# Milk-jug mallet



## JeffP (Aug 4, 2014)

I actually ran across this maker video on an electronics maker site that I frequent.

Some guy melted down milk jugs to make himself a nice joiner's mallet.

http://hackaday.com/2015/02/21/turning-plastic-milk-jugs-into-a-useful-tool/


----------



## bondogaposis (Dec 18, 2011)

Interesting. I can't say I would ever want a plastic mallet, but for some this information seems useful.


----------



## waho6o9 (May 6, 2011)

Good to know thanks JeffP.


----------



## JeffP (Aug 4, 2014)

In retrospect, it might have ultimately been easier and more practical to recycle/upcycle a dead hickory tree than a bunch of milk jugs.

Mostly I was just amazed at how easy it was to melt that stuff into a solid block.


----------



## kludge (Oct 22, 2013)

Ha! You found my video… You got a dead hickory tree and I'll trade you for my milk bottle mallet!


----------



## woodbutcherbynight (Oct 21, 2011)

cool idea, myself I have some Corian sample squares that fit the bill to attach to the end of the mallet. Without using the wife's kitchen tools. (Laughing)


----------



## MrUnix (May 18, 2012)

Very cool.. I can think of a LOT of stuff that could be made from that. I've previously needed to turn some custom parts for fixing various things and have resorted to using epoxy blanks, however larger stuff is kind of difficult due to the heat generated when dealing with thick epoxy pours. HDPE would be ideal for some of those, so yet another alternative to add to the arsenal! Thanks for the info.

Cheers,
Brad


----------



## hotbyte (Apr 3, 2010)

Could it be molded and cut to be runners for table saw sleds, etc.???


----------



## wormil (Nov 19, 2011)

> Could it be molded and cut to be runners for table saw sleds, etc.???
> 
> - hotbyte


I haven't tried it yet but based on what I've learned, it would be challenging but possible. Probably not worth it IMO. The stuff shrinks quite a bit as it hardens and the challenge is preventing air bubbles. There is a youtube channel called, The Art of War, that has some excellent videos on recycled hdpe. The kid (he's 15), makes excellent videos, kinda like a teenage Matthias Wandel.

My wife thinks I'm crazy but I'm saving up plastic to give this a try.


----------



## MrUnix (May 18, 2012)

*My wife thinks I'm crazy but I'm saving up plastic to give this a try.*

I got some in the toaster oven right now, and I'm not telling the wife 

To the question.. I guess you could make runners, but why would you want to when there are so many alternatives available that are WAY easier. If you really have to have HDPE for your runners, run down to your local dollar store and pick up some cheap cutting boards and cut them into appropriate sized strips. I'm more interested in making blanks for turning on the lathe as a replacement for some of the stuff I currently resort to using epoxy for.

Cheers,
Brad


----------



## MrUnix (May 18, 2012)

Dang.. I'm having way too much fun with this stuff 










Cheers,
Brad


----------



## JADobson (Aug 14, 2012)

I just finished a jug of milk and have saved the jug from the recycling bin. There is a mallet (or two) in my future.


----------



## MrUnix (May 18, 2012)

> I just finished a jug of milk and have saved the jug from the recycling bin. There is a mallet (or two) in my future.


I was amazed at how much stuff around the house was made of HDPE when I started playing.. not just milk jugs and juice containers. Squirt bottles (like for mustard), generic screw top pill bottles, laundry detergent jugs, shampoo bottles.. and even those plastic bags you get at the grocery store! And with my limited experiments, you can use a metal form to get some pretty good results, like the heart shown in the picture above.. I used one of those metal cookie cutter things that I dug out of a drawer in the kitchen. No sticking at all and the finish is very smooth.

Cheers,
Brad


----------



## wormil (Nov 19, 2011)

I've run into the exact opposite experience, 90% of the plastic we buy turned out to be #5, polypropylene.


----------



## MrUnix (May 18, 2012)

*90% of the plastic we buy turned out to be #5, polypropylene.*

I hear you Rick.. but I bet you get lots of those plastic bags at the store! Almost every bag I found was HDPE.. Grocery store bags, Harbor Freight, NAPA, Home Depot, Lowes, Ace Hardware, Old Navy, Target, Walgreens.. they were all HDPE. Unfortunately, it takes a LOT of them to make anything useful.. but the good news is they melt down really, really fast! I used an old never-dull can and wooden plug (wrapped in aluminium foil) to act as a piston and made a good sized chunk from some last night:










That chunk is about 1.5" thick and 3.5" in diameter.. just a bit larger than the size of a hockey puck.

