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Wet Riveting the Tanks

Daniel S.

Well Known Member
Hi All-
I'm in the process of sealing my tanks and I've chosen to go the messy route and rivet the ribs while the pro-seal is still wet. I'm kind of curious if most folks who have gone this route clean most of the pro-seal off of the "shop-head" end of the rivet before bucking but after inserting the rivet in the pro-sealed hole... of course we're not cleaning the sealant out of the hole, just cleaning up the tail of the rivet so you can see what the heck you are bucking & then follow up after riveting with a dab of sealant over the shop -head. Or do most people just power through the muck & hope the rivet is set properly? Kind of a dumb question but really curious as to other's method to the madness. ;)
 
Shop heads

I wiped the glob of proseal on the rivet shank with popsicle sticks before bucking. I started with a piece of paper towel but found that the popsicle sticks worked better. You can buy a huge box of sticks at the local craft store for $5.00 or $10.00. Keep a trash can handy because you are going to generate alot of sticky trash :rolleyes:
 
Yes it does help to keep the rivet and the bucking bar wiped clean, you can see better and the bucking bar is less apt to slip off the rivet.
 
Just don't wipe off the outside of the tank with MEK or you will have leaks later on.

Follow Van's instructions and all will be good.
 
The outside of the tank? The outside of the tank will be fine if you wipe it with a damp cloth of MEK and a subsequent wipe with a dry one.

You will not, by that act alone, have leaks, assuming you've prosealed the flange, put a generous amount of proseal on the shop head and added a large fillet along both sides of the rib.

What WILL give you a leak is if you don't seat the rivet in the hole properly because you've got so much ProSeal on the rivet.
 
Bob,

The Proseal will leak if you wipe them clean with MEK.

I only cleaned the top of one tank with MEK while I had the plane home for the new engine. A year after having it painted I have bubbles on the top of that tank only.

Do the research, and not on VAF, and you will find the answer.

Besides, why take the risk?
 
Bob got it right. Everything he said was essentially correct. If the tanks are properly assembled, wiping wet proseal away with MEK is perfectly acceptable. In fact such a procedure was quite routine in the production environment where proseal is used under exterior rivet heads to aid cabin pressurization. If the good folks in the Engineering Department had a problem with that, I'm sure we would have heard about it.

We can all put forth anecdotal evidence to support our opinion. Some builders have reported NOT using proseal under the rivet heads to no ill effect. I wouldn't recommend doing that but there you are. In my case, the leak free, trouble free fuel tanks I built for two RV's were positively awash in MEK as I removed wet sealer from the under construction fuel tank skins. Years later, those fuel tanks continue to be problem free despite liberal use of MEK as a surface solvent so what conclusion would we make of that?

If your tank developed later day bubbles over some of the rivet heads, it was not due to MEK. If an in-depth detailed examination could be done, you will likely discover that either your internal fay boundary, fillet seal or encapsulation method failed inside the fuel tank and that is what really generated the blisters. External use of MEK had nothing to do with it.
 
Working wet

I use paper towels cut into 2" squares for keeping the rivet tails wiped before setting. I use the same towel with MEK to keep the bar clean. This, more than anything, will keep the rivets from cinching over.
I use paper towels to prep the surface, one wet with MEK in one hand, and the other dry immediately following in the other hand. No sense in dissolving all the impurities and leaving them to dry back on the surface, mop it up before it dries.
I wear two or three layers of gloves at a time, easier to pull off one than off and back on. I haven't done my tanks yet, I am picking up the wing kit tomorrow YEA! All these tips were worked out doing wet wing work on DC-6's and Caravans.
 
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