Marty d's CH-701 build log

[kgwilson]

Matte black is best from a reflective perspective and each instrument stands out better. Have a look at most modern cars. The dash is almost always black. It does get warm though in the hot summer sun. Matte black is also easy to touch up by hand if you get marks or scratches on it.

[bexrbetter]

but my wife said she thought white would be better.

 

Are you even allowed to say that these days?

[M61A1]

Are you even allowed to say that these days?

From the previous media sh1tfight... apparently it's not even OK to say "it's OK to be white".

[IBob]

Marty, reflectivity matters more or less depending on position and angle of panel vs pilots eyeballs.

So, for instance, my panel is gloss grey (I know......gasp!) and I have no problems with reflection from it.

 

There's probably pros and cons with any colour.

And endless opinions, variously rigidly held

Here, for instance, is one suggesting that black or white are not suitable:

 

"Basically, neutral mid-toned greys or tans are considered to be the best color to use, because they aren't any other color:

• The base color shouldn't be confused for anything in an instrument display. This precludes using red, yellow, green, bright blues or brown, but also black and white as black is used to represent empty space in instrument displays while white is commonly text and also used for other display elements.
  
• The color shouldn't cause glare. Too light a hue will increase sunlight scattering in the cockpit, reducing pilot visibility in high-sunlight situations.
  
• The color shouldn't be too dark, as in those same situations a dark color will absorb the sunlight and become hot, increasing ambient temperature of the flight deck, requiring additional cooling system capacity for both pilots and instruments (many civvie aircraft have black instrument panels, but other elements of the design typically prevent the panel catching too much sunlight).
  
• The color has to be relatively easy to find or make, allowing touch-ups. Brighter colors are harder to match exactly; neutral tones blend easier and aren't as distracting even if they are slightly mismatched. This is mainly a military concern, where crew chiefs do what they can with what's on hand; commercial airliners will have hundreds of gallons of their livery colors and other standard touch-ups including cockpit-approved colors available at maintenance hubs.
  
• Western thought says the color should be visually uninteresting in order to provide the minimum distraction to the pilot from more important colors in the cockpit. This is where Western and Russian thought primarily differs; Russian designers favored a "mood color" over being completely nondescript, while Western designers favor the background color "disappearing" even if the net effect is depressing to a pilot sitting in it for several hours a day.
  

To be fair, Western cockpits are not always grey or tan, but really there are only a couple more common options. European Mirage, Rafale and Gripen fighters are commonly seen with a sky-ish blue interior, providing some of that mood color benefit while remaining nondescript. Aircraft cockpits in WWII, on all sides, were painted in whatever the crew chief had available, which usually amounted to land-based planes getting the same olive drab that coated every piece of metal the Army owned, while naval variants got one of the various blue-grays used on the ship itself."

 

I reckon the 'correct' answer is whatever you personally really like looking at. As I see it, the perfect colour scheme is the one that gives you pleasure every time you roll open the hangar doors..........)

[M61A1]

Marty, reflectivity matters more or less depending on position and angle of panel vs pilots eyeballs.

So, for instance, my panel is gloss grey (I know......gasp!) and I have no problems with reflection from it.

 

There's probably pros and cons with any colour.

And endless opinions, variously rigidly held

Here, for instance, is one suggesting that black or white are not suitable:

 

"Basically, neutral mid-toned greys or tans are considered to be the best color to use, because they aren't any other color:

• The base color shouldn't be confused for anything in an instrument display. This precludes using red, yellow, green, bright blues or brown, but also black and white as black is used to represent empty space in instrument displays while white is commonly text and also used for other display elements.
  
• The color shouldn't cause glare. Too light a hue will increase sunlight scattering in the cockpit, reducing pilot visibility in high-sunlight situations.
  
• The color shouldn't be too dark, as in those same situations a dark color will absorb the sunlight and become hot, increasing ambient temperature of the flight deck, requiring additional cooling system capacity for both pilots and instruments (many civvie aircraft have black instrument panels, but other elements of the design typically prevent the panel catching too much sunlight).
  
• The color has to be relatively easy to find or make, allowing touch-ups. Brighter colors are harder to match exactly; neutral tones blend easier and aren't as distracting even if they are slightly mismatched. This is mainly a military concern, where crew chiefs do what they can with what's on hand; commercial airliners will have hundreds of gallons of their livery colors and other standard touch-ups including cockpit-approved colors available at maintenance hubs.
  
