Melting Hdpe Plastic

Intro: Melting Hdpe Plastic

this is my first instructable hope you like


first you need to find some HDPE it is number 2 with the recycling triangle or most milk bottles and bottle tops

Step 2: Process the Plastic

cut up the plastic or use a blender ( if you use the latter it will contaminate the blender and be unusable for food )

Step 3: Melting the Plastic

the tools you need are toaster oven or oven if you are using a oven you will need a tray that you cant use for food and a vise

set the temp to 175 c or 347 f

Step 4: Restock the Plastic

you will need to restock the tray you can use pre melted hdpe or milk bottles

Step 5: While It's Melting

ive got a lot of wood lots more than in the photos and i want you to tell me what to do and i what to know if you will like restorations on the fuel can, hoe and yankee drill /screwdriver and of make a metal melter out of a microwave


Step 6: Done

let it cool or grip it in the vise and fold it over and ''weld'' it together

Step 7: Tips and Thoughts

it can be cut with a wood rip saw runs good on the lathe thank you for looking at my

happy making from jimmy at kidintheworkshop



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    13 Discussions


    9 months ago

    I've worked with HDPE, LDPE, PE and PP. I found you don't have to cut it up much too start, just clean it, remove labels and melt it. But I melt it at 375-400 F for an hour or more, remove it, fold, twist, knead it, then heat again at least 3x. Then I take it out and push it into a mold made of wood and apply as much pressure as possible until it cools. The result is a super hard, solid piece of plastic with no voids. I can then sand, cut, drill, polish the blocks any way I want. I've made a bunch of handles for tools and knifes, coasters for coffee table, oversized plastic washers, desktop webcam stand, etc.

    1 reply

    Reply 8 months ago

    I've been working on iterations of this project ever since I published it , with a completely new set of tools they have opened up a new world of possibilities including a project with laser cutters and 3d printers. I am revising this post and adding much much more this year coming

    thanks for an insight into your way of doing this has given min a few ideas myself

    , keep making

    Jimmy Crawford


    3 years ago

    This can be used to cast figures, like instamorph?

    6 replies

    if you could get a heat proof mold you could melt it into it but other wize it get really hot and it a gum like consistency so no sorry by you can carve it

    thanks for looking at my instructable jimmy from kidintheworkshop


    i dont know what you mean it is not liquid it is taffy but instead of using a tray use your mold blend it real fine thanks please vote

    None here is an istructable with the lost wax casting, for make models, but if you say is not liquid .... voted


    3 years ago on Introduction

    i did melted a lot of hdpe and from experience hdpe when melted will not turn liquid it will be more like thick taffy if you want it to be completely flat you could clamp it down between two boards while still melted this way your plastic will be completely flat. and keep in mind that not all hdpe is the same because most containers like the ones you used in the video are blow molded and blow molded hdpe is higher density which makes it less flowable when melted on the other hand 5 gallon buckets are normally injection molded which uses a lower density type of hdpe that flows into the mold without pressure however the higher density hdpe is stronger

    1 reply