Dinged skins from riveting

How do you handle a bad riveting job when you manage to ding up the skins? I am riveting the skins onto my HS. I started Tuesday night on the bottom side since, still being quite new at this, I figured I would be making most of my mistakes there and being on the bottom, they would not be noticeable to most casual observers. To my delight, I did a pretty decent job. Last night, I started work on the top side, confident in my abilities, and yet I managed to bong up a few really bad. Some of the damage to the skin is pretty unsightly, where the rivet gun pounded in the skins pretty bad. Structurally, I think things are fine, but appearance wise -- ugh. Are these "blemishes" (to use a nice term) able to be filled in later, during the finishing stage? If not, I am going have to paint this plane a matte color!

Maybe last evening was a bad night. I got a late start and, too, I was in an uncomfortable and awkward body position to buck the rivets. Maybe I wasn't holding the bucking bar as tightly as I should have. I just know that I hadn't changed the air pressure on the gun or anything since the previous night.

Well, I did ask a tech counselor to come visit and look at things before I close up my VS (where I did a decent job on the skins) and this side of the HS (still need to rivet in the aft spars). If I still have troubles tonight with the opposite-side HS, I will ask him to observe me and tell me what I am doing wrong all of a sudden. At least along the outer edges the pneumatic squeezer is making some fine looking rivets.

Overall, this has been my most frustrating time. Do most guys ding up their skins like this, or am I simply inept???

Jeff,

I have a few places like this as well. I'm told a good painter will be able to fix these.

One thing I did after a few dings like that was purchase the swivel head mushroom set from Cleaveland Tools. I believe the part number is RSMS75. It is alot more forgiving than the non-swivel head. IMHO, it is worth every cent.


Doug

Jeff,

Go to the auto parts store and a tube of glazing putty (thick primer) and some plastic spreaders. Scratch surface apply coat, easy to sand.

Masking tape tip...

I learned at a build center, where I did my empennage, to put a strip of masking tape over the flush head of the rivet set. It won't stop you from a true "ding," but it does help to avoid marring and scratching if the set bounces and skitters on the skin.

Of course, the masking tape is sacrificial and must be replaced regularly, but it does help. I use the green not-to-sticky tape as it is easier to remove after it has been "solidly" applied.

Try this...

I had the same problem learning to use the flush set. I chose to use this one:

http://www.averytools.com/cart/p-31-flush-swivel-rivet-set.aspx

I've been very pleased with it.

java said:

I learned at a build center, where I did my empennage, to put a strip of masking tape over the flush head of the rivet set. It won't stop you from a true "ding," but it does help to avoid marring and scratching if the set bounces and skitters on the skin..

Click to expand...

I started using masking tape, but I tried using some duct tape this past weekend and I like it much better. It also seems to last a little longer than the masking tape does due to it's extra thickness and strength.

Jeff, it appears to me that you are letting the gun bounce and/or move laterally. The bucking bar can bounce, but not the gun! I always try to tuck my arm (elbow) tight to my chest so as to really steady the gun. Also, if you have not polished the rivet set, do so...

Always use the heaviest bucking bar you can, the rivets will set with fewer hits with a heavy bar. I have found that for AD3 rivets 45-50 psi works pretty well for me.

Also, as mentioned by someone else masking tape will help. If you are letting the gun bounce you will have to change the tape often, if you are holding it tight and steady the tape will last for a couple of dozen rivets, kind of a test tool!



JMO and hope this helps.
Larry

I bought a 3-pack of rivet sets (1/2" , 3/4" and 1") with the brown urethane ring on Ebay. The ring helps keep the rivet set square to the work. I bought a swivel set later but never bothered to grind the new rubber sleeve flush to the face of the set before I could use it because the others worked for me.

My $.02,
Steve

Its good to hear that a good painter can clear up some of these because I had similar problems early on. I finally figured out how to set a good fush rivet with no skin damage using what I would call a soft long (approx 2 - 3 seconds) stroke with the rivet gun. It is easier to control the gun and will not depress or dent the skin. On the -3 rivets on the wing, I did the entire right wing from the front, rather than back rivet, and it came out very well.

Remove more of the plastic from the skin so that the flush set can sit right down on the aluminum. Your flush set is likely floating around when you rivet because it is held away by the plastic. The swivel head flush set is highly recommended, as is covering it with tape. FYI, if I ever build another RV I will remove all the plastic from all the skins and not spend any time peeling off strips of plastic. Your minor dings will disappear during paint prep, during which the skins will be scuffed mightily with Scotch Brite pads. Build on.

A few unsolicited tips:

One of the best purchases I ever made was a wide flush set with a rubber edging.

The rubber edging keeps the set from sliding around and the wideness of it helped to keep 'on center' of the rivet being driven and it helped keep the rivet gun perfectly vertical over the rivet.

I forget the part number but I bought it at an EAA show from Aircraft Tool.

Switching to this rivet set virtually eliminated any surface marring or smiling around rivets.

We also use rivet tape, either on the rivets or on the face of the set. 3m striping tape works really well. vans rivet tape works well too.

As most old-timers will tell you, 'let the gun do the work'. IE, PRESS LIGHTLY and operate the gun smoothly. Keep the gun flush against the work. Tap the rivet from the bottom with the bucking bar to "make sure" you are on the correct rivet.

