I am sick and tired of crap epoxy. - Page 1
Forum section: electronics / general

author: Refrigerator
author_rank: Super Contributor
timestamp: January 05, 2018, 02:47:14 pm
content: I am pissed. Yesterday i went to open my HP laptop and one of the hinges ripped itself out of the frame. So i picked up some "3 ton"epoxy to fix it up. I basically drowned the hinge in epoxy but 24 hours later after i came to check on it the epoxy was about as hard as PVC cable insulation, easily carved away with my fingernail.Now i'm extra pissed because not only did the hinge rip out but the epoxy didn't even harden and now i have to carve it out.I tried every single type of epoxy that i found locally and all of them were useless.Next step is to look online, any recommendations ?Ps: Dave, you should add a "burning money" emoticon.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 05, 2018, 03:13:23 pm
content: Quote from: Refrigerator on January 05, 2018, 02:47:14 pmDo you have to mix two parts together? If you don't, get that stuff. If you already had that, it not hardening is typical when you have the wrong proportions.

author: Tomorokoshi
author_rank: Super Contributor
timestamp: January 05, 2018, 03:28:01 pm
content: 5-minute epoxies are too brittle for anything that flexes.This is slightly compliant and works very nicely:https://www.digikey.com/product-detail/en/3m/DP-190/3M155869-ND/386454024-hour cure time.

author: CJay
author_rank: Super Contributor
timestamp: January 05, 2018, 03:32:35 pm
content: If you get the mix wrong, don't mix it thoroughly, if the epoxy has been subjected to temperature extremes in storage then it won't set up properly.It can also be affected by temperature extremes during the cure time and if you use an excessive amount making the epoxy too thick, then it can take a lot longer to cure as it can generate heat as it cures.I've had good experiences with Permabond branded epoxies, Araldite and all the epoxies I've tried from RS components.I've even had success with the cheapest of the cheap discount store epoxy.Basically, most epoxy problems are user error.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 05, 2018, 03:54:34 pm
content: Quote from: CJay on January 05, 2018, 03:32:35 pmSpot on. The only thing I would add is that heat speeds up curing, as most chemical reactions speed up in more energetic environments.

author: jm_araujo
author_rank: Regular Contributor
timestamp: January 05, 2018, 04:01:21 pm
content: To glue plastics (or plastic to metal) I've not yet found a better one than Devcon Plastic Weld:http://www.itwconsumer.com/devcon-products/product.cfm?id=Plastic%20Welder%E2%84%A2%2C%2025%20ml-23I used to buy it online on ebay until I've found a local seller.It cures fast and the working time is relatively short (around 5 minutes, you have to hurry after mixing it), but it adheres like crazy to ABS and other plastics and is very strong. Never used it in your application, but it would be my first choice.

author: Refrigerator
author_rank: Super Contributor
timestamp: January 05, 2018, 04:03:39 pm
content: I've been using epoxy for many years now and i know all the quirks about them. The only problem i have is that the local stuff is about as good as spit and prayer. The "cold weld" ones are even worse. Many moons ago my brother had brought some good epoxy that would be hard as rock and didn't fear heat, nowadays all i can find is just two-part disappointment.

author: ajb
author_rank: Super Contributor
timestamp: January 05, 2018, 04:10:03 pm
content: Definitely choose an epoxy that's specified for the material you intend to use. The Devcon plastic weld is the best I've seen for plastics. Surfaces need to be clean and dry, contaminants will reduce adhesion or can even prevent the epoxy from curing properly. Smooth surfaces may benefit from a light sanding.Mixing thoroughly and in the right ratio is crucial. You can get mixing nozzles that attach to the end of the cartridge so the epoxy can be thoroughly mixed and dispensed directly onto the part. Those work really well. Occasionally you'll find a consumer-grade 5-minute epoxy that comes with the nozzles, but generally only the more expensive epoxies come in cartridges that accept the nozzles.

