During my Star Trek Captain’s Chair Restoration; I found myself wanting to paint match some powdercoat to the existing color of the plastic side panels on the chair.
Please note: Readers are responsible for their own sacrifices to the blood god. Safety first– if you injure yourself implementation of this guide; expect we’ll take no responsibilities. Commentors at Hack-A-Day have indicated that MEK is flammable (as does the label) – so please take the appropriate precautions.
- Glass or metal mixing vessels (an airbursh jar works well)
- Methyl Ethyl Ketone (MEK)
- A set of Powder Coat colors to mix the colors
- A paint sprayer… HLVP, Gravity fed, or Airbrush
- A Panatone(r) Color Cue(TM) or similar device (optional).
Powdercoat using this method appears to be every bit as robust and scratch resistant as normal powdercoat. The author has seen no negative material properties from using MEK instead of a powder coating gun (electrostatic).
For the beginner; Harbor Freight may be a good stop for the primary colors – they usually carry White, Red, Black, and Yellow. Unsure about Green and blue. I also use HF touch up paint guns, HLVP, and airburshes to apply my MEK solutions. Caswell plating is also a good source for many a color. MEK can be purchase in the paint area of most home improvement stores – I buy mine at Lowes.
I wanted to paint match the powder coat because my chair controls have began to peel and rust. They’ll need to be redone so I wanted them to match the newly retr0brighted side panels.
While the used of the color cue is a good starting place – it isn’t required; you can manually mix colors by eye until you get it right… as you’ll see; I used the color cue to get initial color suggestions (or base colors if you will); then added pure white to bring the color closer to that of the plastics.
I started by measuring the sRGB color of a retr0bright-ed side panel using my Pantone(r) Color Cue(tm) device which I got off of Ebay several months ago and it came up with r246 g230 b198. I pulled these values into the RGB to commercial Tints page at EasyRGB.com. This gave the closest RAL numbers which to match to. I then went to google and did a search for RAL-1013 powder coat which returned a result to powder365.com for their ” Oyster White ” powder coat. Then using the HTML code #F6E6C6
I also used the RGB browser to convert to “RAL Classic” listed six colors with % equivalent matches to my original scanned color.
|% 1-?C||Color name|
|96%||RAL 1015 Light ivory|
|94%||RAL 1013 Oyster white|
|93%||RAL 9001 Cream|
|92%||RAL 1014 Ivory|
|90%||RAL 9010 Pure white|
|89%||RAL 9002 Grey white|
I also did searches for other color combinations and ended up selected the following three colors from powder365.
1lb x RAL 1013 OYSTER WHITE (340/10MIN)
1lb x RAL 7035 LIGHT GREY (340F/10MIN)
1lb x TEXTURED ALMOND (380F/20MIN)
The idea was to put each color on a test piece to see how close to match and pick one which looked the best.
For more information on color matching using the Color Cue; please see Pinball Pal’s Color Cue page.
During my research; I also came across a post to caswellplating.com’s forums which talked about mixing the powder with MEK to “melt” the powder into liquid form for the purpose of correct a blemish on an existing powder coated part. This sparked an idea – why not use the MEK to mix powders together to get an even better color match. I have a quart of MEK in the garage – so it was time to experiment.
I knew the grey wouldn’t really match – it was too grey; so I used MEK to melt it and used a hobby paint brush to apply it to the scrap piece. I then used regular power coating equipment to lay down the almond and oyster for comparison. For the last color; I decided to mix some grey, 2 TSP of pure white (purchased at Harbor Freight), 2.5 TSP of oyster together with a generous helping of MEK to turn the powder to a grey-white “milky” formulation. I applied this with a paint gun:
From Left to Right: RAL-7035+MEK (under thumb), Almond, RAL 1013, and MEKMix
The Right most Grey is “uncured” IE that is how it goes on being applied with a paint gun. Looks fully cured already. and the lines were created with standard blue painters tape. Be-aware – that MEK powder liquid acts just like any paint… it will dry on everything. so protect from over-spray and wear gloves. Unlike the powder form of powdercoat; it can’t just be wiped off of surfaces.
The cool thing about MEK powder-liquid is reportedly it can be used on Plastics and Wood… using low cure temperatures. Ideal for paint matching on cases or other non-metal projects.
With MEK; it looks like one could color match any color given enough patience and primary colors to choose from. Now with this knowledge; it was time to do some actual paint mixing for the purpose of matching the side panels.
I went to work on the control panels:
As you can see the control panels are in need of some TLC. As typical for this machine; the Fire control panel label has begun to deteriorate and is peeling away from the metal. So I removed the label manually – then used Xytol to soak the piece for about 5minutes to soften the label adhesive so it could be removed with a plastic paint scraper. I continued cleaning/soaking the bracket until all the label residue was removed:
Then I sandblasted the bracket w/ ALO2 to remove the rust and other residue. And then finally; I wiped the bracket clean with some clean MEK to remove and remaining dust and oil from the surface.
I then proceeded to powdercoat the underside to the bracket with the Oyster White Powder coat.
For the front; I did an MEK liquid mix as discussed previously. This time I started with a base of 2.5 TSP of Oyster White powder coat and added 1.5TSP of pure white Powder coat. I then mixed with approx 1/4cup of MEK to form a 2% milk-like consistency. I color checked the mixture by using a small paint brush to apply the color to the underside of on of my plastic pieces. This mixture was nearly a spot on match to the plastic so I decided to go with it. I loaded the MEK liquid powder coat to my touch up paint gun
And painted the front / sides with this MEK paint match. Here it is “air cured”:
Once it is dry to the touch / safe to handle (usually about 20minutes); I place the bracket in my powder coat toaster oven for initial curing. during my test runs; I noticed that if you attempt a full cure (400F / 20minutes) with the MEK solution still wet – it will “Boil” the paint leaving rough spots. So I put the piece in the oven at 150F / Warming setting for 10minutes to allow the MEK to evaporate. Then I crank the piece up to 400F for 20minutes for the final cure.
