Van's Air Force
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Tank dimple dies
- Thread starter Steve
- Start date
LettersFromFlyoverCountry
Well Known Member
I bought 'em, I can't say I was terribly impressed after building two tanks. I suppose they couldn't hurt but, you know, I was really more interested in having tanks that didn't leak more than I was having the world's perfect RV. I used a LOT of ProSeal and there's a few rivets that are less than impressive.
Now maybe they'd be even less impressive with regular dies, but I don't know.
I know if I had it to do over again, I don't think I'd spend $40 for something I'm not going to use for, like, two weeks.
Maybe I'll sell you mine for $20.
Now maybe they'd be even less impressive with regular dies, but I don't know.
I know if I had it to do over again, I don't think I'd spend $40 for something I'm not going to use for, like, two weeks.
Maybe I'll sell you mine for $20.
FrankK90989
Well Known Member
For the people who have a small lathe they (dimple dies) are not hard to make. I have made most of mine and they work great.
Frank k. N. Mn
waiting for fuse.
Frank k. N. Mn
waiting for fuse.
BJohnson
Well Known Member
Tank Dies Followup
For those of you that have used the tank dimple dies, did you use them on both the skin and the rib, or just on the rib.
It seems like if the tank die were used on the skin, the rivet head would not contact the skin during bucking. However if the tank die were used only on the rib, that would leave a small gap between the skin dimple and the rib dimple to form a seal around the rivet.
Any tips? I'll be dimpling this weekend
For those of you that have used the tank dimple dies, did you use them on both the skin and the rib, or just on the rib.
It seems like if the tank die were used on the skin, the rivet head would not contact the skin during bucking. However if the tank die were used only on the rib, that would leave a small gap between the skin dimple and the rib dimple to form a seal around the rivet.
Any tips? I'll be dimpling this weekend
Captain_John
Well Known Member
Now THAT is a GREAT QUESTION!
I am DYING to hear the answer!
It seems to me that the whole idea is to create a pocket for which the sealant to fill during compression of the rivet.
This makes the dimpling of the rib with tank die argument sound logical.
(I am assuming skin with normal die in this scenario.)
How far off am I from the truth?
I too, will be dimpling soon. I, however have a set of tank dies made available to me from a fellow builder. I plan on using them... correctly!
HELP!!!
CJ
I am DYING to hear the answer!
It seems to me that the whole idea is to create a pocket for which the sealant to fill during compression of the rivet.
This makes the dimpling of the rib with tank die argument sound logical.
(I am assuming skin with normal die in this scenario.)
How far off am I from the truth?
I too, will be dimpling soon. I, however have a set of tank dies made available to me from a fellow builder. I plan on using them... correctly!
HELP!!!
CJtank dies
To answer the previous post: I used the tank dies on the understructure everywhere (not just the tanks), and on all the tank ribs and skin. Why? The tank die makes a larger pocket to fit the normal dimple into. Two normal dimples don't fit together all that great, but the normal dimple into the tank dimple fits fine. The tank dimples give room for Proseal and allow the rivet to be flush. FWIW - My tanks passed the leak test first shot.
To answer the previous post: I used the tank dies on the understructure everywhere (not just the tanks), and on all the tank ribs and skin. Why? The tank die makes a larger pocket to fit the normal dimple into. Two normal dimples don't fit together all that great, but the normal dimple into the tank dimple fits fine. The tank dimples give room for Proseal and allow the rivet to be flush. FWIW - My tanks passed the leak test first shot.
Last edited:
I bought Bob's dimple dies (see top 2 posts). While I haven't yet done the official Vans soapy water leak test, I'll pass on a few tid bits on the topic. I dimpled the skin AND ribs with those dies. It's the proseal that you spread on the rib flange and over the rivet shop heads that does the sealing, not the dimple die joint. The deeper dimple serves to provide extra space so the rivet sits flush on a bed of proseal. In my opinion, it's theoretically possible to assemble the tanks (except baffle plate) without proseal then apply the stuff to all the rib/skin/fuel fitting joints later.
Left tank LOOKING good,
Steve
Left tank LOOKING good,
Steve
BJohnson
Well Known Member
Followup
Putting a dry rivet in a dimple formed with the tank dies results in the rivet sitting below the surface. To buck it in that position, the rivet will back out until the head is flush, leaving a slight gap between the rivet head and the dimple. The previous posts says the rivet sits on a bed of preseal. Does that mean that proseal flows and fills the gap between the head and the skin dimple?
Is this what causes the heads to protrude when using standard dimple dies on the tanks?
Putting a dry rivet in a dimple formed with the tank dies results in the rivet sitting below the surface. To buck it in that position, the rivet will back out until the head is flush, leaving a slight gap between the rivet head and the dimple. The previous posts says the rivet sits on a bed of preseal. Does that mean that proseal flows and fills the gap between the head and the skin dimple?
