sportflyer-RCU

My Feedback: (35)

What is the appropriate fiberglass cloth wt to use for strengthening center section of wing? The 45 in span wing is for a EDF . Tks

rcuman

You will most likely get some mixed replies on this one, but I use 2 0z cloth on my 65" warbirds.

da Rock

That 45" wing actually won't need much. Wings that don't come with reinforcing or kits that don't provide for it obviously have worked in the past without it.

Look at the structure you're reinforcing. You're probably only going to coat 1/16" balsa sheeting with the cloth/resin. So going much beyone 1oz cloth is probably going too far.

What's an "EDF"? If it's an electric, you might not need it at all. If that's a type of foam, then look at the spars and consider either covering the entire wing or not covering any part of it.

sportflyer-RCU

My Feedback: (35)

The wing is 1/16 inch balsa over foam and I used EZ Lam laminating resin to glue the sheeting on. The whole wing is then vacuum bagged .

EDF stands for Electric Ducted Fan .

I have some 0.6 oz cloth . Wondering whether this is enough .

Roby

I'm not at all familiar with the sort of plane you have
but I do allot of glassing.

An electric with 1/16 balsa over foam ,the .6oz cloth
should work fine. If your really concerned ,put on two
layers at the same time.

I like to use Z-poxy finishing resin and then roll off the
excess with toilet paper.


Regards,
Roby

majortom-RCU

My Feedback: (40)

Roby has the right idea. I like two lighter layers, cut with a double taper, wide at the spar, narrower at LE and narrower still at TE. The underlayer should be smaller dimensions by maybe an inch along all edges. That way there is less of a stress riser where the glass stops. On a lightweight model such as you describe, this is probably a bit of over-building, but I like to practice the same principles even where I don't need to, so when I do need it I know how to do it right. Make the underlayer at the TE maybe 1" out from center on either side, underlayer at LE 2" out from center, and underlayer at main spar like 4" out from center. That also puts the strength where it does the most good and distributes the stress. Overlayer would be similar shape, but go a little further out at every point. Two layers of 0.6 oz glass will be plenty for the model you describe. On bigger models, like 1/4 scale, I think a double layer of 1 oz glass is more than enough. Great strength bonus for very little weight. I've seen wings fold at the center joint, so this is not wasted effort.

If you give the glass cloth a light shot of hairspray before you cut it, the edges will not unravel and make a hairy mess. Drape it over a sheet of cardboard when you spray it. Spread the epoxy on the wing first, then carefully drape the cut piece of cloth in place, then dap it down with the point of the brush. Get it dapped down good, then finish with a disposable 3" paint roller from walmart, fine-grain sponge rubber roller.

You can do the whole wing at one time by covering the first side with plastic wrap when you're done glassing, then flip it over and do the other side. I like to use the poly bags that ARFs come in, or backing from film covering, since the heavier gauge does not wrinkle so easily and leave ripples in the cured epoxy. The poly will fall right off the cured glass, no stick at all.

To get the cloth down straight the first time, I normally use a marker and make a line on the cloth to align with the spar and another to align with the center joint. That way you avoid repositioning.

sportflyer-RCU

My Feedback: (35)

The plane is an elect version of BVM's Bob Cat and there is no wing spar on the wing. The fuselage pod is permanently attached to the wing so this adds additional strength to the wing center joint. The tail booms on each wing half will add more strength outside the fuselage area.

So I will use 2 inch wide 0.6 oz wt fiberglass cloth over the wing center joint .

I like the idea of using hair spray to prevent cloth from unravelling. Tks

kdc

I use the self adhesive fibreglass tape sold for covering joints in plasterboard ( is that sheetrock in the USA?) which is narrow so I use two widths for a wing joint. Very convenient but probably heavier.