I operate the gun in "short bursts". IE, burp, burp, burp. I vary the length of the 'burps' depending on the length and size of the rivet, but I usually try to get the rivet driven within a couple of seconds, or it can start to harden and become difficult to drive.

Finally, if the rivet won't "sit down" in the hole when you place it, don't think you can "drive it in". Just don't do it. Pull the rivet and "work the hole" with a scribe until the rivet will sit down flush. If it still won't sit down, grab your countersink tool and 'break' the countersink until the rivet will sit flush.

If it won't sit flush, it dang sure won't drive flush.

Finally, if all has gone wrong and you end up with the "smile of death", bondo is your friend.

Fortunately, of the 14000+ rivets (I think thats the approximate number) on my RV-7A, less than a handful will require any type of cover up, thanks to the above tips.

YMMV

Jeff R said:

How do you handle a bad riveting job when you manage to ding up the skins? I am riveting the skins onto my HS. I started Tuesday night on the bottom side since, still being quite new at this, I figured I would be making most of my mistakes there and being on the bottom, they would not be noticeable to most casual observers. To my delight, I did a pretty decent job. Last night, I started work on the top side, confident in my abilities, and yet I managed to bong up a few really bad. Some of the damage to the skin is pretty unsightly, where the rivet gun pounded in the skins pretty bad. Structurally, I think things are fine, but appearance wise -- ugh. Are these "blemishes" (to use a nice term) able to be filled in later, during the finishing stage? If not, I am going have to paint this plane a matte color!

Maybe last evening was a bad night. I got a late start and, too, I was in an uncomfortable and awkward body position to buck the rivets. Maybe I wasn't holding the bucking bar as tightly as I should have. I just know that I hadn't changed the air pressure on the gun or anything since the previous night.

Well, I did ask a tech counselor to come visit and look at things before I close up my VS (where I did a decent job on the skins) and this side of the HS (still need to rivet in the aft spars). If I still have troubles tonight with the opposite-side HS, I will ask him to observe me and tell me what I am doing wrong all of a sudden. At least along the outer edges the pneumatic squeezer is making some fine looking rivets.

Overall, this has been my most frustrating time. Do most guys ding up their skins like this, or am I simply inept???

Click to expand...

Get some Scotch #811 removable tape

At your local Office Max or Office Depot. Scotch removable magic tape # 811 in the blue box. Just place small pieces over the rivet heads. You can use one piece several times. If back riveting, then place a long piece over a whole row of rivets.

This tape goes on and off easily; and you'll have a mar free finish.

This is the same stuff that tool suppliers were sending to customers...........years ago!

L.Adamson

Wow, guys thanks for the responses.

I incorporated some of the suggestions this evening and things started going much better. One trick seemed to be changing to a larger bucking bar. I am also getting better at controlling the gun. Most of those really bad dings occured when I depressed the trigger too hard and the gun got away from me. I am getting better at both holding a light trigger, and at giving it a shorter blast when I want. I still need to get better, but my second set of skins is certainly an improvement. The tape on the rivet set seemed to help prevent the gun from sliding off. I may try tohe rivet tape and will check into a swivel set.

Anyway, thanks for the help. I feel a lot better now.

TO BE CONSISTANT....

Jeff R said:

Wow, guys thanks for the responses.

Most of those really bad dings occured when I DEPRESSED THE TRIGGER TOO HARD and the gun got away from me. I am getting better at both holding a light trigger, and at giving it a shorter blast when I want.

Anyway, thanks for the help. I feel a lot better now.

Click to expand...

Do a test plate with the rivet that you are going to use. Adjust the air pressure so you can USE FULL TRIGGER to set the rivet. The amount of time you spend hitting the rivet is now WHAT YOU NEED TO CONTROL.
Full trigger then the right amoun of time............. When you get the timing down, all of the shop heads will be the same

pads of round tape

Jeff,
All of the above is excellent advise...
I bought round masking tape pads from planetools.com and you just stick the round pad of tape (that comes on a roll) on the swivel flush set and it lasts a fair amout of rivets. Maybe more expensive but very convenient....
Jim

who was it ?

i think it was Bob Axsom that said throw that swivel set away. and i couldnt understand why. but this is why. if the swivel set is not more over the web than centered on the flange it will walk all over the place. especially on curved surfaces.(the operator using too much force will do this as well) the fixed sets really do a better job. but require a little more care on your part. sounds like im talking out of both sides of my mouth but you can get mediocre results at any angle with the swivel set. but you can really get near perfect results with the fixed set.. if you notice buck tails driving a little off to one side try the fixed set. this is especially true on the canopy skin.

I don't understand putting tape on the rivet set. If you plan on painting, the slight marring is not a concern, right? Am I missing something?

Jeff, I had dings much deeper than the ones in your pic.

When I was working on my fiberglass parts, I just mixed up some risen with micro balloons and filled in the holes. The worst part of my emp was the vertical center rib. If you look at my plane you won't fine any rivet line there because they are all filled in. Don't tell anyone, OK.

Kent

I used a flush swivel set without the rubber ring on my emp and had a few dings . After the emp was done I pulled all the blue vinyl and almost cried - it looked like a golf ball! (not really - defects in your pride and joy are much smaller than they appear to YOU).
Turns out a polished set walks easilly, and once it's not centered over the rivet/rib flange it will dent your skin. I've simulated the ring with masking tape and been much more careful about keeping the set perpindicular to the work, and have had much better results.