Upcycling Glass And Plastic

I really hope my questions haven't been asked here a 100 times before but I am hoping some of you practically minded permies can answer some questions.

Firstly full disclosure; I live in a small house in the UK so my tools consist of extremely little; I don't have a rocket stove or machine tools or anything like that nor do I really have the space to do anything big or grandiose, but there are one or two projects i'm interested in trying but I am not sure I can feasibly do them or not.

I'm mainly interested at this stage of making new surfaces for a few tables and units I have and there are two ways I can see of feasibly doing this;

*Melting plastics;

I read with great interest something on 'instructables' regarding using plastic bottles and carefully melting them to form deceptively beautiful marble-effect blocks. It seems like something that could be done in a domestic oven; my concern is however the risk of toxins. The link i've been reading (please see below) leads me to believe this would not be a problem if you simply melted rather than burning the plastic;

https://www.instructables.com/id/HDPE-Blocks-From-Plastic-Bottles/

*Concrete and Glass;

My prefered idea is using pieces of broken glass, tightly packed, set within concrete. I have seen some people show ways of dying concrete and polishing it to create a stunning effect.

I am not sure how feasable any of these things are on my small scale; could anyone advise me on this?

Melting plastic may be toxic so if you do it, be sure to have plenty of fresh air (open windows/doors, fans blowing).  I may be a bit paranoid about exposure to toxic chemicals because both my husband and I worked in an industry with toxic chemicals and now he has a kind of incurable leukemia associated with exposure to volatile toxins.  So I'm going to tend to run around waving my hands and screaming "Be careful!"

Here is the material safety data sheet for HDPE:  http://www.opalindia.in/PDF/HDPE/Material%20Safety%20Data%20Sheet_HDPE.pdf

I'm really sorry for the late reply been mad over the holidays!

What would it be like doing it in a domestic oven? I'm not sure I understand exactly how toxicity would work; if it released toxic vapours and I then, say a day later, cooked food in the same oven, I assume it would also contaminate that?

Probably sounds like a silly question but i'm trying to attempt a few challenges like this while only having the resources of a little house to fall back on!

I have similiar simple confusions with the glass; I know one can 'dye' concrete but i'm wondering if dyed concrete would keep its colour indefinitely and would basic concrete (such as the postcrete I have left over from work in the garden) be suitable to use for products like this.

Using the same oven for food and plastics sounds like a really bad idea to me.
The VOCs will stick to the walls when it cools down and are released when it is heated up again. So you at least have to heat it up to far above any normal temperature until it stops smelling.

I don't like concrete mixed with glass, at it makes the concrete more dangerous (danger of cuts) and contaminates the glass so it can't be recycled again.

I have seen people also get a similiar effect with resin and glass; would that be a better alternative would you say? I've always been a bit concerned about resin as I imagine it lacks the durability of something like concrete which would make it hard to use in outdoor spaces or, as I want to do, as a tabletop or a finish.

I get the impression that the goal isn't clearly defined.

What do you want to archive?
A functional tabletop?
Artwork with glass as a tabletop?
Recycle the class?

What does it need to fulfill?
Exposure to UV / Rain / Freezing / Oils / extreme temperatures?
Scratches from knifes?
Ability to lift the table?

A tabletop from epoxy resin will get scratches over time under normal use.
Glass embedded in resin might develop cracks from temperature cycles.
Glass in concrete will probably get some water between glass and concrete that expands when it freezes…
A tabletop of concrete might get too heavy to lift, making it unpractical.

No the goal isn't too clearly defined you're quite right, i'm wanting to do some creative things with my waste glass and plastic and what I do need are some durable surfaces to finish off some wooden tables i've rubbed down; something durable and beautiful that I can put things like cups, plates, vases and the like on.

So something quite resistant but also bright and cheerful which is why I was looking at recycled glass in the first place.

Is there any art supply or artist studio in your area that rents kiln time? It wouldn't be done in your house, but you could assemble your recycled glass into a mosaic and then melt it together into a solid glass surface

I am sure that if you're careful, the plastic could be worked with safely, but I would be concerned at every stage of the process about the creation or release of stuff I don't want to be breathing in or releasing to the atmosphere.

If it's all I had to work with, I would make sure that the moulds for the bricks and the hopper containing the plastic to be melted would all be in an airtight retort, with pressure valves for expansion directed into a source of combustion. I would probably use a cinderblock rocketstove setup in the backyard, or a barbeque I wasn't intending to use for food ever again.

I still don't like it. I would rather combust them at extreme rocketstove temperatures then to have them sitting, slowly offgassing into the environment, or losing tiny particles year by year.

