Has anyone actually been able to heat a sprue over an open flame to create an antenna for their model?!? After a lot of delay in even trying it, I attempted it yesterday and, of course, it was a complete failure. The point heat source only affects a small piece of the sprue which then either burns in half or stretches a 1/4 of an inch or maybe a centimeter and then pulls apart. Any suggestions or should I just go with music wire?
Hello!
While stretching sprue takes some practice, it’s a very good thing to learn - many things can be built out of different thickness stretched sprue lengths. I usually take a zippo lighter or a candle for the heat source, and a nice comfortable length of straight round sprue. While heating I rotate the piece and I also move it along its axis. Initially I’m holding it only with one hand, so that whan it starts to droop I know it is getting soft. Then that’s the time to grab the piece with the other hand, heat it a little more, and then take away from the heat source and stretch with a smooth movement. Now the diameter of the resulting stretch depends on how hot the heated piece was, and how fast the initial stretch was. If your first movement is fast, then the result will be a thin fibre, if you go slow you can get a length of a rod like 2mm or 1mm in diameter. Some people go different way - they put one end of sprue on fire, then put it out and then quickly stick the just extinguished end to a metal surface and pull, to get a thin fibre.
Now if the piece you are working on doesn’t get long or thin enough, or if it rips, that means you didn’t heat it hot enough. Try holding the sprue over the flame longer, but with moving it, so that it does’n catch fire.
Good luck with your builds and have a nice day
Paweł
M1 I think there are some You Tube videos on it. It takes some practice but after a while you’ll be able to stretch a very small piece, keep at it. It saves money too…
Terry
I use a candle and use about 4-5" of sprue. I hold the sprue about 2-3" above the flame. I go back and forth and rotate the sprue – about an inch of the sprue gets heated. Then I stretch. You’ll master it in no time. Plus it’s cheap to practice too!
Nope,I have to say it is beyond me also.[:$]
Some plastic stretches easily, some not so good. I keep all the useful sprue from a kit separate so that when I find some that pulls well I can do a bunch of it or know where it came from.
i just use thin wire. one tube at the LHS should last a long time. i just have to be very careful as i work at nose print distance.
I have to agree with the YouTube comment - simple as it sound I struggled trying to get decent (or any…) stretched sprue, I watched a 1 min tutorial on the subject & that was that, easy!
Ok, Guys. Thanks for all of your responses! I’ll keep trying and look at a couple of youtube videos when I get the chance. As was mentioned, it’s cheap to keep trying!