|Jan 06, 2014, 06:05 PM|
How to Refinish and Repaint Your Sport Jet
Hello everyone. I am refinishing my new to me BVM Maverick on another thread started by Gunradd: http://www.rcgroups.com/forums/showt...347346&page=20 and there has been some discussion on starting a thread on how to refinish and repaint your sport jet so I thought I would start it off here rather than post in the "Aircraft- General" under the "Paint and Finishing Tips" section since this is to address the sport jet. There are some that think (myself included) that something like this might benefit those that frequent the Jet section on RCG.
For this thread my thoughts were to seek input from those that have some REAL WORLD experience finishing and painting RC model jet aircraft (EDF, glow or turbine). I would like to invite those with real worked experience to post your process/procedures here so that others might benefit and for those that have questions, feel free to post them here. If you choose to post some "how to's" please try to address the following:
1. What was the plane or surface your prepared/repaired or refinished
2. What types of materials did you use (type of glass cloth, epoxy used to apply cloth, etc.) and what process did you use to apply the medium.
3. How much weight was added by each of the processes (cloth and glass application, primer, filler, paint and clear coat if applicable)
4. What type of equipment did you use to paint the plane or part (air compressor size/type, spray gun type and size, type/brand of paint or primer, etc.)
5.Post photos if possible of your "how to".
Please do not forget to include the weight gain for each of the different processes so people can decide if they want to utilize that process or procedure.
If you choose to post please make the post informative or constructive. If you choose to post please refrain from some sort of post like "I saw video of a guy that did this" or " I have heard that someone does this". We are seeking informative and constructive posts and my hope is that this thread will help some on the forum and these "I saw someone do this" types of post do not benefit the community. I do not mean to sound harsh but the intent is for us to learn from one another so real world experience is helpful.
Please feel free to post your questions and I am sure that others will try to answer them.
P.S. Here are a few photos of what I started with and where it is now. The maroon is the color I got the plane in and the yellow/red is how it looks now.
|Jan 06, 2014, 06:56 PM|
In this first post, let me say that I am going to post the types of products and items as well as the processes I use. I do not claim to be the "all knowing and all seeing" guru of painting and refinishing. Many others are a lot more qualified to post on refinishing methods than I am. I am simply making posts about how I go about refinishing and repainting my planes (pattern and jets) and the products I use.
I have been building and flying model aircraft for about 55 years and have been building and flying RC for 41 years (celebrate my 41st year in April). Over those many years I have used tissue paper, silkspan, silk, fiberglass cloth and polyester and epoxy resins as well as plastic film so I have been exposed to many different finishing methods. During my early years I used clear dope and areogloss paints. As time went by I started to use the K&B Superpoxy until I discovered automotive paints. The problem with the K&B was that their clear coats tended to "yellow" fairly quickly so repairs we difficult when trying to match colors so I moved on to the Dupont line of acrylic enamels. I used these while I was living in Calif. but when I moved to Denver I discovered the PPG brand of paints. I started using PPG in 1990 when I painted my big Tom Cook F-4 and continue to use the brand today. In the early days I was using the single stage (the paint had to have a catalyst added to make it cure and make it fuel proof) but a few years ago I started using what is commonly called the base coat/clear coat paints of some refer to them as 2 stage. The difference between the single stage and the 2 stage is that the single stage takes some time to cure before you can mask or apply the second color where as the 2 stage color coat (the base coat) dries in about 30 minutes and can be masked in about an hour. The nice thing about the 2 stage is that multiple colors can be applied in fairly short time. On one of my jets, I applied all seven colors in one day. Once the colors are applied with 2 stage process, then the decals/details can be added prior to the application of the clear coat. One thing to note is that the 2 stage process MUST have a clear coat applied to protect the fragile base coat from damage. The base coat IS NOT fuel proof as it is applied so a clear coat is a must.
Here are some of the tools I use.
