Utility Mat Turns Waste Epoxy Into Useful Tools

Epoxy is a great and useful material typically prepared by mixing two components together. But often we find ourselves mixing too much epoxy for the job at hand, and we end up with some waste left behind. [Keith Decent’s] utility mat aims to make good use of what is otherwise waste material.

The concept is simple yet ingenious. It’s a flexible mat that serves as a mold for all kinds of simple little plastic workshop tools. The idea is that when you have some epoxy left over from pouring a finish on a table or laying up some composites, you can then pour the excess into various sections of the utility mat. The epoxy can then be left to harden, producing all manner of useful little tools.

It may seem silly, but it could save your workshop plenty of nickels and dimes. Why keep buying box after box of stir sticks when you can simply make a few with zero effort from the epoxy left from your last job? The utility mat also makes other useful nicknacks like glue spreaders, scrapers, wedges, and painter’s pyramids.

We’ve seen other great recycling hacks over the years too. Video after the break.

46 thoughts on “Utility Mat Turns Waste Epoxy Into Useful Tools

    1. If you have Lil bits and chunks. Cut em up and keep them in a cup. Throw them in the mold.
      What I could personally do is use this as a drip tray, then allow any of the Lil bits and drops to alowly build up over time. Yes that means it could take months for them to build up into one of the tools but that’s better than it being in the trash.
      I’d also slice off chunks of flashing and throw them in the mold so the drips will combine together.

      I currently do this with 3d prints. All supports and fails and leftover even the smallest flakes go into a bucket. Then when there’s enough I put them in a pan and melt them all down so as to form a sheet of plastic. Once I have enough of these sheeps in simular thicknesses I make a tabletop or other flat surface.

      For silicone I cut up cured pieces then add them to my next piece as filler so I use less silicone next time.

    1. Cut fiberglass mesh (or carbon fiber) to the shape of the mold and stack a few layers for reinforcement. Saw this in the 90s when a buddy who was into RC vehicles was casting throwaway body parts for tests. Clever stuff.

    2. It does not sound amazing. This sounds horrible.

      Probably because epoxy is largely BPA (or BPS or other almost identical materials so it can claim to be BPA free) and this is like turning toxic waste into toxic tools, not useful ones.

      The only way you should change the way you work with epoxy resin is to quit using it regularly for things like tables or items you are going to be in contact with directly like water containers or hand tools.

      The sad part is that none of this is new information but HAD does not even speak here about known issues with BPA and just presents this as an amazing hack that reminds me about what we did with asbestos to put on a christmas tree as fake snow.

      If you really want to research it further, which people should always go do, there are plenty of legitimate medical studies done with this material by actual doctors and medical researchers that you can go read up on if you want to further your own understanding.

      1. While proper PPE is definitely required while working with it (though even without many folks have gone their entire career working with ’em without to no harm done it would seem) once its cured (if mixed properly) there is very little risk – no more BPA to worry about really as its all part of those stupidly long polymer chains the epoxy creates. And if you are using it to create single use disposable tools for use in the workshop where you are going to be using PPE anyway (right?), there really isn’t any harm at all..

        Also not all epoxy is BPA at all – it is common but there are other options out there.

        If you want to get too concerned about it you should never saw woods at all! Soo much dust some of it rather hard for the body to deal with, oh and don’t use copper water pipes as too much copper is bad, but also don’t use plastic as those might leech plasticisers, can’t use lead etc – at some point you have to stop worrying that tiny little bit of exposure to something that isn’t all that bad – not half as bad as the smog you probably breathe in daily…

        1. Yes, most all epoxy is Bisphenol something. You can even add BPA as a flame retardant to other plastics. Or make clothing or do dentalwork, etc says:

          Not sure one can jump to the conclusion that “many folks” have gone their entire careers working with epoxy resins with no PPE and they have had no harm done to them. Again, please review actual scientific and clinical papers as there are plenty of them out there that are actually interesting to read through and learn more about. We should not do studies to intentionally give this material to humans but we as a society have done animal studies though and harm is much easier to understand that way and it is not really as trivial as you make it out to be, which is to state that there are people who have never had any issue from it at all. That’s a pretty bold statement to make.

