How to choose a̶n̶ a̶d̶h̶e̶s̶i̶v̶e̶ a bond based on material, method, and requirements

[@DaveEtchells]

Here’s a tip for getting things to bond to HDPE I’ve used it to get paint to adhere, suspect it would work for adhesives as well, although I don’t know how strong the bond would be. HDPE is said to have low “surface energy” because it has fairly strong, non-polar C-H bonds on its surface. You can break those up and oxidize the surface just by hitting it with a flame for a few seconds. Oxygen makes polar bonds, so polar paints and adhesives will bond to the oxidized surface. You don’t even have to hear the part up much, just a few seconds of waving a the flame from a propane torch back and forth across it will do the trick. I found out about this when I had a project with a big chunk of an HDPE cutting board in it that I wanted to paint. After some research I stumbled across this flame treatment, gave it a try and the paint bonded great. (Sanding the surface works too, or do both for maximum effect. Sanding apparently works simply by the surface area; I thought it was actually creating opportunities for a mechanical bond, but it turns out that it just comes down to more surface area per unit area, if that makes sense.) Fantastically useful video, BTW; your vids have more utility per unit time than anything else on YT.

[@ferriswhitehouse1476]

thats a great idea with the torch. I have done a little bit of hdpe welding and when you are trying to weld it, the oxide is a problem and you have to scrape it off to get a good joint. And when you aren't very good like me you end up putting too much heat into the parts and oxidizing them accidentally. But that makes perfect sense that a thin oxide layer would increase the surface energy and help with bonding of adhesives. Thanks for sharing :)

[@DaveEtchells]

@@ferriswhitehouse1476 Oh, interesting that just excess heat will make it oxidize too - although I guess it shouldn't be surprising, enough heat and it'll oxidize *rapidly* (burn). It took a lot of searching before I found out about flame treatment, so it seems it's not well-known. It's so easy and works so well I'm surprised it hasn't propagated more among the maker community.

[@davidmalawey]

thank you so much for this encouragement! Also, I am DEFINITELY going to explore this flame treatment. I never expected how much good info i’d receive back from the viewers, by making these recent videos.

[@goodun2974]

To loosen hot glue from a circuit board, put pure isopropyl alcohol on it and wait about 5 minutes. The alcohol will work it's way underneath the glue next to the surface of the board and break the bond between them. It doesn't actually dissolve it, and I don't know how or why it works, but it does.....

[@alamppmala]

Viscosity, I guess? Similar to how ISO (or vodka..) will tend to leak around a water bottle's lid, but water won't. Good tip!

[@patrickcallahan2210]

In a composites class I had in college the professor mentioned that the wetting angle can be a very useful tool in getting an idea if adhesives and materials are going to be compatible (more wetting/angle leading to better bond). In the boat repair world 3M 5200 was the go to if you wanted something to stick and never come off (as such it could be poorly used by rookies creating headaches for the old timers, lol). Also G10 (compressed fiberglass circuitboard material) and Micarta (thermoplastic impregnated things like linen, cotton, and other things) are things used in the knifemaking world.

[@bradnail99]

Great video! Adhesives have long fascinated me. Gluing is the study of a lifetime. Despite all the science one can bring to bear, gluing remains an art. Surface preparation and joint design are just as important as adhesive selection. Nylon, polyethylene, polypropylene, and PTFE (Teflon) are characterized as having low surface energy, which is why they are not easily glued.

[@Jdog1681]

I love your content and how casual it is. You're bringing a lot of expertise to the table. As an EE, this helps me greatly. I love how this is becoming like a textbook digest for everything mechanical design. Not that's it's worth anything, but maybe this helps you for videos like this: - If you're struggling to format and organize videos like this (It's come across to me that you've expressed that), I think some takeaways from Project Farm videos would greatly improve your throughput, flow and organization. To me you come across as the Project Farm of design and principle/component selection. Just be sure you don't copy him too much, I love where you're going. - Patreon seems like a great model for your content. You can get higher value per viewer and it's a great way to maintain reputation/integrity. I think your expertise is a clear, valid, and fair value prop for it. It would also allow you to purchase better supplies to give better and more comprehensive feedback. It would be awesome if you could just really easily integrate all the recommendations from your comment sections. Everyone's learning together here! Thanks for the great work!

