Perfect #30 holes when dimpling

[Tony Spicer]

And not to forget that SPA can supply all your rivet needs.

Tony

[stevegawler]

Thanks Larry!

[Exhaust guy]

The CCP-42 rivets that I used on the forward fuselage are available from Aircraft Spruce and Specialty. They were out of stock during December but John at ACS told me they now have 39,000 in stock. They worked well on my fuselage. Larry v.

[stevegawler]

Tony,

Regarding the CCP rivets you used on the forward fuselage: Are those Cherry rivets or just domed head versions of the flush rivets used elsewhere? When I google I see quite a variety with many prices and specs. Where did you purchase them?

Thanks,
Steve
(Koko's Ops Officer, '2000)

[PlaneDan]

I am a first time "aluminum" aircraft builder, so am learning the same as many of the other builders. I realize that I should probably just keep quiet, but if this helps anyone, it is worth the risk. First, I used the DIENQ in the #40 holes in the skins, and think it does a great job. I had to still updrill to #30, as you would expect.

Regarding dimpling the steel cage and protruded vs flush rivets, I made the following post on Sunday and this is my opinion after taking the leap on dimpling the cage.

<Opinion>
For new builders, or those who have yet to decide protruded or flush, I highly recommend that you NOT flush the fuselage. I am seriously disappointed with the dimple job that I had to do, so the steel cage fuselage would match the flush of the aft fuselage. If I were to make this decision now, it would be to flush as much of the flying surfaces as I choose and not be concerned about going protruded anywhere other than MAYBE the leading edges, and would definitely go all protruded on the fuselage. The only squeezer you can get for the wide section on the longeron for the forward fuselage is very expensive, and I could not justify it for that little bit of use. The other option, which I will document in the next post on my web site, is to make one using a clamp (learned from other builders), which works OK, but I will also show you a picture that you may not want to be seeing on your Panther.</Opinion>

[Lowrider]

Ya know Scott, that may be where I got the idea from a Van's seminar when I was building my RV-4. I seem to remember using a punch and hammer to do the "dent" and then use the Uni Bit to cut the bottom of the dent to accept the rivet body thru the thin alum sheet that was dimpled or maybe it was just #30 or #40 bit. I do remember dimpling the thin material with the Vise Grip type tool. Let us know what your experiments disclose please.

[Jinkers]

Last year at Oshkosh I went to the Vans Aircraft Builder Sport Air Workshop. during the work shop they discussed (though we didn't try it) a method of dimpling/countersinking on metal that wasn't thick enough for countersinking but was too think for proper dimpling. Basically they said to dimple the metal as best you could and then manually countersink the dimple to fit. It would be a lot of work.

Anyone tried this or have any opinions on this method? I think I will take Tony's suggestion and find some scrap to try it on.

[Lowrider]

Thanks Paul and Tony!

[psalter]

The skin is dimpled for a 120 degree 1/8" rivet. And like Tony said the tube has to accommodate the rivet and the dimpled skin. The rivet alone requires about .03 " depth, and the skin is another .032" which adds up to .062 deep, and that is with a knife edge at the hole which is not good sheet metal practice. A countersink should be no more than approximately 2/3 of the way through the material. So, in order to countersink for a rivet and skin you would need approximately .090" thick wall in the tube. Quite a bit more than the .035 wall we actually have.

By the way, with 1/8" 120 degree rivet, you would need about .05" thick material for a proper countersink just for the rivet head. So even that is more than the thickness of the tube.

[Lowrider]

OK, but isn't the skin dimpled to allow a countersunk rivet to hold that skin to the sq tube...maybe a I should be a quiet observer.