Colour Matching

Colour is a visual-mental conception. January 2, 2017 Oakville Model Flying Club 2

Canadian Industries Limited (CIL) – 36 years Paints Division BACKGROUND: Canadian Industries Limited (CIL) – 36 years Paints Division Started as a production lab technician Ended as the senior systems designer, analyst, programmer on an IBM (AS400) mainframe Spent 10 years colour matching. January 2, 2017 Oakville Model Flying Club 3

Automotive Manufacturers: General Motors - Ford – Chrysler - AMC Colour Matching: Automotive Manufacturers: General Motors - Ford – Chrysler - AMC Automotive refinish. Industrial. Stains & Lacquers. January 2, 2017 Oakville Model Flying Club 4

Colour Systems There are two systems: Additive & Subtractive ADDITIVE Additive: Primary colours are: Green Red Blue Combine to give: Yellow Cyan Magenta Primary use is in TV & Colour Photos The additive system is not our concern: January 2, 2017 Oakville Model Flying Club 5

This is our system SUBTRACTIVE Primary colours are: Red Yellow Blue Combine to give: Orange Green Purple Used in paints: This is our system January 2, 2017 Oakville Model Flying Club 6

Colour match accuracy – Within one colour step. Colour Matching: Colour match accuracy – Within one colour step. One colour step – An expert is just able to see a discernable colour difference. Colour Test – 4 rows of 12 colour standard chips approx. 1 ¼” by 1” as standards. The pastel colour matching chips are grey, green, red and blue. These chips are also the same size as the standards. January 2, 2017 Oakville Model Flying Club 7

January 2, 2017 Oakville Model Flying Club 8 One hundred and twenty loose colour chips 1 ¼” x 1” which are a match or best possible to the mounted chips. You are required to score 118 or better. Matching is carried out in a light booth with three light sources. Daylight, incandescent and fluorescent or any combination. January 2, 2017 Oakville Model Flying Club 8

The Two Rules of Colour Matching. Rule #1: If you can buy the colour, BUY IT. Rule #2: See Rule #1 If you can’t buy it then buy the one that is closest to it on the lighter side for light colours but on the darker side for dark colours. You are then going to need small amounts of other colours to “tint” to get the right colour. Real accurate colour matching should only be done for: a) your personal satisfaction or b) for entry in judging contests. For everything else, “Close Enough” will do it…. January 2, 2017 Oakville Model Flying Club 9

Colour Matching Problems.   There is really only one major problem: A METAMERIC MATCH: This provides a color match under one lighting condition, such as incandescent, but a total miss-match under another light source such as daylight. (#4 with tile) COLOUR CHIPS or STANDARDS: Colour standards vary greatly from dead-on to not even in the same ball park. January 2, 2017 Oakville Model Flying Club 10

Lets go back to metameric colour matches.   I can’t stress this enough. You’ve spent hour and hours in your shop and you’ve finally got a perfect match to the correct colour chip. Now you take it outside to compare your aircraft to the colour chip and horrors of horrors, it’s nowhere’ s near the colour of the chip – You’ve got a metameric colour match. (6) The problem could be that in the shop you have fluorescent lamps and outside you have natural lighting. THERE’S NO WAY AROUND THE PROBLEM Try matching it in the light source you will be presenting it in! January 2, 2017 Oakville Model Flying Club 11

Lets talk pigmentation:   1. Titanium Dioxide 13. Chrome Yellow Med. (Red Shade) 2. Lamp Black 14. Natural Raw Umber 3. Carbon Black 15. Natural Burnt Umber 4. Yellow Iron Oxide 16. Phthlo. Blue (Red Shade) 5. Brown Iron Oxide 17. Phthalo. Blue (Green Shade) 6. Red Iron Oxide (Blue Shade) 18. Quinacridone Violet 7. Green Chrome Oxide 19. Quinacridone Magenta Y8. 8. Monoazo Red (Yellow Shade) 20. Carbazole Violet 9. Perylene Vermillion 21. Phthalo. Green (Blue Shade) 10. Quinacridone Red 22. Phthalo. Green (Yellow Shade) 11. Benzimidazolone Yellow 23. Molybdate Orange (Red Shade) 12. Fast Dairylide Yellow 24. Aluminum Paste January 2, 2017 Oakville Model Flying Club 12