          BPA does not just “go away” either once cured. Obviously a BPA monomer is different than it in an actual polymerized state but it never just 100% polymerizes either.

          Using it in or with food or commonly interacted with products is an issue and it is often times hard to even tell if a material is epoxy or not. Especially if it is something such as a computer table or water containing plastic polycarbonate (PC) product which is interacted with and drunk out of daily with for years. Mixing epoxy resins is even worse.

          Most all epoxy is BPA or basically BPA but not exactly BPA (though still very likely a health and safety issue). https://en.wikipedia.org/wiki/Bisphenol_A#BPA_substitutes

          Not only is it basically BPA, there is a huge amount of BPA in epoxy resins. This is not like it has some phthalates (though flexible PVC has quite a bit). This is literally BPA monomers.

          Dust should be mitigated yes so you do not breathe it in and not physically irritate your lungs. It can be handled by the body fairly well though. Handling it on your skin is not really an issue as it is not a hormonal like material. Copper water pipes are not really an issue though there are a few other options. Don’t eat it or consume too much as a supplement but your body actually does need a small amount. Plastics are a huge variety of materials and do not all do the same thing and some are considerably healthier than others and it also depends on additives so you cannot just consider the specific plastic type either. There are medical grade plastics that go so far as to be implanted into the body and are ISO 10993 or USP Class VI, etc. There are also ones with all sorts of junk added to them and I would not suggest those to be generally healthy. That is like saying food is good. Ok. Some are good and some are not but what type of food are you talking about here exactly?

          Lead is generally bad for you no matter the quantity. It persists in your body over time. So no, you should not use lead for things you will be breathing in (like exhaust from lead based gasoline which is still used in fringe circumstances) or obviously touching or ingesting. Saying that all things are bad is not really accurate as there are plenty of things that you need to live. The issue is some of these accumulate in your body over time and that becomes an issue, particularly when your body cannot remove it which it generally wants to do for your own health. Like PTFE products as one example.

          Yes, smog is generally bad. Lead based smog would be worse. There are plenty of things that are not bad for you and that you need and are important for you. Epoxy resin is not one of them. The main issue is how bad specifically something is and what reasonable steps can you take to avoid issues that will likely persist over time.

          Not using epoxy / Bisphenol based products as a food contacting product (many acidic food cans will be lined with it) or one you are going to use as a hand tool is likely a very good decision to make for your health and well being over time. Obviously that is your call to make but I personally make a different decision.

          My point is do not pause your life to never interact with anything. My point is to use PPE when you are going to be creating fine dust. My point is to take a little bit more time and expense to protect yourselves some from known hazards. Still go and do things but just be a bit more mindful of the materials you use regularly. My point is to not expose yourself to known hazardous materials and to not treat everything as fantastic of a product just because it works great or is cheap. We all learned how that did not work well for the cheap “miracle” product asbestos and we actually know that a few products that are somewhat widespread are a hazard and yet many people either do not know or do not care and that is the part that worries me.

          Particularly when the toxic material has cumulative effects like asbestos does.

          Sorry if this comes across as frustrated but I also place some blame here on the editor who seems to express that this is a truly useful tool with no downsides to consider as well as the majority batch of presumably actual responders who all think this material is somehow fantastic and has no issues to be aware of and just use it for anything. It has some uses and I am not disputing that. My only point here is to be careful with some materials that have been studied at length by many different public international groups for many years now and consider alternative products that would be better for your health depending on the material, expected use and your personal decisions.

          1. So this “hack” is about what to do with waste epoxy, when you are already going to be using epoxy for a project.

            So whether epoxy is good, bad, or in-between is really not even relevant. The safe assumption here is that there people who are using epoxy in their projects. Since it’s such a versatile material with few replacements for many uses, I think that’s a safe assumption indeed.

