Chapter 25 Finishing and Painting
07-13-2016 The pics showing the engine cowling in this chapter are not current for my airplane. I now have a Lycoming IO-360 D1A angle valve engine on my plane.
06-16-2012 Notes: Note: My stop action for the rudder is the "little extension" of the wing.
Sam Senmounnareth painted my Cozy Mark IV airplane.
Here is Sam Senmounnarath and my Cozy. If you are in middle Tennessee and you want a Cozy painted, I reccommend Sam for a great job on painting. 615-474 2335.
I finished painting the plane and now I will edit this whole chapter to reflect the lessons learned. My hope is that you can have an even easier time. If you are new at spray painting, I have some pointers in the paint section of this chapter.
While the plane was upside down, I did the following.
1. Did the sump/fairing work
2. Applied micro and got the final finish shape
3. Made the lower cowling lip (since I am making a custom cowling)
Click the pics for larger size.
Here are the flip the plane pics. Thanks to my hermanos.
Nov-2009 to Feb-2010 and more
I changed plans and finished the interior panels, seat props, throttle quadrant console, and the IP/F-28 cover, ect. and then primed and painted with Zolatone. It worked out better to paint inside the plane and then go to the exterior. Now, back to the comments.
The wings are made with featherlite cores and so the contour is already great, and so I just need to not mess it up with the micro. I had to add micro in the middle of the wings for contour before I did any micro work anywhere else. Fill big low spots first and then do the full fill work. What you use to sand the contour is secondary to having great illumination to see the contour defects. White on white is terrible for inspection and if you cast the light at the right angle, then you see where to work. Even after I had put on the first two coats of primer, I found that one wing needed some minor micro work, before the final coats of primer.
I bought some cheap plastic bowls that are about a one gallon size and disposed of the bowl after 2 or 3 sessions. The six inch flexible spatula is all that you need for flat surfaces. I trimmed a two inch black plastic spatula to a curved shape to mix the micro and for micro application on curved surfaces (convex and concave).
Micro mix ratio: For most of the fill on large areas, I used 14 squirts of MGS 285 (fast) epoxy to 22 scoops of micro (Mr Coffee 20 ml scoops). For some areas like the side of the tilted winglets, I used 20 scoops instead to 22 to add some adhesion. It is not necessary to paint on any thin micro before the main fill as long as the surface has been vacuumed well of sanding particles. Adhesion of the micro mix will be promoted by the downward migration of the raw epoxy in the mix toward the glassed surface.You have to butter the micro onto the glassed surface and get some adhesion, before you try to do a final spread. If you don't "butter it on" first, then it's going to roll off the surface as you pull the six inch spatula across the top.
Pic#2 of the 25-2 section shows the very first fill. That is a fill of low spots. Wayne is right about the low spot fill in. It will save you some of the sanding to get the right contour. I sanded the fill in on the low spots to have a smooth transition and then did what was hopefully my second and final fill all in one. Right after I finished applying the micro mix, I used my brush and some epoxy to smooth out the surface. This epoxy will be sanded off the surface and then you will will be dealing with micro of even hardness and it will sand evenly. When I painted the raw epoxy on my finished surface and then sanded it, then the following could happen. If I found a high spot after that point and sanded it, then I would be sanding through the more dense epoxy and have a transition line between harder and softer materials. I want to have one density of micro.
There are places where you will have to come back and add some more micro on the previous micro, and then you will get a little difference in densitiy, but not much. The use of the brush and a little raw epoxy will really cut back on the
amount of third fill work and on pin holes.
Pics #2,3&5: I used clickbonds (placed through a glassed surface and not bonded onto and with a 1 ply BID overtop) for the ailerons and rudders and so I did some different type work on micro work. On the rudders, I taped over the hinges and clickbonds and marked the cut lines for the rudders. I keep the rudders on and applied the micro. I sanded and after I was 95% finished with the sanding, I recut the rudders and then did the last 5% of sanding with the rudders off. The contour of the winglets will be true to plans specs with this technique. You do have to be good with the dremel disk to do this. I used the flexible extension on the dremel to help on the work.
For the ailerons, I microed the wing with the hinges taped and the ailerons taped. After 95% of the wing was sanded, I taped the hinges and the wing side and microed the ailerons and did 95% of the sanding and then took off the ailerons for the last 5% of sanding. It's time to talk about sanding in the next section.
For the elevators, I did all of the micro work on them after taking them off the canards.
Pic #5. This shows a hinge after finishing of the outboard of the winglet and right before I touched this up with micro.