Lets do a little tinting…. 1. First, lets mix red and yellow. This should give us orange. (1) 2. Second lets mix yellow and blue. This should give us green. (2 & 3) 3. Third, lets mix blue and red. This should give us purple. (4 & 5) The purple kind of sucks. There is no way to make a satisfactory purple in paints by mixing ANY blue and red. Before chemistry came into the making of dyes and pigments, purple could only be found in natural products. It was very, very expensive thus being “Born into the Purple” had significant meaning. Purple is not a spectral colour. January 2, 2017 Oakville Model Flying Club 13

Lets look at making a brown. There are two ways of making a brown…. 1. Mix red, yellow and black. (6 & 7) 2. Mix red, yellow and blue. (8) Personally I prefer the mix number 4. January 2, 2017 Oakville Model Flying Club 14

SUBSTRATE: The substrate is of vital importance. In the past paints used the heavy metals. These were lead, cadmium and chromium. Lead has been outlawed for a very long time but cadmium and chromium have now also been outlawed. Chemistry has come into the picture and developed “chemical” pigments to replace the heavy metal pigments. The heavy metal pigments provided excellent hiding over the substrate that the paint was applied to. The newer “chemical” pigments do not provide the hiding capability that the heavy metal ones did thus the choice of substrate becomes important. A light substrate such as white will add brightness to the colour while a dark substrate will tend to darken the colour. Enough said…. January 2, 2017 Oakville Model Flying Club 15

Enough chit chat. Let’s look at a colour matching exercise. Using the Federal Standard Colors fandeck. We will use the colour chip: 34241 – Green. Going to the web site we find that the pigments called for are: Titanium White Yellow Iron Oxide Phthalo Blue Phthalo Green Carbon Black Titanium White Cadmium Yellow We’ll use: Phthalo Blue Phthalo Green Black January 2, 2017 Oakville Model Flying Club 16

WAG - 5 white, 1 green, 1 black, 1 blue – the colour was too blue. It took me 6 attempts to get close to the required colour: (9 – 10 - 11) The attempts were as follow: The numbers indicate the number of drops used. WAG - 5 white, 1 green, 1 black, 1 blue – the colour was too blue. 2. 10 white, 1 green, 1 black, ½ blue – the colour was too blue & too light. 10 white, 1 green, 1 yellow, 1 black, ½ blue – the colour was still too blue and not dark enough. 4. 10 white, 1 green, 2 yellow, 1 black, ½ blue – the colour was still too blue and too light. 5. 10 white, 1 green, 4 yellow, 2 black, ½ blue – the colour was better but lacking yellow. 6. 10 white, 1 green, 8 yellow, 2 black, ½ blue – close enough. January 2, 2017 Oakville Model Flying Club 17

OK – now what do we do with this information: We have 10 white, 8 yellow, 2 black, 1 green and ½ blue drops. These drops are considered as volume and volume is what we can convert. The total volume is 21 ½ drops. The quantity we wish to make is ¼ American gallon or 32 fluid ounces. (Litres for you older folks is 1000 millilitres.) A table will show it best… January 2, 2017 Oakville Model Flying Club 18

32 fl oz Colour/Qty 1000 Mill. Start Mill. White 14.89 oz. 10 466 ml. 460 Yellow 11.91 oz. 8 372 ml. 370 Black 2.97 oz. 2 93 ml. 50 Green 1.49 oz. 1 46 ml. 20 Blue 0.74 oz. ½ 23 ml. 5 32.00 oz. 21 ½ 1000 ml. 905 January 2, 2017 Oakville Model Flying Club 19

Let’s try another colour. This time it’s Federal Standard Colours 30118 AKA the RAF Dark Earth camouflage colour. The Pigments called for are: White Raw Umber Brown Iron Oxide Chrome Yellow Black Red Yellow Black Umber We don’t Have iron oxide, thus January 2, 2017 Oakville Model Flying Club 20

