Super Strong Epoxy with Diamonds and More!

hi we're doing a series of videos on composites [Music] [Music] in the first video a few weeks ago we talked about fiberglass and in the last video I talked about epoxy resin today I'm going to talk about aggregates or add mixtures powders that can be used to change the mechanical properties of the epoxy to use it for structural purposes epoxy is a polymerized plastic and it's a wonderful adhesive but because it has the consistency of honey it tends to be very difficult to build up any kind of macroscopic structure from it when you're trying to use say for example epoxy to create a joint in this case say a right-angle butt joint if I was to put a line of glue on this wood and then adhere this it would be far stronger than say mounting this with screws which produce point loading it distributes the load and it's stronger but because I'm dependent on the breaking of the sort of bond at the edges there the amount of strength that I get is really only the distance across this piece of wood which is about 18 millimeters of 3/4 of an inch in this case because of the nature of the grain I've actually got the disadvantage that I'm actually pulling the fibers apart this would be a stronger joint because of the way that the fibers are running but you don't always have that choice and in any case you have a mechanical disadvantage of a very narrow bit of resistance to tipping versus the leverage of these parts if I put enough force on this I'm gonna break this relatively easily despite the fact that the epoxy is such an excellent glue to build a much stronger joint what we want to do is we want to create something like a triangular gusset so that the load paths across here are from here across here that's far stronger and would be far stronger than the basic material but epoxy won't do that because it runs so what we want to do is we want to thicken up the epoxy to create a mixture that is going to be easier for us to work with and the the workhorse of everything on this table for most operations inside of a composite shop is going to be wood flour this is pine wood flour and you can obtain this in different types of wood pine is the most common and when mixed up with epoxy will create a pace that looks indistinguishable from peanut butter and you'll notice that throughout this whole video I'm gonna be using food references instead of complicated sort of viscosity numbers to describe the working properties and the end points when you're mixing these up because it's easily referral everybody kind of knows what the different foods and the substances are like so peanut butter when we mix this together and I'm gonna show you how we do this and you could use wood flour that comes from say a bandsaw or a table saw your own you could actually sweep it up but because this is so inexpensive it's very consistent when you obtain this in bulk and it's clean it doesn't have any other dust or material in it it probably isn't worst worth harvesting your own the one exception would be if you want to make a joint that has a similar color to the wood that you're working with you can take those particles and mix them in to create a darker mixture but keep in mind that when you add the epoxy it will darken so pine and pine will produce something that looks darker like peanut butter in pine you're gonna have to blend them in order to create those colors in any case for structural application applications pine flower is excellent and we use this so much that for example we order this in large quantities tubs of this stuff in order to build large structures like boats and this whole container full probably costs about $40 so you know it's not much now let me show you how we blend this up instead of what the endpoints are so I'm gonna make up mix up some epoxy here and some gloves a little trick with using gloves is if you are working with these nitrile gloves they're not very stretchy but if you don't have any problem with latex sometimes putting on several gloves double or triple gloving you can dirty up the gloves and rather than taking them off and putting them on you can pull out an hour outer layer of dirty gloves and you have fresh gloves to work with it's a nice way to make yourself fast and also to be very neat in this case we're not gonna do too much so I'm not that concerned about this now we're gonna mix up some resin here and this is a one to two part so I'm going to mix up about a hundred and fifty total give this two good minutes of mixing and always mix up your epoxy combination before you add the powders don't add them to one component and think you're gonna save time because it can affect the amount of epoxy resin part a and hardener Part B that actually touch each other because of differential absorption and the powders so mix up the liquid then add your powders now we've given this about two minutes of mixing and we're going to start adding the powder now I could give you ratios but with the woods being relatively inconsistent in terms of you know from batch to batch particle size and moisture content really the end point here is going to be the viscosity of the final mixture the powder that I'm mixing in here and you want to start by blending it relatively slowly at first because otherwise you'll get these clouds of dust all over the room and as you blend this in you can get a little bit more aggressive once you've got the material wet and we'll keep adding material keep adding powder until we turn this into sort of a runny peanut butter something between peanut butter and yogurt these are gonna be these food references we're gonna get hungry by the time we're done now as you can see it's kind of creamy and kind of runny I can add a little more powder but this obviously wouldn't stand up if I tried to make a paste out of this and try to get this to form a shape it's just gonna sag I could keep adding powder until I got to the point that this no