Blind rivet question

[Eric B]

Looking at the -12 plans, I noticed where it indicates to cleco te VS skin to the skeletal structure and then begin riveting from the leading edge towards the trailing edge. Final drilling and deburing isn't mentioned that I can see. Is that a difference from the -10 and this kit? Everything on the -10 was "final drill, debur". If so, that speeds the assembly quite a bit!
Thanks!!
Edit: I'm guessing you would debur every pre-punched hole even if you don't final drill, just because of the process used to make the hole.

[rcarsey]

I'm not sure what the manual says.. but in practice, I can say that none of the pre-punched #30 or #40 holes have any burrs on them.

Most of the holes line up so perfectly that final-drilling doesn't seem necessary. There are some, especially on the wings, that I had trouble with.. in the sense that the holes look perfectly lined up, but there is just some minute amount of material that is preventing the rivet from going through. The LP4-3's fit so exactly, that even a little bit of primer in a hole would make it tight for an LP4-3. The CS4-4 countersunk rivets almost always fit if you can visually see that the holes line up.. LP4-3's are not forgiving.

That said, just as a rule, I probably should have deburred every hole I put a drill through.. but after going through this a lot..and checking for burrs..and not finding any.. well, perhaps I got lazy in some areas I saw that i was more "cleaning up the hole" than "final-drilling"...

My general rule is that I try to make the rivet go into the hole with no more than a firm push and maybe a little wiggling. All holes should at least visually line up though. If they dont, then you've done something wrong. I remember the VS being a pain because you're trying to stretch the skin, make it flush against the ribs..and get a rivet or cleco in at the same time. I think I did end up final-drilling a few holes..

Edit: #30 drill is 0.1285" and the LP4-3 rivet is 3.2mm or 0.12598" .. so thats 0.002" clearance. An average human hair is about 0.003"..

[tomkk]

Originally Posted by rcarsey

I'm not sure what the manual says.. but in practice, I can say that none of the pre-punched #30 or #40 holes have any burrs on them.

That wasn't the case with mine, virtually all holes had at least a small burr on one side ...

[Eric B]

That's kind of what I'm thinking. Even if I don't "final drill", I'll still run a bit around the holes before I cleco and rivet. It's just nice to not have to put the whole piece together, drill, tear down, debur, then reassemble, then rivet.

[rk2436]

What worked for me as part of the part prep smoothing all the edges and rounding the corners was to run a 30 chucking reamer thru each hole. As the factory holes were punched there is a slight burr on one side. That last thing you want to happen is to get an LP 4-3 stuck halfway in a hole. It also helped me when clecoing parts together to insert a few rivets first then cleco. YMMV

[rv7charlie]

I thought the -12 had the holes punched to full size, with no need to final drill. Is that not correct? Obviously, surface burrs left by the punch/die still need to be removed.

[rv9builder]

Here's what Section 5 of the instructions says:

All drilled holes, or prepunched holes that have been final-drilled to a larger size, should also be deburred. Holes that were factory punched to final size can be inspected and only deburred if needed (with the exception of large holes to be dimpled for screws - see below).

[rv9builder]

Originally Posted by rv7charlie

I thought the -12 had the holes punched to full size, with no need to final drill. Is that not correct? Obviously, surface burrs left by the punch/die still need to be removed.

For the most part, you're correct. There are a few holes that need to be match drilled and deburred, but not many.

[Floresb18]

I had some parts in my empennage that had no burrs whatsoever and the rivets would fit right in. I noticed especially on the tailcone I had to do some deburring and an occasional ream here and there as a small (almost invisible) little burr was preventing a rivet from going in. I got into the habit of just deburring all holes on both sides. Just a quick 1 turn with the deburr tool on each hole, each side.

[RFSchaller]

Most of my prepunched holes did not need deburring, but not all. My test was to drag my index finger across the row of rivet holes and remove any burrs. Sometimes I had to ream a few holes when the rivet would not go in.