[@goodun2974]

I don't use Patreon and I don't monetize any of my own electronics-related videos, but FranLab pointed out recently that Apple has forced Patreon to pay them 30% !!! Yup, 30% ! of any donation made to a video creator via Patreon if it was done with an Apple IOS. I personally would never use an Apple product because I hate the company, but this is something that others need to be aware of.

[@LovableCoolGuy]

for joining polyester webbing to velcro patches (or to itself), i always recommend a strong flexible mechanical bond with some nylon thread and a sewing needle. 😁

[@RichRauenzahn]

Silicone mixed with corn starch makes a great putty similar to similar to Sugru. But you have to use the acetic acid curing version.

[@xsietube]

Adding cornstarch will also allow you to use it for mold making. It works with the acetic acid silicone because it is dependent on moisture to cure. The cornstarch will contain some moisture so it helps the silicone cure more evenly throughout.

[@ChriFux]

awesome work, thanks! ❤ video suggestion: solvents and plastic compatibility

[@davidmalawey]

this was actually a barrier to making the glue video. as i went through, i found myself trying to say “i know this won’t work because acetone won’t even melt it” etcetera, but first i had to describe my experience with the solvents… then id use the wrong terminology and then i have to study more… the overthinking hits hard! but anyway yes the solvents idea is crucial.

[@Mrshotshell]

30:40 The best way to mix anything with 2 parts is to transfer it to a different container/ piece of plastic after partially mixing it to ensure there's nothing left unmixed on the surface. I would also avoid mixing on cardboard or other surfaces that could absorb some of the epoxy and throw off the ratio slightly

[@FilterYT]

Thanks, awesome content. I never would have considered ABS cement for anything other than black pipe. Reminds me to keep my mind open.

[@helmut666kohl]

I have one very interesting glue to add: SMP - Silan Modified Polymer Those absorb moisture from the air and usually harden into a sort of flexible rubber - yet super tacky when uncured. Those are used to lay hardwood floors so the parts can move, but generally stay in place. Also PUR 1K moisture foaming/hardening glues are pretty neat.

[@joshsmithward8848]

Quickly becoming my favorite channel. Thanks for sharing your knowledge and experience. Very practical and I appreciate that you don’t dumb it down.

[@wrekced]

There is a "glue" for plastic scale models that really just melts the plastic together. Maybe something like that would bond that strap to itself. Basically, a highly volatile solvent that would stick around just long enough to melt it a little so you can press it together. Thanks for making this video!

[@F0XD1E]

PVC cement for pipes etc. works the same way, I believe.

[@DrowningTurtle]

You have the most interesting videos man.🤣Keep it up!

[@bradnail99]

MEK and acetone are close chemical relatives. By blending the two the makers of solvent cements can control the drying rate. Acetone evaporates much faster than MEK does.

[@davidmalawey]

this is also gold. i was wondering exactly this question about evap. obviously chatgpt can tell me differences but only a human can summarize with practical centrality. thank you, fellow human.

[@goodun2974]

MEK takes away even more brain cells with it as it slowly evaporates.....😉

[@goodun2974]

​@@davidmalawey, ever worked with Plas-T-Pair?

[@davidmalawey]

@@goodun2974 i have not worked with Plas-t-pear but i am listening! please tell what we can look for!

[@goodun2974]

@@davidmalawey , Plas-T-Pair, or "plasti pair", manufactured by Rawn America, consists of a powdered plastic (probably an acrylic) and a solvent that when mixed with the powdered plastic can form anything from a syrupy liquid to a putty (depending on how much solvent you use), which can be used as a filler or moulded into shapes so that you can repair cracks and missing chunks In pretty much anything from plastic to wood to metal to concrete. Once the solvent evaporates and it hardens, it can be sanded and painted and is extremely strong. It's a little like the baking soda and sea egg blue trick but the powder plastic readily absorbs the liquid in one fell swoop, unlike baking soda and CA glue where you usually have to build up the baking soda and super glue in thin layers (I use water-thin Titebond super glue if I'm working with baking soda). The only disadvantage to plas t pair is that the solvent stinks to high heaven and is best used outdoors or in a well ventilated area, perhaps with a fan or suction hood. When I was an audio repair bench tech we sometimes used it to repair broken plastic parts because it really fuses itself to certain plastics that are otherwise difficult to glue. There are a number of videos on KZbin showing how to use this stuff. Ps, I don't know if accessory coloring agents are available or can be added, but when I was a kid I had a similar product that I don't recall the name of that actually came with black, red, yellow, blue, and green plastic powders or coloring agents so that you could mix the liquid plastic to the color you wanted.

