[burtj]

Hola,

Building first fuel tank. Several of the rivets sit a little bit proud of the surface. I'm dabbing proseal in the dimple before inserting the rivets, and bear down on the rivet gun to try to get a tight squeeze. Ideas, cures, cover ups????

Thanks.

Burt

 

[apatti]

Some folks (me for instance) used a special set of dimple dies for the tanks. They dimple just a little deeper to account for the proseal. Others have said they aren't needed. You can get them from Cleveland; maybe others.

 

[newtech]

Tank dimple dies from Cleveland tool will give you a little deeper dimple to allow for the film of Proseal. After the fact a rivet shaver for your countersink drill cage will let you shave the tops of the proud rivets off.

I am in the process of final prep for painting and just before the detergent wash, acid etch and alodine treatment I hit the river lines with a sanding block with 220 wet or dry paper. Yes it will remove some of the alclad aluminum coating but the very next process is the acid etch and alodine treatment. Please take this paragraph only as a description of how I am doing mine. Taking sandpaper to a line of rivets is not to be done by the weak of heart or those without a true feeling in their hands of what they are doing. If you don't understand the last sentence then you shouldn't be sanding the rivet lines.

 

[az_gila]

Shave it

If the rivets are proud by 0.006 or less (check by comparing to a feeler gauge), then they can be shaved to just about flush, and still be within a Mil-Spec...

http://home.earthlink.net/~gilalex/rivet_spec/rivet_a.htm

Tool example is here...

http://www.averytools.com/pc-448-23-rivet-shaver-bit.aspx

gil A

 

[Noel Simmons]

small tip great results

One other thing you can do to help is dimple the under structure, (ribs) to receive the skin dimple. This means if you use the same dimple dies on the skin as the ribs you will inherently have proud rivets. The top skin's outside is 100 deg and the back side of the skin is 110 deg. So when you dimple the rib the top is 100 deg and the back side is 110 deg's. Then you put the skin on the rib and the interface is thus: skin 110 deg trying to go into a 100 deg hole, add a little pro-seal and the rivets will be proud as a cat covering up in a flower bed!

Try this: make the rib dimples 110 deg on the top surface. Do this by one of these ways.

1: thin material (.032 or less): use a small piece of aluminum that you leave on the male dimple die. this mimics the skin, at times we super glue this piece on the male dimple die. This will pound out after several hundred dimples so you will need several handy.

2: thick material (.032-.040): dimple with your regular dimple dies, make sure you have completely dimpled the hole so hit it twice or three times with the c-frame or twice with the pneumatic squishier. Then using a 110 counter sink true up the dimple.

3: for heavy material (+.040); just use the 110 deg counter sink.

 

[Sid Lambert]

Keep it clean

Also, clean the rivet set in between each rivet. That was the reason I had a few standing proud. I did not use the tank dimple dies even though I had them.

 

[panhandler1956]

Me too

Also, clean the rivet set in between each rivet. That was the reason I had a few standing proud. I did not use the tank dimple dies even though I had them.

Mine are alittle proud too. I suspect the cause was as Sid said keeping the set clean. For reference I didn't use the tank dies either. I plan to shave mine.