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-   -   Poor Rivet Job (https://vansairforce.net/community/showthread.php?t=71824)

RVGator 05-05-2011 03:18 PM

Poor Rivet Job
 
As I proudly announced to my wife the completion of the HS I was showing how perfectly everything fit...



...until I got to the upper right skin...



These gaps vary from .001" to .023". I think I already know the answer but just to make sure...this is a show-stopper correct?

Thanks for the advice.

scsmith 05-05-2011 03:47 PM

Re-do
 
Yeah, you should drill those out and re-do them. Be sure parts fit tight together, use cleco's in every hole except the one you are squeezing or bucking.

cjensen 05-05-2011 03:59 PM

Yep, no big deal to drill them out and replace. Back when I did my HS spar, I had a double row of about 35 rivets "club" over when I squeezed them...didn't know it at the time and figured it out at the end of the session. Drilled 'em all out, and started over!

Sorry the pic is so tiny, but back in 2005, I hadn't figured out the way to size them properly for the internet...:rolleyes:


Bob Kuykendall 05-05-2011 04:09 PM

Quote:

Originally Posted by RVGator (Post 539718)
These gaps vary from .001" to .023". I think I already know the answer but just to make sure...this is a show-stopper correct?

Don't look at it as a show stopper. It's just an intermission, or maybe a sideshow.

I'm definitely with Steve on this. I have pretty loose standards when it comes to how bad a rivet has to be before I'd drill it out. And these are well outside my comfort zone. Like he says, use lots of clecos to keep the parts clamped tight.

Thanks, Bob K.

flion 05-05-2011 05:09 PM

It may be a light artifact, but it looks like you have some chips holding the skin away. Drill the rivets out, use a chip chaser to clean the area out until the skins lay flat, then rivet again. Sometimes clecos aren't enough and you will have to clamp on either side of the rivet, using a narrower bar and set (or a rivet squeezer) to do the rivet.

Jamie 05-05-2011 06:15 PM

Looks to me like the problem is that your spar flange is under-dimpled and not allowing the skin to lay flush.

dpansier 05-05-2011 07:00 PM

This may be helpful to keep the sheets together when squeezing the rivet.
As always, make sure no burrs or drill shaving are between the sheets.

Place a short length of poly tubing over the end of the rivet, the squeezer die will contact the poly tubing first forcing the sheets together before forming the rivet.
The example shown is not the ideal use but will convey the idea.






RVGator 05-05-2011 08:05 PM

Thought so...
 
Thanks guys. Everything else turned out great. This was a shocker when I saw it.

How many of those 35 rivet holes needed a bigger rivet?

Cool idea on the tubing.

vmirv8bldr 05-05-2011 09:43 PM

Dimples
 
I'm with Jamie here, looks like the spar was not countersunk enough to get a flush fit.

I took a piece of scrap and put different dimples in the corners and used it to check depth of countersinks for a flush fit. Be sure to mark the corners though so you remember what is what.

bruceh 05-05-2011 10:40 PM

Driling out rivets isn't fun, but one tip I will pass on is to use a slightly smaller drill bit. I have a full index of numbered bits. Using a #41 or #42 will get the rivet out and will (hopefully) not enlarge the hole if you keep it centered. Drill down enough to get the factory head off, then use some small needle nose pliers to grab the shop head and give it a gentle twist to loosen it up for removal. Pounding the drilled rivet out with a straight punch will bend things!


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