[@MarceloSeravalli]

great, another video I need! thank you!!

[@jamesolivier3192]

I've had great success using black rubberized CA glue to bond nylon webbing. clamped between a couple pieces of ptfe sheet for the cure.

[@davidmalawey]

nice! that’s gold. whats an example of a rubberized CA glue? oh is that the stuff we used for hobby rc car tires back in the day?

[@jonludwig8233]

Like loctite 380?

[@F0XD1E]

​@@davidmalaweyStarbond is a popular CA glue brand that has lots of variety. They come in nicer bottles than the little foil tubes as well.

[@MarceloSeravalli]

Testers hobby glue is 75% toluene and 25% polystyrene, its the napalm of glues. My favorite glue is cyanoacrylate, and I found out you can add cyano to other glues to kind of turn them into a fast drying cement. Cyano and wood glue make a crazy cement type thing.

[@xsietube]

I’ve never thought of mixing CA with PVA, interesting! - You can also add baking soda for a hard, gap-filling CA. Warning, this cures super fast and is exothermic. It’s best to coat one surface with CA and the other with powder and then mate. Another option is coating both surfaces with powder, mating them and then wicking CA into the gap.

[@davidmalawey]

what kind of properties do you get using the hobby glue compared with its nearest alternative? or compared with CA?

[@MarceloSeravalli]

@@davidmalawey Hobby glue is better no doubt, it melts in and it solidifies nicely, but it takes time! CA I feel is more fragile, but the bond is good and it flows like water so it truly wets the joint. I feel CA is kinda the cheat glue hahahah but its awesome and it doesnt come without its drawbacks, it takes skill to get good with CA

[@MarceloSeravalli]

@@xsietube and well the material is also important like you said in the video I find CA works surprising good with rubbers, and with light woods like balsa for models, it really soaks in. But the joint is more fragile than wood glue.

[@goodun2974]

It's important to know that most supermarket or dollar store super glue in little tubes is usually too thick and doesn't work all that well for many gluing applications (this includes Gorilla glue; I've tried many of their products and remain generally unimpressed). My CA glues of choice are Titebond in "water thin" and "medium" viscosity, which aren't carried by every hardware store but Woodcraft and other places that specialize in woodworking supplies will have them, or you can buy them online (Hot stuff by Satellite City is another good water thin CA glue). If you want to do the baking soda and super glue thing you really need water-thin super glue because nothing else works anywhere near as well or is it easily inconveniently. I have a video on my channel where I demonstrate this, as well as various other adhesives including epoxies and ultraviolet-curing resin glues. UltraViolet curing super/CA glues also exist, which will cure more slowly on their own without the application of light, such as deep inside a crack, but at the surface can be cured in seconds with application of UV or perhaps even from sitting in bright sunlight. See my video for more info.

[@randomvariablenj]

3M have some decent videos going through the failure modes (cohesive and adhesive failure) and surface prep, etc which would be useful. Also, one advantage of modified silanes of the "no more nails" type is that they do adhere to more surfaces than is possible with most others.

[@EliKatz]

Delighted to find your channel. So much useful content so well explained. Thank you.

[@savage6394]

49:53 Layering the pages of 2 separate phone book pages together is a good visual representation of this kind of force. Its impossibly hard to pull them apart. P.S. For the younger viewers, a phone book is how we used to look up someone's phone number and/or address.

[@DevinJuularValentine]

Just wanted to say I watched this whole video AND the tape video, learnt a lot and I feel like you're weeks away from Adam Savage mentioning how he watched your video on tapes lol Looking forward to learning more about... Anything.

[@muctex]

Man! It's amazing. Greate work. Keep going 🙏💪

[@NicodemusParadiso]

The name for those plastics that are hard to bond to is "low surface energy". It can be a useful search term if you're not finding anything that sticks.

[@dylanrandle]

Your videos are awesome. Thank you!

