Empty Weight Wrong???

How to keep the Cessna 170 flying and airworthy.

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MeeksDigital
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Post by MeeksDigital »

4stripes wrote:My empty weight is 1324 lbs. This does include oil and unusable fuel. It is a 1952 with some radios, transponder, nav/com, loran, wheel pants.
Cheers Eric
same here, well almost, minus wheel pants and one radio. Empty weight on N5LP is 1319 from what I remember. 1400+ sounds waayyy high!
-Trevor Meeks

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1950 Cessna 170A N5LP, Horton STOL, 180 Gear
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bsdunek
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Post by bsdunek »

N9149A wrote:I should have noted my second set of number included unusable fuel besides paint and avionics.
Does anyone have any numbers on the change in W&B for paint? I recall this discussion back in 1952 when Dad painted the 170. No weight change was logged then, and none when I stripped it in 1987 (my AI said if we didn't add it, we didn't need to remove it!). Now that I painted it again, the paint shop didn't change the weight - just added the fact that it was painted and inspected.

Not that I'm worried - we all forget about the tools and spare parts we carry in the back - don't we? And that's probably more than the paint. 8)
Bruce
1950 170A N5559C
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jrenwick
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Post by jrenwick »

I wish I new how much my paint weighs, but I'm prepared to be surprised how heavy it is. My empty weight is 1410 with Imron paint, Horton STOL additions, tail pull handles, extended baggage, and an interior treatment that looks like it's heavier than stock.

John
John Renwick
Minneapolis, MN
Former owner, '55 C-170B, N4401B
'42 J-3 Cub, N62088
'50 Swift GC-1B, N2431B, Oshkosh 2009 Outstanding Swift Award, 2016 Best Continuously Maintained Swift
N2865C
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Post by N2865C »

jrenwick wrote:I wish I new how much my paint weighs, but I'm prepared to be surprised how heavy it is. My empty weight is 1410 with Imron paint, Horton STOL additions, tail pull handles, extended baggage, and an interior treatment that looks like it's heavier than stock.

John
On a 140 the paint comes in somewhere around 25 lbs. I would guess it would be around 45 lbs or so on a 170.
John
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jrenwick
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Post by jrenwick »

Hard to imagine how something paper-thin can weigh so much, isn't it? How big a stack of paper weighs 25 pounds? On the other hand, a solid stack of plastic sheets....

John
John Renwick
Minneapolis, MN
Former owner, '55 C-170B, N4401B
'42 J-3 Cub, N62088
'50 Swift GC-1B, N2431B, Oshkosh 2009 Outstanding Swift Award, 2016 Best Continuously Maintained Swift
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GAHorn
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Post by GAHorn »

I think red paint is lighter than other colors. :lol:
'53 B-model N146YS SN:25713
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cfiatzph
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Post by cfiatzph »

Things I would consider is if anything was rebuilt like the wings or tail. Won't mention any names but I know of someone that had wings and tails rebuilt. Alot of the stuff put back together was done with thicker skins (probably not legal) and zinc chromated inside etc. Does'nt sound like much but it can add weight and remember aircraft gain weight through dust dirt etc. Still sounds a little high. BTW I think our 170b is like 1350+ or so if I recall.
Last edited by cfiatzph on Mon Apr 30, 2007 6:23 am, edited 1 time in total.
cfiatzph
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Post by cfiatzph »

N2865C wrote:
jrenwick wrote:I wish I new how much my paint weighs, but I'm prepared to be surprised how heavy it is. My empty weight is 1410 with Imron paint, Horton STOL additions, tail pull handles, extended baggage, and an interior treatment that looks like it's heavier than stock.

John
On a 140 the paint comes in somewhere around 25 lbs. I would guess it would be around 45 lbs or so on a 170.
Just imagine if the inside of the wings or tail or fuse (if rebuilt) were done. Also Corrosion X etc. We are talking another 45 or so pounds. Thats almost 100 pounds there. These birds came out of the factory polished right?
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GAHorn
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Post by GAHorn »

cfiatzph wrote:.... These birds came out of the factory polished right?
Not polished, but natural with a bit of accents and decals.

You know, we've got some resources here in our fellow membership that work for the mfr's. How 'bout it fellas...? Anybody got a rule-of-thumb for weight of paint per square foot? (It's hard for me to imagine that an original paint job weighs 25 lbs dry, or that a full paint job weighs 50 lbs. Ten and 20 lbs maybe.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
N2865C
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Post by N2865C »

The approx. 25 lbs. of paint on a 120/140 was determined by weighing the plane before and after paint. Perhaps he was just heavy handed on the paint. That was for full paint.

I just saw on TV this morning a tour of the Boeing factory. They claim the paint adds 600 lbs. on a 777. Mmmmmm..... The length of a 170 is 12% of a 777 (209' vs. 25'). So if Boeing did the painting on a 170 the paint would weigh 72 lbs. for full paint. :D .
John
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ak2711c
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Post by ak2711c »

I thought I would throw my number in here too. I finally got mine weighed. My plane was a heavy plane before the engine conversion because of some of the mods I have done (180 gear,stol kit, ext baggage, 31" Bushwheels, double puck brakes, PPonk, ect...) The new empty weight with oil and unuseable fuel after installing the IO-360 with a constant speed prop was 1471 lbs. I did the math on all of those mods and they add up to close to 100 lbs of added weight.
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c170b53
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Post by c170b53 »

When I painted my plane, I used a gallon of primer, two gallons of paint and one quart of color. So I could weigh that stuff up but somehow most of it ended up either on the floor or walls with the plane was right in front of me.
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Bruce Fenstermacher
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Post by Bruce Fenstermacher »

Remember a major portion but not all of the weight of wet paint is the solvents that evaporate as the paint dries.

Assuming all the paint sprayed made it to the plane you are not adding the same weight as the wet gallon of paint. It will be significantly less.
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mrpibb
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Post by mrpibb »

It will be interesting to see what my plane weighs after I paint it. We stripped about 3 to 4 paint layers off her, I weighed the 170 when we got the new digital scales a few years back, empty weight was 1320 and in 1948 she weighed 1280. I'm painting mostly white, so being there is no color it should be lighter than air right? :D and if I use helium instead of air to spray.......

But then again I have a ragwing so that really dosn't help anyone, does it :?:
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cessna170bdriver
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Post by cessna170bdriver »

N9149A wrote:Remember a major portion but not all of the weight of wet paint is the solvents that evaporate as the paint dries.

Assuming all the paint sprayed made it to the plane you are not adding the same weight as the wet gallon of paint. It will be significantly less.
I've had painters tell me, but haven't verified, that polyurethanes like Imron weigh as much cured as they do in the can. In other words, they don't have any solvents other than the thinner you add for spraying. The process is more like "curing" than "drying". The same is not true of the cheaper one-part acrylic and alkyd enamels.

Miles
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