Plastic Bottle cutters

[Paul_D]

I've seen a lot of different versions of these gadgets that can easily turn use plastic bottles easily into meters of thin ribbon/twine. Youtube is full of different diy versions.

I can see various uses for this like tying back plants or making trellis supports for peas. 
The only downside i can see it that the plastic may make knots prone to slipping. But i have seen one video where they used the twine for lashings then heated it with a hot air gun to make the plastic shrink and tighten up the joint which could work really well for trellis.
Has any one tried making one?

As asked, edit to amend a couple of letters.

[Paul_D]

[Jayb]

Not tried making one (wouldn't know where to begin), I think they are fascinating though.  I nearly bought one recently, but after the initial appeal, I did start wondering what I would use all those ribbons of plastic for. I'm interested in your suggestion for using as lashing and then heat shrinking though.

[Jayb]

I've updated your start post as requested. I love the idea of disposable bottles being able to be put to good use. How long do you think the plastic would last outside?

[Vinlander]

I use heat-shrink tubing occasionally - I could use it a lot more if it was cheaper!

It's a nice idea to use PET strips as heat shrink tape - for all the things I'd use rawhide for in a dry climate (that's a lot of stuff - not just the torture headbands that used to be a staple of 50s cowboy films).

However a shrinking tube without a knot in it is what I'm after - obviously PET bottles come in all sizes (the smallest are complimentary shower bottles and tiny stingy airline wine bottles) but it would be much easier and more versatile to glue them from strips.

Except the best glue I've found for PET is glue gun - and guess what? it would probably give up below heatshrink temps...

Ideally I'm looking for a strong heatproof bond to PET with reasonable flexibility - maybe superglue would work better if the surfaces were sanded matt? I must try. Contact adhesives don't suggest heat resistance to me. Epoxy is more fiddly but may be the solution.

Cheers.

PS. I cut up and use hundreds of plastic bottles - top off coloured ones to make deep pots for cuttings etc. bottoms off clear ones as mini-cloches for individual seedlings. And especially the cylinders you get from cutting both ends off (slug barriers and ring culture), the squares from cutting the cylinders open (patching broken corners of greenhouse glass, as shingles generally, and stitching or glueing them together to make bigger cylinders to protect/grow bigger plants).  They are a lot easier to store and transport with both ends off too. d**n those ridges that are now ubiquitous - they get in the way of nesting cylinders and  mess up half my uses for the squares.

[Paul_D]

Thanks Jayb
I gave it a go last night. Very rough attempt with a bit of scrap wood and a Stanley knife blade. It was really tricky to get started but i managed to get about a 6m strip about 5mm wide from a 2lt pop bottle. Surprised at how satisfying it was once i could start pulling out a constant string.

I tried lashing a couple of sticks together and it was tricky to get knots to hold but not impossible. I think it might have worked better with a thinner strip. It did hold fairly well but it might not have lasted long. I gave it a quick blast with a creme brulee blow torch from the back of the cupboard and it did improve the hold significantly.

I'm going to try and make a neater version at the weekend and see if i can get a thinner cord to see how that works. I imagine the plastic will last a few years as thats why its so bad sending it to landfill. Not sure how heating it up will affect it life span though.

Some good ideas Vinlander. I'd not thought of using the tapering necks of bottles for deep pots. I can picture a long line of bottle tops screwed to a length of 2x1 fixed across my greenhouse next year.
I'd meant to try the slug collar idea using pinking shears for the tops but never got round to it.
Unfortunately we don't use many big bottle so have to scavenge the odd one here and there. I did think about buying a pack of plastic pint glasses from the wholesaler to use as mini cloches as they were about £3 for 50.   

[ancellsfarmer]

Vinlander,
I suggest you try
http://www.screwfix.com/p/no-nonsense-mitre-adhesive-200ml/41795
for your bonding. Used initially as a rapid wood glue (6 seconds!), I have used it to bond almost everything that needs joining, from reading glasses to 20mm limestone slab. It sticks almost anything, in 6 seconds!, including fingers.

[Vinlander]

Vinlander,
I suggest you try
http://www.screwfix.com/p/no-nonsense-mitre-adhesive-200ml/41795
for your bonding. Used initially as a rapid wood glue (6 seconds!), I have used it to bond almost everything that needs joining, from reading glasses to 20mm limestone slab. It sticks almost anything, in 6 seconds!, including fingers.

Thanks AF -but it's so expensive that I intend to try every way to use superglue first.

The mitre glue sounds excellent for boatbuilding - cascamite can be too slow and even more expensive (and useless on plastics).

In the past I've even considered making the original recipe - I saw it on a TV programme - you make it from milk - the vikings invented it for laminating shields.

I just tried PET strip for the problem of canes that split at the thick end - I sort of cross-gartered it about 100mm from the bottom up and tied it off before heat-shrinking the whole thing - it's firm and reasonably smooth - looks like it won't make it much harder to push in... But it's a lot more work than making a suitable size cylinder and just slipping it on before heating - IF it can be made to work.

Cheers.