HS Skin damage

I somehow created a small ridge (for lack of a technical word) in the HS skin while riveting the HS707 rib to the top side of the skin. I'm not sure how I did this, I suspect I had the edge of the bucking bar lightly touching underneath this area when I started pounding. The ridge is about 7/32 in. long and at most 1/64 in. high. Though I'm inexperienced, this definitely strikes me as a concern for the location of a future crack.

I'm wondering what can be done about it and would appreciate any and all suggestions.

Pictures here:
http://gallery.me.com/tilf#100203&bgcolor=black&view=grid

As always, thanks,
Greg

I doubt this would manifest itself into any kind of crack. You might be able to work this out with a burnishing tool to minimize it's appearance. I would try that if it bothers you or simply move on...

my technique

My favorite way of creating skin blemishes like this is to let the bucking bar drift off the shop side of the rivet. A couple of taps from the rivet gun raise a nice dent really quickly...

What I have done is to take my largest and most uniformly flat rivet set in the gun and apply a few taps against the flat side of a large surface area bucking bar, not unlike the suggestion above to use a burnishing tool, which is essentially the same technique. A short burst at 25-30# psi will flatten the dent.

I'm no expert..

How many psi are you running? I found myself having a lot of trouble controlling my 3X rivet gun and bucking bar until I turned the regulator pressure down to 25 psi. Might give that a try.

RE:

25 psi, wow. I've been using a 3X gun at 60 psi. I'll try reducing the pressure and see how it works out.

I had tried less pressure when I was learning ??starting, but thought that the rivets were driven into that triangular shape which, some instruction booklet had described as a result of driving with to low a pressure.

Thanks for the input guys,
Greg

Build class?

Hi Greg-

Yes, 60# is too much for a 3/32 rivet. It's what you should be using (max) for a 1/8 rivet. For a 3/32, I use 35-40 with a 3x gun.

Just a suggestion, in case you haven't already done so, taking a basic RV or sheet metal build class would really provide a lot of confidence and would cover things like how to shoot and squeeze rivets properly, including what pressures to use.

FWIW, almost everyone's empennage has nicks and dings somewhere. As Wally Anderson from Synergy Air (a build class provider) told me: "Do your best and within reason [italicized are my words added] putty the rest." Yours looks like a good candidate for some "putty" when you get to the paint stage.

Hope this helps.

Hello Greg….

Here are a couple links I’ve used for good riveting results….

From Les Bourne
http://www.youtube.com/watch?v=3zQaMz7rtqY

From Brad Oliver’s site….
http://www.rv7factory.com/files/drill_rivet_cheat_sheet.pdf


pk

RE:

Holy Cow! What a difference! I went out a few minutes ago and starting driving the 3/32 rivets at about 30 psi. I was so excited about the results after 3 rivets that I had to run in here and let you guys know.

1) The 3x gun was very easy to control, no bouncing.
2) Not quite as noisy. Wife's comment
3) No pain (or blood) in the hand holding the bucking bar (As if this wasn't a sign that the pressure was to high. I'm mostly kidding of course.
4) Beautifully shaped rivets!

Thanks for the great information.

Sincerely,

Greg