My air compressor is the Craftsman 6 HP, 33 gallon tank that delivers 8.6 cubic feet a minute (CFM) at 45 PSI (http://www.sears.com/craftsman-33-ga...8&blockType=G8). This compressor is not required but the size of the compressor depends on the size of your project and most importantly the size and type of spray gun you use. The smaller the air tank and the less CFM your compressor delivers the more frequently the compressor will have to run to either fill the tank or to keep it filled. IF your gun requires a lot of CFM to spray then the tank needs to be fairly large to keep from running the compressor all the time. Basically, it the compressor starts to run during you spray application, you MUST wait for the tank to fill and the compressor to "catch up" before continuing to spray. If you continue to spray while the compressor is running you risk the possibility of trying to spray with less air pressure than is required to spray your paint.
I use a couple of different spray guns. I have a small 6 oz. "touch up" gun and then one gravity feed gun siphon gun and one HVLP (high volume low pressure) gun. I use the different guns depending on my application but that is not necessary and many people use one gun for everything.
I have the touch up gun from Harbor Freight and have been using it for about20 years. My other two guns are the HVLP from Sears and then I have a gravity feed gun from Lowes (link above). the difference between the conventional spray gun and the HVLP is that the HVLP will allow you to spray the paint at a much lower pressure than a conventional siphon or gravity feed gun. In theory, the lower pressure of the HVLP should result in less paint waste by reducing the overspray that one gets when painting.
|Jan 06, 2014, 07:27 PM|
Here are some of the other items I use in my painting/refinishing process. I like and have been using automotive finishing products since they are designed to last a long time in a rather harsh environment. Some will say that they are expensive and this may be true but I believe "you get what you pay for". One other thing to consider is that buying numerous cans of spray paint (rattle cans) can probably cost as much, if not more than buying the auto paints and related products. While it is true that the initial "buy in" for shooting auto spray paints ( the cost of the air compressor, spray guns, water trap and air hose) can be high, remember that I can get a quart of auto paint mixed to my requirements for about $35. To this cost add one gallon of thinner/reducer for about $20 you can spray a lot of planes. The color coat is typically reduced by about 50% so once reduced you have increased your amount of paint by 50%. Now to this you must add you clear coat and this costs about $75 plus about $35 for the catalyst. Again, this may seem expensive but the paint and clear coat does go a long way. I will tell you that I have about 25 pints of PPG paint in my paint locker and I have had some of those paints for 10-12 years. In fact, I still have the two different mil spec shades of gray that I bought in 1993 to paint my big A-10 and it is as good today as it was when I bought it.
I use the Evercoat brand of filler and the auto body lacquer glazing putty. The Evercoat is used to fill rather deep flaws (usually deeper than about 0.010") and I use the lacquer glazing putty for minor imperfections.
I use the 3M or similar blue painters tape from Lowes for masking large areas. I also use the masking paper from Lowes. It is available in 6", 9", 12" and 18" widths and about 5000 ft. long for about $3-4 per roll.
When masking an area to paint and I want a clearly defined line (for example when masking the yellow off to paint the red or other colors on the Maverick) I use the 3M "fine line" blue vinyl tape. The nice thing about these tapes are that they "turn" really tight corners very well and don't lift. The other tape is a low tack tape from Tamiya. These tapes are available in 3 and 6mm widths and are very good low tack tapes but they are for relatively straight lines and do not "turn" a corner very well.
|Jan 06, 2014, 07:54 PM|
More Stuff I Use
Here are a few more of the items in my refinishing/painting part of the garage. This post covers the paints and a couple of other things.
The tack cloth is an absolute must for anyone painting something. It is a rather tacky surface that collects any loose objects on the surface and should be used prior to the application of the primer, color coat of the clear coat.
I have found the "fish eye" inhibitor to be extremely helpful in preventing a fish eye finish on surface. If a surface is contaminated with an oil or some other foreign substance and you are concerned about the paint "fish eyeing" then I use the inhibitor. You simply add a few drops of the stuff to the color coat (I use this almost exclusively with my single stage paints).