longer ran that this didn't Sag anymore the problem with that though is that you end up with something more like biscuit dough it tends to be crumbly and when you sand it you get a lot of air pockets so rather than try to get the final thickness from the wood flour alone I take advantage of another material this which is a silica thickener it's called capsule or fumed silica this has a particle size down in the nanometer range and because of that it has much more surface area per cc or per gram than the wood does so a very small amount of this material added to this will thicken it up quickly now general rule of thumb general warning is that yes you should always work with a mask and you should always be very careful with these powders for most of these it's it's good advice for this it is particularly important I'm going to break that rule just because I want you to be able to see me and I want to be able to talk as opposed to through a mask but because of the extremely small nature of these particles they tend to get everywhere you really can't work with this outside because even a small breeze will carry this into the air like dust it's finer than dust and as you'll see even if I add this very very carefully you're gonna see some of the particles can get into the air and dance around so I'm gonna be very careful about the mixing of this powder but nevertheless it will still tend to get into the air even if I work with it very slowly you see how it clouds up like that now another little sort of trick is when you mix this the first mixing of this go very slowly until you get it wet into the that'll tend to keep it from rising up into the air once you kind of get it blended in it's not gonna form as much in the way of clouds now you can see I just added two small teaspoons of that material again not to a quantity to an endpoint and you can see the mixture is beginning to thicken up substantially if I add just a little bit more very slowly and you don't want to breathe this either that's part of the reason why you really want to wear a mask with this material but I'm breaking my own rules very slow very careful see the dust coming out of there it's kind of hard to keep that from happening even if you know what you're doing and we're gonna blend this in that's enough see okay so now what we're gonna do for safety's sake I'm gonna close this one up move this away give this a final couple of blends that's pretty nice you could make it a little thicker but it'll do for this demonstration now we're going to create a gusset with this material and if I were simply to take this and kind of lather it in there it'd be kind of a mess it take time it'd be messy you'd get everywhere so a trick that you can use is you can obtain these ebay amazon for about 2 bucks apiece it's a 10 ounce of 300 milliliter empty plastic caulking tube and if we trowel some of this material into the tube like this and we will insert this into the caulking gun we can trim the end of this I can get a nice regular bead of the material to form the joint now one thing that you should keep in mind is that you can't make up a whole quantity of this stuff keep this on the table and then every so often you can just use it whenever you want to because you've got a pot life to this it's gonna whatever you fill this up with you got about whatever number of minutes the pot life for the epoxy is before you have to stop working with it at $2 a pop that's not real bad but the point is if you need to do lots of little applications an easier and more convenient way to do that Oh something I didn't say and I should warn you about don't leave a quantity of the solid material inside the tube when you're done with it it'll get hot so you've got to get rid of got to get rid of the stuff and spread it out there's another method that you can use that's cheaper a little less neat but is pretty convenient if you're doing small amounts of material and that is if you take the epoxy paste in here that we've made up this gusseting material and you take a 1 quart or 1 liter sandwich bag that does not stand on its own it's got a simple square bottom like this don't get the kind with the pleats you can actually put this inside of the bag then once I filled up the bag like this and then I can squeeze this down twist it around and just like I'm doing cake decoration I can use this to apply the epoxy to the joint like this now it's less reach obviously my hands got a closer so I don't have as much you know coverage in terms of being able to get into a tight area but as you can see it works pretty well and produces a pretty nice surface so a trick that you can use for giving yourself a surface that's not only appearance appearance-wise superior but also then is easier for you to lay cloth into because it's a rounding it's a radius you can take sticks popsicle sticks that are rounded or variable sized washers and you can create a nice curved joint by putting the popsicle stick at a very oblique angle you see how I draw this like this and basically I'm not contacting it and I'm not doing anything but as I make the line steeper you can see that I can get a nice rounded joint and as I continue to bring this up the rounded joint will get to look really really nice I mean that's smooth and homogeneous now if I go too far or the stick is too fine I can end up creating sort of a mass on my stick so the trick is always to start at a very shallow angle and bring it up in order to give myself a nice curve if I've got more material I might want to use a larger radius again starting like this and I had so much material that you can see I got a little Ridge even with the large radius so it might have been better to go with an even larger radius but as you can see you can get a nice curve now if you don't want to waste the time to fabricate this material you can actually obtain this in a pre-mixed form from a number of suppliers like west system system three makes