painting curves on models

[mike s]

hello everyone

how on earth do you accomplish painting curvy lines..?

I'm talking about fine work like on Stingray around the nose cone and torpedo tubes

surely not freehand work..? is it done using tape..?

any info would be a great help

cheers
Mike

[Sea Devil]

Hi Mike,

When I painted my 3ft Stingray I used thin strips of electrical insulation tape to make the curves.These are then masked over in the usual way. Paint as soon as possible after masking as the insulation tape can move! There should be no bleeding if the tape is pressed down firmly. I hope this helps.

[Captain Sci-Fi]

I would use masking tape but would always cut a new edge with a scalpel then, as Sea Devil suggests, use thinner taper as it's easier to bend around complex curves. Watch for overspray if you spray paint it can travel quite a distance, for something small I would use a bag to enclose the whole model with a masking tape handle to hang it up to dry if needed. A golf ball sized lump of Plastercine is useful to press parts into to hold them if they are small.

If possible work the colours from light to dark. As a guide it is not uncommon to spend hours masking something that can take just a moment to paint.

Acrylic for plastics, rattle cans they use for car repairs are good. There has been several articles about applying paint.

Take your time and good luck.

[Troy]

Being somebody who makes puppets this isn't something that had bothered me at all...until now! I know the Captain was thinking of making a Stingray kit (hows that coming btw?) that I was keen to get my hands on but this issue of masking up the bendy lines was something that had been worrying me. I know from my experiences with home decorating paint can bleed under masking tape. I see the suggestion of electrical tape and that sounds interesting. What about the Frog tape you see in DIY stores that is supposed to stop bleeding? Does anybody think that would work if cut thinly enough? Or am I worrying to much about it and ordinary masking tape would do?

[mike s]

it all sounds terrifying - the possibility of bleeding is high isn't it..?

I can imagine tackiling a studio scale stingray but what about a small 12 inch one..? - so fiddly

[Captain Sci-Fi]

We sell a vinyl line as a stripe detail, sheets of roughly A4 that would be perfect, you get a large amount and it's not expensive. We sell the perfect scalpel for cutting these materials also:

http://store.scifihardware.com/modelling-accessories/

If you take some paper masking tape and stick it to a sheet of glass then cut one edge to provide a clean sharp line it really works well. The paper tape in wax impregnated and the adhesive is pressure sensitive. If you press it down well paint will not seep under it. Tomorrow I will set up a few models, I have some UFO's to paint anyway, and I will show with pictures exactly what I am talking about.

Like all these skills you will need a little practise and whether you spray paint or use a brush the masking stages are similar.

Spraying: Using light coats is the key, with the first or second coat you are not really interested in making the colour opaque, just get them down light and even. I know this sounds obvious but stop applying paint when the colour is uniform and not transparent anywhere. Overloading the paint, even with spraying will build up a noticeable edge along the masking. Experience is the best teacher so practise often.

Brushing: To help prevent paint seeping under the tape brush at 90° to the edge. Start on the tape and move away never run the brush backwards and forwards. The idea is to encourage the paint to flow without forcing it. Stroke with the brush in one direction, it takes a little practise but will be second nature after awhile. Practise on scrap plastic sheet or cardboard.

When applying masking cut a cardboard mask first, Stingray has long lazy curves. Apply one strip of masking tape along the colour boundary and using a dark felt pen mark where the boundary is to be set up. Use another piece of tape to produce a centre line and mark with the dark felt tip. Align a sheet of ordinary copier type paper to the centre line so you can see the colour boundary through it and retrace onto the copier paper with a pencil. What you are trying to make is a stencil that can be repositioned exactly. You will be flipping this to produce a port and starboard mask, take your time if you make an error you can peel off the tape and replace it with a fresh piece.

It will be easier to show with pictures, honestly...

[Captain Sci-Fi]

Here is a quick guide to masking and painting. I need to put black stripes on a white painted model part (a UFO Base to be exact).

I wet sand the parts to be painted use a small amount of washing up liquid in the water and also use wet or dry type paper, here I am just keying the surface for primer I use 320 - 400 grit and finish with a sponge sanding pad.

I ensure the upper surface is flat using wet and dry paper taped to my cutting mat. After the parts are dimensionally perfect with no voids or other defects that will show it is pretty much ready to shoot the primer.

First big tip -

Try not to handle the parts too much after you have cleaned them, everyone's skin produces lanolin, a natural oil that can sometimes interfere with paint application. I bought a box of latex gloves the same type that surgeons and mechanics use to keep their hands clean, they do the same job here.

Finally I have a ball of plastercine in a small plastic bag to sit the part on while it's still wet. The paint will still be soft for a day or two so you must never lay a newly painted surface on a table or anywhere really even if it feels dry enough to handle.




Later today, applying primer.

[mike s]

thanks cap'n this is great stuff

[Troy]

Yes, just what I need too, a step-by-step guide. Thanks for taking the time to explain. I'll look out for the next installment.

[Captain Sci-Fi]

Round 2.....

