Plastic you can mold in your home for DIY projects

Shapelock 500 gram tub
Shapelock is a plastic that is made moldable with only hot water and is perfect for all kinds of do-it-yourself projects.

I finally got my Shapelock plastic molding beads today and decided to try it out. I’m not associated with Shapelock in any way and I (unfortunately 😉 ) do not get any payment for this mini-review.

For those who don’t know, Shapelock is a polymer (plastic) similar to polypropylene except that it has a very low temperature softening point. The idea is that you heat some water to around 160 degrees F and dump some of the pellets into the water to soften them to a moldable state. After molding, you then allow the plastic to cool and it once again takes-on its hard form. The label likens Shapelock to “modeling clay on steroids” and that’s a pretty good analogy.

Chances are that people reading this site have varying interests in such things as pinball machines, electronics goodies, robotics, and other nerdly, gadgety stuff. I doubt that I need to explain why something like Shapelock is useful for such hobbies, but just imagine being able to mold a custom mount for a bank of LEDs or create a new bracket to test the improvement to your pinball machine you’ve been thinking about. Yeah, that kind of stuff.

Shapelock 500 gram tub
Having a bit of experience with plastics, I knew basically what to expect of Shapelock, so I just ordered the 500 gram container. It was $24.95 plus about $6 for Priority Mail shipping. The also have a “free sample” that you can order and just pay $4.95 for shipping if you’re unsure that it’ll be useful for your purposes.

Now, onto the test…

Shapelock pellets Shapelock pellets
I grabbed a small Pyrex bowl and my trusty Sunbeam Hot Shot Beverage Machine to heat the water (I’m impatient and the Hot Shot takes care of that 😉 )

The Shapelock instructions say not to heat the water to boiling, which the Hot Shot does, but I figured that was more of a safety issue than anything. So, I blasted a coffee mug of water through the Hot Shot and dumped it into the Pyrex bowl, thus promptly cooling the small quantity of water signifiantly right away. Next, I added a few spoonfuls of the Shapelock pellets to the water.

Immediately upon hitting the water, they became slightly sticky and began to clump together. With another minute or two, plus some prodding with a spoon, the pellets were a large, malleable mass in the bottom of the bowl. The individual pellets were still visible, as the plastic does not become totally liquid when heated to these temperatures.

I carefully retrieved the Shapelock blob from the water and drained it over the sink to shed any excess, potentially hot water. The instructions recommend using tongs for this operation, again to prevent anyone from hurting themselves – follow the directions! 🙂

With the blob in my hands, I was able to knead the plastic and the individual beads formed into a more uniform modelling clay like texture. The plastic was very easy to stretch, bend, and mold being much the consistency of Play-doh. I rolled it into a long tube with my fingers and joined it into a circle and fiddled with some shapes. I did not find the Shapelock to be gooey or have any problems with it being overly sticky, although it is highly recommended that you not use other plastic implements to work the material as it may stick.

Once I had a suitable shape (suitable for a mini-review), I left it to cool and harden. It took a couple minutes before the plastic was firm and after about 15 minutes, it was pretty cool and hard to the touch. You can accelerate the cooling process with ice water if desired and I’m sure that pieces of Shapelock with more mass will take longer to cool.

Now, with my folded-ring test object fully cooled, I can say that the Shapelock resin is very strong. As you can see in the photos, I formed a shape that would allow me to attempt to fold the object and it resists quite well. The plastic is hard enough that fingernails won’t do major damage although with lots of pressure, will leave a visible indentation/scratch. For anyone who has worked with high-density polypropylene, this will be very familiar. It’s fairly slippery, ridgid yet flexible prior to breaking, and a milky white color.
Shapelock test widget close-up

The material can be drilled and machined as long as you watch the temperatures. Anything causing too much heat softens the material and will cause sloppy surfaces or gum-up your cutting device. I drilled several small holes in my test piece and all drilled easily, but the material does not cleanly remove from the hole due to it’s slighly rubbery nature. This was not a problem and, for example, a screw could be driven into the holes without any issue, but the hole did not look clean after drilling. Also, without reversing the drill, there was quite a bit of resistance removing the bit, most likely due to the remaining material in the bit flutes. Overall, though, the material is easy to drill.

Overall, I am pleased with this initial experience with the Shapelock. I honestly believe that it will be useful for molding various brackets and gizmos for my pinball machine, slot machine (when I get around to it), radio control airplanes, and many other projects. It is not cheap, but it took a surprisingly little amount to create a blob of useful size. Shapelock is reusable as well, simply requiring a re-heat to soften it and move-on to another project.

However, I cannot recommend this for all projects. Shapelock’s strength is the low-temperature melting point. Shapelocks’ weakness is the low temperature melting point. In other words, simply due to the nature of the material, it obviously cannot be used for anything that generates much heat, such as making a mount for a high-powered motor which generates heat. However, for room-temperature needs, I doubt that there is anything better for the hobbiest who doesn’t want to buy an injection molding machine or pay to have parts machined at the local machine shop.

