The weight of paint?

[GusBiz]

So a while ago someone told me "Gus, every idea weighs something??

I have a few gadgets I would like to add and I am knocking off the ones I think are just too heavy or too silly, (oddly they are often the same item)

So as I am adding all of this weight together it occurs to me that paint could be more weight than any of the other ?ideas? that I have thought of.

The surface area of the plane is not small and there is a wide range of paint jobs from a light coat to a custom show room finish.

I am looking more for the second one so I would be looking for the following (Welcome to the heavy and most likely stupid item)
So this is what would be involved I have been told;

1. Primer layer

2. Filler of surface imperfections
(or as we know it here in Australia, Bog?don?t even ask where that came from)

3. One to two coats of Base Colour

4. Three to four coats of clear that will be then cut and polished into a serious nice paint job

Now all of that may be too much and I know a lot will talk about flutter issues with the Emp, that Filler will be my biggest mass item, that I don?t need four coats of clear etc.

I would like to hear all of that. Bring it on guys; tell me how wrong I am because I might as well hear it now instead of regret not having heard it later.

Also please add the difference in weight that paint made to your aircrafts and please add what kind of paint job it was. A Base with one of clear or the overdone job I am intending on doing

PS. Does anyone know if certified aircraft is tested before its painted or after? I would assume after but I am interested in the whole "but what if you have to change something" discussion

[Walt]

From what I've seen, the average RV tends to gain about 20-25lbs for single stage 2-3 color paint job. I'm sure if you add more colors and lots of clear it's gonna gonna weight more.

[Mel]

The weight that paint adds has a lot to do with how it's applied. i.e. Auto paint shops typically use much more paint than a professional aircraft painter.
I once inspected two RV-10s that were built side by side with the exact same equipment. One was painted by the builder and the other was painted by an auto paint shop.
The one painted by the auto paint shop was 20 lbs. heavier than the one painted by the builder. Both paint jobs were beautifully done.
18-25 lbs. should be a good number for paint.

[rv8guy]

I weighed my -8 with the same scales before and after getting painted by Grady at 52F. I was at 1064 prior and 1096 after, with a small CG shift. The paint remains awesome and still draws a crowd after 5 years. That was Sherwin Williams material put on by a pro.

32 pounds for paint seemed about right to me, and I wouldn't change a thing. I fought many urges to add other stuff, and have the small battery, Grove Gear, and WW 200RV prop

[hydroguy2]

I didn't weigh mine before paint so don't actually know the paint additional number. But N155BK came in at 1095# after paint. 3 colors Base/clear coat sprayed by a Auto painter(that has shot 20 airplanes). I worked with Corky everyday for a month, he knew to keep it light and also knew I was going for a deep shine. We used thin coats, the yellow took 3 to get proper coverage, purple and green were only 2. Then for the clear I questioned the choice of only going with 2 clear, he said if we put it on correctly there will be no buffing, no filling in of the rivets and will be lighter.

I couldn't be happier.

[az_gila]

Originally Posted by GusBiz

....
PS. Does anyone know if certified aircraft is tested before its painted or after? I would assume after but I am interested in the whole "but what if you have to change something" discussion

I visited the Piper Vero Beach factory at it's height in the 70's and one thing still I specifically remember is the line of unpainted planes outside, all with the same N-number rattle can painted on...

The Cherokees were definitely tested unpainted.

[Greg Arehart]

My Rv-9 gained ~30 lbs with a 3-color Imron paint job done by a professional. No clearcoat. I say about 30 because I made a few other mods between the time I first weighed it and then weighed it again after paint. Total weight is 1122.

Greg

[Bob Axsom]

You already know the weight will increase 30 to 40 pounds with a beautiful paint job so you have the basic answer to your question I think. Perhaps surprisingly the weight is not that big a factor in cruise - maybe you know that. Dave Anders if a very famous RV-4 builder with extreme attention to detail including weight. He built his RV-4 with natural aluminum finish and red paint trim stripes and spinner. He flew it for years this way but now the aluminim is covered with white. The plane is described in a decades old Sport Aviation article - I can look it up if necessary - I still remember reading about him temperature controlling the rivets until installation in a dentist oven - detail!!! He set the RV Gold class record 240.58 mph in the AirVenture Cup race in 2010 painted.

When I worked at McDonnell Aircraft in St. Louis starting in 1958 the F-101 had a natural aluminum finish, The F-4 Phantom II was painted with epoyx, and the F-15 was painted with polyurethane. When I built our RV-6A I flew it for a year with no paint except for a thined epoxy resin brush on coat of the fiberglass cowl and fairings. I loved to fly it that way as it seemed very military utilitarian with no polish. I experienced no deterioration so either way works. I am sure in my own mind that the protection and appearance benefits of the weight are worth the sacrifice.

I know that is not directly responding to your original question but I think it is relevent to the bigger question.

Bob Axsom

P.S. The rule of thumb on the effect of weight on cruise speed is 1 kt per 100 lbs.

[GusBiz]

...snip...The one painted by the auto paint shop was 20 lbs heavier

Wow that is way more than I thought an over done paint job would have been, Thanks Mel.

...snip... I didn't weigh mine before paint so don't actually know the paint additional number. But N155BK came in at 1095# after paint

Brian, I am glad you replied. I have probably every photo of your aircraft saved to my hard drive, while my colours will be red black and white, I have decided that your scheme is the way to go. Consider your design stollen! :-). That is a really light weight by the way, considering with paint for both you and Marshall. Good job guys.

Gil,

Got it, I am now going to test before I paint.

Can I ask about rivet filling? I have seen some paint jobs where virtually EVERY rivet has been filled over to create what looks like a composite quality surface. When I saw that the thought I had was "That has GOT to weight a tonne...how could it not?!?"

Is that the case or is the real world amount you use to create a flat surface over a rivet minimal.

Thanks as well to Greg and Bob. Much appreciated

[Mel]

Filling rivets adds weight and lots of labor. I did it on one airplane. It really looks nice but I would never do it again.