Baffles - choice of rivets

Flying Scotsman · #1 03-30-2011, 12:27 AM

Didn't want to hijack another thread re: 470 vs. 426 rivets, but it raises a question that is relevant to where I am now...

There are several "clips" and angles that are riveted to the inlet ramps and the forward baffles (the ones that go right behind the crankshaft flange/spinner). I think it would look nicer if they were riveted with 426 rivets, but plans call for 470s.

Would I end up just having to redo these later due to failure if I went with flush rivets instead of universal, do you think?

TIA...

Steve

Bob Axsom · #2 03-30-2011, 01:08 AM

If I were going to do it I would use 1/8" diameter rivets instead of the usual 3/32" flatheads used throughout the airplane. The choice of countersinking or dimpling has to be decided and dimpling creates a slightly deeper/thicker but stronger installation than the countersunk approach. The safer way is to go with the roundheads which have been thoroughly field tested. The baffles do take a beating and I've had to come up with repairs in a couple of places over the 7 years of operation.

Bob Axsom

Flying Scotsman · #3 03-30-2011, 01:11 AM

Thanks, Bob...yeah, I'm using 1/8 rivets pretty much everywhere. I was just thinking that 426s would look better around all the inlet stuff. It's an aesthetics thing

but I don't want to have to *redo* this stuff unnecessarily. It's been a PITA enough already...

Rick6a · #4 03-30-2011, 04:30 AM

Quote:

Originally Posted by Flying Scotsman

.....I was just thinking that 426s would look better around all the inlet stuff. It's an aesthetics thing.......

Judgement call. I too think the 426 looks slicker in that particular installation (footsteps too) so I installed the 426 in those areas with no downside perceived. As airframe hours accumulate and the years pass, I seriously doubt the decision will ever prove problematic. Right or wrong, this is just one example of the many builder choices we are all free to decide for ourselves.

fixnflyguy · #5 03-30-2011, 06:48 AM

I did all mine with flush rivets, and it looks better, cleans easier and since they are easy to get to with cowls off, it would be no biggie to replace any if they start "smoking". I make my living as a structural specialist in heavy jet overhaul..if your worried,put some pro-seal between the mating surfaces when you shoot them together, and they will never loosen up !
Bill E.
RV-4
N76WE
Advance NC, 8A7