W&B and Paint

[Mcstealth]

I talked to a Mooney guy the other day. With direct knowledge of the question, he said that the new Mooney's come back from the paint shop weighing 50 lbs more than before they flew to the paint shop. The spread is between 2-4 lbs between planes curiously. 

I'm sure a lot of you guys already know this fact.

I wonder what the weight difference was with some of you guys that did a strip and repaint?

Thanks

David

[ArtVandelay]

I know for a fact when my plane was repainted they didn't strip it first, I've been told my plane would take 5 gallons, at about 10lbs per gallon that confirms my estimate. I may have to leave it outside for a couple of years to save up money for a paint job.

[Hank]

I would expect the weight variation to be differences in paint schemes--number of stripes, size of numbers, metallic content, etc. But I would not have guessed 50 lbs!

[DonMuncy]

I don't think they did a W&B on my plane when they stripped and painted it. Maybe they thought they stripped off a three color paint job and replaced it with a three color one, so it came out even  

[Rookie]

Can someone that owns a 77' J post a sample of their weight and balance form with arm numbers on it?

[Parker_Woodruff]

A late model C172 has about 16 pounds of paint per the W&B, IIRC.

[jetdriven]

On July 24, 2016 at 10:42 AM, teejayevans said:

I know for a fact when my plane was repainted they didn't strip it first, I've been told my plane would take 5 gallons, at about 10lbs per gallon that confirms my estimate. I may have to leave it outside for a couple of years to save up money for a paint job.

Sure, 5 gallons but a third of that ends up in the air if they aren't using an HVLP spray setup. 

[Hank]

2 hours ago, jetdriven said:

Sure, 5 gallons but a third of that ends up in the air if they aren't using an HVLP spray setup. 

Don't forget to subtract the volatiles, too. Ain't nothing left but the solids when it's dry. 

[Raptor05121]

On ‎7‎/‎24‎/‎2016 at 10:08 AM, Mcstealth said:

he said that the new Mooney's come back from the paint shop weighing 50 lbs more than before they flew to the paint shop.

50 lbs? I think this is a stretch. I've heard that 737s take ~200lbs of paint, and that's a WHOLE bit bigger than an Acclaim.

Do they install anything or add anything at the paint shop? Interior carpet/components/etc?

[DXB]

I don't get why it wouldn't be roughly even if it was stripped.   Maybe I could believe one has to spray about 50 lbs of liquid paint from the can.  Any paint shop guys or other folks with real world experience on this care to weigh in?

[jetdriven]

I think it is.  We didn't re weigh it after paint. 

[RLCarter]

5 gal. / 50lbs seems a bit much, as far as painting a 4 place aircraft goes, plus the control surfaces need to be rebalanced to avoid flutter and it also needs a new weight n balance done. 

[jetdriven]

New weight and balance is not required, AFAIK. 

[RLCarter]

20 minutes ago, jetdriven said:

New weight and balance is not required, AFAIK. 

for part 91 i don't think so either all the others I believe its required every 2 years regardless of any changes or not 

[Guest]

Re weighing after painting may not be required, but it would be a good idea.  Very few airplanes lose weight over the years, just like humans.

Clarence

[DonMuncy]

I would be really interested in seeing/hearing about owners who have weighed their planes and compared to the calculated weight in their log books. I understand that the factory did not really weigh each plane, but weighed one and used that for all the ones that matched that one in equipment. Or maybe they weighed one and calculated the rest from the equipment. Either way should yield numbers very close to actual. Then all the little errors that get calculated, and all the little things added that "didn't justify" and change in W&B, would make one guess that most planes are heavier than calculated. But it would be interesting to see if this is borne out by actual weighing.

If you don't want to fess up to weighing but not recording, you might tell us how "your friend's plane" came out.

[DonMuncy]

Or PM me and I will let the forum know the results without identifying anyone.

[RLCarter]

Just did a weigh in on my "E" (don't have the numbers in front of me) but I do remember it being right at 100lbs heavier than it was when rolled out of the factory, the number that did stick in my head is the nose wheel, was 471lbs the same as it was 51 years ago

[Mcstealth]

On 8/4/2016 at 11:11 AM, DonMuncy said:

I would be really interested in seeing/hearing about owners who have weighed their planes and compared to the calculated weight in their log books. I understand that the factory did not really weigh each plane, but weighed one and used that for all the ones that matched that one in equipment. Or maybe they weighed one and calculated the rest from the equipment. Either way should yield numbers very close to actual. 

Asked my source about this. 

Each plane is weighed individually. There are three scales embedded into the floor. The nose scale is lower than the mains scale. The plane is rolled onto the scales and a large straight level is placed on two previously installed engineering mounts, that are at the calculated center of the airplane. The plane is then made to simulate straight and level flight. They accomplish this by either inflating or deflating the front tire. All three weights on each tire are then collected and a baseline W & B is established before painting, and then again after painting and all equipment is installed.

Planes equipped the same are usually within 2-4 lbs of each other, and said it was because of the paint. 

DF

[Mcstealth]

Fuel measurements are accomplished the same way, by inflating or deflating a main tire, to where the wings are level, and then fuel is added by weight and recorded.

df

[dooleypster]

Part 135 aircraft are required to be weighed every 3 years, but I don't believe this applies to part 91 ships as most of the Mooney fleet is.

 

[DonMuncy]

 

1 hour ago, Mcstealth said:

Asked my source about this. 

Each plane is weighed individually. There are three scales embedded into the floor. The nose scale is lower than the mains scale. The plane is rolled onto the scales and a large straight level is placed on two previously installed engineering mounts, that are at the calculated center of the airplane. The plane is then made to simulate straight and level flight. They accomplish this by either inflating or deflating the front tire. All three weights on each tire are then collected and a baseline W & B is established before painting, and then again after painting and all equipment is installed.

Planes equipped the same are usually within 2-4 lbs of each other, and said it was because of the paint. 

DF

Thanks David. The information I had been given was obviously in error.