            Then, if you are already using epoxy, already mixing and using it, there well usually be some left over, which would normally garden info l into useless shapes and be thrown away.

            The idea here is to make that waste more useful than simple trash. Modify is saying to make drinking cups from it, but things like paint spreaders seem safe enough.

          2. There are many sculptors in the miniatures world that have been working in green for decades with no apparent issues to them at all, know of more than a few that are still going despite the digital sculpting revolution, there are also those who have become sensitised and had to stop doing the job. But from what I can tell that last group is a very very tiny fraction of the whole. And working in green is something you really can’t do without touching it directly at times, it just isn’t possible to have the full PPE protective stuff going on and actually do the job.

            And I’d have to agree with the author here, if you are working in epoxy you should already be aware of the PPE requirements and as there are not major downsides to using up waste epoxy materials for something useful even stuff you handle like a tool handle – as cured epoxy is pretty much stable and nothing I’ve ever read suggests a properly cured mix is even close to problematic for health – once its set into giant chains its just not available enough to cause harm. It is exactly the same as you saying ‘copper water pipes are not an issue’ copper is really really bad for you in not particularly huge quantities, so anything in the water that pulls in copper from the walls of your pipes really can make them awful for your health. But I agree they are a perfectly adequate pipe material.

            There are way way worse things out there, all of life throws something a little hazardous at you. You literally can’t avoid ‘known hazards’, it is entirely impossible, as known hazards are everywhere, all you can do is try (and largely that isn’t even possible) to keep the dose of whatever you are worried about down. Also in the right place even the most toxic of materials can be the best and safest choice.

          3. it is actually extremely easy to *not eat* the epoxy resin.

            also: nobody is stirring epoxy components with their bare fingers, or whatever it is you appear to think is happening. are you, like, stupid or something?

            furthermore: maybe post some links to some actual peer-reviewed articles to backup your specific claims.

            finally: did you know it’s bad to inhale the dust from metal, or even wood? maybe you should go around and post a long, whiny warning on every maker/diy website that dares to suggest an individual actually work with any of these dangerous materials.

            in conclusion: please, just, shut up.

  1. When I volunteered for a company that use epoxy resin to make equipment for children with special needs, we had separate moulds for stuff like stir sticks for the excess/waste resin. Making that mould into a mat seems like a great idea. Surprised noone thought of it sooner.

  2. >But often we find ourselves…
    I would suggest ‘often find’ should be replaced with ‘must always’ in the article – as there is nothing more problematic and annoying than ruining a part for lack of enough resin, it almost always ends up wasting even more materials and man hours trying to recover from that failure to prepare enough in the first place.

    Do really like this idea though, I’ve always got something to dump much of the excess into that is sort of useful, but using waste resin from previous jobs as the stir stick for future mixes is quite satisfying and being just a sheet mold even if you don’t have enough excess left to fully fill the object you just end up with a thinner one – not really a failure, and being thin parts in the open its easy to test the resin’s cure level – if its set on such a thin part its fairly likely to be set sufficiently in your thicker work pieces.

  3. It’s a neat idea to not waste value resources. Hopefully there will be more information on the tools and utility, as well as how the molds are created as I see utility in making custom version that suit different needs.

    1. That mould would be trivial to make – get a flat sheet of just about anything and run bead of silicon/hot-glue or put some other frame on it to act as the walls of the mould, put the tool shapes down on it and pour over 2 part silicone – being so thin one of the tougher ones would be a good idea – never used it myself but I understand ‘dragon-skin’ to be a good choice for this.
      I’d suggest using some clay type stuff or hot glue underneath your tool forms to hold them in place during the silicone pour and perhaps smoothly seal the edges of the tool forms to the base sheet for a better mould and cast result. But neither is required.