• Western thought says the color should be visually uninteresting in order to provide the minimum distraction to the pilot from more important colors in the cockpit. This is where Western and Russian thought primarily differs; Russian designers favored a "mood color" over being completely nondescript, while Western designers favor the background color "disappearing" even if the net effect is depressing to a pilot sitting in it for several hours a day.
  

To be fair, Western cockpits are not always grey or tan, but really there are only a couple more common options. European Mirage, Rafale and Gripen fighters are commonly seen with a sky-ish blue interior, providing some of that mood color benefit while remaining nondescript. Aircraft cockpits in WWII, on all sides, were painted in whatever the crew chief had available, which usually amounted to land-based planes getting the same olive drab that coated every piece of metal the Army owned, while naval variants got one of the various blue-grays used on the ship itself."

 

I reckon the 'correct' answer is whatever you personally really like looking at. As I see it, the perfect colour scheme is the one that gives you pleasure every time you roll open the hangar doors..........)

I think one might find that many of greens , greys, blue/ green or combination are primers of the era. Most of the US aircraft I’ve worked on have yellow/ green primer of zinc or strontium chromate and the euro stuff has a bluey green/ grey sort of primer in most internal stuff.

 

Totally agree with the “correct “ colour.

[kgwilson]

If you find that after you have painted it you don't like the correct colour all you have to do is find another correct colour and repaint it. Simples.

[Marty_d]

Are you even allowed to say that these days?

If she was talking about that, I reckon she'd say black is better.

[Marty_d]

Well, in the end I went the same way as Mark and bought some Hammertone for the panel. Haven't applied it yet. Probably wait until I get a radio - which is another discussion!

 

In the meantime I finally got the 80 degree water pump housing tube to the number 2 cylinder and put it in tonight. Put it all back together and the hoses on.

 

I got a business called Flexible Drive to make me up some throttle cables & outer tubes, along with choke. Going to pick them up tomorrow so with luck should have that hooked up soon.

 

What else? Made the curved piece that rivets to the top diagonal cabin tube (I believe Savannah's use 2 for this, which would look prettier) and it tensions up the top screen nicely. Reckon I'll lay a very thin strip of rubber on top, or a bead of silicone, before permanently fitting the screen.

 

Starting to think about painting and I reckon I should probably do that before doing too much more at the front end. At the moment it's not too much trouble to remove the engine and get everything prepared, if I keep hooking up stuff it'll just get more difficult to remove it all again... (All your painting advice gratefully received - as long as it's not "get someone else to do it" - I can't afford a professional! It'll be plain white in any case.)

 

[M61A1]

Download a copy of the AC 43 and read on how to safety using split (cotter) pins.........link below

 

https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentid/99861

[bexrbetter]

 

What else?

 

 

If you need ashtrays, I'm your man!

[Blueadventures]

Agree, M61; same thought when I saw the image. Marty you will need to turn 90 degrees so head goes into slot and bend is over the nut side and other back over the bolt end. All need to be this way. Comment to assist you. Cheers.

[IBob]

Marty, I did my own paintwork, found it pretty daunting but it came out ok. Since I'm not skilled with the gun, I put some thought into mounting/tilting the various parts so I was always spraying at an easy angle.

 

For the wings I made a couple of supports so that the surface was tilted at 45deg towards me. I would then lift this flat immediately after painting to get it away from the floor and also to minimise runs (an excess of paint can make for a run at each rivet).

 

For the fuselage, I put a rope from the shed roof, crossed, over and round the engine mount, back up to the roof. With this in place I was able to lift and rotate the fuselage by the mount; once the weight was back on the rope, it gripped the mount and so held the fuselage at an angle. You can only get the fuselage over so far this way, as most of the weight is in the belly. I should also mention that I had a temporary 'undercarriage' a piece of 4x2 , bolted on through spacers, which kept the fuse clear of the floor while I messed with the rope.

With all this in place, I then painted the fuse in 4 sessions, one side at a time, masking the rest out as required. For masking I used the thin poly film with the tape already attached at the edge, comes in a roll from paint shops.

 

For the painting, you cannot have too much light: if you look at spraybooths where they do the flash jobs, the walls and ceiling are all lights. The only way to see how the paint has gone on is by looking at reflection of lights in the surface.

