Esser's Build

[Esser]

Hey jiott, I do have a dremel but none of the sanding bits I have are small enough to get into these places. I havent been abel to find any that are less than 3/4. I have tried to cheat with the stones but they end up getting gummed up and arent meant for the application. As for hysolling the varnished ribs, they were epoxied to the frame before varnishing. I just need to add ribs in the vert stab and was wondering if sanding will work or if the varnish goes too deep.

Cheers

[inzersv]

I did the same thing and varnished some of the ribs and stiffeners before bonding. I sanded (roughed up) the area on the ribs and stiffeners that needed bonding and then applied the Hysol. That was about three months ago and they seem to be holding together well. Hysol seems to be good stuff.

[jiott]

Dremel has sanding drums that are 3/8" dia. and 5/8" dia.

I think if you scuff sand down to the wood you will be OK. The book calls for 3 coats of epoxy varnish on the wood. That's a lot of varnishing and is a real pain, especially on the wings. I needed to wear a respirator while varnishing to avoid feeling ill, but I did the 3 coats.

Jim

[Esser]

Well I was able to squeeze in a couple more hours of work on the plane before I flew back to work.

First off, when I epoxied all my horz and vert stab ribs in they were straight as an arrow and I thought I wouldnt need stiffeners. I varnished them because I was worried about the warpage but they indeed still warped. I'll chock it up to the great lakes 100% humidity and the the fact that I was only able to get 2 coats of varnish on not the required three. I am going to leave it for now but I am going to sand the ribs and put stiffeners on every single rib that isn't against the steel frame.


Since the elevator isnt installed I zip tied the push rod up so that it can swing free if i need to move the control column


So learn from my mistakes. Even though the instructions call for stiffeners on the ribs you find necessary, put them on right away. It might save you a lot of work since mine were very straight when they were first installed.

[HighWing]

I am going to leave it for now but I am going to sand the ribs and put stiffeners on every single rib that isn't against the steel frame.

So learn from my mistakes. Even though the instructions call for stiffeners on the ribs you find necessary, put them on right away. It might save you a lot of work since mine were very straight when they were first installed.

I think what I would do in this situation and for that matter for all rib stiffeners regardless of timing is to make some half inch by half inch thin aluminum angles - maybe like .025". Cut then to the effective length of the rib and rivet them in place using aluminum rivets with a little Hysol at the rivet to seal the wood. There is no real force on the ribs except moisture warpage and gentle finger pressure will straighten them. No need to sand and I suspect a bit lighter than the wood stiffeners.
Lowell

[Esser]

I think that is a great idea Lowell. The rivet on the rib wouldn't pull right through?

[jiott]

As I found out on my elevator ribs, you need to put the stiffeners in even if the unstiffened ribs are perfectly straight. When you cover and shrink the fabric it will pull the steel tubing in slightly and buckle the ribs if they are not stiffened.

Jim