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How to make really good hard plastic while reusing and recycling plastic bags at home! Via this method, you can make ANYTHING you want to, out of hard, lightweight, real plastic that's astoundingly durable. It comes out very similar in texture to recycled plastic lumber.

best of all, this method involves no fumes!

I'm gonna show you how to make plastic wheels for your robot!

I first heard about stewing plastic bags to make new things from Dave Huebsch's book " Village Assignment " about interesting adventures had while running a charity/NGO (" Common Hope ") in Guatemala. He, amazingly, repaired the bottom weight-carrying main bearing of a washing machine with a big plastic disc made of stewed plastic bags, which actually was such a good stand-in replacement that it held up for several years. (and here are some more Guatemalan Handy Tricks)

I had to try it right away, and the first couple times I just burnt plastic, until I came up with this method.

By the end of this, you'll be able to make yourself a knife sheath, mold around your shoes and make DIY hard-toe sneakers, wheels, bearings, bushings, or any kind of plastic part! Take pictures and post them in the comments!

Step 1: Materials

Collect all the plastic bags you can get, they shrink down a lot.
Shredding them will make your final texture finer.

Use an old pot that you aren't going to use for food any more, or get one secondhand for really cheap at a thrift store.

Find a stick or something else you can use for a spatula.

I liked the clothespin a lot because I could pick things up as well as stir.

Oh, and oil! (I used canola because it was right there next to my stove. If you're, for example, making a bearing you can impregnate it with your personal favorite grease.)

So grab your favorite oil, here's why:

Plastic bags are made of LDPE (low density polyethylene) which melts at 248 F.

I got the temperature wrong and tried doing this in a homemade double boiler filled with water (to regulate the temperature to water's boiling point), which, of course, just made hot plastic bags.

After the double-boiler mistake I re-read the LDPE melt-point and discovered my folly! So I came up with melting them in oil.

Cooking oil boils around 350, which is far too hot for plastic, and which you don't want anyway (splashing boiling oil = no fun unless you're a hun), so I keep it to a nice low-viscosity canola oil heat and things work just fine.

If you wanted a smooth, non-oily finished surface, consider using wax instead.

