madmaveric

madmaveric

Well Known Member
Tip for new builders, check your holes before riveting

Hi Guys,

I just wanted to pass on a tip for new builders as it could be overlooked when first starting out. This tip is to always look into the holes before putting a rivet in to check the pieces are lined up correctly.

The reason for mentioning it is that it isn’t something I hear suggested to new builders often (I guess most people automatically do it without thinking about it).

This weekend I had an issue with a bent tab inside the Horizontal Stabilizer which I only noticed by looking through the hole just before inserting the rivet (I always check them as I go).

As my build process involves full priming and Duralac (joining compound) I have to clean most holes out using the wrong end of a #30 drill bit, this will scrape excess paint off the hole and help line up the pieces without opening out the hole. During this process I managed to bend one of the tabs inside the structure without realising it at the time (I was probably getting tired as it was near the end of the day), when I came to rivet that hole I could see the inner piece was not packed together as normal, I had no way to get to it as it was inside the spar and the skin was on.

Luckily I managed to check that it was seated correctly using a borescope (a £20 usb webcam type off amazon). I have no idea what I would have done if it hadn’t pulled the tab in so suggestions are welcome if it hadn’t worked.

If I hadn’t noticed I would have just inserted and pulled the rivet as normal, this would probably have made the rivet expand in between the pieces. With the scope I was able to wiggle the rivet further into the bent tab and then pull/wiggle the rivet slowly with the hand puller to help it set.

Sadly I didn’t photograph from the hole at the time (to show what to initially look for) but I did record the borescope and security camera footage if you want to see what it looks like from inside the stabilizer

https://www.youtube.com/embed/q2bVcs

Not sure if I’m ‘teaching granny to suck eggs’ but if it gets one extra person checking the holes before setting rivets it will be worth it.
 
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Very clever, especially the superimposed video. How in the world did you do that? "Music" however plays horribly on my iPad! Thanks for sharing.
 
I wonder

Clever use of the camera (music also not working for me). Begs the question with all the kits out there, how many of those tabs were incorrectly riveted. You were certainly not the first to experience this. Fortunately with all the redundancy built into the design, "probably" will not be an issue ... but time will tell.
 
BigJohn said:
Very clever, especially the superimposed video. How in the world did you do that? "Music" however plays horribly on my iPad! Thanks for sharing.
Click to expand...

Hmm there shouldn't have been music on it. That was probably from the security camera recording the radio in the background (I have it on in the other part of the garage to remind me it is after midnight and time to stop building :D).

The superimposed video is done using cyberlink powerdirector program on windows. I have a copy I brought years ago and it allows you to do all sorts of editing fun :D.

The main reason I decided to make the video was only after I realized I had recorded the borescope video (completely by accident). I then though it might be worth doing to show the possible issues that new builders may not check for (i.e. looking in the holes to make sure everything is in line).
 
Another area to pay particular attention to is the connection of the tail to the fuselage center section. After the fact, I found 4 or 5 rivets in the lower corners that had simply pushed the tabs up and the rivet done nothing. Was not easy to drill out and fix, but more importantly it could have been missed entirely. If you have your tail attached, you might want to look at this area more closely, since it is sort of hidden after assembly.
 
Tabs

Excellent advise and great video. I always checked those tabs for that every reason. Most are accessible so I use a piece of windshield washer hose to hold parts together while the shop head forms.
 
I had the same issue with a few of the wing tabs. They will pull up with a cleco but drop back without the cleco meaning that they wont rivet up flush. I found the easiest way to deal with them was to use a little bit of super glue. Then when the cleco was removed the tab is still in contact with the skin allowing the rivet to go in easily.

Alex
 
Alex Edwards said:
I had the same issue with a few of the wing tabs. They will pull up with a cleco but drop back without the cleco meaning that they wont rivet up flush. I found the easiest way to deal with them was to use a little bit of super glue. Then when the cleco was removed the tab is still in contact with the skin allowing the rivet to go in easily.

Alex
Click to expand...

Great idea. I hadn't considered using a drop of glue, thanks.
 
I just riveted the tailcone to the fuselage .... except for those few rivets that DonFromTX referred to.

I can get a cleo in but not the rivet, the tabs won't stay in place. Maybe I'll try the super glue suggestion.
 
Perplexed, I waited until my son came to visit, and put him inside. He held the tabs down while I put a rivet in. Obviously we removed the worthless rivets first. This is so easy to miss if I were to become a DAR, it is the first place I would look.
 
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