In my case, I had strip lights all down one side (only) of my spray tent, behind me when I was spraying. So I would spray, then quickly move round the other side of the job so I could check the reflection of the lights. If you are quick, any dry spots can then be fixed by spraying thinners on the affected area, though you need to be careful this doesn't make runs if the job is tilted.

I bought a decent gun, and am glad I did. I also bought a measure for paint/hardener/thinners mixing: it's just a ruler with big clear markings. I started off with a set of DIY ladles for mixing, but found the measure more accurate and far less messy.

I also bought tack cloths for final dusting before painting. And I ended up with a full-face mask, hooded disposable overalls, and gloves. Prepsol is good for cleaning overspray off the mask. Meths and water is good for cleaning aluminium.

I won't say anything here about actual paint systems: it seems everyone has firm views about about what is 'right', and no two of them seem to agree. Good luck!

[IBob]

PS if you're going for white, do not use a white primer/undercoat: it makes it near impossible to see how the topcoat is going on as you are spraying...........

[Bruce Tuncks]

It took me a lot of deciding to choose acrylic over 2 pack. The disadvantages of 2 pack are that it kills you and, mainly, it adds about 5 kg more weight. Of course, 2 pack does look better.

[IBob]

Hi Bruce, I wouldn't dispute that 2 pack is dangerous stuff. There are ways to mitigate that with suitable gear and ventilation, but basically you are right.

 

I would dispute the extra 5kg (unless acrylic is very lights?) The weight of my Savannah with 2 pack is almost exactly the same as the weight of another local Sav with lacquer.

[kgwilson]

I did my own painting. I'd never spray painted anything before except from a spay can. There are some good youtube clips on spray painting. I bought a HVLP spray gun kit via Ebay. It was cheap and as good as expensive ones I found in the shops. There are 2 guns, one for touchups or small jobs & a large one. I also bought a water filter to remove humidity from the air supply. This attaches to the gun itself. I used Prekote to prepare the aluminium. It is non toxic & is used by all manufacturers now in place of alodine which is highly toxic. Primer/undercoat was one pack Hi-Chem super etch grey. The base colour white was a 2 pack Dulux Luxathane and the metallic blue was Dulux Quantun FX. I had to buy the minimum 4 litres of the blue & it wasn't cheap $450.00 in 2015. I've still got half of it.

 

I did it all in my hangar. I cut a hole in the back wall & stuck a great big industrial fan it it to suck air through but had the doors open to get plenty of light. I hung the wings and other bits from the ceiling & made a rotisserie for the fuselage bolting the front to the prop flange & the rear to a welded jig attached to the stabiliser spar. It didn't work as it put too much stress on the engine mounts. I laid the fuselage on its side to paint the bottom & then painted the rest of it upright. The only runs I got were on the wings when it was windy & I had the doors shut so the light was poor & so was my painting.

 

Painting the stripes was a mission. The whole fuselage had to be masked and covered but it was better than vinyl as I could not get the correct colour.

[M61A1]

Agree, M61; same thought when I saw the image. Marty you will need to turn 90 degrees so head goes into slot and bend is over the nut side and other back over the bolt end. All need to be this way. Comment to assist you. Cheers.

 

My preferred option is pin 1. If you've ever had a long thin split pin slide up and under the skin on your forearm or the back of you handwhile work on an aircraft in a confined area, you will appreciate it.

Edited March 18, 2020 by M61A1

[turboplanner]

The disadvantages of 2 pack are that it kills you.

"can" kill you. It doesn't if you wear the correct mask (I'll leave anyone wanting to paint in two pack to check the respirator specification)

The respirators aren't expensive.

The benefit of the paint is it's more chip resistant.

[turboplanner]

My preferred option is pin 1. If you've ever had a long thin split pin slide up and under the skin on your forearm or the back of you handwhile work on an aircraft in a confined area, you will appreciate it.

For someone who builds and aircraft, and is then qualified to service it, training in the basics, like this, would improve reliability by a huge margin.

Cotter pins don't need servicing every day, but things like setting a carburettor float/how to measure with a menuscus etc. are the types of things needed.