Masking,

Paper masking tape is good stuff, it has a low tack glue which leaves no residue. It is paint resistant even at baking temperatures. It can be cut with great precision, it's readily available and relatively cheap. The adhesive is especially formulated to be pressure sensitive. This means if you press it down it will usually bond tighter to whatever surface you are using it on.

Compare this image to the two below, I am trying to show what happens to masking tape when pressed into a curve. The width of the tape forms a radius, the inside of the curve has a shorter distance to cover than the outside. If the tape is too wide for the radius it will wrinkle. Paper masking tape can be stretched a little but beware this will effect the sticking power of the glue as it will need to cover a bigger surface area due to the stretch.


Shadows to highlight the wrinkle issue. Do you think paint would get under here?


A better solution is to slice the length of the tape to reduce its width, see how I have managed to pull a very tight radius when the tape width is reduced?
In effect you are reducing the difference between the edge radii.



Dusting a few light coats is much better than applying heavy ones, it will clog all the detail and you increase the risk of a paint run.









Here is the completed masking scheme, remember the dark over light principle? The masked panels will be black but only between the edges.


Nearly masked up ready for the next colour, I just need to cover the top side and it's done. I use a scalpel with a No: 45 blade, I like the long straight blade with a very fine tip for this work. It slices the tape very cleanly as the glass doesn't yield and tends to guillotine it's way through. These knives are very very sharp try to avoid cutting the tape after application to the model it will cut the surface and leave unwanted marks.

I use a piece of glass cut layout and cut the tape, it will give a very defined cut to the tape and a crisp edge to the paint line, I borrowed this glass from a cheap photo clip frame I bought at Ikea. I can put it back later and the wife will never notice.

Lastly, I always remove the masking tape as soon as possible once the surface is touch dry by peeling it back on itself. It is less likely to tear the new paint and ruin the edge.

Tomorrow, getting things symmetrical the art of paper masks.

[dazzo]

use tamiya narrow masking tape, you can then use normal masking tape stuck to that,its not cheap but you wont get a cleaner line

[Captain Sci-Fi]

Hi Daz,

I am a cheap skate and always recut commercial tapes depending on the circumstances and the width required.

For those that don't know Daz recently sold an Airfix Stingray built and finished which was just superb. I wish I had the money that it sold for, it's a grail kit for me....

Would you mind posting up a picture of it please Daz? It's a really good example of how to paint the subject.

[dazzo]

Hi Bernie,thanks for the compliment,not sure if i still have the pics but will have a look mate

[mike s]

now THAT'S a paint-job boys

Mine 1 - overall view.jpg

Airfix Stingray 1a.jpg

[Captain Sci-Fi]

That is gorgeous, me want, me want.....

[mike s]

well NOTHING would make me part with it...

...ha ha er that's exactly what I said about my Sugar Smacks Joe car wich I owned for precisely 1 day defore doing the dirty

I reckon about the only thing that could prise it off me would be some kind of deal involving a boxed Lone Star Stingray - very unlikely I know

Originally Posted by Captain Sci-Fi

That is gorgeous, me want, me want.....

[Captain Sci-Fi]

I keep looking at those images and my heart is all a flutter. I love this version of Stingray, Airfix did a great job.

[Captain Sci-Fi]

The third bit.....

So here we go with the second application of colour, masked and painted in under an hour.




I could have taken a little more time to cover the upper parts but that has to be sprayed silver anyway. As usual with this kind of work, removal of tape takes 5 mins, application can typically be 10 times that.

Tip: Try to think about the layers of tape and how they will lay. If you load two or more layers at a paint edge then you will have a noticeable "step" once the tape is removed. Sometimes this will be deliberate to infer a raised panel or other feature.

Martin Bower and Bill Pearson are masters of this technique of masking and painting, they have chosen this and the paper mask method because it is quick and very effective when used by skilful hands.

One example you may want to study is Martin's paint work on the Immunity Syndrome Glider, that beautiful patchwork of shades of the same colour. It's a masterclass of turning an acre of plain orange paint and making it live as a working machine, look at all the extra interest that he added by skilful use of masks. I really admire this technique, but there is more than one way to achieve it.



Later, paper masks to define lines, using a computer to make simple masks (unlocking the power of Powerpoint) and setting out geometry.

[fab1]

I have painted lines on small sailing boats and have used a masking tape in the past called fine line tape which is designed to achieve non bleed curves etc. And yes it worked very well. I also will be painting a 3ft Stingray so reading the above thread with great interest.

Need a pointer myself with moulding, Im going to mould the barrel of the Thunderbird gun which is a conical finned shape, can I do this in one or do I need to make the mould in two halfs?



sorry about the image quality

[Captain Sci-Fi]

I would mould the handle as one part and the barrel as another,

Use a cocktail stick or barbecue skewer to push the resin around those flutes so you don't trap air between them. If you use fast cast or similar you can see any air as it is transparent until cured when is fogs an becomes caramel coloured.

A dab of superglue and paint away....