author: bd139
author_rank: Super Contributor
timestamp: January 05, 2018, 04:10:20 pm
content: Devcon 2 ton epoxy is my goto. You have to actually apply it properly though rather than just slop it on. Not a lot of people know that.1. Both surfaces need to be cleaned and roughened up if it's plastic. I use a Dremel and a wire brush attachment.2. Then score both surfaces (quite deep) in a cross pattern with an xacto knife or something.3. Sueeze it out (equal parts carefully) and mix it. I use a cupcake case and a coffee stirrer nicked from Starbucks. Mix it for a long time. Literally 2-3 minutes, not just a quick whizz.4. Spread some thinly on both contact surfaces.5. Leave it 2-3 minutes again.6. Then fill with it.7. Then leave it 24 hours before even farting near it.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 05, 2018, 04:12:40 pm
content: Another tip would be to get the nastiest, most industrial stuff you can find. Even though you need to be mindful what you do, it's typically a lot better than consumer grade stuff. Just make sure to protect yourself and whatever you do, don't glue any part of yourself to anything else.

author: Cerebus
author_rank: Super Contributor
timestamp: January 05, 2018, 04:19:26 pm
content: My general purpose "go to" epoxy resin for general repairs and small layups is Devcon 2 Ton Epoxy (Part no. 33345 for the 250ml pack). Thirty minute open time, 30 minutes more to set, 8-12 hours full cure. Water clear, low-medium viscosity, good balance of toughness versus strength, not too hard or brittle, long enough open time that you're not rushing to mix it and use it. short enough setting time that you don't need to keep parts clamped for hours.Look out for resins that, like the Devcon, have a "Use by" date on the pack - that way you know whether you're buying fresh resin or not. This stuff has a shelf life and starts to fall off in specification once the shelf life is reached, and won't even cure properly 18 months or so after the expiry date.My best recommendation for all epoxy resins is, get the mixing ratiosby weightoff the professional data sheets for the product you're using and mix by weight,notby volume. Buy a small scale off ebay that reads to 0.01gm resolution or better so that you can mix small quantities without messing up the ratio.Also, I keep some small sheets of fibreglass tissue, carbon fibre cloth, Kevlar cloth, and Kevlar felt handy. A small patch of the appropriate one for the job added to a repair can double, or more, the strength of the repair.

author: Refrigerator
author_rank: Super Contributor
timestamp: January 05, 2018, 04:25:26 pm
content: Quote from: Mr. Scram on January 05, 2018, 04:12:40 pmI've had an encounter with some industrial epoxy when i tried ripping a magnet out of a motor and even at about 200oC the epoxy was still strong enough to rip the magnet in half. I could only wish for epoxy like that. There is an old saying that in terms of solvents and adhesives the harder it stinks the better it is.

author: Vtile
author_rank: Super Contributor
timestamp: January 05, 2018, 05:54:19 pm
content: My experience with many of these supermarket epoxies is that they do take several days for the final cure (to harden fully and get fully dry surface). You are not applying it in cold garage (I doubt, but just in case) aren't you?

author: edpalmer42
author_rank: Super Contributor
timestamp: January 05, 2018, 06:44:42 pm
content: The best epoxy I've found is J-B Weld. One part is white, the other is black so the result is a nice metallic grey. After a day, it's so hard that you can't bend a piece the size and shape of a large coin. If you use pliers, you can break it, but not bend it. Search youtube, one guy built a cylinder head out of J-B Weld.Ed

author: SeanB
author_rank: Super Contributor
timestamp: January 05, 2018, 07:40:45 pm
content: Pratley and Araldite epoxies are good, though the best are the ABE industrial products, though the straw yellow colour and the 8 hour gel time are a little inconvenient, but it does cure into a stronger than concrete mass, which considering the major use is structural bonding of concrete is not surprising.Otherise there is a powder and superglue system that is quite good, and does cure pretty fast as well, though the powder is messy to work with. you can emulate it with ordinary gel superglue and talcum powder though, just mix and use really fast in situ.

author: Refrigerator
author_rank: Super Contributor
timestamp: January 05, 2018, 07:48:18 pm
content: Quote from: Vtile on January 05, 2018, 05:54:19 pm20oC is not cold and my bedroom is far from a garage (although it's slowly getting there)

author: ez24
author_rank: Super Contributor
timestamp: January 05, 2018, 08:07:42 pm
content: Watching

author: gibbled
author_rank: Regular Contributor
timestamp: January 05, 2018, 08:31:44 pm
content: West System produces a great series of structural epoxies. I like their 105 system for all sorts of repairs. Its not perfect however, its mixed at a 5-1 ratio and is slow to cure without the application of heat to kick off the reaction. 858d hot air station set to 100c works well to speed up the cure. Various fillers can be used to modify the materials properties.I fill separate syringes with resin and hardener to allow precise metering of small amounts.https://www.westsystem.com/