[IBob]

Temperature is also very important for painting:

I painted during a cooler part of the year, but my spray tent (which was inside my workshop) had 2 small kitchen-type extractor fans to the outside. While these did not move a lot of air, they actually worked very well, steadily removing the mist and fumes without stirring up dust or creating undue air disturbance. And, by happy accident, I discovered I could easily raise the temperature inside the tent by cutting a rectangular hole at the opposite end to the fans, and positioning a 2.3kW domestic radiator in the hole: the fan action drew air in past the radiator, and once that had fully heated up, the temperature inside the tent rose steadily.

I would generally start mixing paint when the dollar thermometer on the wall reached about 24'C, and turn the heater half off when I finished painting maybe 15 minutes later, by which time the temp would be 27 or 28'C.

 

Fortunately, aircraft are made of aluminium (or fabric): I went to watch a truck being painted, and they heat-soaked it for hours beforehand to ensure the steel was all up to temperature.

[M61A1]

For someone who builds and aircraft, and is then qualified to service it, training in the basics, like this, would improve reliability by a huge margin.

Cotter pins don't need servicing every day, but things like setting a carburettor float/how to measure with a menuscus etc. are the types of things needed.

Agreed....That's why a bit of study of the AC 43 is a worthwhile exercise before even starting. It covers the acceptable methods of just about everything.

For the most part a cotter pin installed and vaguely bent will not fall out, but is will catch on other things, like wires, hose and maintainers digits.

I saw a guy recently who is building and will require quite a bit of rework because he didn't understand the importance of edge distance in riveted structures.

In regard to the carb float, I understand what you mean, but it's largely irrelevant with Rotax stuff and most two strokes. Rotax insist that you buy a $90 gauge to set the float arms in the Bings on the 912. Two stroke stuff is generally a set dimension of the float arms without regard to the actual fuel level.

[Marty_d]

I'm about to open my mouth and show my ignorance...

 

The engine I bought is second hand out of a training aircraft. Do the carb floats need resetting before use? (There's a lot of setting up to do and I haven't watched the entire Homebuilt Help DVD yet - although I don't think the installation one goes into a lot of mechanical detail).

 

Thanks for the info on the cotter pins. They're not in permanently yet (that one was a trial bend, the others just have them straight through unbent for now).

 

Bob, fantastic job on the paint and thanks for the setup info - the heater on one end and fans on the other is a good idea.

 

Oh, I went into Flexible Drive and picked up the cables. It's good work and will fit the existing engine ends, with new stop/adjusters where the throttle pulls on the pair. Will take some photos after I install.

[Kyle Communications]

I was not even aware of AC43 until I did the MPC course via SAAA so if The Mistress has to be registered under VH I can fully maintain her and also do W&B. AC43 was also shown and spoken about and used at the L1 course I did the 2 weeks after the MPC and it is a must for anyone. Its downloadable for free but extremely cheap is you want a hard copy. It is available from Amazon.

The Rotax owner site is a great resource as well..its worth the subscription for all the data and manual and SB and videos on the site. I am sure it has the info and videos on the site

 

 

 

The full soft copy is available for the original and the new addendum 2B at the bottom of the pages below

 

https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentid/99861

https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/document.information/documentid/74417

[M61A1]

Do the carb floats need resetting before use?

They should only need setting after component replacement. Like floats, float arms or needle and seat. However if you find you have issues that could related to float bowl fuel levels, that's a good place to start.

[IBob]

Hi Marty, thank you for the positive comments, and I would like to suggest this: don't give up on the idea of colour.

 

I had lots of people tell me 'just paint it white, then stick on some printed stuff'. And it was tempting.

But I also have a mate I used to do shopfitting with half a lifetime ago. And he said you want to enjoy looking at it every time you open the hangar doors.

 

It took me ages (months, years while I was building) looking at pics of Savs online, to settle on the (very simple) colour layout. And it's anything but original: heaps of Savs are painted exactly that layout. But to me it looks good, and it just works on the shape of the aircraft. I think that's important: a layout that looks good on one type of aircraft can look rubbish on another.

Then it took me ages to find the blue. In fact I couldn't, and in the end I rounded up my shopfitting mate and we went to Mitre10 and looked at all the housepainting colours, got the colour card and I had the colour mixed.

 

The masking was very simple. I really, really enjoyed putting the colour on, it was much easier to see than the white. And I've ended up with an aircraft I really enjoy looking at, and that gets heaps of positive comments.

I think if I'd painted it white and stuck on some decoration it would have been just another hohum white aeroplane.

After all that time and effort, I reckon it's worth that little bit extra.........