      The tool profiles can be 3d prints or just be cut from thicker cardboard if you don’t have any existing tool to duplicate, just don’t use the corrugated card or make sure to glue some paper over the edges of it or something – I’ve found silicone won’t usually bond to cardboard even without mould release waxy coatings. but that would be a good idea in general. Though as the tool forms are pretty disposable anyway…

      1. I was going to comment that it’s not a new idea, and that I’ve seen it done for quite a while now.. untill I bothered checking instagram with your handle, and noticed it’s you who I’ve been following for ages anyway haha xD

  4. this idea probably originated in the concrete industry
    where there is always left over concrete that has to go
    somewhere,so,waste block which is roughly molded
    concrete blocks,and around here they are +- 4000lbs
    and $50 ,which is a realy cheap way to get a little inertia
    good one on the epoxy molds

    1. I know the concrete company that invented the “pi key stopper” some time back. They dump all the excess mixed concrete into a set of moulds that they then sell as giant forklift movable legos to stop ram raids and unauthorised site access. Very neat way to get rid of, otherwise, many tonnes of waste!

    1. Indeed, though seriously I have tended to pour left over silicone onto a flat surface or into something like a bottle cap – its either a useful easy clean mat or creates a little silicon pad that can be useful in so many things – put a hole in the middle of it and you have a vibration damping isolation washer, make it thick enough its a great foot for your projects (though to actually get that foot attached can be a pain if its not got any mechanical features to latch it in place, as practically nothing but silicone itself sticks to it…

  5. Firstly I thought there was no con, no issue. This is a really good idea, even if “reuse” comes after “reduce”,

    but everything else is wrong. The presentation format, the fact that this is not open nor customizable and sold for 60 bucks (yes silicon isn’t cheap but still)

    1. You could support a local genius and cough up $60, spend the time and make one yourself, or wait until China mass produces it for $10 and send your money out of the country. Your choice.

    2. Just because your time is free and you have a high paid day job in tech that pays for your making, doesn’t mean everyone is like that. Some people expect to get money for their brilliant ideas, products, and even time.

    3. The mats are as cheap as I can make them. The large mats cost about $68 worth of silicone to make, the small ones are about $35, because I won’t use cheap, crappy rubbers to manufacture them. Each mat takes about an hour of labor from start to finish, including packaging and shipping. I do all of the “marketing” an other one-man business stuff on my own time, so I won’t even include any of that.

      There’s the pigment that goes into each mat, incidentals like PPE, utilities for the shop (it’s gotta be warm and ive gotta run the extractor fan while im working with this stuff), tools, packing tape, and whatnot. It all adds up. All in all, i’m paying myself about 10 bucks an hour to create these. And the price does not reflect all of the equipment (a few grand’s worth) I had to buy in order to develop and produce them.

      But the crux of it is really that, given enough use, the mat can pay for itself, or at least part of itself. Stir sticks cost money, spreaders cost money, and they cost carbon too, if you’re buying them online or retail. The mat uses money you already paid to the epoxy company to subsidize those tool purchases.

      I understand cynicism of having grown up being pitched “amazing” things on the internet. I have it too. And you don’t know me from anyone else, but I favor transparency and discussion, so thank you for bringing this up. It’s important to know where the money goes when people are pricing “green” tools or goods

      1. Kudos to you for a thoughtful and polite response to this criticism. I was already going to buy one, but they’re out of stock now. Given your great response here I’ll definitely sign up for the in stock notice and buy once from you once you have more :)

  6. Great idea, but stirring sticks? Resin (even fully cured) can cause very odd reactions or interactions when exposed to different materials. Best to keep the number of unknowns as low as possible

  7. Hi Keith
    Absolutely brilliant idea! I hope I am not overstepping by giving business advice. I understand your pricing. I think you could reduce the price a little by not offering customisation. You offer the mat in 8 different colours but nobody will not buy your map because they can not find their favourite colour.
    Remember the slogan of the Ford T model. You can have this car in any colour provided the colour is black.

    1. i appreciate that. The customization is just me messing around. In order to keep it fun for myself i experiment with the colors. As of now I’m just doing flat colors because of the new demand, which obviously i agree is a good idea haha. The price is based off the cost of the silicone (crazy high) and the minimum amount of work I have to do on a basic-colored mat, and incidentals.

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