Pic #2: This the low area fill on the wing. Sanding has not yet been done.
Pic#3&4: This is right after the second fill with the use of a brush and raw epoxy to smooth out the micro.
Pic#1: SANDING: I did 95% of the sanding with a Bosch "Sheetloc" palm sander. This is only possible if you have very good lighting. I have eight sets of fluorescent lights in my shop and then I added the hand held light. I used 60 grit sandpaper for about the first 75% of the sanding. I added a vacuum hose to the end of the sander to help on dust. I moved the light at different angles to show contour. You need the light from above to prevent eye fatigue.
Pic #1-3: Here are more pics of the winglet rudder micro work.
1. I taped the hinges on the outboard side and taped under the "spur/stop" on the inboard side of the winglet.
2. I marked the lines for the re-cutout of the elevators. These sharpie lines must be preserved through the finish work. I have the lines marked on the masking tape also.
I held the rudder at the neutral position and added micro over the inboard cut line first and let that cure. This allows for a true shape of the airfoil from LE to TE.
The middle pic shows the hinge area after tape removal and before touchup. This technique also worked well for the forward LG cover.
Pic#1: After I took this pic, we, Joe and I, took the LG off to give more room to paint the bottom. With this elevated setup, we can paint the top and bottom of the fuselage without the flipping the plane work.
Pic#2: This shows the 1/8 inch thick plates screwed onto the 2x6 boards to add reinforcement. I added an "L" shape outboard 2"X6" to prevent a twisting action on the 2"X6".
Pic#3: I cut 1/4 inch thick aluminum pieces of 2020 allow and bolted them to the lift tabs hard points.
NOTE: I left some space between this metal piece and the fuselage hard points to allow the angle changes that came with the jacking up process at the rear. This saw horse is really well screwed together. I used four 1/4 diameter lag bolts on each "lift tab" piece. After this picture, I raised the front LG to prepare for painting. Since I did the interior painting first, I put another saw horse under the fuselage, just aft of the front LG to be extra safe.
I used the advice of Joe, my brother-n-law, for painting equipment selection. The low pressure HVLP systems are nice for saving a little paint, but the Zolatone will probably not work as well with that system. I wanted a gun that would spray Zolatone, primer and the finish exterior paint. I read that a builder used an HVLP spray system to apply Zolatone, but you are going to get too much "spitting" effect with the lower pressure. The Zolatone has microspheres of various colors intermixed with the base color and they make the output at the nozzle openings have more resistance as they pass through. A low pressure makes for a jerky stream, and that may account for the various ratings on this product. The Zolatone is perfect for the interior work. After Zolatone, there is no need for covering anything except for the seats.
The third pic above is of the Binks 2100. Aircraft Spruce sells the model 2001 and it does not have the air adjustment valve at the base of the grip. You really need that. I have a pressure feed tank hookup with a quart pot. The pot I got is listed as model FR-201 and I got six foot hoses to connect the two. The price was great at Paint Sprayers Unlimited.
The Binks 2100, 2 Qt Model FR-201 pot, and hoses cost just a little over $300.
The next piece of equipment needed is the mask. I got the Drager X-plore 3500 with the P100 filters (AS 12-02266) and ordered some extra P100 filters (AS 12-02260). You need the extra filters on hand. You don't want to max out the first set of filters and just carry on, because you are in the middle of a paint application and it takes three days to get more filters. With the filters the air is fresh smelling.
The biggest expense is the air compressor. You got to have a lot of air for the Binks 2100 and the Zolatone needs more pressure than the other paints, so I got the 30 gallon Kobalt at Lowe's ($429).
I used the Zolatone Desert Camo paint. If you use the Zolatone epoxy primer first then the durability is great. Zolatone is great at filling in the imperfections. After the first coat, I placed some micro in a few dip spots and painted the second coat. My armrest are fixed with access panels cut out to allow the removal of the FW area controls and so I made a smooth finish and rounded contours and the Zolatone is the final finish.
1. I started to get PPG Concepts White topcoat and use the PPG epoxy primer underneath and two things concerned me. If you take away the brand name "Concept", you still have a polyurethane paint with additives for UV protection. The "Omni" line from PPG is much less expensive, but does not hold up as well. I did not find reference to the "Omni" brand as being a polyurethane, but it must be, because that was offered as the "downgrade" choice to reduce price shock. Between the lines, it sounds like the expensive UV protective additive is the difference.
The TPI Polyurathane (from Aircraft Spruce) has the expensive UV protective additive that prevents the yellowing for sun exposure breakdown and is half the cost of the PPG "Concept" polyurathane. So, I got the generic and not the brand name.