Is this what causes the heads to protrude when using standard dimple dies on the tanks?
Captain_John
Well Known Member
Soooo, we install the rivet dry? There is no need to dab proseal into the outside cavity of the dimple?
This is precisely what George Orndoff does in his videos.
Do I have it right?
1) Insert rivets into dimpled skin.
2) Tape rivets into place.
3) Put a layer of proseal on stiffener and/or rib.
4) Place stiffener/rib onto inside of tank skin.
5) Back rivet to specs.
Do I have it right??
CJ
This is precisely what George Orndoff does in his videos.
Do I have it right?
1) Insert rivets into dimpled skin.
2) Tape rivets into place.
3) Put a layer of proseal on stiffener and/or rib.
4) Place stiffener/rib onto inside of tank skin.
5) Back rivet to specs.
Do I have it right??
CJ
Rick6a
Well Known Member
Proseal notes
In addition to your notes I would add the following: Take a tip from some companies in the aerospace industry and.....place a dab of proseal on the countersink dimple with a Q-tip or similiar before inserting the rivet. Squeeze out is good! Also, encapsulate each and every rivet shop head with proseal before closing up the tanks. There must be some reason the big boys do it that way.
Rick Galati RV-6A "Darla"
In addition to your notes I would add the following: Take a tip from some companies in the aerospace industry and.....place a dab of proseal on the countersink dimple with a Q-tip or similiar before inserting the rivet. Squeeze out is good! Also, encapsulate each and every rivet shop head with proseal before closing up the tanks. There must be some reason the big boys do it that way.
Rick Galati RV-6A "Darla"
Captain_John
Well Known Member
Yes, inserting the rivet's manufactured head into a bed of proseal is a practice my fellow building buddy did on his firewall.
It is something I had in the back of my head and was thinking of doing anyways.
Thanks, Rick and All!
CJ
It is something I had in the back of my head and was thinking of doing anyways.
Thanks, Rick and All!
CJHow I did it,
Put the tank skin in the cradle. Cleco all ribs into place. Mix up about 30 gr of proseal for each rib. Remove one rib at a time. Put on 2 pairs of latex gloves then:
1. Spread proseal on the rib flange using a pop stick.
2. Cleco the rib into place inside tank skin.
3. Starting at the leading edge, remove one cleco, replace with a clean rivet, set the rivet. Work from leading edge aft alternating top to bottom. Put the cleco in a container filled with MEK or lacquer thinner for cleaning later. Clean proseal from the bucking bar and rivet set as you go along.
4. After each rib is riveted in place, cover the rivet shop heads and the rib/skin joint with additional proseal . I used an acid brush for this task.
Elapsed time approx 1 hr.
Steve
Put the tank skin in the cradle. Cleco all ribs into place. Mix up about 30 gr of proseal for each rib. Remove one rib at a time. Put on 2 pairs of latex gloves then:
1. Spread proseal on the rib flange using a pop stick.
2. Cleco the rib into place inside tank skin.
3. Starting at the leading edge, remove one cleco, replace with a clean rivet, set the rivet. Work from leading edge aft alternating top to bottom. Put the cleco in a container filled with MEK or lacquer thinner for cleaning later. Clean proseal from the bucking bar and rivet set as you go along.
4. After each rib is riveted in place, cover the rivet shop heads and the rib/skin joint with additional proseal . I used an acid brush for this task.
Elapsed time approx 1 hr.
Steve
Rick6a
Well Known Member
Prosealing tip
If the work schedule permits, a less messier way of working with proseal is to fay seal all the internal ribs at one time then 100% cleco the ribs to the tank skins looking for good squeeze out around all the edges of the rib flanges. Touch up any voids, then walk away to let the sealer cure. Enjoy your weekend. Later, remove the clecos and wet install the rivets, set normally. A lot less sealer mess to deal with. Don't worry about cured proseal sticking to and ruining the clecos. They will work just fine, sometimes the clecos even hold better if well worn or installed in slightly oversized holes.
Rick Galati RV-6A "Darla"
If the work schedule permits, a less messier way of working with proseal is to fay seal all the internal ribs at one time then 100% cleco the ribs to the tank skins looking for good squeeze out around all the edges of the rib flanges. Touch up any voids, then walk away to let the sealer cure. Enjoy your weekend. Later, remove the clecos and wet install the rivets, set normally. A lot less sealer mess to deal with. Don't worry about cured proseal sticking to and ruining the clecos. They will work just fine, sometimes the clecos even hold better if well worn or installed in slightly oversized holes.
Rick Galati RV-6A "Darla"
