Martin McIntosh Posted January 2, 2017 Share Posted January 2, 2017 I need some canopy vacuum forming material in at least 12 1/2" by 16 1/2" to fit my moulding box but the only stuff available from all suppliers I have tried is A4 which is too small. Any ideas out there please? Quote Link to comment Share on other sites More sharing options...
Philip Ogden Posted January 2, 2017 Share Posted January 2, 2017 Try these people, **LINK** or **LINK** . Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 2, 2017 Author Share Posted January 2, 2017 Thanks Philip, I shall give them a try. That must be S.H. Grainger, didn`t know they were still around. Quote Link to comment Share on other sites More sharing options...
Barry Meredith Posted January 2, 2017 Share Posted January 2, 2017 Try Barkston plastics in Leeds. The supplied me with PETG in around 2 meter by any legth you require. Quote Link to comment Share on other sites More sharing options...
Richard Norman Posted January 2, 2017 Share Posted January 2, 2017 My material of choice is for canopies is PETG sheet. A Google search for that should provide a fair amount of choice. For example: http://www.ebay.co.uk/itm/CLEAR-PETG-Sheets-1250mm-by-2050mm-Cut-to-Size-All-Thickness-PLASTIC-SHEETS-/201518059054?var=&hash=item2eeb698e2e:m:mPCsatOvbpdjiH9jhSJ4D_g http://www.plasticstockist.com/PETG-Sheet.aspx https://www.simplyplastics.com/catalog/sheet/petg-sheet/clear-petg-sheet/c-24/c-89/p-254 As it is widely used you may even find someone able to cut to size locally and save delivery. Hope this helps. Richard Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted January 2, 2017 Share Posted January 2, 2017 School Technology suppliers do every size and colour Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 2, 2017 Author Share Posted January 2, 2017 Thanks very much guys, lots to go on now. Martin Quote Link to comment Share on other sites More sharing options...
ROSS MANSELL 1 Posted February 14, 2018 Share Posted February 14, 2018 As of 14 FEB 2017 . A4 PET 1mm thick TRENT PLASTICS (uk..CHECK Google). 0.64p for an A4 size inc vat. 10 sheets postage was £2.99. 1.5mm thixk A4 is 0.96p both prices inc vat. As I use a dental vac I buy 5" x 5" plastic from Aliexpress..free postage but prices vary with thickness and number of sheets per box (some have 20 sheets others 30). so be careful! (The dental vac does a good job). Prices vary and they can occasionally be picked up less than half price (I paid £38 for mine ex Amazon returned item!!! bargain of the centruy!! ..Check their Open Box section for anything.... Both worth checking out. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 14, 2018 Share Posted February 14, 2018 What thickness is recommended for a largish (20" long) caopy? Martyn Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 14, 2018 Share Posted February 14, 2018 Posted by Martyn K on 14/02/2018 14:22:54: What thickness is recommended for a largish (20" long) canopy? Martyn It is actually the depth too Martyn, for example 20" by 1/2" depth could be very thin plastic A canopy 20" by 4" deep would work with 1 mm plastic Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 14, 2018 Author Share Posted February 14, 2018 How do you actually intend to form it? I have done a few but with only about a 10% success rate. Lots on Youtube but they all seem to have the same problem, creasing from the corners of the box. Have tried acetate and PETG with A4 and A3 size boxes, grill and heat gun methods, vacuum or not, run out of ideas. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 14, 2018 Share Posted February 14, 2018 Posted by Martin McIntosh on 14/02/2018 16:01:10: How do you actually intend to form it? I have done a few but with only about a 10% success rate. Lots on Youtube but they all seem to have the same problem, creasing from the corners of the box. Have tried acetate and PETG with A4 and A3 size boxes, grill and heat gun methods, vacuum or not, run out of ideas. If you are lucky, a vac forming machine is really easy to use, but is aided by getting the whole of the sheet so hot That it sags under its own weight and it smells hot The same process without a machine In the oven, so hot that it begins to smell, or with a heat gun, used with hand protection On a former the vacuum is introduced or the plastic pulled just long enough until it cools Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 14, 2018 Share Posted February 14, 2018 Thanks Denis. At least I know what to buy.. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 14, 2018 Author Share Posted February 14, 2018 Thanks Denis, but tried all of that. Along with all of those Youtube guys I must still be doing something very wrong since many products these days are packaged in this way. Anybody know of a video which shows how to do it properly? I mean with a home built set up of course, not a professional machine. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 14, 2018 Share Posted February 14, 2018 Posted by Martin McIntosh on 14/02/2018 20:15:11: Thanks Denis, but tried all of that. Along with all of those Youtube guys I must still be doing something very wrong since many products these days are packaged in this way. Anybody know of a video which shows how to do it properly? I mean with a home built set up of course, not a professional machine. Sorry Martin, I just read your creased corners comment It sounds like you have built a frame with a vacuum OK, the former is important, timber is best, totally smooth, with no undercuts, and bees wax rubbed in or furniture polish This gets warm and becomes a release agent If you can, bore tiny holes right through the thick part of the former to allow air out Now creased corners are one or more of the following former too deep, drill holes Sheet not hot enough right to the edges Sheet too thin, as it gets stretched it gets thinner, so start off with thick sheet Make sure you are using thermoplastic as some plastic is already at its limit Warm the sheet until it smells Keep asking Quote Link to comment Share on other sites More sharing options...
