Scale Wendell Hostetler 30% Piper Cherokee Glass Fuselage Build.

[TonyHallo]

Married the right and left halves this morning. The halves were joined with a thickened epoxy mixture of milled fibers and colloidal silica mixed to peanut butter consistency, this was applied with a Mono-eject tube cut off to about 1/8" opening. The mixture that squeezed in was smoothed with a brush on a stick then carbon strips were placed on the joint that could be reached, plan to finish the remainder through the door opening after the fuselage is removed from the mold. There is heat on the mold now so it may get removed later today?

Continue to work on the remaining small parts, finished the stabilator tips and working on the second main gear fairing.

After looking at the stabilator skin mold decided to wet sand it smooth, don't know I didn't do this before? At any rate it is sanded down to 2500 grit and waxed ready for PVA. Have plenty of carbon left so thinking 1 1/2 and 4 ounce glass, 1 layer of 5.7 carbon fiber, will see how that works.

 

[TonyHallo]

It's out! Weight came in at 3.86 pounds, was estimating 4, so I'm happy. The door stayed in the mold, the clear packing releases very well. Tomorrow I plan to cut away the door area and finish the seam tapes. It feels really light.

No need for the plug anymore! I filled two contractor garbage bags with debris from vacuum bagging, I think most of the epoxy went to the curb.

 

[dhal22]

Geeze…….

 

[TonyHallo]

Here's what it looks like with the cowl and tail cone installed. I need to revise the tail cone that was previously made. The tail cone should go all the way to the point where the fin trailing edge intersects the fuselage. When I made it I wasn't worried about minor details, now that I began scale competition I need to rethink a few things. Plan to glue the tail cone on and finish the seam, then cut it off at the correct location and make a new mold.

 

[TonyHallo]

Have the first stabilator skin in the bag. All those dots puts me in mind of the candy I bought when I was young, you know, the white paper strip with colored dots of candy glued to it. Started getting the rudder mold ready to lay up.

 

[TonyHallo]

Epoxied the tail cone onto the fuselage and filled the seam with Super Fill. Needs block sanded down and it will be ready to cut. I am kind of two-blocked on moving forward with cutting it loose, the fin trail edge needs trimmed by possibly a 1/4", I would like to have the rudder in hand to determine the cut line of the fin before finding the cut line for the tail cone.

 

[TonyHallo]

The third protype came out of the mold as a failure, I thought the larger vacuum pump would be able to pull the glass cloth down into the edges of the corrugations so I started with full size pieces of cloth, previous lay ups were done with strips of glass cloth cut to the width of the corrugation centerlines, this allows the cloth to flow into the edges rather than form a catenary curve at the intersection. There were too many imprfections so this one is going to the curb, lesson learned. Sure glad I din't make that mistake of the vertical fin!

Have the rudder molds ready for PVA will lay up the rudder before do the second stabilator skin. The forth skin came out of the as expected and the lightest one yet, lay up schedule was two layers of 1 1/2 ounce glass laid in strips followed by one 5.7 ounce carbon fiber. I did use thickened epoxy around the corrugations as well.

For the rudder planning two layers of 1 1/2 followed by a 4 ounce layer. Then glue foam blocks into the cavity, these will get hot wired flush to the top of the mold. The mold will get closed the thickened epoxy around the perimeter with the foam glued with polyurethane type expanding glue, Seen this done on a glider build on one of the composite forums, he used 2 pound foam, I plan to use expanded bead poly foam Should be plenty adequate.

 

[TonyHallo]

I have the rudder halves laid up, once these are done there is one more stabilator skin to make and I will be out of molds. Will need to make a new mold for the tail cone and cowl once it is modified. I had a heck of a time getting the bag sealed, even used a piece of fuel tubing as a stethoscope and could find a leak on top, flipped the left side over and found nothing, flipped the right side over and under the mold was a 1/16" hole in the plastic, and this was a new piece of plastic that I started with. Put a piece of masking tape over it and went up to 28" hg.

 

[dhal22]

A clinic............

 

[TonyHallo]

One pound foam fillers were cut to shape and the thickness reduced hoping the foam follows the shape of the corrugation. Foaming Gorilla glue was use to attach the foam fillers to the skins. This was rolled on with a very light coat. The parts were placed in a vacuum bag, the glue seems to like vacuum, started at 10" hg, using the old pump that has bleeder control, wasn't to worried about crushing the foam so the vacuum was increased to 22" hg, I could see the glue start to foam between the skin and filler at the higher vacuum, left it 22 for a while then reduced it back to 10" hg. Once this cures the fillers will be cut flush with a hot wire. This may end up becoming a protype, if the process is successful I may end up laying up with less glass to reduce the weight, one of the skins has a defect that can very easily be repaired, the final weight will make the decision.