[dsm8]

It appears that the holes drilled for the botom part of the right elevator spar are too large for the CS-4 blind rivets. The rivets prevent the skin from coming off the spar, but they do not hold the skin flush to the spar, they just kind of float up and down a little.

Should I drill out the rivets and get a larger size rivet or should I get a new spar, skin and stiffeners and start anew

Help

Don MacMillan

 

[Lionclaw]

Don, what size drill did you use for those holes?

On mine I reamed the majority of the holes with a #30 for the blind rivets. The 6 closest rivets to each opening in the skin (where the hinge goes) I did with a #40, as I was able to reach them through the opening with a 4" no-hole yoke.

This might be a stupid question, but I'd assume you dimpled both the skin and spar in the same places with the same size dimple dies?

The only other thing I can think of is perhaps faulty rivets? Are the mandrels separating before the rivet is fully set?

 

[dsm8]

I drilled them out to #30, but I notivced they were a litlte large, I fear that maybe a larger drill bit was used inadvertantly, althoug I only have #30 and #40 bits


Thanks

Don

 

[N916K]

It sounds like you did everything correct. Try a -4 solid rivet for size. It may just seem loose because of the long pin attached to the blind rivet. The hole does get larger when you dimple and that may be the first time you've dimpled a -4 hole.

 

[dsm8]

The blind rivets seem to be holding okay until I start to separte the upper skin from the lower skin and that is when it starts to pull away. I realize that this will not be a normal psoition once the skin is riveted to the ribs on either side. My fear is after a certain period of time it will pull away. I am going to have my EAA technical expert look at it and get his input

Thanks

Don