[@davidkafka2452]

What I’ve noticed that distinguishes professional grade adhesives from more dollar store adhesives is how they specify what materials the compound is compatible with whereas the lower grade mass marketed adhesives will claim to work with everything. The closest thing to a “safe” adhesive brand is probably 3M, professionals use their products quite extensively across a wide range of industries.

[@oghaki5097]

Awesome video, subscribed

[@bzboii]

couldn’t put this video down :)

[@bobThebuilder-mj8ht]

Fr homie matching my freak like fuck

[@steventhehistorian]

What do you do with all your test pieces once you've completed your experiments? Do you keep them all in a bin or something for future reference, do you toss them, or do you leave them all over the place? I ask because I have a million tiny little scraps of materials with various adhesives/solvents/paints scattered around my shop where I've experimented putting [medium] on [substance] and for some reason I can't ever bring myself to just throw them away lol. Sometimes I get to cleaning it up, but then I always hesitate because it's like...what if there are useful observations to be made as the interaction of [medium] and [substance] are given more time or exposed to sunlight, etc... I'm a habitual packrat and the worst part is that I can't break my ways because I always have what I need in a pinch...so I am constantly rewarded with dopamine for having a ton of broken and semi-disassembled mechanisms, etc.

[@coolcoolercoolest212]

This video is like unlocking a super power.

[@henslee]

I think the epoxies that you would use for an art project are not the same strength wise as something designed for boats or structural use such as West Systems epoxy.

[@davidmalawey]

i bet you are right. if i wind up with more cash i’ll find out for sure 😊

[@goodun2974]

I have a video about adhesives on my channel where I demonstrate use of various epoxies as well as CA glues, silicones, and UV cured resin glues.

[@goodun2974]

Devcon "2-Ton" has been available from hardware stores for 40 or 50 years, and in my experience you're unlikely to find a stronger epoxy! Generally speaking, a slow cure epoxy will be stronger than a fast-curing epoxy, partly because it allows the glue time to "wet" to the surface and grab hold of any rough-upped "tooth" that you've sanded or scratched into the surfaces being glued (or to soak into the pores if it's a porous material that can actually absorb a liquid). It's important to note that there is a regular slow-cure JB Weld epoxy and then there is a fast-setting version called JB Kwik; and as with all epoxies, if you have sufficient time and can wait overnight for the glue to cure, youll get a stringer bond with the slow-cure variety. Building boats from fiberglass and resins, however, likely requires an epoxy with different characteristics because of the amount of vibration and stretching forces that the boat hull will be exposed to, and because you cannot have voids where the glue doesn't penetrate or the boat hull will fail and out lives at risk. The mixed resins will need to be as thin as possible, have a fairly long working time, and have very low surface tension so that the resin easily spreads out and soaks in via capillary action. The fiberglass cloth itself likely plays a big part in safe boat building and I am guessing that there may be different grades of the glass cloth with varying degrees of stretch or different diameter fibers that can be chosen for certain applications. A certain amount of stretch is probably called for: when I was installing marine navigation equipment for a living we had a client from a multi-millionare family who was an avid scuba diver, and he had a boat custom-built for him with Kevlar cloth instead of fiberglass cloth; the boat developed lots of stress cracks and a few structural cracks and had to be reinforced with metal pillars inside. Absolute rigidity is not always a plus! I would have liked to have seen you mix up one of those little plastic cups full of epoxy, especially the fiberglass epoxy resins, because then you might have been forced to talk about the amount of heat that epoxy throws off as it cures, which can occasionally be dangerous to a project, or to your home, if you have excess mixed adhesive left over in a container. Epoxy resins can smoke and fume from heat, or perhaps distort low temperature plastics, and a big enough container of mixed epoxy can theoretically catch fire as it cures!

[@JonGreer-s7e]

Where can I get the wrench you used on the oatey cans? is there a name for it? Thanks.

[@SlowExpensive]

WeldOn is the name I think

[@Crappy.Consumer.Reports]

Wow. I never really understood the word “toughness” until hearing your definition.

[@goodun2974]

Not mentioned here is that CA glues cure faster in the presence of cellulose or other carbon-based organic materials, such as wood, cotton and so on (sometimes curing a bit too quickly as a cotton ball saturated with super glue will demonstrate: It smokes and fumes and might even catch fire, and you definitely don't want to breathe those fumes or get them in your eyes because permanent damage can result ). By the way, some woodworkers who turn pens or other other small objects on a lathe actually use CA glue as a hard durable wood finish, applied in thin coats and built up in layers.