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 05, 2018, 09:29:56 pm
content: And above all, mind the application. Lid hinges are under an impressive amount of stress. They're made as small as possible to save on cost, space and weight, and that means metal (usually?). No plastic can ever repair a metal part. Your only option in that case is to get full replacement hinge parts -- which usually involves taking apart the screen as well, and they may not be very cheap parts, either.Tim

author: Refrigerator
author_rank: Super Contributor
timestamp: January 06, 2018, 08:01:15 pm
content: Quote from: T3sl4co1l on January 05, 2018, 09:29:56 pmIn my case(pun intended)the hinge ripped itself along with the screws and the threaded inserts out of the frame. I had a lenovo laptop where the metal part of the actual hinge broke in half but those were easily fixed with a TIG welderPs: now that i think of it that was a weak pun

author: chris_leyson
author_rank: Super Contributor
timestamp: January 06, 2018, 08:37:05 pm
content: QuoteI glued a mirror back onto a galvo with Loctite "double-bubble" 5-min epoxy. No big deal really but I just happended to be using that galvo for testing a control loop at the time. Anyway there is an anti-resonance in the control loop due to the stiffness of the shaft and mirror and I just happened to notice it was much lower than normal and so out of curiosity I checked it twice a day for a week. It took about 5 days for the anti-resonance peak to drift to its final value, in other words about 5 days for the epoxy to reach its final strength. I never was convinced we were using the right epoxy for optics but you can't argue with some people.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 06, 2018, 10:45:50 pm
content: Quote from: chris_leyson on January 06, 2018, 08:37:05 pmYou have to love hard data!

author: ajb
author_rank: Super Contributor
timestamp: January 07, 2018, 01:23:11 am
content: Quote from: chris_leyson on January 06, 2018, 08:37:05 pmThat's a neat test! The results are not at all surprising, though. 3M DP-100, for example, which is a general purpose 5-minute work time epoxy, has a specified cure time of 24-48 hours--cure time being defined as time to reach 80% of its ultimate strength. So five days is certainly believable. Curing can generally be accelerated by heating, to a point, but of course this means that any mismatch in CTE across the bond will result in thermal stress when the part returns to room temperature. In the worst case, this can even cause the part to fail when exposed to lower temperatures. I went to a whole seminar on adhesives for optical assemblies at a conference a few years ago, it's a surprisingly interesting and involved subject.Quote from: Refrigerator on January 05, 2018, 07:48:18 pmMost epoxies are probably going to be fine at 20C, but much lower than that can certainly start to noticeably slow the cure. One of the heaters at work broke recently--conveniently in the middle of a cold snap--and apparently our production folks started having trouble with an epoxy when that area got down to probably 14-15C.

author: mc172
author_rank: Frequent Contributor
timestamp: January 07, 2018, 01:33:37 am
content: Quote from: Mr. Scram on January 05, 2018, 04:12:40 pmWhy would there ever be a market for "consumer grade" aka inferior stuff? They'd have to run a separate batch, thus costing more money than to simply run the same batch, with fewer people buying it due to inferior effect. It seems like an old wives tale to me.This begs the question - what is the "most industrial" stuff that you yourself can find? Is it Gorilla Glue, due to its impressive marketing machine? Or, Axson Epolam, which is available in "industrial quantity"? Is that "industrial"?

