Introduction: Recycled Plastic Mallet

I have to see so much plastic ending up in trash everyday.

Even if we recycle it, think about the energy involved, each time, to recycle a staw, that's been used for maximum 1 hour when it could last decades, if not centuries.

So i asked myself, what kind of object is not likely to end up in the trash ? What do we not find in trash ? Tools.

Nobody throw tools away, they'd always give it to someone or keep them just in case.

So making a tool out of recycled plastic helps it stay in use longer.

Now what kind of tools can you make out of plastic ?

Hammers cannot, plastic isn't hard nor heavy enough, but mallets can ! this is how you do it.

Step 1: Collect Some HDPE

Basically all you need to do is look for recycling logo n°2 on any plastic thing you put in your trash.

Those items are very likely to be made out of HDPE :

You need about 300g of HDPE to make one mallet. The plastic caps on the picture are 150g, so in the end, it's not that much.

Why is HDPE suitable for making a mallet ?

  • It is relatively soft, so that it doesn’t leave impact marks on wood when assembling things.
  • It has a good impact resistance and is not brittle like PC or PLA.

Tell your friends and family to save their plastic waste for you. You'll collect a lot more, a lot faster.

If you don’t wish to collect HDPE by yourself and prefer to buy some, there’s always the Preciousplastics Bazar, on which you can find ready-to-melt materials.

Step 2: Shred It Down to Pieces

You may use scissors, you may use a shredder machine form the
Precious Plastics Project.

I suggest you sort plastic flakes by colour so that you can compose your pattern afterwards.

I personally use glass jars to store my plastic flakes but it’s really up to you.

In order to make one mallet, you need around 300g of HDPE, that is roughly 3 to 4 big jars.

However, if you're using parts that already fit in the mold, it is not mandatory to shred them.

Step 3: Build a Mold

At this stage you have two options : you can build a wooden
mold, that is very quickly done, but will only last 1 meldown, or you can build a steel mold, that will last longer.

If it’s the first time you do this, i’d advise building a wooden mold first.

My mold was made out of 5mm regular plywood, i roughly cut 5 pieces in order to get a box of internal dimensions 70x70x110mm.

Those pieces are assembled using little nails on the sides. It doesn’t have to be extremely sturdy.

To prevent HDPE from sticking to your mold, you may use some baking paper on the inside.

Step 4: Find a Handle

The handle need to be approximately 35 to 40 cm long. Your handle should’nt be thinner that 3cm

I used a piece of sledge handle but if you're not planning on hitting real hard, any broomstick handle should do. If you have acces to various types of wood, prefer Frene or even Hickory.

I used a little hacksaw to cut notches at one extremity of the handle, this will help the plastic grip on it.

If it fails, you can always cut an eye through the mallet and assemble it the traditionnal way, but this technique is faster and less work intensive.

Step 5: Find a Suitable Oven

Any oven that can reach 220°C is suitable.

As a precaution, don't use your kitchen oven for this. I don't know what residu may stay there.

Step 6: Melt the Head of the Mallet Down

Safety first : you need a gas mask todo this, HDPE fumes are dangerous. You also need gloves to manipulate the hot mold.

If you can, melt the thing outside.

A good temperature is just below the melting point of HDPE, which is 120 to 180 °C (248 to 356 °F).

The trick is to pour a little amount of plastic flakes into the mold, put it in the oven, wait for the flakes to have melted and repeat this process until your mold is almost totally filled up.

Beetween refills, you can use a tool ( mine was a 19mm Spanner, so, any tool ) to squish the molten material together, you don’t want air bubbles in that mallet.

Step 7: Stick the Handle In

The handle needs be preheated a little before you can stick it in, otherwise you won't get good results.

Pay attention to stick the handle square to the head !

Step 8: Let It Cool

There’s a lot of heat in that mold
and HDPE is a relatively good thermal insulator, meaning it’ll take hours to cool down completely. Don’t rush it, think of all the work you’ve put in his so far, let it cool overnight.

It is important that your handle stays true to the faces while cooling, clamping it down is a good idea, as HDPE tends to shrink a lot while cooling,

Step 9: Shape the Faces

You’ll have a very square output,
it’s better to round off the corners, you can even grind in a round face.

You have different tools that will do the job :

* Wood Rasps

* Belt sanders

* Disc Sanders

* Angle grinders with sandpaper discs

*Sandpaper ( Get an aggressive grit, like 40 in order to be effective)

When the shape is about right, you can give the surface a cleanup with higher grit sandpaper and then slightly melt the surface with a heatgun, it gives the mallet a better finish.

However, don’t expect HDPE to be polished : it’s a soft plastic, you won’t get it polished.

Step 10: Finish the Handle

A little linseed oil never hurt nobody.

Step 11: You're Done ! Go Hit Things !

The first thing i did was to destroy the mold.

Very rewarding.

Step 12: Can It Actually Last As Long As a Classic Mallet ?

This is a picture of the first mallet i made, after one year of use in a blacksmithing workshop.

It's quite resilient to me so far, and i have been hitting things really hard with it.

Step 13: Make More ! Experiment With Plastics !

I have so far made quite a few of these mallets, and i've been selling them on ETSY so i had the opportunity to make a second video about how i used a metal mold in order to produce many of them.

Other plastics that can be suitable for a mallet are the other polyethilene plastics : PER ( the red and blue one), even PELD ( the whitish one ) works fine, you can experiment and let me know, i'll be very interested.

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