ALSO: oil is not required per se --
if you had a constant temperature hot surface that you could guarantee to keep down around the melting point, you could do this just fine with no oil or wax!
<p>use an oven set to 350, on a cookie sheet with wax paper to melt the plastic.</p>
<p>Ok so how will I know exactly what type of plastic the bags are made of? Is there a symbol to look for or what?</p><p>Thanks :)</p>
<p>So, it's been a while since I had a Plastics and Ceramics course. If you process it like this, does the plastic remain High Density Polyethylene, or could some of it be degraded into a lower-grade form?</p>
<p>So I had a thought here. What would the results be if you used a toaster oven to heat a pan partially filled with plastic to 250 degrees. Would the results be liquid enough to cast?</p>
Could I get opinions on whether or not my idea will work? <br>-Use an induction cooker to heat a pan filled with HDPE material and a little oil to about 250 degrees. Heat and stir until evenly melted. (I think the induction cooker has the means to maintain a steady temperature.)<br>-Make a wooden mold that uses a 2x4 for a bottom and has wooden sides and ends. Line the mold with parchment paper. <br>-Pour (or drop) the melted HDPE into the mold. Lay a piece of parchment paper on top. <br>-Place another 2x4 on top that's the exact same size as opening on the top of the mold. Clamp the top down and allow to cool. <br><br>This should create a solid block of 2x4 HDPE. The length will be limited by how much HDPE I can melt at one time. I'm hoping I can create 2x4 lumber and build a small bench. <br>
Video not connected. I'm interested.
<p>SWEET!</p>
<p>I like this. Sweet and Simple, or is it Simple and Sweet ? Not sure. But it looks nifty and I have visions of a homemade kayak in my head. (Might start a little smaller :-) Thanks for sharing!</p>
<p>Here's a video of a different method that uses bottles, seems less messy, and won't require ruining pans.. maybe. https://www.youtube.com/watch?v=kUR6_bQLU-E&amp;ab_channel=PeterBrown</p>
Peter Brown's shop time for the win!!
<p>Would the end product be toxic to animals? I was thinking about making a wading pool for my turtle.</p>
No it should be fine because HDPE is non-toxic in small quantities. That's why the FDA allows milk cartons, water jugs, container lids, and coffee cans to be made with it.
<p>Most supermarket bags are HDPE. Some stores like electronics, clothing etc use LDPE because they are softer and feel more &quot;luxurious&quot; but still all are made out of PE. PE along with PP are considered the safest plastics for food containers (milk bottles, tupperware etc), so it's safe for water also.</p><p>The general idea is identical (except of the absence of pressure) to the one in a plastic recycling factory. Just take care they are clean and better without prints. Colored are just fine as natural.</p><p>If you are still concerned take some glass and silicone and you have the safest result :P</p>
<p>Without industrial controls, there's no certainty of what hydrocarbons or other stuff may be present in the material or produced in the process. You can't know what machine oils, cleaners, inks, etc. were used in making the original product, much less what it's been exposed to since. Imho, I would avoid any use that involves food or water for plants or animals, humans included. Especially if there's heat involved. Though Bpa is falling from use in many plastics, it's still common, and now we're learning that the replacement bisphenols may be just as bad :/</p>
<p>I would not advise it. You cannot use a vinyl pool liner for a fish pond as it contain chemicals to retard algae. Those bags may be coming from many different manufacturers with many different compositions.</p>
<p>thank you</p>
<p>Hmmm, I wonder how this could be implemented into construction</p>
<p>Our municipality (Moreland, Victoria, Australia) has used it for making park benches, car-parking wheelstops and bollards. They worked with a local plastics recycler and are able to accept a much wider range of plastics for recycling - including plastic bags - than most municipalities in the State.</p>
<p>Looks good!<br>Here's a similar Instructable giving a method of making machinists wax by melting plastic bags. Hope this helps somebody!</p><p>http://www.instructables.com/id/Machinable-Wax/</p>
<p>define &quot;lumber&quot; for me?</p>
<p>wood</p>
<p>I use a similar method to melt pieces of mild crate or soft drink crates to pressure mold plastic items . I have built a mini frier using an old kettle element hooked up to a thermostat switch which keeps the hot oil at the right temperature . I cut up pieces of the crate which are quite thick and drop them into the oil . I have my molds standing by which are made out of Pratley putty ,( a two part putty which you mix at a ratio of 1/1 and hardens around the shape of the object being copied . ) . As soon as the plastic reaches a thick treacle consistency ,I picked it up with tongs and drop it into the mold making sure there is enough to overflow the mold so it will fill both halves . Then I clamp the mold together under pressure for a few minutes to force the plastic into both halves to take the shape of the mold . Nice thing about the oil is it acts as a release agent too so the molded item pops out easily . Two issues to take care of though is firstly fire I don't need to warn you about how flammable oil is . Secondly , the molded item has a tendency to &quot; weep&quot; and becomes a bit tacky and has to be washed with a good detergent periodically until it stops . But it is a good way to make small hard to get parts . I make remote control buttons out of hard plastic as the originals tend to wear and become &quot;gummy&quot; with use . Hard plastic will outlast the remote . </p>