[@RogueMaverick_]

Awesome

[@alamppmala]

What were you powering the small board with in the hot glue LED portion? I was reminded of RC LiPo battery packs, but I don't recall ever seeing a display on one

[@GrowlingBearMedia]

When you shout out a channel, i just sub without asking lol

[@davidmalawey]

you won’t regret this one!

[@VHS_PAL]

Is there a way to prolong the life of silicone, once the container is opened to air? I use it infrequently from small hand-squeezable tubes.

[@goodun2974]

I bought some long, tapered plastic plugs that sort of look like stepped drill bits that are supposed to be good for plugging up the silicone tube and keeping air out, but I have not tried them yet.

[@kizzjd9578]

Could you do a video on ms or stp sealants? They are a non solvent based silicon/polyurethane hybrid and becoming very popular in the building industry. Examples are soudal T-rex or sika stick and seal 111, or sika extreme grab etc.

[@goodun2974]

At 6:00 when you're discussing silicone adhesives, you didn't talk about the chemical base that evaporates or cures when exposed to air. Most high-quality silicon formulations will release vinegary acetic acid fumes when they cure; this might be specifically mentioned on the tube, or it may say it contains "acetoxyl-something", which indicates it will emit the vinegary smell as it cures. Unfortunately, GE (and perhaps other manufacturers) used to make an ammonia-based latex "silicone" (GE "HomeLine") that had poor adhesion and strength compared to the vinegar-based stuff. Something to be aware of is that the vinegar released during curing may corrode metals, especially copper and brass, so you may have to consider what materials you are working with. Silicon rubber is often used to secure electronic components to circuit boards, which is generally okay as long as you're not putting big dollops of the acidic vinegar-based stuff across copper foil traces or component leads because It could cause corrosion or perhaps be conductive, at least until it has fully cured. You definitely don't want to assemble something with uncured silicone and seal it right up so there's no air flow because the fumes could be trapped inside and that's definitely bad for copper foils and wiring. ( You can buy special silicone that is rated to be safe for all electronics applications, but a small tube of it will cost you about $50!) Also, contrary to a widespread misunderstanding, if the silicone says "RTV" on the package or tube, this *DOES NOT* Inducate that it's suitable or "safe" for radio, TV or other electroncs; RTV stands for "Room Temperature Vulcanization" which merely indicates it's a wet paste that cures to rubber at room temperature. Silicone is very useful for certain electrical and electronics projects but never put it directly on anything that is carrying current/voltage, nor metals or component leads that are prone to corrosion from exposure to acidic compounds or vapors.

[@kizzjd9578]

Id be keen to see a test on ms or stp adhesive/sealants.

[@bradhayes8294]

I've never found an adhesive capable of bonding polypropylene to polypropylene. I've successfully plastic welded and used mechanical means, such as spiral rivets to join them, but no adhesive. Any ideas?

[@4lecsg]

I would try joining that hook to the bin with heavyduty double sided tape.

[@douglas2lee929]

Sir, your site is amazingly useful. However, please work on your audio rig. Maybe get a lav mic if you don't have one. Some vid's have adequate volume, but many do not. Thanks. From Minneapolis

[@toericabaker]

U should check out florist tape

[@davidmalawey]

hey you mean that stretchy translucent stuff? I am curious…

[@toericabaker]

@@davidmalawey green, waterproof, slightly conforming, sticks to itself but nothing else... for binding bouquets and stuff.. doesnt have an adhesive if i recall correctly

[@Michie1391]

Self amalgating tape

[@alamppmala]

Seconding the florist tape suggestion. It's kinda like masking tape that you'd use in a wet environment. Think of wrapping flower stems you just pulled out of a vase of water.

[@JKTCGMV13]

Hell yeah

[@AtimatikArmy]

I saved an old satellite dish... when are you going to make the video explaining why it was a good idea to save this thing?!

[@kizzjd9578]

Liquid nails is horrible. I never use it and i always come across previous work where it was used. Its very brittle and debonds very easy.

[@georgehoskins1228]

HDPE is high density polyethylene not polypropelene

[@jtreg]

ok but why the cross? Fun fact: these are banned for MPs in the House of Commons. Thankfully.