If this sounds interesting to you, I’d recommend grabbing the free sample or perhaps one of the smaller tubs to try-out. I know that I’ll be using it for all kinds of projects and I expect this 500g tub to give me at least 50 more blobs the size of the one you see in the photo (sorry for the imprecise guess) and that’s if I don’t re-use any of it.

NOTE: It appears that this product is also available under the brand name “Friendly Plastic” so you can keep an eye out for that as well.

Please head-over to the and join the plastics discussion forums to post your questions, ideas, and projects. There is a forum for Shapelock/Friendly Plastic specifically, as well as a forum to post your projects, and several others. I’ll select projects from time-to-time and feature them on the top-level page too! The forums are new, so don’t be shy and if you have ideas to suggest a better structure or anything, use the Contact link.

CLICK HERE to order a discounted tub of Friendly Plastic which is more commonly available if you can’t find Shapelock.

75 thoughts on “Plastic you can mold in your home for DIY projects”

  1. That is a cool looking substance, does it bond to other plastics, or would you have to use screws or glue (would glue cause any sort of melting effect?)

    dugg 🙂

  2. Now take it to the next level. Go investigate Kydex, another thermoplastic. Takes more heat and it’s more of a “cut out flat pieces at normal temp and then heat and bend” sort of thing, great for odd-shaped brackets. It can also be molded around things, like cellphones, knives, guns…go google “kydex holster”.

    It’s not as moldable as the stuff above but it’s much tougher. Thicknesses of .125″ or more can be used to custom-mold sports armor, knee/elbow pads and the like.

  3. Did you try “freezing” your ring before drilling? Just pop it in the fridge or deep freeze for a while. It shouldn’t get too brittle. (If it does, you can re-mold it.)

  4. When pulling the drill out of a hole, i recommend still pulling the trigger while pulling. it will leave a clean hole.

  5. Thanks for the tips! I was still running the drill while pulling it back out, but it was slowly turning due to the small piece I was trying to drill. I think that freezing the piece might help also if a clean-looking hole is needed. The leftover material in my test case was easily removed with a knife, so no matter how you do it, it works great.

    AFAIK, there is no way to permanently make the plastic “non meltable”, Luke. This is a thermoplastic and you’d need some kind of chemical reaction (like epoxy) to make a non-thermo-sensitive type object.

    Also, sorry to all of the Diggers and other visitors who found the site offline this morning. The sudden rush of traffic from the front-page appearance on digg caused my hosting company to think I was getting a DDOS attack and they disabled my account. I guess if they would have looked at the referrer, they could see it’s all coming from one site (digg) but oh well. Thanks for sticking with me and making this my first real Digg 🙂


  6. That is funny 🙂 The firestorm of traffic from being ‘dugg’ appeared to be a DOS attack 🙂 That is just too funny ;D

  7. Yeah its cool, I saw it on Make Magazines podcast, but i have yet to see any one do any thing cool or useful with it, so far its all talk.

  8. I think it’s probably one of those things that lives a secret life in projects. Nobody probably thinks to take a pic of a lowly home-made bracket or other things it’s used for. My guess at least…

  9. Once you have made a shape, could you then spray or paint it with some sort of flastic/glue to make it more permanant, so that even if it does melt a bit, the outside layer will hold it together?

  10. I wonder if you could mix in other materials before you mold it into shape to give it more strength or flexibility or electrical conductivity or whatever….

    Sounds like something fun to check out. Thanks!

  11. To prevent sticking during drilling, consider submerging the part in cool water. The tip of the drill bit will be submerged, but that shouldn’t hurt anything. The water can absorb LOTS of heat before it reaches the softening point of the plastic.

    Also consider drilling with a slightly smaller drill then, after cooling, following with the proper-sized drill. The less material removed, the less heat will be generated.

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  14. I think I just found an alternative to the $300 my dentist wants to custom-mold me a thinner mouthguard than can be found in sporting goods stores! The sample pack looks perfect for this!

  15. Thanks for posting this review. It looks like it will be perfect for my next project. I have an old Sunto watch that I have little use for, and was planning to mod it to affix it to the inner pocket of some of my jackets (I’ll post a more thorough description of the process on my site in the next couple of days), and this looks like it would make the perfect substance to work with.

  16. Anyone know if this could be used as a mold for resin? Or would the resin stick to much?

  17. @Tony: I’m not sure what kind of resin you’re wondering about (acrylic, polyester, epoxy, etc.) and that would make a potentially huge difference.

    If I assume that you’re trying to cast something using acrylic or polyester, I’d say that the Shapelock would work just fine. As with most molds, you’d probably want to use some release agent (silicone spray for example) but I don’t see why you could not use the Shapelock to form a pourable resin.

    There is, however, one caveat. Many 2-part resins generate heat. Some generate quite a bit of heat. That could be bad considering the low softening point of the Shapelock.