In the photos below you will see four cans of paint. From the left to right you will see: The can on the left is the PPG Delstar acrylic enamel single stage paint. It is very good and if catalyzed will stand up to nitro as high as 70% and to gas and kerosene. Wonderful stuff but it does take about 24 hours to dry. The second, third and fourth cans are all base colors for the PPG 2 stage paint system. The Deltron (second can from the left) is the high end paint form PPG and it is very good but rather pricey. The third and fourth cans from the left are two cans of the Omni which is the PPG "house brand". It is very good and reasonably priced. Again the Deltron and the Omni are 2 stage paints which means that they must have a clear coat. The really nice thing I like about the 2 stage stuff is that you can thin it to spray with an airbrush. I thinned it about 100% for use in my Iwata airbrush and it worked very well.
The next photo is of a clear coat that I have just started using. It is very good and it is less expensive than the PPG clear coat. It is compatible with ALL of the PPG series of 2 stage paints. It comes ready to spray but can be thinned with lacquer thinner to a max of 10%. The clear is applied in two coats.
The last photo is of the Duplicolor line of products. They offer a cleaner, a primer and a gloss and matte clear coats. I have all three products. I used them on my A-4 and they worked well. The cleaner worked well as did the matte clear. As mentioned previously, I did not care for the way the primer sanded so I would not use it again but I would use the matte clear and the cleaner. I have not used the gloss clear from Duplicolor so I can not comment on it. I will say that the matte clear comes ready to spray and does not require any thinning but it can be thinned if desired.
|Jan 06, 2014, 08:23 PM|
Over the years I have used many different primers and here is what I am using now.
The primer I use depends on what the underlying surface is in need of. For example, if I have a glass fuse that is pin hole free and does not have any weave to be filled then I use a non-filling sandable primer. However, if I have a surface like the Maverick wings or tails that either have some weave showing thru or I have just reglassed, then I will use a filling sandable primer. The thing about the filling primer is that it will fill the weave and you can sand almost all of it off. If I am repainting a plane and there are some remnants of the previous color on the surface to be painted (this might be paint that I could not remove for some reason) then I will use a primer surfacer/sealer. The reason for using the surfacer/sealer is to keep the old colors from "bleeding' thru to the new color. I have had this happen to me so I speak from experience.
I am currently using two different types of primer. I am using the Omni (again PPG) epoxy primer as well as a PPG brand of sandable lacquer primer. The lacquer primer is very good, dries quickly and can be wet or dry sanded with good results. The Omni is a catalyzed primer that dries fairly quickly and is very sandable. Recently, I have tried the primer from Duplicolor. This is available from a auto parts store like Autozone. It works well but is a little difficult to sand and I would not use it again.
|Jan 06, 2014, 10:16 PM|
Wow thanks Ed!! I always get too rushed and end up hurrying up my coats. I like a "wet" look and thick coats seem to be the best way to get it without color sanding? Looking forward to learning your methods
|Jan 07, 2014, 08:09 AM|
This will be a great thread.
The materials you listed are great and will deliver great results. As you mentioned they are a bit pricey initially.
One spot for sourcing base coats could be the guy who does your paint & body work locally. They mix paint for a job and almost always have pints and ½ pints left over. This extra paint is almost never thrown away so it can be used "on the next job" ( which never happens ).
Since we're not usually worried about an exact shade on models, this left-over paint will work great. Keep in mind that different brands of auto paint require their brand of reducer.
Although, most can be cut with lacquer thinner, that stuff is very "hot" and can cause other problems like melting the old top coat, drying too fast, etc.
Do a test piece first.
The Harbor Frieght HVLP spray guns work fine. Can get them on sale sometimes for $12 bucks.
