The right amount of "Dimple"

[boom3]

I have just completed the riveting on my Horizontal Stab and I'm having a blast!!

I've searched and found some threads on this topic but thought I would post a couple of my picts and see what everyone thinks.

My question is "Should I keep dimpling the way I have so far, or do I need to lighten up a little?"

I am using the Avery 3/32 spring dimple dies. When I put them in my pnuematic squeezer, I adjust it so I can just spin the dies when it's completely closed. When dimpling the skins with the squeezer, I end up with a nice dimple and a ring around the outside of the dimple from the dies. I try to duplicate this "ring" when using the C-Frame tool. Usually about 2 whacks with my hammer and I'm there. When riviting the skin, I end up with another "tool ring" from the rivet set when I use the squeezer.

I'm not overly concerned or anything, the question just came up in my mind after I went and looked at a couple of other un-painted RVs completed and further along. Looking closely at their dimples, there were very very few if any dimpling tool marks. Mine on the other hand are pronounced and every dimple has one.

In your opinion, do I need to lighten up or keep doing what I'm doing?

Thanks everyone!

[cytoxin]

those look fine to me. i use that big white uhmw hammer and only one whack. was two, but i realized that one was a plenty. as far as the squeezer you can overdue it easily, but it sounds as if your doing it perfectly. good luck with your project looks goos so far.

[osxuser]

Mostly, those marks will polish out when you are done putting everything together. Most unpainted RV's are polished. You don't NEED those marks for anything. I've never used more than one good blow in the C-frame to dimple anything. FWIW, I don't use a rubber mallet, I used a 12oz Ball Peen hammer in the C-frame. People said it leaves a crisper dimple, and I've found that to be true.

[DGlaeser]

My dimples look like that also. I adjust the squeezer so the dies touch. The circle mark you see is just a mark on the alclad - the metal isn't indented or anything. When you paint it, you won't see a thing (try it on a piece of scrap). I don't think there is such a thing as 'over' dimpling using the dimple dies, and I viewed the circle mark as an indication that I didn't 'under' dimple - especially when using the C-frame.

Build on!

[scard]

Opinion: If you can spin the die at all in the tool when fully closed, you should tighten it up. It should be adjusted tight enough to where it just barely starts to deflect about a 3" yoke when fully closed in a pneumatic squeezer with no material. This is assuming a thin material .032 or less. It doesn't sound like you are squeezing it enough. If you do a row of light dimples in the right part, it will curl it up like you had bent it around a mandrel. The tool marks on the skins are fine if they are just blemishes, no matter how big. If they are actually deforming the material and putting some kind of groove in it, the dies have issues.

[rv7boy]

Jeff,
The only concern I have in your photo is to make sure your horizontal stab in the background doesn't fall off its supports. I can't tell from the photo, but it appears it is only resting on the two supports. If you have a tether or piece of "safety twine" keeping the nose from "tumping over" (an Alabama term), then all is well. You've put too much work into the stab to be considering a "scratch and dent" re-work project!!!
Sincerely,
Don

[RScott]

Don Hull is right! Remember the Seattle earthquake about 10 years ago? Don't take chances with that HS falling.

Also, setting the dies loose will distort the metal. Drill holes in a strip of metal, dimple a few with the dies loose and a few with the dies tight & you'll see the difference. As others have said, you want to adjust the squeezer so the dies are tight. The squeezer will not damage the metal (as long as you don't miss a hole! It's happened!).

[cytoxin]

Originally Posted by RScott

The squeezer will not damage the metal (as long as you don't miss a hole! It's happened!).

the squeezer will certainly damage the metal if not set properly. as the yoke spreads and the squeezer comes over the bump it will put dents (thinned metal) on the throat side of the dimple. under squeezing may cause deflection sheet wise, but over squeezing will cause it to deflect edgewise.

[AX-O]

Originally Posted by rv7boy

Jeff,
The only concern I have in your photo is to make sure your horizontal stab in the background doesn't fall off its supports.

Same concern that I had when I stored mine. This is what I did. The write up is HERE.

[boom3]

Originally Posted by rv7boy

Jeff,
The only concern I have in your photo is to make sure your horizontal stab in the background doesn't fall off its supports. I can't tell from the photo, but it appears it is only resting on the two supports. If you have a tether or piece of "safety twine" keeping the nose from "tumping over" (an Alabama term), then all is well. You've put too much work into the stab to be considering a "scratch and dent" re-work project!!!
Sincerely,
Don

I have it secure. You can't really see it but there is a large fender washer in the middle holding the HS-714 to the wall. After all that work, there's no way I'm putting that thing in jeapordy.

Thanks for your replies, I feel better about the dimples.