this and effectively it's a proprietary mix of some of the thickener and some plastic flowers flower may be talcum powder but bottom line is it works very well it has similar properties and it will save you time but this will cost you about four or five times as much per volume as making it yourself so it's it's your choice what your time is worth the next thing that you might want to do is you might want to be able to say take care of defects in surfaces if it turns out that let's say we've got this example here where we've got a joint between two boards that has sort of a crummy interface point here it's got some damage that I created with a hammer it's got scratches it's got holes and dents we want to create what's called a faring compound something that you can sand and will provide a nice smooth surface for that application we use glass hollow glass microbeads of balls micro balls and a phenolic microbeads these materials here when added in approximately equal volume to the epoxy will create a nice sandable paste that has about the same toughness as the wood it won't be removed any more quickly or many any more slowly than the underlying wood the wood flour produces a very tough material that is difficult to sand and so it's it's not as easy to work with when you're covering large surfaces so let me show you how this stuff is made now we've mixed this for about two minutes and now what we're going to do is we're going to add the bees unlike the Caviezel you can see that this powder tends to fall it doesn't create quite the dust because these are sort of micron scale powder is those two nanometer scale powder you'll want to add an amount of this approximately the same as the epoxy so when I blend this in I don't use weight I generally don't even rely on volume with experience you'll get a feeling for adding less than you need and then eventually what you'll end up finding is that you'll tweak the last 10 or 15% by adding more powder but remember you've already mixed the epoxy so always under add the powder you can always add more but you can't really take it out because the material flows you can fill joints by simply allowing the material to sort of grip in there it will run in it'll form a bead you can remove the additional material if you choose to but the stuff sands very very easily so it's not really that critical that you get it ultra flat and you'll probably save more time having to sand that additional material off then if it turns out you win a little deep and you made a dent and then you have to do a second batch now filling up the scratch I think and get away with that and even the the shallow dent here because it will run into the sides of the the dent but for something like this it's so steep that if I were to try to get this to flow into the surface it's gonna create a little bubble which might be a void if I sand it into it or may actually have a bubble that creates a crater after this cures so when you have steep edged holes like this or dense Ashley use a drill and broaden it out and create something more like a crater or a dent you actually remove wood in order to make the hole go away this will feel much better because the liquid can get into the bottom of the hole in order to cover it over now when you're done with this cheap way to take care of any of the bumps you could actually just do this and leave the surface covered up but as you see you can sometimes draw some of the material away and this stuff sands so quickly that I tend to be rather generous with this in a horizontal application also for what it's worth in this material where it's runny you're going to get excellent bonding because there's plenty of extra epoxy in this but in the drier mixtures sometimes it's a good idea to wipe it down with a little bit of the uncured epoxy before you apply this just so that it sticks and you get good absorption of the material into the wood you don't starve the joint be careful though not to be generous you don't want a layer of clear epoxy underneath your filling material because you'll end up creating something that acts as a lubricant and prevents you from being able to actually apply this to the surface now if we aren't dealing with a horizontal surface and again this material here will sand off in about 15 seconds it's very quick so even though this looks really very very thick don't worry about it it'll it'll work fine it's very very fast and it isn't worth getting obsessive about trying to remove the the last couple of millimeters now if you have say a defect that's a vertical you can't reorient this then go back to your cabin sell and adding cab Asil to this material here that is running you can create something that is much more like plaster and will hold up to a vertical surface now take a little bit of this and we can place it into a joint excellent huh not at all difficult and this will stay this will cure and the sands off very easily this already is starting to get warm so rather than throw the whole pot away I'm going to break it up into smaller quantities so that it doesn't melt my garbage bag or my cup moving on this material here is microfibers this is a polypropylene this is a glass microfiber this when added to the epoxy will actually produce a stronger material then will the wood flower it's about equivalent with the polypropylene I don't like it quite as much because it's more difficult to work with as I'll show you in a sec but if you want something that is actually substantially stronger the glass microfiber is the way to go this will produce a stronger joint but again it's more difficult to work with I'll show you what happens when you mix up some of this alright this has been about two minutes now I'm going to now start adding some of this powder to some of this micro fiber glass this also doesn't tend to blow around very much it's kind of ties itself up in knots but you'll see the property of this one blended in it's a little weird