DBono99

My Feedback: (1)

Hi All Will I be saving enough weight to go to 1/32" wing sheeting instead of the 1/16", the width of the LE sheeting and the TE is 21 1/2 by 1 1/2..That is for half the WS. This plane will be for E flight.

Thanks Dan

cutaway

Ounces come from grams trimmed all over the place ;->

mmattockx

If this is a built up wing, 1/32" will be very fragile and leave no margin for sanding or anything else. I have sheeted foam wings for a hand launch glider with 1/32" and even that was delicate enough to require care in handling. I think you would be better off using 1/16" and very carefully selecting your wood for minimum weight.

Mark

BMatthews

Rib spacing will also play a big part in this decision. If it is the usual 4 inch spacing as on a lot of 3D models then I'd stay with 1/16. If it's more like 2 inch spacing then you could get away with 1/32.

If it IS the wider spacing then find or order some contest 1/16 and use the lighter sheets that come in.

Campy

My Feedback: (1)

You will save some weight with 1/32". As mmattockx said, it will be more fragile. Just be careful with the sanding. I would also suggest using an alphetic glue such as Titebond, rather than ca for attaching the 1/32" stuff. Titebond sand much easier than ca.

On the flip side, MANY of the plans from the UK and Australia I have seen use 1/32" sheeting.

Last year I built a Lysander from Dennis Bryant plans. The plane is designed use a 60 - 90 2 stroke and has a winspan of 80". The LE and TE sheeting on the main wing is 1/32" as well as the full sheeting on the tail surfaces.

Dennis Bryant is/was a VERY WELL known modeler in England (He would be England's Nick Ziroli ) and I am certain that if there was a problem using 1/32" sheeting on a glow plane, Dennis Bryant would not have used it.

CoosBayLumber

My Feedback: (1)

I moreover agree with Mark on this. 1/32" is very fragile. The A/C can smack a bush and result is a hole in the cover. There is 1/20" balsa, which will take just a bit of sanding, but still better of going with 1/16" but look for the lightweight contest variety. Some of the glow flying models of teh 1950's used to specify to use 1/20th. But 1/32 is most often used on rubber powered.

There are various methods of saving weight other than skimping of the covering thickness.

Wm.

BMatthews

Just a note on sanding sheeting. It's a very good idea to sand the sheeting for the basic surface finish BEFORE applying to the wing. Just smoothen it on your building table so it's flat. You can smooth the factory sanding finish without the pressure from the sanding block pushing the sheeting down between the ribs and avoid it sanding the area over the ribs more than the area between the ribs. A few years back a buddy of mine couldn't understand why his sheeting was getting a "quilted" look to it. He was sanding the leading edge sheeting while it was on the model. We saved the day by using fresh paper and just pulling the block over the sheeting without any downward pressure at all. Took a while but it finally sanded the 1/16 down to around 1/20 where it matched the low spots that were over the ribs by that time.

longdan

I would say don't do it. It's way more trouble than it's worth. For some reason, it shows up the slightest varaition in the ribs, and you can't sand it. If you try to sand it, it's so flexible that it pushes away from the sandpaper between the ribs, and you only end up sanding it over the tops of the ribs, making it look even worse. And unless your ribs are spaced 1" apart or less, it will sag when you apply the covering. It's not strong enough to resist the pull when the covering shrinks. I recently did a D-tube in 1/32 thinking I was being smart and saving some weight, but I would never do it again. The stuff is just too thin. Use the 1/16 and save the weight elsewhere.

winglift

My Feedback: (10)

I would suggest that you try to save weight in other areas. The weight savings by using 1/32 is really not that much. There are plenty of areas that you could find to save an equal amount of weight, but that is your choice. If you do use 1/32 then take the advice already given in this thread, especially use Titebond and sand before applying to wing. Good luck.

DBono99

My Feedback: (1)

Hi All
Wing rib spacing is 1 5/8" apart..Looks like alot of ribs 30 all told ffor a 46" WS.

I'm think I'm going to stick with the 1/16 sheeting..

Thanks Dan

dreadnaut

My Feedback: (5)

Re-space the ribs to 2", cut lightning holes in the ailerons and elevator, or build up the elevator and rudder. Carve the lower cowl block from foam, cover with 2oz fiberglass with epoxy resin (just enough to wet it). When cured melt out the foam with Acetone.

Another way to save weight, but is a lot of work, is to use dope and silkspan to cover (google Brodak for a source)

DBono99

My Feedback: (1)

Hi:"build up the elevator and rudder" Isn't the elevator n rudder built up??..I like your cowl idea. Can you expand on your technique for making the cowl..
Thanks Dan

dreadnaut

My Feedback: (5)

Looking at those plans, I see that the stabilizer and vertical fin are built up, but the elevator and rudder are not. The elevator is kind of narrow, and could benefit from some lightening holes. The rudder could be built up.

For the lost foam cowl, carve the block from some white styrofoam, and snad it to a farly smooth finish. Lay up a layer of 2 oz fiberglass with epoxy resin, Z-poxy finishing resin is good for this. Take some paper towel 2'' wide rolled up to the size of a pencil, and use this a a roller to work the resin evenly into the layup, and soak up the excess.

Once it is cured, wet san it till it is fairly smooth, clean it, spray it with primer to fill all the little pinholes you WILL have, and wet sand it again. Repeat until you have a good finish. The last snading should take the primer down to where it is translucent, but not hitting the fiber glass. Now you can use acetone to melt out the foam.

DBono99

My Feedback: (1)

Hi All
dreadnaut Your right about the rudder & elevator. I got confused with the plane I just finished a Bingo 20, all the tail feathers were solid sheet 3/16 I made them out tof 3/16 sticks..

Looks like the 1/32 is out of the question..Going with 1/16 or maybe just leave IT open...

Another question, If you can make It out on the plans..the stab's. LE isgot a curve in it..What would be the best way to achive this.I believe the measurements are 3/16 wide,1/8 high/thick..Thats a probelm when downsizing a plane..

Thanks Dan