Stretched Sprue.

[Jimmyjet]

I realy enjoy working with stretched sprue, one big bonus, it's for free!  This may be old news to many, but anyway, here goes. (Also doing this post to see if my Photobucker pics will work!....they did!)

 

 

By varying rates of heating over a candle and stretch out rates, with a bit of practice all sorts of thicknesses can be made.  By allowing it to hang by one end to cool, this will normally result in a dead straight piece of sprue.  If you have a large span to cross, glue one end with superglue, then draping over the othe end, hold it taught and super glue it, hold tension till dry.  Easy way to do aerial wires.  Insulators can be done again with super glue blobs painted white.

 

You can do complex riging jobs on smaller scales.  You need deviders to measure the span between struts, cut the measurede length of straight sprue then pop into place securing with blobs of white wood glue. The easy wat to apply glue is dip the ends of sprue into a little pool of glue. White wood glue is great, because it dries clear and has the added bonus of shrinking slightly when it dries, to add a little tension to the sprue.  Attached are pics of my Roden 1/48th Bristol Fighter all done with stretched sprue.  Will work well for short span areas/aerial wires on a 1/32 scale.  As I said, complex rigging on 1/72 can be done and contrary to popular belief, with this method, it's fun!

 

  

 

 

[geedubelyer]

Hi James,

Welcome to the forums and thanks for the tip.

I'm working on a 1/48th scale Spitfire that needs aeriel wires and I've been considering alternatives so may give this a go if I can produce a piece of consistent width.

Did I read somewhere that introducing a hot nail or similar to the vacinity of the stretched sprue taughtens it?

Incidentally, I've found that sprues from different manufacturers stretch differently. Some stretch more easily and further than others. It's worth experimenting.

 

Cheers.

[BradG]

Looks great. I did try stretched sprue many years ago, but I just kept setting the damn thing on fire or it would snap or curl and then I found knitting elastic. That worked much better for me.

[Jimmyjet]

Yes holding a hot nail etc close to the sprue can tighten it, but you are walking a narrow path here!  A thin piece, can easily burn through.  It takes some practice, but if you get it pretty soft, almost melted, and pull the sprue apart at a constant but fas-tish pace, you can get a very thin, uniform piece.  It cools very fast and I instantly drop one end and let it hang.  It will be dead straight then.   Also yes, different plastics will be easier/harder to work with.  I save all my black sprues, no need to paint the stretched sprue then.

[Iain]

Safety matches: easier than hot nail!

 

Light match - extinguish flame - hold hot end close to stretched sprue.

 

Bob's yer confused aunty... 

 

Iain

[wunwinglow]

....and if you shape the sprue before you stretch it, you can get sections like RAF wires.

 

Tim

[Iain]

And if you use hollow plastic lolly sticks you get very fine tube 

 

You do need to get it evenly heated though...

 

Iain

[Guest Peterpools]

James Welcome aboard

The joys of stretched sprue and memories .. wonderful stuff and way back in the day ... a modeler's best friend. I still am fond of stretched sprue and use it when the occasion arises. One thing I have found is NOT all sprue stretches the way, some better then others. Over the years, my favorite plastic sprue to stretch is Hasegawa plastic - just seems to work so much better. The old silver/gray plastic wasn't fond of being stretched.

Peter

[Out2gtcha]

If you heat and stretch some flat thin styrene strips the strips tend to stay the same thickness relative, and you can make great little flat cockpit dip-switches. I really like it for those types of applications.

However, I found that using stretched sprue for rigging on 32nd planes is problematic at best for me. I never had any issues getting it on, but the sprue was very delicate, and always seemed to start sagging over time requiring a bit of heat to bounce back tight.

After moving to WnW recommended nylon flat thread and EZ Line, I have not used sprue for this application since. However as above, there are plenty of great uses for stretched sprue I still use, and is a very handy thing to keep in the modeling arsenal.

[Heavens Eagle]

As someone already noted, different plastics stretch differently.  I found that light colored plastics that don't have much heavy pigment in them will stretch much easier and finer.  Light grey Revell plastic will pull quite nicely whereas the old sliver Monogram type plastic doesn't pull worth a flip.

[Out2gtcha]

As someone already noted, different plastics stretch differently.  I found that light colored plastics that don't have much heavy pigment in them will stretch much easier and finer.  Light grey Revell plastic will pull quite nicely whereas the old sliver Monogram type plastic doesn't pull worth a flip.

 

 

You are correct, although if you work it enough the old silver stuff is good for cockpit switches as you dont even need to paint them......................as you said, they dont melt and stretch as good as the lighter new stuff, but with a bit of experimenting with tension and heat you can get them to stretch.

[EvilCarrot]

What would be the best method to evenly heat the sprue? Do you hold it over a candle flame?

[Bill Cross]

What would be the best method to evenly heat the sprue? Do you hold it over a candle flame?

You have to practice. I recommend a candle for a variety of reasons.

 

Sometimes you can move the sprue back & forth over the flame, and that will give you a larger bit of molten styrene. The larger the blob, the more you can stretch it out.

 

As someone pointed out, it's free, so if you **** up, you're not out anything more than your time.

Edited December 30, 2014 by Bill Cross

[Hardcore]

A hot plate would probably work too. Melting point for styrene is 240°C

and glasspoint is 100°C.

Edited December 31, 2014 by Hardcore