I am sick and tired of crap epoxy.

[CatalinaWOW]

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.

[Mr. Scram]

Why 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"?

As 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.

[bd139]

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 set
2. Which brand is best to glue your tinfoil hat on with.

[Refrigerator]

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 set
2. Which brand is best to glue your tinfoil hat on with.

Now 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.

[bd139]

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

[ConKbot]

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.

[BU508A]

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.

I 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

[sarel.wagner]

Two really good epoxies, West Systems and Pratley.

Rgrds

[smile]

Get this weicon epoxy stuff, industrial strength
https://www.weicon.co.uk/product-category/epoxy-resin-systems/plastic-metal/?orderby=rating

But price is crazy too

[CopperCone]

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.

[thm_w]

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

JB is the good stuff,

[aargee]

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.

[BradC]

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.

Interesting, 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.

[Ian.M]

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.

[Refrigerator]

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.

The 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.

[T3sl4co1l]

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

[Ian.M]

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.