Flush Rivets not so flush

[TheBoatLife]

I'm doing the rivets on the vertical stabilizer, the first real batch of riveting on this project, and I'm a little unsure of what to do or if I need to worry.

Most all the flush rivets are great, nice and flush, but there are a few that aren't perfectly flush. I know drilling out and removing rivets is potential to cause more problems, so I started with the worst of the 3.

I drilled it out just fine, but dropping a new rivet in I realized the rivet doesn't sit flush so it wasn't bad method with the gun, I'm assuming maybe I didn't dimple it correctly?

Is that anything to worry about?

 

[RViator60]

Usually when I had a rivet not set flush, it was because I didn't hold the factory head down firmly when I expanded the rivet. Your technique will get better, but practice setting a few more rivets on a scrap piece to refine your technique. If you haven't yet, get the practice kit from Van's. Personally, I would never tolerate a non-flush rivet. Proper technique will become more critical as you proceed with more complex components, particularly the fuel tanks.

 

[RWoodard]

Could be that the hole is underdimpled or you didn’t go quite deep enough if you opted to machine countersink. Could also be that you’re applying too much pressure with your bucking bar. I’ve seen a lot of this when people are first starting out. The bar actually bounces against the back of the rivet to make it mushroom out into final form. I’ve had experienced builder helpers put so much pressure on the rivet that I had to engage my shoulder and some body weight to keep the flush side of the rivet from being pushed out of the hole. This is too much pressure on the bucking bar side of things.

As others suggested, you may want to play around with some scrap to get the hang of it. Since it’ll be a real inconvenience to take your VS apart enough to re-dimple the offending holes, I would suggest using a debarring tool or a countersink tool adjusted adjusted to be less deep than normal to increase the depth of your existing dimples. This technique isn’t something you’d want to do on every hole for fear of reducing the strength of the finished part, but for a couple of holes here and there disbursed around a bigger piece, you should be just fine.

 

[TheBoatLife]

Got it, thanks.

I drilled all three rivets out.

Two of the offending ones were just poor technique, the first one was just not dimpled enough. All are good now.

Thanks for the quick responses

 

[D-Dubya]

Is there an experienced builder in your area that could work with you for the next rivet session or two? Even better, is there an upcoming EAA RV Building school that you could attend? Either (or both) would be helpful and build your knowledge base and confidence. It might help prevent damaging a piece or two as well.

 

[TheBoatLife]

Is there an experienced builder in your area that could work with you for the next rivet session or two? Even better, is there an upcoming EAA RV Building school that you could attend? Either (or both) would be helpful and build your knowledge base and confidence. It might help prevent damaging a piece or two as well.

I took the SportAir workshop class, but that was a year and a half ago. And I did some practice kit stuff, but that was months ago. I'm just second guessing myself here and there as I make small mistakes and want to avoid turning a small mistake into a big one.

Plus for some reason it stuck in my head from some video or other that a few less than perfect rivets are usually better than the result that's possible from a less than perfect removal.

 

[AlphaCharlieBravo]

I took the SportAir workshop class, but that was a year and a half ago. And I did some practice kit stuff, but that was months ago. I'm just second guessing myself here and there as I make small mistakes and want to avoid turning a small mistake into a big one.

Plus for some reason it stuck in my head from some video or other that a few less than perfect rivets are usually better than the result that's possible from a less than perfect removal.

Sallys or Pepes Pizza?

I use the middle tool to align the holes on occasion when a rivet doesn't drop right in. I use the top tool and place it into the dimpled hole in the rivet and apply some gentle pressure to "seat it". I'll use the deburring tool for a swipe to let it sit flush. All different techniques.

Hope that helps.

 

[TheBoatLife]

Sallys or Pepes Pizza?

I use the middle tool to align the holes on occasion when a rivet doesn't drop right in. I use the top tool and place it into the dimpled hole in the rivet and apply some gentle pressure to "seat it". I'll use the deburring tool for a swipe to let it sit flush. All different techniques.

Hope that helps.


View attachment 57650

Yes that definitely helps, trying to soak in all the info and techniques.

And Modern.
Although all 3 are great

 

[georgemohr]

Note that its really hard to 'not dimple enough' if you are using the right tools. So that's a concern, I'd get someone to have a look at what you are using to dimple. Maybe post pics here and describe how you setup the tool.

 

[D-Dubya]

Plus for some reason it stuck in my head from some video or other that a few less than perfect rivets are usually better than the result that's possible from a less than perfect removal.

As I understand it, Van's builds in a safety factor to their riveting calculations, as they know that we are not (usually) professionals and aren't cranking out 737's all day. So if every rivet isn't perfect, your plane won't fall out of the sky. And yes, it's sometimes possible to do more damage drilling out a rivet than just leaving it alone. But I wouldn't leave any with the flush head protruding proud of the skin. Part of what comes with experience is knowing when to leave it alone and knowing when to go back and do it better. I think Kenny Rogers had a song something like that a few years back.

That circles me back to my original statement of having someone look over your shoulder for the next few riveting sessions. Most builders are more than happy to give back to the RV community and lend a hand to newbies every now and then. Don't be afraid to ask. The EAA Technical Counselor list has people that usually have experience with more than one RV.

 

[TheBoatLife]

Note that its really hard to 'not dimple enough' if you are using the right tools. So that's a concern, I'd get someone to have a look at what you are using to dimple. Maybe post pics here and describe how you setup the tool.

I'm using a C frame dimpler, however I did have some issues with a few dimples where I was trying to position the skin and spread the skin apart enough to knock the dimple in and actually use the hammer at the same time. That's where I had the issue with not dimpling enough, when I didn't have enough hands. I did figure out a method but there were a few knocks of the dimpler i was still figuring out the best method.

 

[Aer0bat]

Sallys or Pepes Pizza?

That's a thread that will make the slider/tip-up debate look incredibly civil.

 

[georgemohr]

I'm using a C frame dimpler, however I did have some issues with a few dimples where I was trying to position the skin and spread the skin apart enough to knock the dimple in and actually use the hammer at the same time. That's where I had the issue with not dimpling enough, when I didn't have enough hands. I did figure out a method but there were a few knocks of the dimpler i was still figuring out the best method.

Ok yeah that's probably the tool with the most variability. We wound up getting a DRDT because of the simple repeatability and less hammering. Also the pneumatic squeezer is a win for some of the dimples.