The SAAF Forum

Ok here is what I have found with stretched sprue: Firstly its very available, any piece of surplus plastic tree from a kit will do. Grab an old plastic tree, black is a good colour, silver is good as it is the right rigging wire colour really. Find a length of straight sprue in the tree, and cut it out. Must be long enough to be held with finger tips. Avoid sprue with a hollow centre. You will find some plastics better than others.

Heat source, a candle works great. Hold the sprue above the candle, turning it to evenly heat the sprue section.

Here is the art to it, the softer it is, and the faster you pull it apart, the thinner it will be. You need to play around with this, it is quite good fun. You need to make lengths, of the same thickness, may take a few attempts. But you can vary the thickness, as was the case on real aircraft, a thicker piece will represent a double rigging wire, quite nicely/acceptably, on a 1/72 kit.

For rigging to look good, it needs to cool dead straight. Nothing looks worse on a kit than sagging rigging wires! It cools fast. Immediately after stretching it out, release one end and let it hang vertically for a short period, holding the one end vertically. It cools so fast you only need to hold it for a short period. This should allow for a dead straight piece of sprue. If you keep tension on it or take slight tension off it immediately, you will have a bowed length of sprue, useless to man or beast! I find the best way to get it to cool straight, is to let it hang under it's own weight, infact the piece of unheated sprue, acts as a slight plumb weight, keeping it nice and straight, as it cools. Lay it out straight on a flat surface. Lay it out straight, as this will also avoid it bowing. Choose the correct thickness on your stretched piece as it will vary, cut it from the rest of it, and you should have a length of usable dead straight sprue, ready to be cut to required lengths. Another reason to lay it out on a flat surface, is so you can cut it easily to do the rigging.

Measure the distance carefully between the struts of your model using a pair of old classroom deviders, allowing for a little overlap measure it out on your length of sprue and cut. Here is the tricky part, you need to gently hold the sprue with tweezers (grip too hard and you will kink the sprue), dip each end in white wood glue and position in place on the model. white glue is great, as it dries clear and shrinks slightly, putting a slight tautness on the rigging. It dries slowly, so you can move the piece of sprue about, to get it perfectly positioned.

You will find it quite good fun and you can do complex rigging jobs on 1/72 kits. On larger kits, it is tricky as if the piece is long, it can sag due to the white glue slow drying. Here is where super glue works. Glue one end to the strut, let it dry, hold the other end on the other strut, keeping the tension on, then glue it, gently holding the tension till the super glue sets. Trickier/fiddlier, but does work.

Enjoy!

Thank you for the detailed discription JJ. One question: Do you drill small pilot holes in the stuts and/or wing to place the 'wires' or do you simply glue them as is? In case of the latter, do you trim the spruce at angle to better mate with the aircraft?

I don't make holes for the stretched sprue, you actually can't, otherwise you will need to bend the very tips to fit the holes or the piece of sprue will bow. It all goes about retaining the straightness of the stretched sprue. I find if you just glue it to the strut, by slightly lying it across the very end of the strut, it looks fine. Basically it is far too thin to cut at an angle, not required. This stuff will stretch out to human hair thickness, if not finer....head hair that is!!

However, if you stretch it out too fine, it can be just too hard to work with. It is remarkably strong it is. Will tend to hold its shape (straightness) well. As I said, you will be able to do some very intricate looking rigging on 1/72 kits, using this method. Start from the fuselage struts and work outwards.

It's great for Second Word War aircraft aerials and antenna wires as well (Spitfire MkV IFF wires, drill a small hole in the fuselage sides, super glue a longer piece of stretched sprue on each side, more or less at the correct angle, when dry, stretch it out to the tailplane tips, gently hold the tension with the surplus sprue, superglue, holding the tension, release when dry, carefully cut away surplus sprue. Result, very fine, IFF antenna wires.). On a 1/32 Spitfire for example, it's as thin a "wire" as you will get, however you will have to super glue it, which as I said, is/can be, a bit of a fiddle. On said Spitfire, I had to repair it a few times as people handling the model didn't easily see it untill... "twang"! Oh yes, DON'T even try to glue it with poly glue..the glue will instantly just melt/dissolve the sprue.

Jimmyjet has described the process of using sprue simply and in a most detailed way.

I basiclally do the same when when making the sprue to the required thickness / length,except I use a different technique when attaching the sprue and making it taught.

I cut the required lenth of sprue needed,then attach the sprue with a wood glue or Kristal Kleer and leave it to dry for 24hrs.

I then use a low heat source to tighten the sprue,the wife smokes cigarettes (the only good use for cigarettes is tightening sprue).
By running the cigarette up and down the length of sprue at a distance of +- 5cm the sprue heats up and suddenly tigthens and makes a nice straight piece of sprue.
Practice is required to get this right and I don't suggest that a person must smoke more!

Sprue also has a unique character in that it retains it's shape when stretched until it becomes too thin to use,a flat sprue will remain a flat sprue.

This is also important when building a Tiger Moth as the flying wires between the fuselage and struts are not round but aerodynamically shaped (like a flat piece of oval rod) with the sharp end's facing fore and aft,but this is really nitpicking.

Great to see jimmyjet back on the forum!

Geoff

As requested by Jimmyjet, here are pics of his Bristol Fighter. Well done Jimmy!

Carumba Dude!!! Beautiful

Hi there.
I found a modelshop "gaspatchmodels.com" in Greece that sells turnbuckels for rigging.
1/72 and 1/48

Regards


Botties

Also worth a look for the bi-plane modellers is this.site, http://www.bobsbuckles.co.uk/ , for all the 1/32 and 1/48 turnbuckles and accoutrements.

_________________
EX ALTO VINCIMUS

I have used the sprue thing for a 1/72 Offag 153, but I found that the glue on the ends of the rigging (white wood glue) made little "blobs" that didn't look right to me.
Do you guys thin the glue or use as is?

Maybe I just put to much of it on and it could not shrink enough

What works better, wood glue or clystal clear?

T

Hi

I need advice on rigging, for 32nd a scale Camel.

I have four options...

1) Sprue method described above but unpainted
2) Mig rigging, but its 0.03 mm. This may be too thin for 32nd.
3) Fishing line, 0.25 mm, also unpainted.
4) Invisible thread, 0.12 mm black.

There is also EZ line which I don't have.

What are your comments on the above?

_________________
https://www.flickr.com/photos/141742650@N08/albums

Marc, go for EZ Line. Ask Tony or Gary at GRSM. It's the best to work with.

Maybe just check though. Some British biplanes had aerodynamically shaped main bracing wires I.e. Not of circular cross section. Do some research. This will be noticeable in 32nd scale.

I use shielded cables for my 1/72 rigging:



The part that looks like hair is actually the shielding of the cable. Copper 0,05mm thick and covered with aluminium. It is braided around the rest of the cable and you have to undo the braid which is the hardest part. Then you cut it to approximate size and roll it between a ruler and a glass plate and it wil be straight. Then just cut it to length and fix it with white glue. I have found Canopy glue to be the best option as it dries invisible and makes a very strong bond, even on paint.

Here is an eample on my 1/72 Breguet 14 that is rigged that way, although I have to say that it doesn't look that silvery on the original model.



I think coaxial cables have the same shielding. And a short piece of it last for a lifetime.