2. The color chart at AS is great and I selected Lemon Yellow. I was going to use a second color, but AS could never get it off of backorder and after waiting two months for a gallon on Trainer Green, I cancelled the order for green and simplified the paint scheme. A better choice, as it turned out. So, order the accent colors way ahead of time, if they say that it is not in stock.
3. The use of the same reducer in the epoxy primer and the top coat of polyurethane is very important. The chemistry of the formula is hidden from us, but each reducer is different for that formula "family" of components. PTI offers a "Sandable" primer, but it does not use the same reducer "PT1003" (Type 2&1) as the Epoxy primer and polyurethane top coat. Here we go again with "branding" of chemical products. In this case, I don't have to know what the PTI folks mixed up in the reducer (thinner).
4. The product information downloads about the chemical makeup, the application, ect. is better provided for with PTI than the combination of the PPG site and the guy at my local auto paint store, "bless his soul".
Just be sure to print off all the linked info sheets. You need the one for primer application and top coat application. For example, the primer info sheet says to mix the catalyst and primer and let it sit for one hour, before applying.
PTI is sold by Aircraft Spruce
AS # Quantity
PTI Epoxy Primer Yellow Gal KT 09-00932 4
(catalyst is included in KT)
PTI Epoxy Thinner Reducer Gal. 09-00936 1
(The Alkyd & lacquer thinner PT1003 Gal 09-00942 is listed under reducers. But the part number given with the download page from PTI,on Solvent/Reducer shows that a PT-1003 TY 2 reducer, #09-00936, should be used. The AS site is not easy to use on this, and I will go with the PTI company information and not AS.)
PTI Polyure Insignia White (gal.) 09-17925-14 4
PTI Polyurethane Catalyst (gal.) 09-01256 4
PTI Polyurethane Thinner (gal.) 09-01658 1
(The download page on Solvent/Reducer form PTI shows this to be PT-1003 TY 1 reducer listed as 09-01658)
PTI Polykick 09-01610 2
(I plan on painting the wings outside and a 1% usage of this product will help speed the cure)
For me I wanted two colors added on the bottom of the fuselage and so I ordered 3 gallons of Insignia White and one gallon of Lemon yellow and one gallon of Cuby Sport Trainer Green. I hope that the "John Deere" look works out.
The Zolatone Desert Camo is wonderful stuff. Thanks goes to my brother-in-law, Joe, for doing this painting and starting the process of making me a painter.The pic of the cover forward of the IP shows how sharpie marks made after the glassing will bleed through. I came back and did some touchup work and covered the marks.
Summary of the ideal painting session. My last four sessions worked out like this.
Log of paint coats and quantity:
I mixed one gallon of primer with one of cat. and did two coats on the wings (including canard), FHC canopy, FWD of the TB, all control surfaces, front nose door, LG, canard cover and LG cover. I had more primer left over, so I did one coat on the rest of the plane (fuselage). (saw horse mounts were made priviously)
Minor sanding done over the whole surface with 220 grit, followed by minor micro fill with flexible steel spatulas. I used a palm sander for part of this and some hand sanding. Some more minor micro work on the FHC was done and sanded later in the week.
I re-sanded by hand with 220 grit on all surfaces. The left hand rubbed the surface and the gloved right hand used a half sheet to clean the surface. I sprayed the sufaces, brushed, and then wiped with clean Tee shirts. It had only been a week, but the surfaces still need prep work.
I mixed up 1/2 gallon of primer (&1/2 of cat.) and did two coats of wings, control surfaces, LG, FHC and FWD of TB and interior of the door and two covers.
I checked out the wings in the morning light and the right wing needed some more micro work on the top, so no painting today.
I applied primer on the micro work and a few minutes later, I did one coat of primer on everything except the control surfaces. Including all of the fuselage, except a small part of the left strake. It took 1/2 gallon (1.0 with cat.) of primer to do that.
After light sanding with 220, I applied a light coat of top coat and then a full thickness second coat and then the Cicadas started to land on the wet paint. The work still looks great, but I could not continue with the final coat, without some minor sanding. Also the pressure pot acted up on the pressure setting. So I will continue later. After the final coat of white, I will tape on the bottom of the wings and paint the lemon yellow color there. I mixed way too much white. I was able to use less than 1/4 gallon (1/2 with cat.) The next day, I bought two pressure pots at Harbor Freight. I had wasted over a $100 dollars worth of paint and the pots cost less than that. I recommend having a second pressure pot ready for backup. This aircraft paint is too pricey to waste. Next lesson is mix no more than 1/4 gallon (0.5 with cat.) at a time.