As to glass, my much better half assists a glassblower and his wife on their homestead. His wife is a ceramicist of note and does her own wood firings. They generate an unbelieveable amount of glass and pottery that can't be recycled, and some pieces are quite striking, so what they are doing is creating a gabion wall-like structure to fill the space under their deck, for which they will curate the facade from the best pieces available.

Back to the plastic, I think perhaps compacting plastic material into large bricks and then perhaps seeing if they can serve a structural or insulative purpose sealed into an alternative or natural building would make me more comfortable than heating plastic to a pourable state in a home setting.

-CK

Casie Becker wrote:Is there any art supply or artist studio in your area that rents kiln time? It wouldn't be done in your house, but you could assemble your recycled glass into a mosaic and then melt it together into a solid glass surface

Different glass bottles have have different coe (coefficient of expansion)- meaning they all cool at different rates. Glass bottles melted together will separate as they cool (sometimes with some force) . This is true even for bottles of the same brand. You can get art-glass with a guaranteed coe, but not random glass bottles. Whilst it is possible mix such glass you need much higher temperatures- a furnace rather than a kiln!

Glass in concrete looks awesome, but I've only ever seen it done with some serious grinding equipment to get the surface flat. Just casting concrete over glass in a form and we ended up with just a load of air bubbles and badly adhered glass...

Take it from someone who accidentally set a plastic plate on a hot stove burner and didn't notice - you don't want to melt this stuff inside! the plastic aeresolizes and you can smell it throughout the house, and it did get into the food that was cooking on another burner.
we couldn't use that burner even after multiple thorough cleanings because the plastic smell would still emanate whenever it was turned on.

Double boiler on a gas grill or outdoor fire would work.

Thank you Charli.  I didn't know about that concern.  What I usually see is individual items melted down.  Is making glass tiles to mortar together any better?

Casie Becker wrote:Thank you Charli.  I didn't know about that concern.  What I usually see is individual items melted down.  Is making glass tiles to mortar together any better?

Anything made from a single glass source will be fine- so each tile made from one bottle would work, you just can't mix them. Or if you did mix them- be prepared for a lot of failures! You can usually kiln-melt float glass (clear window glass) together with a reasonable success rate. Again anything from the same sheet of glass is fine, occasionally different sheets mixed together will separate as they cool- but way less than bottles do.

Thanks for the really useful replies everyone (as always on this forum) so if I can narrow down what we are saying;

* Plastic = requires either a dedicated oven or is best used as a bulk building material

* Glass = best used either as single types melted and worked together or if using glass fragments from different sources best combined with another medium.

In terms of using glass with another medium then what can we use? If concrete is hard to successfully use together with glass is resin the way to go?

You can use concrete in glass- it just won't look like your picture without some serious sanding/grinding equipment (which you can rent, so might not be horrifically expensive). The smaller you grind glass up the less sanding you'd have to do to get a flat surface (I think), but the less you'd be able to see the glass colours. It's pretty common here to use ground glass as aggregate in concrete- but glass as fine as sand wouldn't look very special.

Glass tiles/bits in mortar/tile adhesive (mosaic style), as Casie said- could look really nice. Depending on the shape of the glass you might not get a very flat table, or you put a flat resin layer on top, or find someone with a kiln to melt bottles/etc flat before you use them for tiles.

I've never tried resin, but as you'd putting that on top of the glass and covering it entirely it might be easier.
Whatever you use getting most of the air bubbles out of irregularly shaped bits of glass will require some attention to detail!

Here are a couple of articles that might help:

https://homeguides.sfgate.com/make-clear-countertop-30429.html

https://homeguides.sfgate.com/make-recycled-glass-counters-102656.html


This guy's youtube makes it look so easy:





And this one might help:

Thanks Charli you always give really good answers! I was quite tempted to look into getting a little rock tumbler and sorting out some of these empty bottles I have.

Anne Miller the precious plastic stuff always looks fantastic; I get the impression they use some serious kit to get the sort of items they have there though; the tiles are absolutely fantastic though so i'd love to be able to make those.

Thanks, Charli. I was going to bring up the coefficient of expansion, but I didn't want to be the only one nerding out.

I would keep in mind, when trying to upcycle, that not heating this stuff up, any of it, is more environmentally friendly than any other course. Leaving aside the creation of airborne pollutants that we don't want, using energy to change the stuff to another form increases it's embodied energy costs, if not defeating the purpose, certainly making it a less environmentally-friendly one than the thread title suggests.

-CK