sahartman21

Finish shaping the wing tips with a sanding block.

Cut some pieces of 2 ounce fiberglass cloth and tack it in place with 3M 77 adhesive.

Mix a small amount of Skin It epoxy and spread it in place with a plastic squeegee.

sahartman21

Trim the excess fiberglass from the wing tips with a sanding block.

sahartman21

Here's another method how to make a gapless hinge. Kevin Matney told me how.

Cut a piece of taffeta (nylon fabric available from Michaels or wedding shop) about 1.25" wide.

Tack it on with some 3M 77 contact glue.

sahartman21

Tack on the 3/4 ounce fiberglass to the wood with 3M 77.

Mix up some Skin It epoxy glue and apply it with a plastic squeegee.

Put the parts between layers of peel ply (polyester fabric).

sahartman21

Put the peel ply and parts in a vacuum bag. I used 4 mil plastic and sealed it with latex caulking.

Turn on your vacuum pump (6" of HG vacuum) and allow the air to be removed.

Leave the parts alone and let dry overnight.

sahartman21

The next morning you can open the bag and remove the tail surface from the peel ply.

Just pull the sheets apart to remove the parts.

Use a sanding block to trim the edges.

sahartman21

Use a Dremel tool and cut off disk to cut a slot on the bottom at the hinge line.

A razor saw is used to cut the hinged surface free.

Use a small file to widen the slot enough to allow about 5/16" down elevator.

fizzwater2

My Feedback: (61)

You're using a triangle file, right?

sahartman21

A triangle file was used but you can also fold the surface back and use sandpaper or a flat file.

Just be careful not to sand through the hinge.

sahartman21

The elevator horn was made out of a piece of 3/32" wire, 3/32" wheel collars, and a piece of sheet brass.

Solder the parts together with silver solder.

sahartman21

Align and tape the wing to the fuselage.

Drill some test holes to confirm you have the correct location for the dowel pieces.

If the holes are off a little adjust the location and try again.

sahartman21

Use a 3/4" hole saw to drill holes for the dowel pieces.

Apply some tape to close off the hole on the top of the wing.

Mix some epoxy and micro-balloons and glue the dowels in place.

Allow to dry overnight.

sahartman21

I vacuum bagged the wings similar to that done on the tail. This method was explained to me by Ed Smith and Kevin Matney.

One wing uses a piece of 2 ounce fiberglass cloth as a hinge. The other uses taffeta as the hinge.

Lightweight 3/4 ounce fiberglass cloth goes over the entire wing.

Skin It epoxy was applied and spread with a squeegee.

The wings were places between pieces of polyester cloth (peel ply) and then placed in the vacuum bag.

The pump was turned on and parts were let to dry overnight.

twitte1

Scott,

Any concern that the wings/tail might warp while in the bags overnight. I do not see any weights holding the wing down flat to the floor.

Trey

wrstew

My Feedback: (30)

Trey- the final shape has been formed during the bonding of the balsa to the foam portion shown in earlier posts. This operation adds the hinges and final exterior glass. This appears to be the top side of the wing, what I'm wondering is: do you plan on doing the opposite side in another phase? Great job on doing the work to show us the build. Randy

sahartman21

I actually applied the fiberglass cloth on the bottom of the wing in addition to the top. Sorry I don't think there were pictures.

1) There were three layers of fiberglasss cloth applied to the center section. This time widths of 4", 10", and 14" were tacked on with 3M 77.

2) The aileron hinge (2 ounce glass or taffeta) was also tacked on with 3M 77.

3) Lightweight 3/4 ounce cloth was appled to both the top and bottom of the wing.

4) About 1.5 ounces of Skin It was applied on the bottom of the wing. It was spread with a squeegee.

5) About 1.25 ounces of Skin It was applied on the top of the wing. It was spread with a squeegee.

These were then placed in the peel ply and vacuum bag to dry.

The torque rods will be installed later.

PylonDave

Do you get a very smooth finish out of the bag Scott??

sahartman21

The finish is smooth but it is not perfect.

You get a smoother finish using the peel ply in the bag than if you just applied the finishing epoxy with a squeegee alone.

The surface is only as smooth as the peel ply and bag. I ironed the peel ply so there were no wrinkles.

The following picture shows what the wing looks like after some sanding.

The hinge made of 2 ounce glass is smoother than the one done with taffeta. We will see what holds up better.

PylonDave

Would you get a smoother finish using Mylar instead of peel ply??

sahartman21

Mylar is likely to be smoother over the flat areas. Peel ply is likely to be better over curved areas.

The peel ply is more flexible and is likely to be smoother over slightly curved areas. As an example the wing tips on the Singer are eliptical. I suspect that peel ply would work better on the tips.

Concerning the Proud Bird finish, I had a couple imperfections on the bottom of the wing due to the folds in the the vacuum bag. Other than that there were no significant issues. I just sanded out the surface a little.

sahartman21

The following pictures show how ailerons were installed based upon the taffeta hinge.

Heavy duty aileron rods are used.

Drill 3/16" holes to route the rods to the other side.

Use a Dremel tool with cut off disk to cut a slot for the ailerons.

Use a file or sanding block to widen the slot to about 3/32".

Use a razor saw to free up the ends and adjust the slot to allow about 5/16" throw each way.

sahartman21

Cut the slot for the torque rod as needed.

A hobby knife was used in the center section.

A small Dremel tool was used behind the ailerons.

A small amount of oil was applied to the torque rods.

The ends were tapered as needed to fit.

sahartman21

Scrap pieces of balsa were used to block off the hinge line from glue.

Some Skin It epoxy and micro-balloons were mixed for a relatively thick mix.

The mixture was applied to cover the aileron torque rods. These will have to be overfilled a little as the glue settles as it dries.

sahartman21

I used a Dremel tool to grind the epoxy and micro-balloon almost flush with the surface.

A sanding block was used to finish the sanding.

sahartman21

Here are a couple pictures of what it looks like from the top.

My experience so far is that this type of hinge is quicker to install than a conventional hinge.