I will summarize the last week's work. I finished painting the plane (except engine cowlings, which are to be made after the engine install).
Outside work in the summer time is best to be done in mid-morning or late in the day.
1st day: I did the final white top coats on the top of the wings and TB, FHC. Since I had stopped half way through, due to equipment problems, this was a tack coat and two full thickness coats. I mixed one quart of Poly top coat(1/2 gal.)
2nd day: I used some 3M Vinyl Tape 471+ (1/2 inch wide) to tape for the transition from white to yellow. Here is my tape routine. After the Vinyl tape is placed on the transition point, I next placed two widths of 3M masking tape (2") that over lapped the Vinyl tape. Next I placed a 2" piece of packaging tape over the masking tape that overlapped the Vinyl tape and finally taped plastic over this to cover every last inch of surface of previous top coat.
3rd day: This sesson and the next three are finally working out like they should with no hitches.
I started writing a log of mix times and coat times. Today I did five coats of Lemon Yellow on the bottoms of the wings and on the LG cover and nose door in the AM and finished priming the fuselage in the PM. For both sessions, I mixed a "pot full" which is one quart (two with cat.).
4th Day: After a light sanding with 220 grit, I did five coats of Lemon Yellow on the bottom of the fuselage, strakes and on the nose area. (one "pot full")
5th Day: After light sanding of the overlap areas between colors, I taped off for the transition and did four coats of Insignia White on the top of the strakes and fuselage. I did four, because the fourth coat looked so good, that I did not want to risk having a five coat not be as good. (one "pot full").
After four hours, I pulled off the tape.
Finally I get to use some primer! The big concern is what is the finish going to look like and it's looking good.
Pic#1: Joe, brother-n-law, had to show my ghost one more time before they got painted over.
Pic#2: Beautiful Tennessee weather. We had two days of 85 degree sunshine and so we set up outside and painted. The trick is to make the saw horses on cloudy days and just get ready. I used 1/2 inch bolts recessed into some 2"X10" short boards and bolted them onto the wings and then screwed them onto the plywood piece mounted on top of the saw horse. The trick is making the saw horse the right height. The short ones are 31" tall and the taller one is 40" tall. I just set the canard on some cushions on saw horses and flipped it over after the top side dried in the sun and primed the opposite side. The LG is mounted on the table by using two long drill bits and safety wire and screws into an old table. Also in the pic are three covers, TB and FHC.
Pic#3: Control surfaces hung up. I tipped the edges over and Joe got the top and bottom painted first and I wore my mask.
Pic#4: This is just the first coat. We used up the first gallon (two gallons counting catalyst) painting two coats for all other surfaces except the fuselage and it got one coat. I will do one or two more coats of primer on everything and then go for the top coat. The first day we painted and in half a day of the next day we sanded with 220 grit and did some minor micro work and it's almost ready for the primer again. Once again, I used a palm sander and hand sanding. It helps at this point, if you were able to move the parts into the sunshine for the final sanding.
Note: With good finish work, it looks like 2.0-2.5 gallons of primer (4.0-5.0 counting cat.) will prime the whole plane. I bought four gallons.
Pic#1: The white area is the area where the FHC laps over the longeron and onto the side of the fuselage. There are two coats of primer (one light and one full thickness) and two coats of top coat (one light and one full thickness). This area gets taped off to limit the paint thickness there. So far I have three coats of primer on the rest of the exterior, but I am going to put one more coat of primer and three coats of top coat for a total of seven coats. That sounds like a lot, but the primer hides a "multitude of sins".
Don't chase the pin holes until after the second coat of primer. I used a small plasic syringe filled with light micro to squirt into the pin holes and immediately wiped off the excess. You should not be sanding on the nice flat surfaces for pin holes to be filled.
Sorry for the "chasing of rabbitts".
Pic#2: The brightness of the white paint makes photo work hard.
Pic#4: Wheel pants. The air inlet and outlet scoops are lined up for cooling of my b. pads. The reflections make a funny look on the white glossy finish.
Pic#5: Lower profile WP.
Pic#6: Strakes with three coats of primer. One more coat of primer will make it ready for the top coat. I can either place the top coat 30 minutes after that last coat of primer or let cure, sand and then paint.
Notes: Note: My stop action for the rudder is the "little extension" of the wing.
Note: My stop action for the rudder is the "little extension" of the wing.