author: ajb
author_rank: Super Contributor
timestamp: January 07, 2018, 02:16:26 am
content: Quote from: mc172 on January 07, 2018, 01:33:37 amIt's not so much that there are "Industrial" and "consumer" versions of the same product, but different products for each market, and there are definitely products marketed/labelled specifically for industrial/non-consumer use. Flip through a 3M or Henkel industrial catalog and you'll certainly find products that say "FOR INDUSTRIAL OR PROFESSIONAL USE ONLY. NOT INTENDED FOR CONSUMER/RETAIL SALE OR USE" right on the front of the can.AFAIK, "industrial" products can be exempt from certain consumer safety and environmental controls that consumer products are required to comply with, presumably because they're intended to be used by people who know what they're doing and have suitable PPE. So if being "Industrial" allows an adhesive to contain more of a particular solvent or something then being "Industrial" could go along with improved performance. Whether that's relevant to a particular application depends is another question.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: January 07, 2018, 05:21:12 am
content: Industrial products may also come with a penalty, in that they assume that the user will have all of the tools and expertise to use the product properly. So the material can assume care measurement of the components, careful surface preparation, age control of the ingredients, proper mixing and proper curing conditions.Consumer products may be adjusted to be forgiving of mix ratios, surface preparation and age among other things. Since there is no free lunch they may perform less well by other metrics.Depending on your access to precision scales or volume measuring tools and your diligence in use consumer products may actually be the better choice.An interesting case of consumer influence on product comes from my relatively recent move from the desert Southwest of the United States to the much cooler Northwest. In the Southwest the hardware stores carried epoxies with setting times nominally ranging from 10 minutes to 2 hours. In normal summertime outdoor/shop temperatures that meant a setting time from a barely usable 3 minutes up to around 20 minutes. Here in the Northwest the only thing I find has a nominal setting time of 5 minutes, and at winter shop temperatures takes all day to set.

author: Mr. Scram
author_rank: Super Contributor
timestamp: January 07, 2018, 05:53:30 am
content: Quote from: mc172 on January 07, 2018, 01:33:37 amAs others have answered correctly, consumer grade glues generally provide more leeway in a number of areas. They will be less dangerous to process or less dangerous when abused, have a smaller impact on the environment when disposed of incorrectly or more forgiving when processed, for instance. They can be less concentrated, are often available in smaller quantities or are a cheaper variety. Obviously, the packaging will also be different. Consumer products need to sell themselves with fancy packaging, while more professionally oriented materials are generally packaged in a practical manner. I can assure you it's not an old wives tale. Most stuff sold to the public in quantity has to be fairly fool proof.Obviously, I was being a bit fulsome in my previous comment. There are materials out there that can be outright dangerous to you or others. As a consumer, you often won't easily get your hands on the proper and sometimes dangerous industrial stuff, but looking for the more industrial leaning adhesives can certainly help. Going for two part adhesives is a good start, as a lot of consumer products are developed for convenience rather than ultimate strength. I typically look for these things in shops that mostly supply professionals or other shops, rather than consumers. They can often provide good advice too, as they tend to know their stuff.It's actually not that different from the tools more familiar to us. Those can be found in consumer grade varieties or more no nonsense professional grades too. Adhesives aren't much different. There are Aoyue adhesives, and Weller ones, so to speak.

author: bd139
author_rank: Super Contributor
timestamp: January 07, 2018, 09:25:05 am
content: Looking at some other threads on here at the moment, I’m surprised this hasn’t devolved into:1. There’s a government conspiracy to make our epoxy not set2. Which brand is best to glue your tinfoil hat on with.

author: Refrigerator
author_rank: Super Contributor
timestamp: January 07, 2018, 09:53:35 am
content: Quote from: bd139 on January 07, 2018, 09:25:05 amNow that you mentioned it this is exactly what's going to happen.Anyways, I fixed the damn laptop. Got me some 5min epoxy that is pretty all right and fabricated some steel sheet into a sub-frame to really stiffen things up in there. The brass threaded inserts that were ripped out are now soldered straight to the steel sub-frame. Everything seems to holding well so far. The 5min epoxy is about as hard as poly carbonate when it cures.

author: bd139
author_rank: Super Contributor
timestamp: January 07, 2018, 09:59:14 am
content: Cool good luck.For ref if anyone else wants to buy a laptop that the hinges don’t break on, look at the thinkpad T series. They are machined stainless and are screwed to the screen chassis and the main chassis which are both titanium

author: ConKbot
author_rank: Super Contributor
timestamp: January 08, 2018, 06:18:35 am
content: If you want to glue to plastic, I haven't seen anything better than 3m DP8005 or DP8010. Rather than going for solvent to soften it, they use a chemical which lets the monomer cross link with the base material. I've used it for gluing ABS 3d printed parts into pelican cases (polypropylene, quite solvent/chemical/epoxy resistant) Comes in nice double tubes for no measuring, you just need the 3m dispenser gun.The chemical also crosslinks DNA, making the uncured component carcinogenic, and it smells about as toxic as it probably is.