ROSS MANSELL 1 Posted February 15, 2018 Share Posted February 15, 2018 A recently viewed a video on YOUTUBE which showed simple vac forming using plastic picnic plates obtainable usually from supermarkets ( I have seen some in a UK supermarket).... Quite thin and cheap. Might be worth a punt. They may need a rim cut off but they appear ok for small size moldings. Go here https://www.youtube.com/watch?v=oJVFxK5pseA&feature=youtu.be This video is 1 of a series of 3 also shows a small vac forming box , made very cheaply.....details of which are mentioned in the US Model Airplane News website (search) and also the video mentions a couple of sites showing the plans for the box. (a small version of the plans is shown on the MAN article,....) By the way..ref my earlier re plastic sheets. RAPID have some white sheets ( Plasticard).. 457mm x 254 @ £10 for 10 sheets at this price I snapped up 20 sheets for stock! p&p £2.99. delivered next day by courier! Other colours ( inc clear) different price s. Edited By ROSS MANSELL 1 on 15/02/2018 10:11:21 Edited By ROSS MANSELL 1 on 15/02/2018 10:25:20 Edited By ROSS MANSELL 1 on 15/02/2018 10:27:38 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted February 15, 2018 Share Posted February 15, 2018 This makes it look so easy Martyn Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted February 15, 2018 Author Share Posted February 15, 2018 Thanks for your suggestions. The methods shown in the videos are exactly what I have tried and my vacuum boxes are about identical. Huge sag in the acetate/PETG but the corners still crease. Vacuum is variable speed so have tried it high and low. Will just have to try again but already got through an 8x4ft sheet of PETG to get five forms for my Lanc. Those guys really do make it look simple. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 15, 2018 Share Posted February 15, 2018 Posted by Martin McIntosh on 15/02/2018 11:00:24: Thanks for your suggestions. The methods shown in the videos are exactly what I have tried and my vacuum boxes are about identical. Huge sag in the acetate/PETG but the corners still crease. Vacuum is variable speed so have tried it high and low. Will just have to try again but already got through an 8x4ft sheet of PETG to get five forms for my Lanc. Those guys really do make it look simple. You will hit the " sweet spot " soon Martin, it takes a couple of 8 x 4s to learn. When you get the rhythm, then follow that always. Now a new tip The sheet is clamped and tight and hot Flick it, and if too cool it will sound like a drum, as it gets hotter it will sag and no longer drum Vacuum at this point If a sheet is not too badly distorted, it will reheat and go again Allow a sag of only 1/4 inch to start with Trouble is different colours and materials do react slightly differently, but not much Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted March 4, 2018 Author Share Posted March 4, 2018 Got one done at last using a rather long winded and unconventional technique. I made a plaster of Paris cast from the original ABS. This kept cracking so I coated it with GF, sanded down and applied three coats of release wax. I then slowly heated it to 180C and pulled the framed acetate over it. This took several reheatings, finishing off by pushing a ply former over it and applying a heat gun and vacuum. Where there`s a will there`s a way. Thanks for the tips. Quote Link to comment Share on other sites More sharing options...
Mark Stevens 1 Posted March 5, 2018 Share Posted March 5, 2018 Plenty of suppliers of PETG sheet in the UK for larger sizes, I've just had a batch of 5 A3 1mm size sheets arrive last week for the final mouldings on my Lynx. (The big IR Exhaust diffuser boxes fitted on the rear, the balsa plugs are done and I've already vac-formed the front intake sections) As a side note, RCM&E and A.S.P. (Publications) as they were back then, actually sold a kit to build a Vac-Former.(Over 30 yrs ago now) I bought one of those kits, assembled it and am still using it quite frequently. It is not for sale anymore but I have had clearance to share the original instructions / drawings online for anyone who wants them. I don't have them posted up on a website anywhere but can send as PDF files to anyone who is interested or even post up on here if there is scope to do so Mark Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted March 5, 2018 Author Share Posted March 5, 2018 This is my modified A4 vac former. The A3 is similar. Much the same as I have seen on youtube. That PDF would be very useful if you could put it on here or send it to me, thanks. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 5, 2018 Share Posted March 5, 2018 Why the curved corners Martin? Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted March 5, 2018 Author Share Posted March 5, 2018 Its because I was (and still am), getting creases from each sharp corner, so I gave it a try. Most of the guys on youtube are having the same problem. Tried everything under the sun to stop this happening so must be doing something fundamentally wrong. They just crease the moment I turn on the vac. despite trying various temperatures. Don`t need any more at the moment hopefully but I am determined to get to the bottom of this since it cannot really be that difficult. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted March 5, 2018 Share Posted March 5, 2018 thanks that makes sense Quote Link to comment Share on other sites More sharing options...
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