Cheers,
Brad


----------



## smitdog (Aug 20, 2012)

Nice, I didn't know the grocery bags were HDPE… I've got a huge trash bag full of them in my "good intentions pile" to go back to the store to recycle. Looks like I may have to "borrow" the oven! Do you think the ink from the printed bags would create fumes at that temperature though? I work in the printing industry and some inks can be nasty… A lot of them are soy based now but I'm not sure about plastic bags. If they are oil or latex based it could get nasty. I'll do a little research first before fumigating my house…


----------



## waho6o9 (May 6, 2011)

2 cool


----------



## hotbyte (Apr 3, 2010)

Somebody needs to combine an E-Z Bake oven and Play-Do Factory for all this plastic


----------



## MrUnix (May 18, 2012)

*Do you think the ink from the printed bags would create fumes at that temperature though?*

I didn't notice any unusual fumes when I did the grocery bags, and I was baking for a couple hours.. I doubt there is enough ink to make much of an impact anyway.. I actually had worse fumes when doing the blue chunks in the first picture I posted above; those were laundry detergent jugs and they didn't wash out completely, so I had that nice fabric softener kind of smell coming from them.

FYI: In that first picture, the beige chunk was from milk jugs, the whiter one was from some generic pill bottles that the wife gets through a mail order prescription service, the blue were laundry detergent jugs like mentioned, and the multi color one was a mix of bottle caps, a mustard bottle, and some left over bits from the first few attempts. I folded, twisted and generally mashed it up to get the variation and layers of color.

Cheers,
Brad


----------



## kwolfe (Feb 12, 2014)

Did you melt them in the can or on the sheet and then in the can. I think my wife would kill me if I used the sheet directly. I have a few old big coffee cans laying around. Did you say 350F for melting?


----------



## wormil (Nov 19, 2011)

> I used an old never-dull can and wooden plug (wrapped in aluminium foil) to act as a piston and made a good sized chunk from some last night:
> 
> Cheers,
> Brad
> ...


I like how that turned out. Any issues with air bubbles?


----------



## MrUnix (May 18, 2012)

*Did you melt them in the can or on the sheet and then in the can.*

Melted in the can and the oven was set at 350F. I also tried with higher temps (up to about 375), which seemed to melt it a little more, but also made it even more sticky and harder to work with. The stuff turns into basically a really sticky chewing gum consistency, so it seems much easier to just melt in the form you want to use. A coffee can would probably work, but the ridges might make getting it out once it hardens a bit difficult. You might need to just consider it a one-time form and cut it off when done. The only issue I had with the can I used, which I didn't think about before starting, was the top 'lip' of the can is rolled inwards, which hung up the plastic when trying to remove it. I drilled and tapped a hole for a screw on top of the blank to thread in a screw and use it to pull past the lip, but that didn't work; so I used a pair of metal shears to snip off the top lip to get it out.

*Any issues with air bubbles?*

There were a few air pockets in the finished chunk, but not very many and they were very small. I used the blunt end of a cold chisel to mash it down while melting.. put a few layers in, let them melt, mash down, repeat. I'm pretty sure that if I had taken a bit more time, let it melt more and did some more mashing with something smaller like a punch, that I could have removed them all.. Smaller pieces also seem to work better than larger ones.. a shredder might be helpful in that regard.

Cheers,
Brad


----------



## JeffP (Aug 4, 2014)

When I posted this little thread, I had no idea it would grow to start threatening to unseat the stumpy nubs thread!

(well maybe not yet…but still surprised it got this much attention)


----------



## wormil (Nov 19, 2011)

I played around with another technique but haven't worked the kinks out yet. Once/if I do, I'll post info about it.


----------



## MrUnix (May 18, 2012)

*When I posted this little thread, I had no idea it would grow to start threatening to unseat the stumpy nubs thread!*

Sometimes a spark is all that is needed to start a forest fire 

Looking forward to your technique Rick.. I have noticed that you get more little voids when melting in a form, mostly around the edges and really none in the middle. For the discs I made where i kind of rolled and folded them on the oven pan sort of like you would making bread dough, the interiors are completely void free and just the outside edges are rough.. Since you can work the material like you would wood, if you make the blank bigger than needed, you can cut and shape to size, which should produce good results.

I also found out that a lot of the plastic garbage bags are HDPE so I've experimented with them a bit.. I need to make a handwheel for my Makita planer/jointer that I'm restoring and was looking for some black material to use, which was what prompted me to look into using them. I figure I can make a round metal form larger than I need and then turn it to size/shape on the lathe which should work nicely.

Cheers,
Brad


----------



## JohnChung (Sep 20, 2012)

Just curious. When the mallet it whack on the wood. Does it leave some plastic residue?


----------



## wormil (Nov 19, 2011)

Another one…





View on YouTube


----------



## MrUnix (May 18, 2012)

That was a way cool vid Rick.. thanks for pointing it out.. I like how he made that plunger and the centering plug for the handle.. very creative.

