Making smoothly curved mask lines

Here's a partial view of an upcoming build (you can see the whole thing in the build thread, but this is the part that matters for this discussion):


It occurred to me recently that I have no idea how to create those mask lines. Although this OR render shows the fins outlines to be segmented, in the real deal they will be smooth curves.

I know this is going to be a lot of slow tedious work, so I'm not looking for an *easy* way to do it... I'm looking for a way to do it at all. The Tamiya tape I normally use certainly won't bend like that. I also want to avoid tape joints as much as possible, since they seem to be the most likely sources of bleeding. So what's the best way to attack this, if there actually is one?

You could always get Mark to cut you some black vinyl just a tad smaller than the fin itself. The Neon yellow/green would look like a border.

Gary Byrum said:

You could always get Mark to cut you some black vinyl just a tad smaller than the fin itself. The Neon yellow/green would look like a border.

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Mark can also cut custom masks for painting. He did some for me and the paint job turned out great.

take wide masking tape, like 4", and cut curves from it. If you cut it on glass ( window not fiber) it won't hurt the adhesive
or call stickershock

x 4 StickerShock

Mark did the flames for this build that I am working on now. Depending on the paint, and the surface you lay your mask down on, the mask is certainly very capable of creating very clean lines. The picture does not do the result justice as it was taken from my phone but the lines are very sharp and accurate.

since its easier to cover lighter colors with darker ones, id shoot the lime green, then use some 3M 1/8" fine line tape to do the tapeout.ive pulled some pretty tight radii with it and no bleed through either.pull the tape while paint is tacky.

Either frisket paper or liquid frisket works well. Kinda like the old trick of using rubber cement. If applying to painted areas, be sure the paint is cured and remove by rolling and rubbing gently.

pythonrock said:

take wide masking tape, like 4", and cut curves from it. If you cut it on glass ( window not fiber) it won't hurt the adhesive
or call stickershock

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I think this would be the most economical approach.

TangoJuliet said:

I think this would be the most economical approach.

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Yeah, I guess I'll practice a bit and see how I do. If it doesn't look like it's going well then I'll order some mask from Mark, at least for the most difficult pieces.

Although it is counter to standard practice, my plan right now is to paint all black, then mask it, then paint a coat of white (which will not be totally white white), then the fluorescent yellow/green. The white and yellow/green will be done by hand brushing. I'll practice this sequence on some scrap to confirm that the result looks good before actually committing to it though. I will also consider alternative approaches (like vinyling the black on the fins) and see if something else makes more sense.

I'll also have to see if I can score some of that fine line tape and experiment with it too. Frisket is something I've never even heard of before, will need to go look into that.

frisket films another good choice. it can also be called masking film. its used often in custom painting. you can get some ideas by surfing with terms like "masking paper airbrush layout" to get an idea of how its used. I did this gas tank with friskit film:



those bright spots are just the from the flash on the camera hitting the flake at the right angle

Body shopsupply outlets sell automotive painting vinyl masking tape such as 3M Fineline down to 1/16" width. I have used it or 1/8" for small radius curves such as used for painting flames. I then use vinyl graphic positioning backing (used to keep everything aligned when applying vinyl graphics, not sure actual correct name) to fill in the other areas requiring masking. Basically you place the backer tape over the whole area and use a sharp exacto knife or single edge razor blade to to cut the mask just through to the underlying tape and remove unwanted backing tape. This vinyl tape is really easy to use and leaves very fine precise paint edges when removed just before the paint is completely cured.

Greg

I have had to paint similar outlines on models at work.

The way I would do it would be to paint the entire model lime green, mask the paint line edges with the blue 3M fine line tape, use a little masking tape to hide the rest of the fin edges, plus a little hand cut tape here and there and then paint the rest of the model black.

If I were short on the lime green paint, I would spray the edges and leave the black areas mostly unpainted.

I did flames on my Wildman sport: I taped down some wax paper put down blue painters tape in strips, stuck to the wax paper. Drew out my flames then cut with exacto. Then carefully peel it up. It turned out pretty good.
Was my first try and I'm sure my next go will be better.

Cricut makes stencil material and transfer paper that would undoubtedly work better. I have both but have yet to try. I've even had some success with that press and seal stuff made by either Glad or Reynolds. But it was tough to work with.

You can get vinyl fine line tape at any good art supply store in the drafting department. Usually 1/16 width but other sizes are available.

How about spray liquid mask then use a Xacto to cut lines - lot of RC car painters use this method

Nick@JET said:

How about spray liquid mask then use a Xacto to cut lines - lot of RC car painters use this method

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Nick has your answer: Liquid Masking is the best way to create intricate designs on curved and compound curve surfaces. In the sign industry for decades we used a material called Grip-Mask, a liquid rubber suspended in a water based vehicle. Today the practice has all but been replaced with custom cut vinyls but there are occasions where the old Grip-Mask method must be used..On compound curves.
Hobby Liquid Masks I've found over the years are OK but a thinner mixture. meaning instead of spray or burshing on 2 coats to get a thick enough dryed film to X-Acto knife and peel, it takes as many as 4 coats. Still it works it just takes a long time to apply. Each coat will take overnight to dry, so 4 days before one can knife & peel before painting.
If you can find a Sign Supply that still has access to Grip-Mask it may be worth taking a look at a Gallon. I've been using from the same Gallon purchased back in 2001
below are a couple of other options I've found at local hobby shops but again they take several more coats to obtain a thick enough .010" thick dry film.

Another material that Might help but has a limited size and fairly long learning curve is Parafilm-M. a wax based stretch and apply mask. It can be overlapped to apply to larger areas but I've found it somewhat difficult to work with on large areas. It is great for small details and intricate designs that can be contained within it's 1.0" width. Parafilm-M adhears to the surface with the heat from your hand. is then knifed and peeled just like the rubber based Masking liquids.
Hope these thoughts helps a little.

Another consideration: monocote heat shrink covering, they also make a peel and stick Trim version.

So, just to put a cap on this thread (for now), I was at my LHS today and nabbed some Tamiya Masking Tape for Curves in the 3mm and 5mm sizes (not knowing which I really needed.) I experimented a bit on a melamine shelf and feel like I got the knack pretty quickly. Without undue effort I was able to do around 3/4" radius with the 5mm and 3/8" radius with the 3mm, so I think I am set. I'll now do some test painting and see how it goes.

The shop also had a few varieties of liquid mask, but I decided that if I can get the tape to work, it'll be more comfortable and straightforward for me. Thanks for all the ideas!

MikeyDSlagle said:

I did flames on my Wildman sport: I taped down some wax paper put down blue painters tape in strips, stuck to the wax paper. Drew out my flames then cut with exacto. Then carefully peel it up. It turned out pretty good.
Was my first try and I'm sure my next go will be better.

Cricut makes stencil material and transfer paper that would undoubtedly work better. I have both but have yet to try. I've even had some success with that press and seal stuff made by either Glad or Reynolds. But it was tough to work with.

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my wife used her silhouette cutter to make mine, it's a great way for her to participate!

fm