W

Ward Johnson

Member
I have read some posts about waiting for the "40 hr run off" before painting the plane, and yet I see some photos of nearly completed planes with paint already, and some first time flight photos with paint.
I assume the 40 hrs is to allow the plane's skin to shift a bit due to stresses of flight. More likely the forty hrs is to allow the pilot to make changes to the airframe to stabilize flight. What is the true story?
 
40 hours is the traditional fly-off time that you're given by the inspector (these days, you frequently get 25 if you're using a standard engine/prop configuration, and for the most part haven't done something wacky). Many people wait until after this period is done to paint the plane. The reasoning is that:

1) if you need to make a change or something breaks, you want to take care of it before painting so you don't have to touch up.

2) your plane will be taken apart and reassembled in some form or another for inspections, tweaks etc... For example, it's not uncommon to have to remove the cowl multiple times while you get all the bugs out. Why subject the paint job to this, right?

3) it's a great excuse to just get it in the air and fly. Who the heck wants to wait for paint, right? There are lots of planes out there that have seen their fly-off periods come and go with no paint job in sight.
 
Ward Johnson said:
I have read some posts about waiting for the "40 hr run off" before painting the plane, and yet I see some photos of nearly completed planes with paint already, and some first time flight photos with paint.
I assume the 40 hrs is to allow the plane's skin to shift a bit due to stresses of flight. More likely the forty hrs is to allow the pilot to make changes to the airframe to stabilize flight. What is the true story?
Click to expand...

I know that for me (and others) there were three reasons for painting after the 25 hours:

  1. I had decided I really didn't want to paint the plane myself and didn't trust towing it to some auto paint place. Therefore - I'd need to fly to the paint shop.
  2. I could make little tweaks without worrying that the plane was already painted. This turned out to not really matter - no tweaks were needed.
  3. I wanted to fly the **** thing.
Out of these three factors, #3 was by far the biggest reason I chose to paint the plane later.
 
Prepping for Paint

Ward Johnson said:
I have read some posts about waiting for the "40 hr run off" before painting the plane, and yet I see some photos of nearly completed planes with paint already, and some first time flight photos with paint.
I assume the 40 hrs is to allow the plane's skin to shift a bit due to stresses of flight. More likely the forty hrs is to allow the pilot to make changes to the airframe to stabilize flight. What is the true story?
Click to expand...
Several hours into my 25 hour run-off phase, I heard a loud vibration emanating from beneath the aircraft. I slowed the aircraft down and headed for home. Upon landing I discovered the (2 piece) wheel pant intersection fairing starting to come apart because I originally butted the parts together and this builder induced design flaw allowed high speed air to find its way between the parts and work its inevitable magic. It peeled part of that brand new after-market fairing away and it flapped like a reed in the wind. I reworked the fairing with a few layers of cloth so the forward section overlaps the aft part of the intersection fairing and the problem was quickly resolved. I would have been dismayed to have already invested in an expensive paint job before discovering that flaw.

In theory, there is some chance that flight testing may uncover the need to readjust the incidence on the horizontal stabilizer. Imagine the empennage fairing rework that would subsequently entail! Most would agree they would much rather have that expensive paint applied after discovering and rectifing such a problem rather than having the paint shop rework the area later.

Rick Galati RV-6A "Darla"
 
Lots of stuff

Rick6a said:
Several hours into my 25 hour run-off phase, I heard a loud vibration emanating from beneath the aircraft. I slowed the aircraft down and headed for home. Upon landing I discovered the (2 piece) wheel pant intersection fairing starting to come apart because I originally butted the parts together and this builder induced design flaw allowed high speed air to find its way between the parts and work its inevitable magic. It peeled part of that brand new after-market fairing away and it flapped like a reed in the wind. I reworked the fairing with a few layers of cloth so the forward section overlaps the aft part of the intersection fairing and the problem was quickly resolved. I would have been dismayed to have already invested in an expensive paint job before discovering that flaw.

Rick Galati RV-6A "Darla"
Click to expand...

I was thoroughly in the camp of painting before flight. I'm not anymore. Like has been said there are many things to crop up during the fly off. The problem is being disciplined enough to take it out of service for painting. I made a commitment that I wouldn't take my plane to anything important unpainted!!!

My first flight with all the extras (wheel pants, fairings, intersection fairings) resulted in the rear half of the right wheel paint fairing departed. It might have been the 198kt ground speed down the runway!!!!

I made overlapping cuffs on these parts so no air can get it and cause problems.
 
I painted everything except the wheel pants, prior to flight. I made no modifications to the airframe, used new conventional parts, and basically built it per Van's recommendations. I had no squawks during ground or flight testing that would have led to changing anything that might spoil the paint. It was a lot easier to paint the plane in pieces, then assemble it.

If you are doing a lot of experimenting with airframe or engine components or are not painting it yourself, waiting to paint makes more sense. If you are doing a basic Van's standard, and want to paint it yourself, then painting during construction works well, especially if you have the extra room for the spray booth during construction.

JMHO

Roberta
 
It seems to me that painting the bottom of wings, fuselage and tail might be a bit hard to paint once all assembled. (runs, hard to reach etc) What if you just painted the bottom and other parts that won't ever be subject to paint damage, then painted the rest after all the bugs worked out? I've often thought about this, am I missing something?
 
to paint or not to paint

I plan to paint my aircraft as pieces before final assembly. I also plan to paint it myself. I know another RV builder that just finished the final assembly and he painted it in pieces. Beautiful work. Half of my garage will become a pressurized paint both. (don't tell my wife - she doesn't know yet). The large parts (as stated earlier) are much easier to paint when you can rotate them around - top to bottom on a rotisserie. I don't think I'll ever "dismantle" my aircraft once it has been put together for the test flying. As for the cowl removal and knicks and dings - well - you're gonna have to change the oil eventually. For anything else - be extra careful and get some help. My $.02
 
While it's still all very fresh in my mind...I'd suggest painting afterwards. I have not seen any problems with the paint but the logistics are a killer if you do it at the homestead.

One thing I'd highly recommend is sealing the lap joints of the skins prior to flying anywhere. That oil mist is going to get into areas you can't see. It'll seep out from under the seams...and maybe..under the paint. I did this whole thing in the garage. Knowing that before hand forced me to make sure EVERYTHING was right. Incidence, fairings, canopy, tail, rudder, flight controls and all those.."put off until its at the airport" things had to be done.

If I had the room or a place out of sight and mind from on-lookers, I'd have preferred doing it after flying a bit. On the other hand, some extra hard work during the build will make it much easier at the end.

This and other photos were taken before the first flight. It flew the next day and has flown the 40 without anything other than a trim change. The only other issues were instrument calibrations that I screwed up while playing too much in the garage :eek:

http://www.experimentalrv7.com/paint.htm

rvglare.JPG
 
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