  18. From the Make blog posting, here are some comments that might be useful. I’m not sure if other blog’s comments should auto-appear here or not (this is my first blog) so please let me know if they should 😉

    Posted by: Giusp on March 22, 2006 at 02:56 PM

    I got some of this stuff last week and have been playing with it a lot, here are some things I’ve found out recently…

    * With a pasta roller, you know, those silver machines you see at home goods stores, you can make nice even sheets for making good looking constructions. Making little planks also gives you ‘stock’ that heats up very quickly.

    * Fusion brand rustoleum plastic spray paint sticks to it very nicely, so it can be painted, if you should need to.

    * It has been advertised to be able to be machined, but since it behaves like nylon or delrin, that’s not really true. It didn’t like it when I tried. I haven’t tried drilling or tapping it yet (hmmm, that sounds not quite right)

    * With a hot putty knife you can connect new hot pieces to previously cooled constructions. I keep the putty knife in the same hot water pot where I’m heating the stuff. This gives you something to fish it out with.

    * It’s available in colors under the name ‘friendly plastic’

    * It’s very cool stuff with a ton of uses. After you play with it for a while you start to see all kinds of things it could help with.

  19. Micro-Mark sells a two part RTV Silicone putty for mold making. They also sell liquid RTV Silicone and casting resins, mold release spray, etc.. I’m wondering if any of the major plastic suppliers have a similar polypropylene- I’m a cheapskate. How is it with hand filing?

  20. For my fellow cheapskates – I know you are out there – I will share my ghetto-fabulous method for molding scavenged plastic. ABS plastic dissolves in acetone! Get a good thick piece (television/CRT housing, motorcycle fairing, etc.), and make a pile of shavings by repeatedly drilling holes in it. When you get a good amount, dump them into a small disposable container with a bit of acetone. Stir until gooey. Remove the blob and mold. It will take at least 24 hours to fully cure, so be patient. Also, air bubbles inevitably get into the mix, making this recycled ABS weaker than original. But it won’t melt at 160 degrees, either.
    This stuff gets really sticky when molding! It is manageable though, if you keep your fingertips wet with acetone.
    This method can be used to repair cracks in a motorcycle fairing!

  21. I used this material many years ago. It has its good points. I have developed a nifty shape changeable material available in sheet form that can do amazing things in addition to forming shapes. All you need is 105 degrees to soften enabling you to change a shape to what you desire.

  22. Hi Andrew,

    It’s not very transparent at all. If you stretch it thin enough, you might say it has a small amount of translucency, but it’s certainly nothing that you’ll be shining light through or using to build clear windows for models or anything like that.

    The color of the pellets and the ring I made in the photos shows the final, hardened color.


  23. hello everyone i have a question for whoever might know the answer. well i’ve been trying to find a way to mold my own car body parts such as my own custom designed body kit for my chevy s10 1996 and to be able to create my own design the way i want it to be would be really cool so im asking is it possible to use the shapelock pellets to design lets say a front air damn or side skirts? if someone could please reply that would be great my e-mail is thanks again

  24. Hi Arty,

    While I it would technically be possible to use Shapelock to mold a car part, you must consider the temperatures involved. As you can see from the review, it’s a low-temp plastic so that means that it could soften just from sitting in the hot sun over black asphalt, for example. It might not blob and goob, but it could get soft enough to deform when you start driving due to air pressure.

    The more common method of making custom car body panels is with fiberglass. This is a well-known process and that’s why any whale-tails, spoilers, air dams, ground effect kits, etc. that you buy will likely be fiberglass. It’s easy to work with once you know what you’re doing and have experimented a bit and it’s fairly cheap. I’m sure that some time on Google or the public library will yield tons of info on laying (forming) fiberglass.


  25. Thanks for sharing this product. I have not come across this before and though I can’t at the moment think of what I would do with it, I believe there will be a future DIY project where I could put this to use. Definately eaiser and safer than using a hot plate type product.

  26. Hi Brian,

    The plastic is quite rigid and hard when it is cool, so I don’t think that you could make a collapsible tubing from it, if I’m envisioning a similar item as you’re thinking.

  27. Would this be suitable for making molds for casting plaster or conrete? That is, to create a mold by shaping the product over an object, then removing this and (when cool and set) pouring in plaster or concrete?
    If so, what release agents would you recommend?

  28. Where could I find something like this that would dry and harden as a clear plastic?

  29. I just sent for the free sample, to be used for fitting Fangs for a costume party later this year. For people who don’t like or trust the stuff that comes with the kits available from some sources, this is an excellent product and safe as well.

  30. Great idea Tony. I’d imagine that this kind of home-moldable plastic has all sorts of uses in theatre/costume makeup. Thanks for the comment!


  31. micsaud, I beleive it’s the same stuff used by the company Dental Distortions. Other companies use some kind of powder-liquid mix. But I think the hydroplastic stuff is better since it’s remoldable.

  32. Whoa! I’m probably the last to find out about this! This is really cool though! I have to try it out myself! Thanks for sharing the info 🙂

  33. Thank you for the article! I was searching for a polymer that can be used for making waste mold and that are reusable. Your article really helps! sadly I cant get it in my country.

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