I know not to hold it to close or it will burn up, so I got a little birthday candle so not to have a big flame, and I held the sprue in a pair of pliers on each side of the sprue, and I held it just about two inches above the flame, it took a little while before it started to give, then real quick it pulled apart.
It never once pulled thin, before it would go thin snap it came apart, of course it didn't snap, but it did come a part, in shorter, but not much thinner pieces, could anybody tell me what I was doing wrong? Many thanks for the help.

hiya straight
what I hear you are doing sounds right to me
our own faust is writing a beginners guide, wich shows the same thing.

See Zero I read that quite a while back, and I thought I had remembered it, but when it kept on just pulling apart without it getting thinner, I figured I had to be leaving an important step out, see it would just get a little thinner like it was going to work then poop.
Maybe I'll try tomorrow when I'm not hurting, cause maybe I'm applying to much pressure or something. With this medications I'm on, sometimes I can't tell how much pressure I'm giving, that could be it. Thank you for the come back.

my pleasure straight it always works for me

so no problem.

just heat and pull

Straightedge,

I had the same problem.... I had great difficulty in getting thin stretches of sprue.... the trick for me was to heat the sprue so long taht at first one of the ends bend upwards (stretching now will give you thicker stretches), and then waiting untill it falls down (is almost molten) then stretching fast, I got great lengths that were less then 0.3 mm thick and 0.4m long easily.

Ahh and yes, I have burnd some stretches....

Good luck, and cheers,

Harm

straightedge

It takes a bit of practice, but like the drawings above wait until one end sags then pull in one firm but gentle motion. After a few warm ups to learn this lesson again I can get a full double arm stretch of hair thin sprue.

I usually start with a piece about 5 inches long and just use my fingers, not pliers - I think you may lose a bit of control with pliers. The mistake I used to make is putting tension on the sprue while it is heating - that way it starts to stretch before the centre is properly heated, ergo the snapping when it hasn't thinned much.

I have read in some forums that different "types" (i.e. quality) of sprue from different manufacturers are good or bad for stretching. I can't tell - I usually build airfix 1/48 or Tamiya and have no problems with either.

Brian

The secret is in the speed that you pull. They always come out... thin and longer... when you pull fast. Just a nice steady... fast pull.

My 2¢
Jim

It doesn't really matter how big the flame is - just hold the sprue farther away from the flame to reduce the amount of heating. I usually hold it 1 - 2 inches above a normal candle flame. Roll the sprue around in your fingers to heat all sides, move it back and forth a little bit to heat up a longer section. Once it is really saggy, remove it from the heat and then pull it apart. If you pull really fast, you'll get hair-thin stuff. Pulling very slowly will produce thicker stuff.

Just experiment until you get satisfactory results.

First, keep the sprue over the flame 'till it starts to bend, then move the sprue from the flame and stretch it. Just as easy as that, I had no problems...

The only other thing I can add is try a passive heat source, like a soldering iron, rather than a flame. That way you have a little more control over the melting process.

Art

After seeing what you guys are saying now, I was awful close, I thought if I had waited another second it would of turned into a puddle of plastic, but I guess somewhere before there, and to where you say to pull, this happens.
I do know one thing though if I'm going to hold it in my hands, I'm going to get a bigger piece, cause the one I had was turning up at both ends, so I know I wouldn't want to hold that when it does that.
I don't know for sure but maybe this sprue wasn't the best to use either cause some of it like turned into BB's, and it didn't catch fire, I've never seen plastic do this before without it catching fire.
Thanks to one and all of you, I'm going to give all of your ideas a shot today until we come up with a honorable weld seams to put on all my tanks before I paint them.


Kerry

ATTENTION !!!

You won't believe how nice I am, I made a quick movie just for you guys. In under 10 seconds you'll have a beautiful long antenna

Stretching sprue

(Compressed with DivX codec, 570 KB in size, length 10 secs)

I hope you'll find it useful

Wow, thanks for this thread! Thanks for your time.