Front side skin to longeron

[paul330]

I'm riveting the forward fuselage side skin (F-1069) to the longeron (F-1013). How do you get the very front rivet under the F-1001J firewall gusset? Anything thin enough to fit in is simply not going to have the weight to set the rivet.

I was considering removing a bit more metal in the skin dimple, opening the hole to 1/8 and using a cherry-max.

Any suggestions?

 

[jtrollin]

You just need a larger selection of bucking bars. I think I used my tungsten bar, but it just fit.

 

[paul330]

Hmmm.... I have half a dozen bars including a tungsten one. None of them is close to fitting. I got the second last rivet OK with a bar about 1/4 thick but the available space for the last one is further reduced by the rivets holding the gusset to the firewall angle. I could find a piece of iron and grind it down but I think it would end up so skinny as to be useless..

 

[rleffler]

My reply isn't going to add value to the discussion. I don't remember having an issue in this area. Since it was over a year ago when I assembled this section, I don't remember any specifics. I only have a couple bucking bars, which would back what John stated.

 

[johngoodman]

I don't remember where it was, but I came across a similar situation. Took a large screwdriver and used the tip as the bucking bar - but - I held a heavy bucking bar against it for mass. Funky, but it worked.
John

 

[paul330]

I actually went with the option of drilling out to 1/8 and using a cherry max - worked beautifully. Obviously you can't go increasing the hole size willy-nilly but I believe the standard is no more than 2 together and no more than 1 in 10 average. Also the bottom most rivet on the skin behind the spar was a %&^$# so I used one there.

First time using cherry max and I am impressed. Will definitely use them as necessary now - much better than screwing up difficult rivets, drilling out etc, etc. Mind you, at 75c a piece you can't go mad.