I use them at my body shop painting anything from a wheel barrow to Jaguars. I've had all the fancy-schmancy spray guns and I can't really tell the difference in how they paint.
The only thing is that the expensive guns have over the cheap ones is the ability to stand up to repeated cleaning overhauls. And replacement parts.
But for $20 compared to $300-$500 it's a no-brainer.
|Jan 07, 2014, 10:57 AM|
Great to have you on board. Looking forward to your input.
I would agree that paint and body shops can be source for paints they no longer need. The nice thing about the paint supply place I use is that they can match the Monokote or Ultracoat colors. All I have to do is to take them a 4" square sample and they will color match it. I have had them match the Monokote and UltraCote Black, white, Cub yellow, regular yellow, Corsair blue and a number of other colors.
Each has its own advantages.
I would agree on the differences between the cheap and the expensive guns. In fact, my 20 year old Harbor Freight touch up gun needed some parts and I could not find them so I bought a new gun for $12.99.
|Jan 07, 2014, 12:14 PM|
Ed great thread. Maybe I'm jumping the gun here, but once the fuse was ready to go, how much total weight did it add.
Primer, base and color coats, and clear. Probably the most forgotten weight to add to the equasion in scratch building or kits when trying to project an AUW.
|Jan 07, 2014, 01:14 PM|
I am sorry to say that some of my data is not as terribly definitive as I had hoped but here is some info.
I have recorded the info on the weight gain on the wings and the tail. The weight gain on the wings is a lot more accurate than the fuse for the following reasons. Very little repair work was done to the wings but a LOT of work was done to the fuse. I only added a little filler to fill some weave and I added three small pieces of glass cloth to the wing tips to repair damage. The fuse is a different story as I removed the intakes and from them I removed 3 oz. of weight in the hush kit removal. I also had to reglass the horizontal and vertical tails and I did not do as good a job of keeping track of the weights after each phase.
However, having said all of this here is what I can tell you:
The weight gain for the wings:
Stripped with filler and glass cloth repairs 18.6 oz.
( the left and the right wings gained exactly the same weights so only one wing is shown)
Wing repaired with primer added and sanding 19.6 oz.
Wing after Yellow base coat added 19.7 oz.
Wing after all colors added (no graphics and no clear) 19.7 oz.
As you can see, the weight of the filler, primer and paint added about 1.1 oz. to the wing. This may be a little misleading as I did all of my weight measurements in ounces and not in grams. If I were to do it again, I would weigh things in grams. Reason for this is that if you look at the difference between the weight of the wing between the application of the yellow and the application of the trim colors (red, silver and blue) you will see that there is no apparent weight gain. Well this can not be the case but since measurements are in ounces, there is a good chance that the rest of the colors added something less than an ounce. My guess would be that the trim colors added about 15 grams or less.
With regards to the fuse, this weight gain is a little more difficult to determine but I will tell you what I think I added.
The weight gain from the reglassing of the horizontal and vertical tails and the addition of the primer was about 2 ounces. The weight gain for the addition of the yellow base coat was about .6 ounces. Weight gain for the addition of the trim colors (again the blue, gray, black, red and white) looks to have been about 20 grams so a little less than on ounce.
I have not yet added the clear coat but from this point forward I will record the weights in grams so I can better determine how much weight is added. I am particularly mindful that it is the clear coat that adds most of the weight from a paint job so I have asked a good friend of mine who is a retired paint and body guy for some pointers on how to spray the color and keep the weight gain down. He has made some suggestions and I will try them on this plane. If it works I will share it.
|Jan 07, 2014, 01:44 PM|
Need Some Help
I would like to take some of the posts I made on the Maverick Refinishing thread and post them here but I really do not want to retype all of the info for each of the images. I can copy and past the text from a post but I do not know if that will bring the images and their text with the copy and paste.
Can anyone tell me how (if it can be done) to copy and paste a post from another thread AND bring the images and supporting text with the text from the body of the post?
Thanks for the help,
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