What material for vacform canopies?

[Rick Brown]

Hi chaps.

I need to make a copy of a damaged vacform canopy and was wondering what material to use?

Ideally I'm looking for something cheap that can be sourced locally.

I'll be knocking up a vacform machine soon then taking a mould of the original canopy using milliput. I can then repair the damage picked up by the mould before reforming a new one.

And no, I didn't damage it myself! Mr postman was a great help in this matter!

Cheers,

Rick.

[tomprobert]

I've used Milliput in the past and it works rather well.

Tom

[kev67]

Are you talking about the materials for making a vac form machine or the materials to make the mould

[Rick Brown]

Sorry for the misunderstanding chaps.

It's the vacform material itself I'm after.

Rick.

[ben_m]

Neither- I guess the question is the material for the canopy itself. I think I read on here that Aeroclub used to sell sheets of clear for this purpose.

[Rick Brown]

Gawd, my native English language is poor this morning!

Yep Ben, it's the material for the canopy.

I can get in touch with John at Aero but I was hoping to source something locally.

Rick.

[cmatthewbacon]

Easter egg packaging, the clear boxes roller blinds come in, or any of those clear packages you have to cut your way in to to free, say, headphones (and then avoid cutting yourself on the sharp edges) all work well in my experience. Clear plastic lemonade bottles don't... PM me if you want some roller blind box...

Bestest,
M.

Edited December 17, 2013 by cmatthewbacon

[Rick Brown]

Easter egg packaging, the clear boxes roller blinds come in, oh any of those clear packages you have to cut your way in to to free, say, headphones (and then avoid cutting yourself on the sharp edges) all work well in my experience. Clear plastic lemonade bottles don't... PM me if you want some roller blind box...

Bestest,

M.

Fantastic M!

Christmas coming up, bound have loadsa junk wrapped with that stuff for the kids!

Rick.

[Black Knight]

Use plastic packaging that has PET on it, Its less likely to yellow through age.

[Rick Brown]

Use plastic packaging that has PET on it, Its less likely to yellow through age.

Not sure about this, my cats came in a basket..........

Rick.

[cmatthewbacon]

Trouble with PET is that it's difficult to soften. The packaging materials will soften nicely under a grill, and you can see them sag as they do, so you know when they are ready (take them out quickly though, because they'll go white if you get them TOO hot). Try that with PET and it shrinks, dramatically and while staying quite hard. PET will soften in very hot water (From memory I asked my Uncle the chemist and he told me that it goes at 80-85C), but it cools and hardens quickly -- good if you are draping it over a former, but not much help for plunge moulding or proper vac-forming. That's why I gave up on PET lemonade bottles. In America, it seems to be different stuff, because US modellers describe using with great success doing exactly what I did with no luck at all...

bestest,

M.

[Rick Brown]

I'm actually looking forward to making a former now!

I think I'll make the mould tonight with Milliput and then source a box, etc over the next couple of weeks.

Thanks for all your advice Gents,

Rick.

[BritJet]

I've been using PET for about 15 years and yes it does cool quickly which is useful when doing a batch of mouldings. You can tell when it's hot enough as it will wrinkle and smoke. Worth trying drinks bottles as it is a cheap source of material at least until you get the hang of using it. Just make sure it is dry before use as moisture can cause issues

Steve

[BritJet]

For a simple vacformer make an open top wooden box with a plywood base and add a pipe through one of the ends/sides that will fit onto the household vacuum cleaner pipe (ask what that is if you're not sure!). Glue and seal all of the joints with epoxy resin and glue some strong metal mesh onto the open part. Your mould goes on top of the mesh and the vacuum will suck the plastic down over it. You may need to add a plinth to the bottom of your mould to allow for the curvature of the material at the base.

Make two frames out of hardboard/plywood with a border approx 20mm wide and with the holes large enough to fit over the wooden box allowing a small amount for the thickness of material. Sandwich a sheet of plastic between the two frames and use a bulldog or similar clip on one side and mole grips on the other.

Heat the plastic under the grill (don't heat from below as the heat builds up too much) until it sags and smokes. Remove from the heat and position over the mould/wooden box and then switch the vacuum on. After about thirty seconds you can turn the vacuum off and remove the moulding. If you're doing more than a couple of mouldings you might want to invest in some welding gloves such as these - http://www.machinemart.co.uk/shop/product/details/red-welding-gloves?da=1&TC=SRC-welding%20gloves

Hope that makes sense but let me know if anything isn't clear or you need photos etc.

Steve

[Cheshiretaurus]

best material is 0.5mm PET G worth the investment

[Rick Brown]

Machine being designed in me head as I sleep.

Thanks guys.

Rick.

[perdu]

And the gennulman has earned a ceegar

I saw this on Thursday, ordered some and this morning (Saturday) I have had a pack of really excellent moulding clear stuff delivered

Works superbly too

Thanks for the tip Mark

[Iain Ogilvie]

This stuff - Vivak^® PETG - was recommended to me - should be pretty UV stable.

Generally available (last sheets I bought from local model railway shop - Howes) and vacs beautifully - here's first test pull on my Lightning canopy:

HTH

Iain