brass this is brazing rod I'll use that for rebar for this repair and now I'll show you how to prepare it the first step is to use a grinder rough sandpaper or a file that had grippy texture to the surface of the rebar running it over the coarse wheel on this bench grinder quickly gives this brass rebar a very coarse texture for the epoxy to grip to I want this piece of rebar to be long enough to extend through the knob and down into the shaft aways so I'll just cut off a couple inches of this roughened brass rod and that we have a suitable piece of rebar for this repair the diameter this rod is three thirty-seconds of an inch and I want a clearance hole to be a little bigger so we'll go with an eighth inch drill bit to avoid alignment problems bullet tip bits like these from Dewalt are extremely useful for repairs like this and tell you what I'm gonna go 5/32 instead of an eighth of an inch if I can get the camera to focus you can see the bullet tip design of this bit so it drills its own pilot hole and helps me drill a rebar hole right where I want it the drill press is helpful for this particular repair but often freehand drilling is just fine and I want to drill the hole very near to the center of the X that's marked out by the shaft on the bottom of this knob by using a drill press I can assure that the hole runs straight through the center axis of this knob so now I've got a hole running true through the center of the knob and even if it's a little off-center it's still gonna work fine and you'll see why I hope you can see this okay I put a clamp on the shaft to keep it from going down and kind of stabilize it and I chucked this same bit in my Makita drill and now the crucial step is to line the knob up right where it goes using those alignment arrows and going by feel till the knob drops right where it needs to fit now I'll use the hole in this knob to guide that bit down into the shaft plastic likes to heat up but you can see the hole is slightly off-center on the shaft like it was on the knob but as long as the hole lines up and it's within the that plunger shaft that's going to work great and my rebar it's the length of this drill bit so I'll pull a bit out a little bit to make sure the hole is deep enough to hold the rebar I'm gonna go a little more I think that'll do and now that the bit bottoms out in that hole I know when my alignment marks line up that the rebar will drop all the way in and by having the hole slightly larger than the diameter of the rebar it leaves room for epoxy to fill the hole and it also helps alignment from being such an issue if the hole had a line up precisely I want a mixing stick with a flat end on it boom JB will puts a little mixing tray on here which is kind of cute but I'm going to use a scrap of wood with sharp corners for a mixing palette instead this repair won't take very much material but I'll generally over mix rather than under and just wear rubber gloves for this operation if you're squeamish about the glue as it is I just give this a mix until it's a consistent grey in color this is where the sharp corners on the wood block help for mixing put this little popsicle stick leave something to be desired as a mixer so I'll switch to a trusty putty knife that's going to do and this is a fresh batch of jb weld as you can see it's a very creamy consistency when this stuff sits around for a while it tends to get thick and pasty nevertheless I'll push this over to the edge of the block like so then I just want to roll this piece of rebar in there to give it a good coat of epoxy and I want to prime the whole down in this plunger and it's important to get the epoxy all the way down there there's gonna be an air bubble in there that makes it difficult just keeps one the push air out of there so I just kind of work it until I'm convinced that that that hole has got epoxy all the way down pretty much like that and I'll do the same thing with the knob to make sure the hole is primed all the way through this is where those rubber gloves would be paying off once I've got everything all primed to satisfaction I'll realign the linemen marks and wiggle this until I can feel that it indexes in the right position there it is the sweet spot and then push the rebar home I keep checking alignment each step of the way to make sure that that knob is going to end up just where it's supposed to be and as somebody in Hollywood might say that looks fabulous and interestingly enough the alcohol that I keep in the bottle is the best solvent to use for cleaning up the epoxy well that's still wet I'm going to add a piece of tape over the top of this repair to hold everything in place while the epoxy sets with everything in place it's just a matter of letting the epoxy set up the package shows the curing times of setting in four to six hours cures in fifteen cures