<p>any idea how to make a ball for a dog out of the presented methods? ? </p>
<p>you should not freeze it, as that will cause it to fold and wrinkle as it cools and contracts. In fact, you should cool it as slow as possible to give it a chance to crystallize regularly. Also, baking it in an oven works better. Also, you should apply pressure while it is cooling so it will crystalize</p>
could this missed step account for the bounciness?
<p>actually, it should be bouncier if allowed to cool properly. cooling to fast may cause brittleness.</p>
<p>Is there any reason you couldn't stick it in an old cake pan and heat it in an oven? </p>
<p>That's how most seem to do it. They also fold over the soften plastic to give it a marble effect then cool under pressure since this plastic will shrink as it cools ... You'll get rid of most air bubbles as well.</p><p>It also avoids having oil or whatever mixed in with the plastic. HDPE is slippery enough on its own. I certain don't want to play with hot oil, the hot plastic is bad enough to handle - use proper gloves and protection.</p><p>Search Google for some info, YouTube, etc. on the process.</p><p>A good find is <iframe allowfullscreen="" frameborder="0" height="281" src="//www.youtube.com/embed/rpXq6mnbCus" width="500"></iframe></p><p>You basically have to use a non-stick surface, make sure you melt (not burn) the pieces of plastic. Magic temperature seems to be around 350 F (175 C) in oven. Don't use the oven in your kitchen, just to be on safe side (spills, ...) I use a small counter top oven out in garage, just for such work.</p><p>Be safe, have fun.</p>
<p>Excellent video. Thank you so much.</p>
<p>That's my question, also.</p>
I can't wait to try this!
<p>Set up your double boiler but instead of using water between the pots use cooking oil. This will let you get the temp up to the melting point. This set up is easy to control the temp.</p>
<p>There was this: &quot;If you wanted a smooth, non-oily finished surface, consider using wax instead.&quot; That sounds to me like the oil/wax affect the texture of the plastic.</p>
Whether I make it or not, your 'ible made my day. Probably the cutest I've ever read. You are absolutely adorable and I wish you great success in your future.
<p>How would you die this material for making lumber. I guess you could make a lumber form and pour/place/pack the material in the form. People have said the material should be pressurized while drying. Guess you could use bricks or something else for this purpose? At any rate, here is a link to making plastic lumber.</p><p>http://www.prosalesmagazine.com/products/decking/how-to-make-plastic-wood_o</p>
Hi great article, I would like to try this at home I just have a few questions. <br>1- can you use any type of material to make the mold with, or does it have to be plastic? <br>2- Do you have to freeze the melted plastic once you have them in the mold to harden? Or can you just let them harden at room temperature?
<p>I can answer that. The mold can be anything with a melting temperature higher than the melted plastic. I've used a plaster cast before, it worked fine. </p><p>No, you don't have to freeze the plastic, that step says &quot;if you want it to cool FASTER, put it in the freezer&quot;. You can totally just let it cool at room temperature. Unless you're impatient.</p>
<p>It is possible that rapid cooling in a freezer could change the characteristics if the plastic. </p>
<p>indeed. It will not crystalize uniformly and will be prone to breakage and may fold</p>
<p>Hey there,</p><p>Yes, your mold can be made of anything that can withstand the initial heat of the melted plastic (caution it will burn skin - so be careful).</p><p>I don't think freezing is necessary - just speeds things up.</p>
<p>An Induction burner would be great for this as it keeps a steady temp. Garage sales would be a great place to find old stainless steel pots to melt in, and a mixer to use. As for the turtle tub, they make pond liners in various sizes and shapes. If it is a small turtle anything that holds water. Sometimes we have to buy things:)</p>
<p>Stainless steel pots will not work on an induction burner. It has to be magnetic in order to work. Just carry a small magnet to the garage sales and if it sticks, the pot will work.</p>
<p>What precise temperature is needed to melt the plastic? Would an immersion circulator, like is used for sous vide water-bath cooking, work or would it be too cool?</p>
<p>Sous vide circulators a) don't get above boiling water temp, and b) will be destroyed if you use anything but water. They're not made for anything else. You'd be better off looking at a chemist's heating mantle with a temperature control or maybe a chemist's hotplate/magnetic stirring device and a pyrex beaker. That might let you work without the oil.</p>
<p>Thanks, ardrhi. I was just thinking of vacuuming the plastic shreds inside something that is then submerged in the water bath. But if it doesn't get hot enough, that answers the question! :)</p>
<p>A good pressure cooker can exceed 1 bar, at which water boils at 250 deg F - just enough.</p>
<p>Yeah, but it's also a good pressure cooker.</p>
<p>Yeah, but it's also a good pressure cooker.</p>
<p>Hmmm...worth a try!</p>

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