AltcarBoB Posted June 11, 2020 Share Posted June 11, 2020 I need some approx 1mm rod to beef up a very wobbly aircraft undercarriage. I thought stretch some sprue I used to do it all the time 40 odd years ago when many kit instructions told you to stretch sprue for aerials and wires. I found some Tealight/Nightlights in a cupboard chopped some sections of sprue and got down to it. An hour later I have a burnt finger, lungs and eyes full of styrene fumes and a pile of bits of half melted sprue but no sections of decent stretched sprue. Every time I thought I was getting a decent result the sprue would snap, some bits of sprue wouldnt stretch at all just go soft then snap as soon as I tried to stretch it. One piece of sprue just caught fire without softening. I have a box full of usefull bits of sprue from about 20 different plastic kits nothing I tried wanted to play ball. Has Styrene changed since I was a teenager or am I doing something really dumb. 1 Link to comment Share on other sites More sharing options...
Black Knight Posted June 11, 2020 Share Posted June 11, 2020 a. yes, there are now different varieties of plastic. some stretch, some don't b. use a thick piece of sprue. hold over your flame, rotate and also, play it along the length of the sprue, ie get about an inch worth pf sprue soft and shiney. Remove from over flame. Then start to pull, just a bit, to see how it goes, maybe let it cool for 1 second, then start pulling again. The thicker your sprue the thicker you can make the pulled section, the longer the softened part the longer that stretched part can be. 1 Link to comment Share on other sites More sharing options...
lasermonkey Posted June 11, 2020 Share Posted June 11, 2020 Coincidentally, I had a sprue stretching session the other night. I also used a tea light, as I find these to be the safest way of doing things. Anyway, what I do is cut a reasonable length, at least three inches (to prevent burning your fingers) and the hold the sprue a good inch and a half above the flame. Practice will show you where the sweet spot is, but I prefer it if the sprue melts relatively slowly, as this gives much more control, as well as not filling the room with acrid fumes. If it's catching fire, it's too close. As it starts to melt, slowly rotate the sprue, and once you can see it sagging, remove from the flame and stretch. Remember to keep it taught whilst it cools to prevent it from curling. You'll have to practice to get the right diameter results and this will depend on which manufacturer's styrene you're using. If you stretch slowly, you'll end up with a larger diameter. Try to keep the rate of stretch constant, as it's easy to end up with a varying cross section along the length if you don't. HTH, Mark. 2 Link to comment Share on other sites More sharing options...
AltcarBoB Posted June 11, 2020 Author Share Posted June 11, 2020 Thanks guys I think I was trying to stretch it whilst still over the heat or holding it too close. I will go and buy some more tealights and have another go. Link to comment Share on other sites More sharing options...
Jamie @ Sovereign Hobbies Posted June 11, 2020 Share Posted June 11, 2020 I do it like Mark says - you've almost got to slowly spitroast the sprue. What works quite well for getting consistent thickness is to not melt the middle but one end, then stick it to a piece of card and sharply pull as far and fast as you can. If you stretch slowly it cools as you stretch it and it'll be thicker and thinner along the length of the bit you stretched. Link to comment Share on other sites More sharing options...
CedB Posted June 11, 2020 Share Posted June 11, 2020 I got on fairly well after Matt gave this advice and I watched this video: 1 Link to comment Share on other sites More sharing options...
dromia Posted June 11, 2020 Share Posted June 11, 2020 My preferred method is slightly different. I use a piece of card, melt one end of the moulding tree in your heat source 'till it is nice and soft and blobby but just before it ignites. Push the melted end onto the piece of card where 'twill stick. Hold the card on the table and wait 'till the melted tree is the right consistency and then gently pull away. As has been said it is all about eye and feel, practice makes perfect and not all moulding tree plastic is suited to the process. The stretched plastic will keep the profile of the original which opens up all sorts of possibilities. Link to comment Share on other sites More sharing options...
AltcarBoB Posted June 11, 2020 Author Share Posted June 11, 2020 @dromia nothing to do with the thread but I like your profile photo. Hard to see as its a small picture but is that an Enfield P61 Musketoon your holding. Link to comment Share on other sites More sharing options...
dromia Posted June 11, 2020 Share Posted June 11, 2020 Not quiet, they are Sniders from my collection, three band Pattern 53 conversion, a two band steel barrel and a carbine which I am holding. 1 Link to comment Share on other sites More sharing options...
dromia Posted June 11, 2020 Share Posted June 11, 2020 BTW in my younger days I shot quiet a few times at Altcar. 1 Link to comment Share on other sites More sharing options...
AltcarBoB Posted June 11, 2020 Author Share Posted June 11, 2020 1 minute ago, dromia said: BTW in my younger days I shot quiet a few times at Altcar. I am about 10 minutes walk from the ranges. I shot there a fair bit until a few years ago but the prices got a bit silly for full bore shooting so I retired my LE No4 and just pop away with a .22LR single shot these days. When my FA cert comes up for renewal I dont know if I will bother with all the hassle and paperwork. 11 minutes ago, dromia said: Not quiet, they are Sniders from my collection, three band Pattern 53 conversion, a two band steel barrel and a carbine which I am holding. Lovely I am exceedingly jealous. Never handled a Snider but I hope to one day. Link to comment Share on other sites More sharing options...
dromia Posted June 11, 2020 Share Posted June 11, 2020 Aye my shooting days are drawing to a close, been selling of my collection the only Enfields I have left are a 1913 No.1 a No4T a No5 and Long Lee Metford. Mainly shoot Blackpowder now muzzle loading and BPCR just one three band Snider left, my Brown Bess and my cannon get some hammer still and I take the odd red and roe when the freezer empties. Injoy my BSA small frame Martinis still especially my Famous 12 and the 310 Cadet. Fine ranges at Altcar and I have fond memories from there. 1 Link to comment Share on other sites More sharing options...
AltcarBoB Posted June 11, 2020 Author Share Posted June 11, 2020 16 minutes ago, dromia said: Fine ranges at Altcar and I have fond memories from there. Could get a tad breezy though 😏 Link to comment Share on other sites More sharing options...
dromia Posted June 11, 2020 Share Posted June 11, 2020 Aye outdoor shooting is all about the wind. 1 Link to comment Share on other sites More sharing options...
AltcarBoB Posted June 11, 2020 Author Share Posted June 11, 2020 Think I have cracked it. Now I need to find some burn and blister ointment. Who knew that hot semi molten plastic would be hot 🙄 Link to comment Share on other sites More sharing options...
Mr T Posted June 12, 2020 Share Posted June 12, 2020 Glad that you have sorted your problem. I find these days I stretch sprue a lot less than I used to because I now use a lot more fine brass and nickel silver wire from Albion and Eileen's Emporium. For really thin flexible stuff, fine beading wire from places like Hobbycraft also works well. Still there are a lot of times when stretched sprue is still the best and is cheap, the only real cost being tealights which are cheap enough and have other uses (for example, creating a romantic atmosphere for wooing). The modern grey plastics that Airfix use seem to be tricker to stretch, the old Airfix silver grey seemed to work well. Link to comment Share on other sites More sharing options...
AltcarBoB Posted June 12, 2020 Author Share Posted June 12, 2020 I found the sprue from a Valom kit stretched the best I made enough fine sprue to rig a squadron of bi-planes. Link to comment Share on other sites More sharing options...
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