SteelMike

SteelMike

Well Known Member
So, how strong do you think proseal is?

I'm trying to make myself feel better about some rivets in my tanks that I know must be bad. It's really tough to get those rivets set right with the proseal and all.

I'm worried about the rivets I drove in the T-405 (I think) tank attach angle on the inboard end. I'm guessing that's a load-bearing structure? I drove those rivets last night and they didn't turn out so good (I think - I'm only going on feel because you can't really see 'em).

Do I drill them out? How to deal with the metal shavings? Is it a critical structure? Will the glue suffice where my rivets won't? Can anyone commiserate?

As usual - thanks in advance...
 
Proseal strength

Proseal is a sealant - NOT an adhesive, so it's structural properties are NIL.
When you say the rivets are bad - you mean the formed heads may not be perfect? Unless they are really really realy bad, I'd leave them alone. The archives have a number of stories where trying to replace 'bad' rivets turns out even worse.
Whenever possible, rivet first, and apply proseal after, especially on the inside of the tank.
 
More?

IIRC, there is room for more rivets on that angle. Have you considered addiing a couple of additional rivets?
 
SteelMike said:
They're bad enough to be concerned. Is that angle a critical structure?
Click to expand...

If they are bad enough to be concerned, I personally would drill them out for peace of mind. Why worry about those rivets every time you go flying?
 
Sounds like a decision

Sounds like you've determined they're bad enough to worry you. That means bad enough to be replaced. You'll sleep better, if nothign else. Drill them.
 
If you can drill them and punch them, you shouldn't get any shavings. Just make sure you catch the shop head. Now's probably the best time to do it before the proseal really sets up.

If you don't, you'll never feel good about flying it.

As mentioned before, you should never count on proseal to do anything more than seal your tanks. It has absolutely no structural value.
 
Yeah, I may drill them out or add some just to feel better, but then there's the question of metail shavings getting into the proseal or the tank itself...
 
So the manufactured head is on the fuel tanks interior? I was thinking it was the shop head........
 
Hmm... Now that I think about it, I think I put the rivets in backwards! Doh!! (It was a bad night last night...). They should have been manufactured heads on the inside, shop heads on the outside, because the thicker material is on the outside. However, I don't think it is physically possible to drive those rivets from the inside - it'd be impossible to get the gun in there, and you can't drive them before installing the rib, because then you wouldn't be able to get at the shop head of the skin-to-rib rivets...

Anyway, it's the formed shop heads on the inside of the tank that I'm worried about. They seem (by feel) uneven or pretty layed over. And of course they're in backwards...

It really was one of the worst build nights I've had so far...
 
Here's a thought.

If you get one of these devices from Avery, you can insert the Cup Set (from your squeezer set) into the heavy bucking bar.

http://www.averytools.com/pc-617-19-dimpling-riveting-block-set.aspx

Place your mfg head inside and use this bucking-bar/cup-set to hold the mfg side tight.

Then shoot the shop head with a back rivet set. You should get a really nice rivet.

I've done this a couple of times and it works great. I've found a dozen different uses for this tool and this one seems to be a good fit for the application.

Phil
 
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SteelMike said:
Hmm...think I put the rivets in backwards! Doh!! (It was a bad night last night...). They should have been manufactured heads on the inside, shop heads on the outside, ...
Click to expand...
Relax SteelMike, you had it right the first time. The T-405 rivets are normally set with the manufactured heads on the outside of the fuel tanks where you can see them. I would not hesitate to drill out and replace defective rivets but if you feel you cannot do so without causing damage there are always alternatives. :)

It is best to CONTACT VAN"S and discuss this issue with them before proceeding. The T-405 tank attach angle is a critical component. As the forward attach point for the wing assembly you want to make certain the angle is firmly affixed to the fuel tank. It is very possible you can add at least one or more additional rivet attach holes to the T-405. I have identified at least 7 possible locations where I believe #30 holes can be added and AD4 rivets installed to augment the hole pattern called out in the drawing. As I am no engineer and don't pretend to be, do not take my word for it. Contact Van's for a factory suggested fix. Include this photo if you wish. Let us know what they say.

dwdixf.jpg


When you are done, make certain to fully encapsulate those rivet heads with proseal too!
 
I had one rivet in that location that raised a question mark in my mind as well, on my right tank. Rather than try to drill it out, I left it in place and added two more rivets for good measure.
 
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