Once the piece cooled to room tempeature; I did a test match against a retr0brighted piece. First; here’s the stock Oyster White (back of bracket):
Notice the slight yellow hue vs the plastic piece.
Here’s the MEK paint match 1.66:1 (oyster to pure white):
I call that a match!
Incidentally; The Color Cue captured an sRGB255 value of 237, 225, 192 for the color matched piece (color code EDE1C0).
Please check out the remainder of the worklog – where I used an airbrush and a laser cutter to create powdercoated labels on the pieces:
1982 Sega Star Trek Captains’ Chair Restoration
15 Replies to “Paint matching powdercoat to other colors”
I like the amount of detail you are putting into this project.
I was curious, how do you clean the gun after you are finished? Would regular paint thinner work?
What do you mean by Gun?
If you mean the sprayer which applies the MEKed (liquid) powder coat; then MEK or Xylol will do a good job of cleaning the sprayer.
On my AirBrush; I use MEK to clean it as it doesn’t take much.
I have been looking and looking for info on mixing powder paint with MEK. I am so glad to have come across your Blog. I realize that you cured your pieces but what I want to do is this. I want to paint cement flooring. I have heard some companys have done this and it turns out great. I will try to mix a little bit at first and then make a forumula to increase the amount. If you have any pointers I would be glad to hear them.
I would have thought foot traffic over cement would cause the powercoated surface to scuff and scratch… unless you wax it like other hard flooring.
I don’t really have any suggestions… other that if you do a large room with MEK…. MAKE SURE you VENT the room real well while it cures.
Post some pictures – I’d be interested in the results.
I was told this by one of the Dupont reps. As soon as I have some time I will try to mix up a small batch with power coat that I have and try a small area. It is suppose to be quite durable. Its a good way if it works to use up recycled powder paint.
I just stumbled across this thread whilst searching for powder coat mixing tips. A fantastic blog and I am very grateful for your very detailed description!
I do have one question though. I am looking at powder coating a car water pump and so I need to limit the bake temperature to about 110*C max to avoid damaging the seals etc. I like the idea of using MEK to then spray on the powder coat. You mentioned you can then bake at a lower temp for plastics or wood, do you know / have you experimented with what temp works, and how durable the finish is afterward?
I’m not 100% sure you even need to “Cure it”. MEK basically turns the powdercoat into a “paint”… so you could just leave it that way.
Is the water pump plastic housed or does it just have orings?
If it’s a plastic housing; then it might be an issue spraying MEK onto surface of the plastic. MEK works with the powder because it dissolves the plastic particles into a plastic liquid which can then be mixed. you’d end up doing the same thing to the plastic housing. In the powder/mek solution; it’s probably not enough to worry about; but your mileage may vary.
I haven’t experimented with powdercoating anything other than metals; so can’t really provide any useful data.
I’d say try it and see what’s the final result…. just be prepared to have to buy another pump if things go really south.
On the piece I did on the blog; the coat was very resilent even before bake. I did the bake just to be paranoid. I don’t have any tools to measure abrasion resistance or other properties of the MEK powdercoat; so YMMV.
Finally; if your worried about overall baking; you might try using a heat gun to cure the powdercoat in sections. I haven’t tried this; but I imagine it’s work with enough patience.
Hi! Could you upload video of you mixing powder coat with mek?
Amazing write up. I just have one question, what is your mixing ratio on the MEK with the powder coat I read you used a 1/4 cup make it milky like a 2%. I’m just a little confused on that.
It’s not an exact science to obtain a ratio.
In my case; I mixed the powder to MEK to have a consistency of 2% milk so it’d spray thru an airbrush.
Does that help?
Yes it made sense after I tried it, pretty straight forward and using good judgement on the mix. I got it to mix perfect and I got it to spray nicely out the gun but it looked like crap when it came out the oven. It stuck really good to the scrap metal I used but it had a crackled look to it as if it reacted to something. Maybe I am missing a step or maybe I’m using the wrong kind of powder, not sure.
Did you let the MEK/powder mix completely dry before baking it? I’m pretty sure I let my mix “cure” in the texas heat for several days to be sure the mek had evaporated.
I guess the powder type could make a difference.
No I did not I left it in the sun for about an hour, it looked dry so I threw it in the oven. Maybe that’s where I went wrong I’ll give it another shot
One other suggestion, Mavi… maybe put on a very light coating. I honestly don’t remember how heavy I put the color on when I did it.
so all I really know about the subject of powder coating is from messing around with powders without the proper elecrostatic application tools. So what I have noticed is this……. the thicker it seems to be, the more prone to chipping it is……. although that also seems to be linked with the consistency of thickness with which it is applied. So after reading this interesting thread….. I would submit that a couple of things that might make for better results using this unconventional (and right up my broke-ass allley) technique, would be to mix it as thin as possible while still getting the consistency that makes for a good deep rich color once it has dried… he mentioned a milk like consistency but like I said, IDK. and another thing that may help would be; once you are spraying it, if you seem to be getting good coverage with one pass of the sprayer, then really focus on overlapping your sprays as little as possible because that could result in sporadic areas where the thickness is not consistent and therefore more prone to sustaining damage than the more consistent spots……. the reason powder coats done properly are so strong is because the thickness on any exposed and grounded surface your painting is dictaded by the amount of charge you are putting into the gun so inconsistencies are damn near impossible and it is bonded as much to itself as it is to the piece your painting……. IDK. maybe I’m rambling but it seems like these are the important aspects of a ghetto-rigged powder coat tech……..