Streched Sprue

its a matter of how fast you pull after melting the sprue... faster, thinner straighter.....
Slow = slightly thicker and more bent

How do you get to Carnegie Hall? Practice, practice, practice.

I use a cheap lighter under a piece of sprue several inches long. Twirl the sprue over the flalme until it drops to a 90 degree angle. Let go of th lighter (if it's out!) and garb the dangling end of th sprue. Pull with an even constant pressure. Pulling slowly will make a thicker piece, faster a thinner one. Pull too fast and it will break. hence the Practice, practice, practice advice. Once you get the thickness you want, keep the pressure on until the sprue cools. If you have a "spare hand tool" (alligator clamps in a stand with articulated arms) and a weighted alliagtor clamp, you can hang the sprue over the edge of your bench while it cools. Should only take a minute or two.

I must disagree with the slower=bent statement above. You can just as easily get a thicker straight stretch. But, yes, you can bend a thicker one as it cools.

First, do this next to the kitchen sink faucet. I use a candle, hold the sprue about an inch over the flame, rotating it so it heats evenly, once it starts to melt pull with even pressure, the thinner it gets, the further away from the flame, as not to burn through. The secret to getting it to stay straight is to quench it under cold running water once you have acheived the thread like thickness that you prefer. Keep pressure on both ends and run it under the cold tap. This instantly cools and hardens the thin sprue and it won't pigtail on you when you release pressure.

Steve

thanks for the info! I'll try it tonight...hopefully without burning down the house!!

For the really thin strands, I just take 2 sprues,
I stick the end of one in the flame until it actually catches on fire.
I remove it, a little puff to put out the flame then touch the melted plastic to the end of the other sprue and pull,
I can get strands 5' long thinner than a human hair that way.

I could get longer, but my arms wont go that far apart, I'd have to pull it from a stationary object and pull across the room, but I believe I could get a 20' long piece, in 1 shot, from a sprue only big enough to keep from burning my fingers.

Not to start a tit for tat arguement, but if you pull the sprue while its in a 45 degree angle to slow and have over heated it (which its not hard to do) it will give a natural U ' ish type shape after you release pressure.....
Anyhoo,
You naturally want a taper to the sprue that you have stretched considering that most antennae go from thicker at the base to thinner at the tip..

And thanks for the info Crocket and Iroc, sounds like very interesting techniques.
Another guy on here uses "cat whiskers" of all things, hahahahah, poor cat

I cut a piece of sprue about 2 inches long, and hold it above a small candle, the kind that is about 1cm tall, and comes with a tin housing. I hold it there, rotating between my thumbs and forefingers until I can see the plastic give way a little. At this point, it all depends on the thickness that you want. As stated above, the faster you pull it apart, the thinner the 'string' will be. Practice at it a couple of times, and you'll feel comfortable in no time.