author: BU508A
author_rank: Super Contributor
timestamp: January 08, 2018, 07:16:21 am
content: Quote from: edpalmer42 on January 05, 2018, 06:44:42 pmI can second that. I've used J-B Weld for some of my projects and it is really good stuff.https://www.jbweld.com/Another Epoxy I can recommend is the industrial / professional stuff from Araldite.Here you can find a list of them and where to use it:http://www.huntsman.com/advanced_materials/a/Your%20Industry/Adhesives/Industrial

author: sarel.wagner
author_rank: Regular Contributor
timestamp: January 08, 2018, 09:35:07 am
content: Two really good epoxies, West Systems and Pratley.Rgrds

author: smile
author_rank: Regular Contributor
timestamp: July 04, 2018, 08:37:37 pm
content: Get this weicon epoxy stuff, industrial strengthhttps://www.weicon.co.uk/product-category/epoxy-resin-systems/plastic-metal/?orderby=ratingBut price is crazy too

author: CopperCone
author_rank: Super Contributor
timestamp: July 05, 2018, 12:47:17 am
content: I saw a youtube video that showed some loctite super glue from home depot being cut open to reveal a container of russian super glue.I am considering buy over priced stuff from digikey or something in the future now.For plastics I was impressed with the home depot brand super glue that has a sensitizer stick, which you rub on the plastic first before gluing with what smells like cyanoacrylate. I kind of wonder if the sensitizer would interact well with epoxy.

author: thm_w
author_rank: Super Contributor
timestamp: July 05, 2018, 07:06:30 pm
content: Quote from: edpalmer42 on January 05, 2018, 06:44:42 pmJB is the good stuff,

author: aargee
author_rank: Frequent Contributor
timestamp: July 06, 2018, 12:56:23 am
content: Like others, JB Weld for those difficult situations.Back 40-odd years ago, my father brought two tins of Metalset home from work (Airforce), it was used (amongst other things) to bond a broken hinge on a wooden box that has been in continuous use to today.https://www.smooth-on.com/products/metalset-a4/, looks the same as the day it was applied.

author: BradC
author_rank: Super Contributor
timestamp: July 06, 2018, 04:40:59 am
content: Quote from: aargee on July 06, 2018, 12:56:23 amInteresting, the application notes state : "The surface should be sanded till clean followed by wiping surface with solvent (acetone, MEK, mineral spirits). Let solvent evaporate fully before applying A4."I started doing that a few years ago. I use clear PVC priming fluid which is roughly a 50/50 mix of Acetone & MEK. It made a massive difference to my long term success rate with difficult bonds. Prior to that I used to use either Metho or isopropyl, but the extra oomph of the priming fluid really made a significant difference.I like the look of that product, and since there is an agent for it over East I might get some to supplement my adhesives container (which currently contains 5 minute & 24 hour Araldite, JB Weld & Devcon Plastic Welder). The metalset-a4 looks like it will do most of what the JB weld does, except it's much stronger albeit with a much lower temperature resistance. Another tool in the box.These days I generally use a either the 24 hour Araldite or the Devcon Plastic Welder. Since I started heat-curing the Araldite I found it a lot more versatile to work with. I do have a soft spot for JB weld though. For a (relatively) high temperature domestic epoxy it's pretty impressive.That reminds me, I need to buy some more Plastic Welder. The last batch I bought from Amazon is almost gone. I need to find a local source for it so I don't have to stock up and can get it fresh.