The other day, the wife made some soup or something and had a few cans she was going to throw in the recycle.. they were smooth walled and just slightly bigger than the diameter of the inserts for my Delta scroll saw and band saw, which triggered another idea for this stuff. I figured I could use the cans and then shave a bit off on the lathe to make them the correct diameter and slice off replacement inserts on the bandsaw.. I've been making them out of wood in a similar way, but they are pretty thin and a bit flimsy.. so I gave it a try. Turns out that when the HDPE cooled and shrank, it was exactly the right diameter I needed! I sliced off a couple and wound up with some really great, stiff inserts for both machines:










The only thing I had to do was sand them smooth on the top face, drill and cut the slot, and then to finish them off, I heated up a soldering iron, melted the edge in one little spot, and then pressed it out with a pin punch to make the little tab that fits in the indented area to hold it firmly in place when inserted in the machine. I tried to make solid blue, but there were some variations in the color even using the same bottles (fabric softener bottles). Doesn't make much difference, and they are super smooth so I don't need to wax them like I did with the wood ones I had been making.

Cheers,
Brad


----------



## wormil (Nov 19, 2011)

What a great idea. I have a bandsaw I will be putting back into service come spring and it is missing the throat plate.


----------



## wormil (Nov 19, 2011)

I've been trying to remember where I saw the hdpe bandsaw throat idea then the mallet thread made me look this up.

I've been saving milk jugs but have no time for it yet, been working on my boat.


----------



## MrUnix (May 18, 2012)

> I've been saving milk jugs but have no time for it yet, been working on my boat.


LOL - You and me both  Working on an old Hunter sailboat between restoring a couple old woodworking machines and building a bunch of other stuff. I have been doing the HDPE thing quite a bit lately, and usually at night when I can't be working on the stuff outside.

A couple more examples of what is possible;

Here, I'm refinishing a Biesemeyer commercial fence, and it was missing the plastic end cap - so one was made out of HDPE. Made a wooden form for the initial chunk, cut to size, then shaped on a router table:










It was also missing the cam-lock knob, so:










Embedded a nut into the HDPE while forming, then when cooled, turned on the lathe to shape.

Here are some levelling 'feet' for a mobile base I made - using carriage bolts and rotating them while the HDPE cooled so they would rotate and pivot slightly once everything was solid:










They got welded onto the corner of the base using those threaded rod connectors. Fixed wheels for the base were also made - formed in a can and then turned on the lathe:










Or, more on topic - here are a couple of mallets I made along with a speed control knob for my scroll saw that was missing when I originally bought it:










The uses are endless and I'm constantly finding more stuff that I can make out of it 

Cheers,
Brad


----------



## JoeinGa (Nov 26, 2012)

Thanks to who ever brought this one up to the top. I'm gonna add to my favs so I can try this.

*"Hey Honey! Save me the milk and laundry soap jugs!"*


----------



## splatman (Jul 27, 2014)

> They got welded onto the corner of the base using those threaded rod connectors. Fixed wheels for the base were also made - formed in a can and then turned on the lathe:
> 
> - MrUnix


Those are called Coupling Nuts.


----------



## MrRon (Jul 9, 2009)

If any of you have metal working experience, you may know there is a product used by machinists called machinable wax. It is quite expensive if bought, but can be made economically at home. It uses ordinary paraffin wax and HDPE plastic. The links will show you how it is made and used. The stuff has many uses and is reusable; just melt it down and reform into any shape you want. The last link gives a comparison of Shore Durometer values.
http://www.machinablewax.com/technical.php 
http://www.instructables.com/id/Machinable-Wax/ 
http://tomwade.me/tw/machinist/machinable-wax.pdf
http://www.paramountind.com/pdfs/paramount_durometer_scale_guide.pdf


----------



## MrUnix (May 18, 2012)

> If any of you have metal working experience, you may know there is a product used by machinists called machinable wax. It is quite expensive if bought, but can be made economically at home. It uses ordinary paraffin wax and HDPE plastic.


Machinable wax is cool stuff and great for prototyping and making molds, but I don't think it's very appropriate for making a mallet or any application where durability is needed (like in those wheels I made for the mobile base).

Cheers,
Brad


----------



## MrRon (Jul 9, 2009)

> If any of you have metal working experience, you may know there is a product used by machinists called machinable wax. It is quite expensive if bought, but can be made economically at home. It uses ordinary paraffin wax and HDPE plastic.
> 
> Machinable wax is cool stuff and great for prototyping and making molds, but I don t think it s very appropriate for making a mallet or any application where durability is needed (like in those wheels I made for the mobile base).
> 
> ...


The Durometer hardness is around 55 shore D scale which is a shopping cart wheel. Being a model builder, I can think of many uses for HDPE. I have been buying rounds and flats of HDPE in the past to make small model parts.


----------

