Help with installing Elev. and HS tips

Hi guys,

I am very confused in what all needs to be done with installing the empennage fiberglass tips. I have gone through various posts but I am now more confused. There is mention of Balsa Wood, epoxy, filler, etc... I know i want to go through the balsa wood route but i have no idea how to proceed or what to buy. For example, what epoxy do i need to get, many kinds. Can someone please tell me what is all required or list some steps. I am building an RV7A and am done with the Empennage (minus tip installation).

Thank you.

Omar.

I used balsa wood also

What I did was cut out the balsa wood from sheet using the outline of the piece you are attaching it to. Check the fit, sand as needed. I set it inside the edge (Hor tip or vert tip) maybe 1/8 inch so it would be more stable. Mix a little epoxy, spread on the edge of the balsa wood, and set in place till dry. Might need to tape it in place so it holds.

Next day layup Fiberglass cloth strip with epoxy so half the strip is on the balsa wood and half on the tip-all on the inside. Two cloth w/epoxy layups should do the job structurally. Then I mixed epoxy and filler (I used the West System epoxy and the filler for this last part was a West System product like a brown talcum powder). Now coat the outside of the balsa wood with the epoxy and filler to make it smooth with the edge of the tip.

Jim
RV9A

I just went through this with my HS and VS tips for the 9A. First, you will need to trim off some of the trailing edges I was able to get these within 1/8" of the elevators and rudder. Once the tips are ready for filling, I used some of the scrap aluminum. Scribe a line and grind, trim, file, sand to fit snugly about 1/8" of an inch back.

I used some proseal to temporarily glue the backing plate in place.

After things set up, I mixed some epoxy (West System) and flox and made a nice fillet on the inside to permanently hold the backing plate in place. On the outside I used epoxy and micro in a thick paste to fill the exterior side. Sand it down in the center and make a nice curve up to the original fiberglass sides.

Super light and strong.

To add to Jim's post, get some West Systems Epoxy and the slow hardener (206 i believe) and a pump kit. Takes the guess work out of mixing the epoxy and hardener together. Also, get some unwaxed paper cups (i.e., Dixie or Solo) for mixing and some popsicle sticks or tongue depressors for stirring. Use a acid brush or chip brush to apply to the part. Be sure to saturate the cloth before applying or you get air pockets between the fibers and it will be a weak layup. Once dry, sand and fill as needed for a smooth surface. Fill with micro balloons or flox with is mixed with the epoxy/hardener to about the consistency of pudding. There is another product called FiberFil (spelling) that does the same thing but is a bit more expensive over the long haul.

Lastly, there are quite a few posts on this subject. Also, if you can, try to attend on of the EAA SportAir Workshops on Composites construction. Answered alot of my questions and worth the investment. With the EMP you learn all of this fun stuff 'cuz there's lots more of it later on

Good luck.

Jim, do you have pictures of what you did please?

jimbo said:

What I did was cut out the balsa wood from sheet using the outline of the piece you are attaching it to. Check the fit, sand as needed. I set it inside the edge (Hor tip or vert tip) maybe 1/8 inch so it would be more stable. Mix a little epoxy, spread on the edge of the balsa wood, and set in place till dry. Might need to tape it in place so it holds.

Next day layup Fiberglass cloth strip with epoxy so half the strip is on the balsa wood and half on the tip-all on the inside. Two cloth w/epoxy layups should do the job structurally. Then I mixed epoxy and filler (I used the West System epoxy and the filler for this last part was a West System product like a brown talcum powder). Now coat the outside of the balsa wood with the epoxy and filler to make it smooth with the edge of the tip.

Jim
RV9A

Click to expand...

Do you have pictures of what you did or a video?

more questions on Bruce's method

thank you Bruce,

1) what aluminum sheet metal thickness did you use? i have various sheets metals from the trim tab bundle Vans sent me.
2) you mentioned the expoxy, flox, and micro. do you have links to where i can buy all this? i looked at West system products and they have tons of choices. can you please direct me to specific products?

your way seems easy, hopefully it will work out for me.