author: Ian.M
author_rank: Super Contributor
timestamp: July 06, 2018, 05:20:56 am
content: Most of the fast consumer epoxies are crap. As the O.P. is in Europe, probably the best easy option is to get Araldite Standard which takes about 8 hours to reach a 'green' cure*and at least 14 hours to fully set. Prepare surfaces by sanding and solvent wiping then allow to dry for at least 12 hours so they are solvent free. Do not touch the surfaces after preparation.Mix a lot more than you need so you can get an accurate mix ratio - its a consumer product so its equal parts by volume, and unless you've got a high resolution digital balance + the exact densities is difficult to mix by weight. Using a clean 10ml measuring spoon and knifing off the excess of each component would help get an exact mix ratio. Use plasticine dams if required to prevent it flowing away from the joint. Make sure the joint is mechanically supported while it cures. After it reaches a 'green' cure, post-cure in a warm place ideally at around 60 deg C, keeping the joint supported for 24H.That's about as good as you can do without getting a specialist industrial product.* 'green cure' - firm but still indentable with a finger nail.

author: Refrigerator
author_rank: Super Contributor
timestamp: July 07, 2018, 06:27:27 pm
content: Quote from: Ian.M on July 06, 2018, 05:20:56 amThe cheap 5 minute epoxy that i've been using behaves sort of like what you've described, it becomes firm but indentable and continues to stiffen.Recently i've noticed that it doesn't harden as well as i remember it, it used to become like glass but now it's just as disappointingly soft as all the other epoxies.I think it might be because i've opened it a long time ago and been using it since so it may have aged or absorbed moisture but the decrease in hardness is very noticeable.I've noticed, albeit kind of too late, that the 5 minute epoxy that i've been using softens in contact with solvents and becomes about as hard as hardened hot glue, maybe even softer.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 07, 2018, 06:37:24 pm
content: Old epoxy cures poorly. I've had "2 ton" epoxy where the one component yellowed a bit, and the other component became granular. Curing was very slow (days to reach ~full hardness) and strength was quite poor (after ~weeks, obviously brittle and weak).A combination of polymerization (the components contain oligomers, I think, which can stick together on their own, without the other component), oxidation, UV degradation and so on.Tim

author: Ian.M
author_rank: Super Contributor
timestamp: July 07, 2018, 07:14:16 pm
content: Epoxy, (resin and hardener) properly stored in bulk in well sealed containers has a long shelf life and often still retains most of its performance well after its expiration date. However the resin component is prone to separation and crystallisation at low temperatures, and unless it is warmed up till the crystals melt, then thoroughly remixed, they cause incomplete curing and major degradation of its mechanical properties. Many epoxy hardeners degrade in the presence of moisture and carbon dioxide, and if the hardener is excessively degraded by absorbing moisture or CO2 from the air before use, or the joint absorbs too much moisture and CO2 while curing (e.g. due to excessively low temperatures slowing setting + high humidity), again the result is degraded mechanical properties, compounded by 'amine blush' - a waxy film on the surface produced from the reaction of the hardener with moisture + CO2, that will cause adhesion failure if it isn't totally removed before further gluing or painting. Yellowing and crystallization round the container opening is indicative of such degradation, and is *NOT* resolvable.Because consumer packs in tubes or syringes are so small volume, shelf life is poor and if stored in cold, damp or excessively warm conditions the the odds are against you. Syringes are particularly problematic as the plunger seal is often non-hermetic, and once opened the caps are often fairly ineffective. Foil tubes are much better, as until opened, there is a foil seal, and they usually have well-fitting screw caps, so as long as they are mechanically protected by the pack and if partially dispensed, squeezed carefully so crossing creases resulting in pin-pricks don't form, they can be usable for a long time after first opening. However the crimped seal at the other end can be suspect so its a bad idea to use the last few ml of an old tube in a critical application.Most clear and translucent epoxies have low UV resistance, and if used outside should always be overcoated, preferably with opaque paint, but if a clear finish is required, then several coats of a UV resistant two component varnish may be used.A further note: Epoxies are incompatible with Polyester resin products - polyester resins have poor adhesion to cured epoxy and the curing by-products of polyester resins tend to inhibit epoxy cure, so unless the polyester resin is well aged in a low humidity environment so all volatiles have outgassed to a minimal level (years rather than weeks), adhesion of epoxy to cured polyester resin can be poor due to incomplete polymerisation of the boundary layer. Epoxies are typically inhibited by carboxylic acids (e.g acetic acid), so its also worth noting that spirit vinegar mixed with an equal quantity of acetone will get uncured epoxy off tools and out of brushes, and ordinary table vinegar + detergent and sand or a similar mild abrasive is one of the better ways of getting it off skin.