now you can see that this is not that different from the wood flower but it tends to be more like a jelly kind of like snots and it's a little more difficult to work with when you're trying to produce a gusset it's not bad but you have to get a little bit of experience with working with it moving down the line these are the chopped fibers instead of microscopic you know submillimetre fibers these things have dimensions lengths on the order of a few millimeters this is glass this is carbon and this is basalt now all of these materials will add a substantial amount of strength versus the wood material and you will use these in areas that you don't really want a nice finish who saw how nice that joint was that I put together it really look pretty smooth it would be very nice to put fiberglass over it these because of the spiky nature of the fibers don't work very well but if you've got a hidden joint and you want a lot of strengths they are putting oak together you want something really strong using the chopped fibers is a good opportunity or a good option the difference between the fibers is that this is very cheap this probably cost about 20 cents 25 cents the carbon despite the fact that it's carbon fiber is not that expensive because it comes from offcuts when they're manufacturing pristine rolls of carbon fiber and so this is sort of what's left over nevertheless this is the strongest of all of the materials it produces a gusset or a macroscopic structure that is as strong in modulus compression and tension as solid aluminum it's as strong as metal and this can actually be used to do what we just did with the wood with aluminum properly preparing the surface and making up material like this you can avoid the heat damage that's associated with welding aluminum you'll get a joint that's nearly as strong you can also avoid the heating of structures that may have says-- heat sensitive components on them rather than welding and if you don't know how to weld this produces a nice alternative however it has working properties that are challenging and I'm going to show you what this is like when you mix it up okay now we've let this go for about two minutes and I'm going to add the carbon now you don't need to add very much of this as you'll see this is just maybe two little scoops of the material not very much and you'll see what happens right now we've got this running mixture with these carbon particles in it as we start to blend this in and the very very tiny fibers much smaller than the glass begin to wet out with the epoxy what you end up with is something that looks like your cat threw it up it's like hair balls it's nasty and I didn't even add quite enough carbon at this point but as you can see it's a kind of stringy fur ball looking material but with a little bit more carbon in it as I said the structural properties of this stuff are awesome now if it turns out that you're into green and we've discovered that nowadays what's becoming very popular in the concrete industry we have been working with concrete ultra-high performance concrete and did a little bit of research and these are basalt fibers essentially degassed lava molten rock is extruded just like the glass forming it into fibers it can be made into rebar can be made into a mesh of cloth what's nice about this is unlike the talia Krillin nitrile hydrogen treated you know petroleum product of carbon this is potentially green and it's intermediate in terms of its properties it's not quite as strong as the carbon it's not as expensive as the carbon and it comes in a variety of different lengths the shorter the length the easier it is to work the longer the length the stronger it is I've worked with this a little bit and actually I kind of like it it's kind of a neat material so it's something to keep in mind and we'll get into that more when we get into the concrete now the following three powders here graphite aluminum powder and dendritic copper these can be added to the epoxy to create a tougher material frequently aluminum powder is added to say this keg of a boat it makes it much more damage resistant all of these block UV light epoxy is sensitive to UV degradation when you put these metal powders or carbon powder into the epoxy it will prevent the UV light from transmitting it to the material and prevents breakdown of the of the epoxy in addition unlike a die these materials can change the color of the epoxy and can be used as primers if you want a dark primer you want to light primary on a brown primer you can have something underlying your paint that if you scratch it you're not going to see white or some other material underneath it acts as a great primer in addition what's pretty interesting is this dendritic copper dendritic copper is electrolytically grown and it's fractal it looks like a fern or a snowflake underneath a microscope and because of its extremely high surface area and it's large-scale sort of bi-directional structure flat plains fern like this material acts as a really good thermal transmission material we've been working with graphene and silver powders and Diamond powders in order to try to create a competitive thermal grease something that can beat Arctic silver it's harder than we originally thought and much of it isn't so much the materials it is the dispersion within the the silicon oil that's frequently used as the matrix turns out that epoxy tends to disperse this material very well and as a consequence when we make up a material with this in epoxy it is competitive with the thermal epoxies out there about the same thermal conductivity but far less expensive if you look for thermal greases you can get them relatively inexpensively look for thermal epoxies and they're incredibly expensive this works just about as well this is nanoscale aluminum nitride this also is a high thermal conductivity material doesn't work as well as the dendritic copper when mixed into epoxy as a thermal medium