Here’s how it worked out: 1. 3 Red, 15 Yellow, 2 Black – Too black, too green (12 - 13) 2. 3 Red, 15 Yellow, 1 ½ Black – Too light lacking brown 3. 1 Red, 5 Yellow, ½ Black, 2 Umber – Too light but right tone. 4. 1 Red,15 Yellow, ½ Black, 3 Umber – Success….. January 2, 2017 Oakville Model Flying Club 21

Let’s talk about types of paint. I consider there a two types, ENAMELS & LACQUERS. Within the ENAMELS there are various general types. These are air dry, baking, epoxy, waterborne. Also in three basic levels of gloss. Full Gloss, Semi Gloss and Flat. Within the LACQUERS there are two general types. These are Nitrate and Butyrate. The nitrate is manufactured using nitrates commonly called gunpowder cotton. Butyrate is commonly described as DOPE. Enamels cure by crosslinking the resins while lacquers cure by evaporation of the solvent. Another major difference between the two types is that lacquers can be dissolved with appropriate thinners and enamels cannot. January 2, 2017 Oakville Model Flying Club 22

All butyrate lacquers are fuel proof especially for electric… More: All butyrate lacquers are fuel proof especially for electric… Nitrate lacquers are NOT fuel proof except for electrics… Enamels other than full gloss contain a powder to rough the surface thus lowering the gloss level of the enamel. The problem here is that this “roughing” causes little hills and valleys in the surface of the paint and these tend to capture and hold dirt. January 2, 2017 Oakville Model Flying Club 23

The methods of application are numerous. Some are: Spraying Dipping Applying: Generally it will be necessary to reduce the paint for proper application. The methods of application are numerous. Some are: Spraying Dipping Pouring Brushing Electrostatic to name a few. For our purposes the most logical are Spraying Brushing January 2, 2017 Oakville Model Flying Club 24

Reducing: Generally it will be necessary to reduce the paint for proper application. Reducing involves mixing the “paint” with a reducer/solvent to get the “paint” to flow properly during application. Be especially careful when pouring any of the reducers/solvents. Acetone has a flash point of -20C (-4F). When pouring it from one container to another static electricity builds up and when the static charge is high enough… guess what? January 2, 2017 Oakville Model Flying Club 25

Spraying and Brushing: There are several ways to apply by spraying. There are also several types of spray guns available, some of which are: - Professional - Touch up - Air Brush What you want to get is a HVLP (High Volume Low Pressure) friendly sprayer. With brushing you will want a soft bristle brush in a width suitable for the task. My widest brush is one inch. January 2, 2017 Oakville Model Flying Club 26

Spraying and Brushing: The most common problems with spraying are: ORANGE PEEL RUNS BLUSHING Orange Peel commonly occurs because the material being sprayed is too thick in viscosity. Another cause of orange peel is that the spray gun is held too far away from the surface. Runs simply occur from too much material being applied while still wet. Blushing occurs when applying dope in a humid atmosphere. January 2, 2017 Oakville Model Flying Club 27

Spraying and Brushing: Take care of your equipment. Spray Guns: The most common method is by “spray back”. With this method you hold a rag over the nozzle of the gun and pull the trigger. The suction or gravity tube will be in sufficient thinners. The best method is to dismantle the spray guns and ensure that all parts are sparkling clean. If you don’t thoroughly clean you run the risk of contamination with the next colour that you spray. Be very aware of overspray. In your house it could cause an explosion. January 2, 2017 Oakville Model Flying Club 28

Spraying and Brushing: Take care of your equipment. Brushes: Cleaning your brushes with a strong solvent followed by a wash with warm water and soap will allow you to use the same brushes for years. On a personal note, I prefer to use brushes since there is no overspray. I have also found that the finish is virtually equivalent to the spraying method with far less cleanup. January 2, 2017 Oakville Model Flying Club 29

FINI January 2, 2017 Oakville Model Flying Club 29