to a dark grey that's all wonderful but a heat lap will greatly increase that setting time a word of caution though a heat lamp when it heats up the epoxy makes it runny and if there's anywhere for it to run out of the repair it'll just flow right out and you'll lose it and this repair everything is contained it's not going to run out anywhere so I can use a heat lamp to accelerate it sometimes I have to tip the project so that the epoxy is pooled or puddled so it just forms a puddle or is heating this a project like that upside down the epoxy will just run out so a heat lamp is great to accelerate it as long as it doesn't cause the epoxy to run out of the repair I'll put some of the same epoxy from that batch in here in the light of that heat lamp and I think with the heat from the heat lamp this blob of epoxy on that stick is going to flow off that little paddle but that's alright it'll give me an idea of the curing time of the epoxy and the repair I decided to use this little spatula to smooth out the epoxy under the washer part of this knob the epoxy has gotten pretty runny because of the heat from the heat lamp but I can smooth it out underneath this washer and it'll help the repair cosmetically if not structurally and it also gives you an idea of things that you can do when your repairs are different than this and need a little more attention than the initial application of epoxy so you can see by the clock on the wall it's just about eleven o'clock I mixed up this epoxy it 915 shut off that heat lamp and you can see that the epoxy under the heat lamp it's just warm to the touch yeah and it's as hard as a rock in an hour and 45 minutes well the rest of the stuff on the mixing board is still all gooey so you can see the difference the heat makes I could have just as easily left this overnight and not sweated the heat lamp but for the sake of the video I wanted the fast-track it to show you what's possible take off the clamp this epoxy is still not as rock hard as jb weld gets it'll be that dry by morning but it's plenty strong to demonstrate the effect in this repair needs these alignment marks anymore and see the heat from the heat lamp softened up the glue on the back of the tape but that's that's a good repair a little bit misalignment of the knob I didn't get this Trude up as perfectly as it could have been you can see it wobbles a little bit there but it'll be more than good for using this it also kind of demonstrates if the repair is more critical I would have made some sort of an alignment fixture to get the axis Trude up better as it was I just stuck that tape on there and didn't pay enough attention to the alignment but it's still going to be plenty good and extend the life of my cheap little sprayer for a while so I guess I can wrap up this video $100 repair of a $10 sprayer but I hope you get the idea of how a piece of metal can be used as rebar for repairing epoxy parts I've done this with a lot of tools parts of my vacuum cleaner all sorts of things that snap and I really want to keep the part whether the value is really there or not to justify it but jb weld a clearance hole and a piece of rebar will go a long way towards making permanent effective repairs and i'm sure that the repaired knob is now stronger than the not repaired knob but anyways i want to wrap this up try to get this video published and i've got cabinets here for that master closet to do i spray-painted the drawers today and had all the parts out drying so i wanted to get this thing taken care of while i was kind of on the interim between lacquering drawers and staining parts anyways if you liked the video poke the thumbs up button i'd appreciate it and consider subscribing to next level carpentry there's all sorts of content this is a little bit unusual for the channel but I thought it might apply to some things that you encounter in the shop or on the job I want to thank all the new patrons on patreon they're really helping support the video production effort here at the channel there's a growing list and I appreciate each and every one of you for going above and beyond to support the channel t-shirt sales at teespring have been robust since these new ones came out and you can see these in the link right below this video get one of those if you're liking what you see here at next level carpentry I'm not sure what the next video uploads' going to be but in the meantime as always thanks for watching dueling spray bottles

Channel: Next Level Carpentry

Views: 19,323

Rating: 4.9323673 out of 5

Keywords: epoxy, plastic, broken, busted, busticated, repair, fix, hack, mend, next level carpentry, diy, best, fast, fastest, strongest, strong, better, simple, rebar, glue, gorilla, gorrilla, jb weld, elmers, superglue, super

Id: V_NlfJr3SOE

Length: 16min 7sec (967 seconds)

Published: Sun Aug 04 2019