but what we found is that when you blend the two of these these small particles seem to get in between the the leaves the dendritic copper and provide what appears to be a superior material at far lower costs we'll get into that when we get into the thermal interface materials moving down the line this is boron nitride boron nitride cubic is the second hardest material known to man just behind diamond hexagonal it tends to have molecular properties similar to graphite or molybdenum disulphide it's a very lubricating slippery material when added to the epoxy this material is almost like a poor man's Teflon or an ultra high molecular weight polyethylene but something that you can mold into low friction surfaces it also makes it tougher it's kind of an interesting material and is again very inexpensive moving on these here our ballistic samples for ballistic barriers essentially armor plating and what we did is in doing so much research as we did back behind me you can see some of our concrete speakers learned a little bit about what makes concrete so strong it isn't the cement that acts as the glue in this case epoxy it's what you put in it when you take particles of a single size or homogeneous size and you try to pack them together the greatest amount of density that you will get is about 67 percent the rest is voids in this case would be filled with epoxy or cement if you're making concrete in order to get a stronger material because it's the admixture that adds the strength not the cement not the epoxy you do a thing called densification and the way that works is you take large particles like gravel and you add between them smaller particles like sand to create more dense filler for the matrix because it's the glue doesn't matter how thin it is it just matters that it contacts everything so what we decided to do is to build essentially epoxy based concrete but we're using some really unusual materials these are aluminum oxide abrasive grains they are very very tough they're hardened they're ceramic they're much stronger than say gravel or granite but the point is they're also somewhat porous on their surface so they get an excellent bond with the epoxy but because they tend to be rather large what we've done is we've added silicon carbide now if you look carefully in my hand at this material you'll see that the silicon carbide has it got a very porous rough granular surface again excellent for bonding to the epoxy and it tends to fill the gaps in between the gravel so we get more densification and an ultra-high performance concrete what is done is they add us a third powder which is called fumed silica it's not the same as the cab a cell it's more of a micron to two micron scale silica powder to again increase the densification and double or triple the strength of the concrete in our case we elected to use titanium coated diamond now this is actually not that expensive from China and the reason for the titanium coating is that Diamond itself if you look at sort of abrasive diamond tends to be rather slippery rather smooth it will bond to epoxy but because of the slippery particles you don't tend to get the good sort of mechanical tooth type of bonding that you can get when you put the titanium coating on and because this is a titanium that under temperature goes to titanium carbide which will actually form a covalent bond with the diamond the bond between the metal and the diamond is as strong as the titanium two orders of magnitude stronger than the epoxy and then when this is used as the final filler for the concrete we create these disks in this case we've got the ceramic aluminum oxide and the silicon carbide and in this we have the diamond and the silicon carbide and the purpose for this is that as a ballistic barrier if a high velocity projectile were to try to run through here the large gravel is likely to fracture or redirect it cause it to tumble or distort the very abrasive very hard and tightly bonded silicon carbide will abrade the material or the fragments that go through it and the diamond will help to hold everything together and add theoretically potentially not sure additional resistance to penetration placing a layer of say Kevlar or Dyneema on each side of this to prevent the fragments from being able to get through or spall or fractured material from being able to leave the front surface that's something else we're going to work on but these things are remarkable because not only can we potentially build composite armor that would be moldable but it's something you could do yourself you don't have to have sintering ovens you don't have to have you know any fancy equipment other than a small vacuum chamber that can get online and these materials which are not that expensive this is probably about 30 bucks worth of diamond this is about 50 cents worth of silicon carbide this is about a buck worth of this gravel it's not that expensive so in sort of conclusion there's a lot of different powders you can use here the workhorses are here the exciting stuff the sort of cutting edge stuff is over there but if you like what we're doing here I'd really appreciate it if you'd subscribe ring the bell give us a comment anything that you can do that shows engagement with the channel helps YouTube to promote us and most importantly if you know people that might be interested in this or might learn something from this appreciate it if you'd share the videos because that again increases our our audience and helps us to grow so I want to thank you very much for your watching the program and I will look forward to seeing you soon you have a good night [Music]

Channel: Tech Ingredients

Views: 258,955

Keywords: Diamonds, Epoxy, Wood Flour, Fumed Silica, Plastic Fibers, Glass Fibers, Carbon Fibers, Aluminum Powder, Copper Powder, Carbon Powder, Aluminum Nitride, Boron Nitride, Silicon Carbide

Id: 6KjlyXKeo8c

Length: 33min 52sec (2032 seconds)

Published: Fri Feb 14 2020