What is the best way to mask off circles prior to painting with an airbrush ?

What is the nest way to mask off circular shapes on a piece of work prior to painting with an airbrush ?

Previously I rolled some Blue Tac flat and cut circles out of it use a set of hole punches. This did work well for smaller circles but became more difficult as the circles got larger. I also tried cutting circles in masking tape using the hole punches but this was not successful.

What about cutting circles in plasticard and using minute amounts of blu tac to hold it in position? I suspect that you may still not get a sharp edge but this could be remedied with a lining pen.

Mick

Hi Brian not knowing your sizes have you thought of self adhesive circles Staples,ebay have them 8 - 25mm.

H

That sounds like a very good idea Harry, with the caveat that the underlying paint film should be properly cured, say 2 weeks, otherwise the adhesive may lift it.

Mick

Masking film though sticky backed plastic "Fablon" will also work and a compass cutter or scalple blade held in a normal compass.

On the small size stuff you seem to be working with masking tape does not give a crisp enough edge.

Loose masks are OK if using inks and water colours on a white (paper) background as you are not spraying much material but if its enamel on a model then you need something that will not lift from teh air or allow the paint to creap under.

If its a circular component you don't want to get paint on like the end of a cylinder then apply masking tape and then pull a needle file backwards at 45degrees around the edge, this will split the masking tape and you can peel away the excess. Very similar to using a hammer to trim a Gasket.

J

Edited By JasonB on 14/01/2015 07:45:08

For the likes of a 6" circle, masking tape will do it, make sure it sticks on the inside of the circle(presuming that's the bit to be painted), don't worry about the out side of the arc, you can put paper under the outside to extend the masking.  Smaller the diameter the narrower the tape. 

Ian S C

Edited By Ian S C on 14/01/2015 10:14:57

Hi

Depends what size. In the past i have used brown parcel tape and cut out circles with a "compass cutter"

**LINK**

Sorry ebay link but you can buy them in most craft shop & "The Works"

regards

Steve

I got my compass cutter from one of the 'junk' stands at the ME show years ago. Almost Christmas cracker quality but it works. Pretty easy to make one though.

A tip with peel off plastic templates like Fablon is to remove the backing, then cut 1/4 to 1/8 off the backing around the target profile edge and put it back on the sticky bit. Then you can apply to the work with only a thin line of sticky edge which is more controllable and easier to remove afterwards.

That's a good tip Bazyle.

Neil

I just read a piece about painting a loco, and the author needed 1/4 circles for the corners of his lining. He used Frisket Film, which is a low tack masking film used by the air brushers. it is also very thin, .001" much better than normal masking tape, and shapes can be cut using templates and a scalpel. I need to do this on my 4CD so intend to give it a try. If you google it there are dozens of sellers, a pack of 10 sheets can be had for a tenner or thereabouts. I would be interested to know if anyone has tried it.

Chris Gunn

As I said above masking film can be used "Frisk" is a brand name much like Hoover.

As its low tack it does not take so well to compound curves but takes well to flat or single curved surfaces. The Matt one is easier to use as it can be drawn on with a pencil if needed.

I know of at least two Model Engineers that have small desktop stencil cutters much like you find in a Signwriters that does the vinyl cut letters. I think you are a member of Traction Talk, if you have a look back through Julia's GMT build she showed these computer cut masks being used.

J

I normally use my Ioline vinyl sign plotter for cutting masking circles from adhesive sign vinyl. For airbrush work on signs etc, I use the airbrush industry standard material called "frisket". Here is a link to one supplier **LINK**. It has a very light bonding adhesive that allows it to be applied to dry-to-touch painted surfaces. It cuts easily and gives a superb crisp edge. It is easy to remove immediately after airbrushing. Background masks are simple to remove. Positive masks such as those required by Brian are also easy to remove. However, in order not to disturb the clean edge I apply a tab of masking tape close to the edge of the frisket to enable me to lift the edge without damaging the paint work. The frisket cuts superbly with a good knife such as "Exacto". I prefer dissection scalpel blades myself. Frisket is available in many artist shops.

Bill

I guess I was a little slow typing out this one.

Bill

Jason, just looked up Julia Old's thread on Traction talk, for anyone interested it is pages 92 and 93. I read that Julia was able to use a Craftrobo stencil cutter to cut stencils for her 6" GMT belly tank. She also used stencils for the wheel spoke lining which seemed a much quicker method than I just used to do the wheels for my 6" 4CD. I used lining tape, I got reasonable results on the straight sections, mixed results on the curved ends, but I knew that before I started. Stencils would have been a better bet as far as curved and tapered lines are concerned.

Bill, I think I was reading your piece about Frisket film.

Chris Gunn

I think the self adhesive round labels are a good idea if they can be found in the correct sizes....which they probably cannot !

I will order a compass cutter and have a go at this method. The smaller circles (5mm diam) are the tricky ones ; I think the larger circles (20mm diam) would be a bit easier. I may use the Blue Tac for the smaller ones and the compass cutter for the larger ones.

Never used it for this application but you can buy masking fluids from any art shop when doing water colour washes or any hard edge technique with acryllics. Paint on.

I hate decorating so i buy a cheap low tack blue paper masking tape from a (scottish) auto detailing co on-line and can spend a few hours masking up architraves, skirtings etc and then dosh out emulsion with a wide brush and roller - avoid all the stress (and care) of cutting in. Walls and ceilings only ever get done in white (cheap, clean and in huge tubs). Woodwork is stained or varnished (never painted). A whole room gets done in a day and the tape comes off without marking the underneath or lifting it.For hard edge spray lines on heli canopies I've used the plastic 3M masking tape

Since posting some days ago, I have got some Frisket film, and I made some templates out of thin brass to cut out masks from the film to paint the quadrants of a circle at the corners of my tanks. I found that cutting the film needs a sharp scalpel, (thanks Dave), and the edge of the brass template needs to be nice and smooth. I cut the first set from the masking paper through, but seemed to get some feathering on the edge of the cut. I did some from the film side and these seemed better. I positioned 4 masks to form the corners of a rectangle, and painted through with Craftmaster lining paint, removing the masks after the paint had gone off for about 20-25 minutes, and I got acceptable results. There was a little bleeding of the paint here and there, but this was down to me I think. I joined the corners up with the lining masking tape, and the job was done to an acceptable standard. I think with practise the results will improve.

Chris Gunn