Rivet Shaving

mlwynn · #1 07-25-2006, 10:29 AM

Hi all,

Anyone have experience with a rivet shaver?

I finished assembling and testing my tanks a couple of weeks ago. All is well except that I have a number of rivets that are slightly proud along the baffle line. I am not sure if I insufficiently countersunk or if some of them are in a little crooked. It would probably have been better if I had clecoed the entire line and then riveted later when it was less goopy. Never-the-less, the problem is there. My options are: 1) live with it 2) drill them out and reset them or 3) try to shave them down.

I have seen advertisements for rivet shavers. It looks like they take a flat blade and level what you put them over. It also looks like there is tremenous opportunity for making some really interesting holes and/or gouges in the skin at the same time. Anyone used this tool successfully? Tips?

Regards,

Michael Wynn
RV 8 Wings
San Ramon,CA

Hawkeye7A · #2 07-25-2006, 11:48 AM

I had the same problem you describe with the baffle rivets. Almost all of them tipped slightly. So, on the second tank I took extra care to ensure that the clecoes were perpendicular to the skin indicating that the skin and baffle holes were properly lined up. I got pretty much the same results although not quite as severe(using a pneumatic sqeezer). I used a shaver on them and found if you hold the cage down firm on your workpiece with your non-drilling hand, it does a very nice job removing only the high metal. It is basically an end mill cutter though so you need to pay close attention while using it to avoid a runaway. IIRC I used a low to medium RPM on the cordless drill. Hope this helps.

N916K · #3 07-25-2006, 12:54 PM

I used a shaver bit on a standard microstop countersink cage. I found if you set it a little shallow and work very slow that it will work quite well. Be careful on the tanks because of the curve you may end up taking more off than you want. As far as speed goes, I've tried an electric drill and my high speed air drill. I like the high speed drill but I had no run away problems with the low speed eletric drill.

I've never used one of those expensive rivet shavers, maybe they work much easier.

Rick6a · #4 07-25-2006, 01:06 PM

Quote:

Originally Posted by mlwynn

Anyone have experience with a rivet shaver......I have seen advertisements for rivet shavers. It looks like they take a flat blade and level what you put them over. It also looks like there is tremenous opportunity for making some really interesting holes and/or gouges in the skin at the same time. Anyone used this tool successfully? Tips? Regards, Michael Wynn
RV 8 Wings San Ramon,CA

Mike,

I am very familiar with rivet shavers, used them for years in the production environment and I often used one to shave the steel stem of a Cherry rivet to surface flushness. I even put one to work on my RV, but mainly for subtle cosmetic reasons:
http://www.vansairforce.com/communit...ead.php?t=2322

I wouldn't waste my time loading a rivet shaver bit into a common countersink cage. The average air drill motor cannot develop the serious RPM's a dedicated rivet shaver motor turns at. In addition, a good rivet shaver usually has two rubber stop pads attached to the working end of the motor to help prevent the shaver from "walking" across the work.

The best tip I can give you is to test your adjustments on a piece of scrap before shaving your rivets for real. Set it too deep and you'll wish you left well enough alone.

Brian Denk · #5 07-25-2006, 04:17 PM

Tall rivets along the tank baffle flange are very common. Mine too. Tried a rivet shaver. Could not get the hang of it so pressed on. Know what? YOU WON'T CARE after you paint the plane. With a few coats of primer and paint, they look much less obtrusive. Problem almost disappears. If still in doubt as to what to do, do NOTHING. Move on and work on something else. "Problems" seen as monumental now tend to fade with time.

"What? Oh those tall rivets? They're Vortex Generator rivets. I can fly backwards now."

RScott · #6 07-25-2006, 06:29 PM

I had high rivets also & traced the problem to not putting enough pressure on the squeezer to keep the rivet from backing out slightly when the ram first starts to compress the rivet.

About shaving rivets: Early in my project I had a high rivet. I have the kind of shaver that goes in a countersink cage. We had a builder's group meeting at my place & a very experienced AI showed us how to use it, which was pretty straght forward, except that he put some double sticky tape under the C/S cage, which kept it from walking around. Worked great, but was a trial & error kind of thing, shaving a little, adjusting the cage, shaving a little more, etc. Not the kind of thing you want to do on the 82 or so rivets on each side of a tank baffle.

rv9aviator · #7 07-25-2006, 06:58 PM

Why not just use a flat mill file and gently file the high spot down. Maybe I am completely missing the reason why to use a shaver. I can see it if you were going to polish and not paint but the small scratches from the file will fill with primer easily. Please educate me.

RV8RIVETER · #8 07-25-2006, 08:19 PM

I couldn't bring myself to pay the $$ for a rivet shaver for just a couple of rivets. So, after thinking a bit, got out the old handy "speed tape". Very thin aluminium tape. I put tape on the offending rivet, carefully cut/removed the tape covering the rivet and then sanded it down with a roloc disc on my die grinder. The tape protected the skin around the rivet from errant movements just fine. Now, the rivet is not "prefectly" flush, but it is very hard to see bare, and if you are going to paint (which I have not done yet) I'll wager it will not be discernable.

N674P · #9 07-25-2006, 10:00 PM

I may have just gotten lucky - I use a shaver in a countersink cage with very good results...
My shaver is I think 3/8" dia from one of the tool houses (Avery?) and a dedicated countersink cage - since I got a grip of them cheap between ebay and Boeing Surplus. I set it up when I had a few high rivets on my rudder to where it's maybe a few 10 thousandths higher than the skin, then starting away from the rivet slide it across it.
Now on my wing spars I countersunk the platenut rivet holes a little too shallow. I had several riveted in before I got the countersink to the right depth, and knew I didn't want to drill the high ones out. I pulled the dedicated shaver out, already adjusted, and made really nice dots on the spar! Flush, really shows up against the anodizing, and not a scratch or scuff on the spar itself.

briand · #10 08-28-2006, 04:25 PM

Well I finally got the #@*^! to seal up the baffle on my first FTand ended up with the same high rivet problem. Naturally the top ones are the bad and the bottom rivets are ALMOST perfect but still a little high. I'm worried about there bing a structural issue though. Anyone else? It looks bad but if its safe I can live with it. I'm sure some of my "so-called" friends will all point it out but I'll just tell them to go build one better. I know there 84 rivets on each side but you probably wouldn't ever find a production airplane that has such a defect wether its just cosmetic or not.