I'm practically ready to start covering my TF Corsair 60, so I thought I should weigh it first. My work has a shipping scale that is accurate to 0.05 lbs (almost 1 ounce). I don't want to attract attention so I took it to work at 2am when there's no chance anyone will still be there.

Everything is installed and functional. Engine is an RCV 90 with an APC 3-bladed 15.75x13. Home made on-board glow. Robart retracts and air system. Main gear doors. Retractable tailwheel. Tailwheel doors. The Rx is complete and functional, Rx, batt, all servos (1 for each aileron, 1 for each set of flaps). Cockpit kit, Dummy radial.

No pilot yet. And I forgot to bring the canopy.

Here's what I got...

Wing: 2.80 lbs
Fuse: 5.65 lbs
Cowl: 0.40 lbs
Prop and prop nuts: 0.35 lbs
Total precovered weight: 9.2 lbs !!!!!!

My goal was less than 10 lbs. I'm not going to make it. I was so distraught doing the sum in my head walking back to the car that I forgot my wing on the scale! I have even more respect for those who can build it in the 8 to 9 lb range, covered.

I know the finished weight range for this plane is from about 8.5 lbs to about 12 lbs. I was wondering what the typical precovered weight range is. For those who have built the TF Corsair 60... What was your weight before covering? What was your weight after covering? What options did you include in either case?

If I glass with water based polyurethane and paint, what might my plane weigh when it's finished?

Thanks,
Juice

I have practically the same question: How much weight will be added if I cover a Top Flight 60 size P40 with fiberglass + paint?

I just started with my TF P40. Although I just finished with the tail feather, I can see this plane will not be very light. I will have an OS 120 w/ pump, pneumatic retracts with struts, and split flap. I hope, with fiberglass covering, the total weight will still be under 12 pounds. Is this an realistic expectation?

How much weight can I save if I switch to MonoKote covering? My preference is still to fiberglass and paint it.

Thanks.

IMHO, paint doesn't add that much, i weighed my wing glassed, then painted them and re-weighed, not much difference

2.165lbs glassed w/polycrylic and 1 oz glass, doubled in the middle third on bottom

2.265 lbs primed and painted

the primer and paint only added .1 lbs 16oz in a pound (unless i'm high), so 1.6 oz worth of primer and paint. i'd guess it's about the same on the fuz.

as for the glass/poly, since it adds strength and dent resistance, the structure can be lightened, by increasing the size of lightening holes mainly, to compensate. i didn't have my scale before glassing, so i don't have figures on what she weighed before the glass

i have no idea what moneycoat weighs, but i've used it once and will never touch a sealing iron again!

I should be working more, but instead I've been doing covering weight calculations.

First, this is how I estimate the total amount of covering material required for the TF Corsair...

700 sq-in Wing top
700 sq-in Wing bottom
1100 sq-in Fuse (estimate with 50" long cylinder with 7" diameter = 2 x PI x 3.5" x 50")
500 sq-in Tail surfaces (estimate)
------
Total estimate =3000 sq-in = 2.3 oz/sq-yard

A typical colour monocote is about 7 grams/sq-ft = 2.2 oz/sq-yard. So the total monocote weight should be about 5 oz.

I've read a typical glassed and painted covering job is estimated about 4 oz/sq-yard. I hope this is for a epoxy/resin method. I'm using .56 oz/sq-yard fiberglass and water-based polyurethane. Maybe it might be lighter, but we'll use the 4 oz/sq-yard for now. Total glassed/painted weight should be 9.2 oz.

So maybe I can still meet my 10 lb goal. Maybe I'll be a little over if I take in to account the weight of glue for hinges and other unforseen stuff.

I didn't think the covering would be so light. Come to think of it, my numbers go against the general understand that "a glassed and painted covering will add 2 lbs". Can you guys see anything wrong with my math?

Juice

I weighed my 80" Hawker Hurricane before and after glassing. I used .56 oz Sig cloth and Z-Poxy finishing resin. Net weight gain 7 oz. The secret was a roll of toilet paper. I take a roll of TP and roll over the freshly epoxied surface to absorb any excess or pooled resin. Discard the wicked sheets as you go so that a clean fresh roll is applied to your epoxy/glass master piece at all times. Extra epoxy does nothing but add weight.

After adding all the rivets, hatches, epoxy primer, epoxy paint, and weathering. The weight gain was a pound and a half.

I think precolored iron on covering (fabric and film) has a place in scale modeling and I have used it on a few subjects. However I really like the results that paint achieves and epoxy paint is my favorite. I will be crest fallen when my stash finally runs out.