danielhv

danielhv

Well Known Member
So yesterday I started prosealing the ribs in the tank. I got them riveted up, and put the fillet on 2 of the ribs... and ran out of the batch I mixed up. I was so a$$-whipped (please God, dont let this thing leak!) by this stuff at that point that I called it quits for the day. My question is this... is it ok to wait a day or two before I go back and put a fillet on each rib and then a dab on each rivet head? Or is there some reason this has to all be done at the same time? Also, on the end rib, I didnt really do the dab on each rivet head... but instead smeared a thick layer in all directions with my finger to cover everything. I was thinking about doing this to all the ribs... Will this provide enough seal or should I go back and put the dab on each? Here is a pic of what I'm talking about:

img_2972.jpg
 
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proseal

Daniel,

Make sure each and every rivet is well dipped in Proseal and then the shop head well covered. Better to fillet when installing, but you can do it later as well.

For the end ribs, the fillet is more critical than the dabbing, given the shop heads are outside the tank. According to your photo, I would say what you did on the shop heads is fine, but it's the fillet that really matters here.

You really want to avoid any rivets leaking once that rear baffle is on. Mind you before installing the baffle, you may want to test by filling with water. I mangaged to pick up and correct two rivets leaking this way.

Once the rear baffle is installed, should you discover a leaking rivet, you may correct by using blue locktite and a vaccuum cleaner to create suction and draw the locktite inside the tank. Proseal diluted with MEK, to make it more liquid, can also work here.

Good luck with the rest of the tanks,

regards,

Normand RV 8 Fuselage slow build.
 
psychose said:
You really want to avoid any rivets leaking once that rear baffle is on. Mind you before installing the baffle, you may want to test by filling with water. I mangaged to pick up and correct two rivets leaking this way.
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Checking for gross leaks with water is OK, but don't depend on it. Gas is less dense than water and will leak through places that water won't.
 
Mel said:
Checking for gross leaks with water is OK, but don't depend on it. Gas is less dense than water and will leak through places that water won't.
Click to expand...

So when the day comes that I am ready to put the rear baffle on... can I just buy enough avgas to fill the tank in the craddle and see if it leaks?
 
I think you're tanks will turn out just fine. I just finished mine, you can see the progress here:
http://moener.blogspot.com/

I wouldn't worry about the mess or risk of dealing with avgas. Just make sure you put a decent bead of sealant in front of the rivet line before you push the rear baffle on. It does indeed form a fillet. I have proof here

Also, don't worry about covering the shop heads of the two outside baffle or the rear baffle. If you form a nice fillet on the inside, the fuel will never reach those spots. (I did this on one side, and then realized it wasn't neccessary so I skiped it for the baffle and the other side.)

Just test the tank by presure testing it with air using a balloon, and if it holds, you're all set.
 
Not to much in front

RyanM said:
I think you're tanks will turn out just fine.
Just make sure you put a decent bead of sealant in front of the rivet line before you push the rear baffle on. It does indeed form a fillet.
Click to expand...

Make sure the bead of sealant is nice and healthy and right along the front edge of the rivet line and not to far forward before you push in the rear baffle. On my first tank I was frightened by Vans instructions about using too much sealant to avoid "pillows" or something like that. It turned out my bead was just a tad too far forward and it didn't make a fillet against the rear baffle. What a nightmare that was to fix!
 
try a U tube manometer

RyanM said:
Just test the tank by presure testing it with air using a balloon, and if it holds, you're all set.
Click to expand...
I agree that you don't need (or want) to mess around with Avgas for leak testing, but I didn't get good balloon results. It was hard to get the balloon sealed well, and then when I did, it inflated and deflated by itself. It was due to the ambient temperature change in the shop.

A better, and more importantly easier, way was to look a long clear tube up to the tank, one end open, and filled partially with water. Make a U shape from the tank down and back up vertically. Mark the tube on the upward vertical side where the water falls when you pressurize your tank. You can then watch it move up and down (literally). After a couple of days you'll see that it moves up and down and isn't trending down. No leaks (I hope). BTW - the hardest thing was to seal the fuel filler cap and the tank test valve.

Good Luck - your tank looks great.
 
Build on - use plenty of proseal, leak test with a DIY-manometer, and seal the cap and drain with Fuel-Lube (EZTurn).
 
danielhv said:
So yesterday I started prosealing the ribs in the tank. I got them riveted up, and put the fillet on 2 of the ribs... and ran out of the batch I mixed up. I was so a$$-whipped (please God, dont let this thing leak!) by this stuff at that point that I called it quits for the day. My question is this... is it ok to wait a day or two before I go back and put a fillet on each rib and then a dab on each rivet head? Or is there some reason this has to all be done at the same time? Also, on the end rib, I didnt really do the dab on each rivet head... but instead smeared a thick layer in all directions with my finger to cover everything. I was thinking about doing this to all the ribs... Will this provide enough seal or should I go back and put the dab on each? Here is a pic of what I'm talking about:
Click to expand...

One thing I noticed with your photo (though it may just be my monitor or teh way the photo reproduced) is that the sealant looks very dark in color like it is quite a bit rich in catalyst.
The proper color is typically a medium gray. How are you measuring the material ratios. A little extra catalyst doesn't hurt but if you get carried away it does degrade the performance of the sealant and the working time is reduced.
 
Missing T-410 Reinf. Plate

Daniel,

I could be wrong, but it looks like this photo is of the ouboard tank rib. It also looks like you're missing the T-410 reinforcement plate on this rib (no holes/rivets). This plate would have covered the tooling hole that you've plugged with something else... pop rivet? You'll definately want this plate.
 
re: leak check

danielhv said:
So when the day comes that I am ready to put the rear baffle on... can I just buy enough avgas to fill the tank in the craddle and see if it leaks?
Click to expand...

That's how I did mine for the RV10. Stood them up in the craddles, filled 'em with gas, just laid the rear baffle in place for a cover, & let them sit for a couple of days. Worked great.:) No leaks either.

Marshall Alexander
 
re: gas

I checked mine for the RV10 with gas. I stood them up in the craddles, filled 'em with gas, just laid the rear baffle on for a cover, & let them sit for a couple of days. Worked great. No leaks either.:)
When I got the rear baffle installed, I filled them again, clear full with a little extension tube on the vent line for expansion. Worked great, again, and again, no leaks.

Marshall Alexander
 
cln1owner said:
Daniel,

I could be wrong, but it looks like this photo is of the ouboard tank rib. It also looks like you're missing the T-410 reinforcement plate on this rib (no holes/rivets). This plate would have covered the tooling hole that you've plugged with something else... pop rivet? You'll definately want this plate.
Click to expand...

Oh ****.... :( I thought there was only one (inboard)!.... What do I do?!? :( :eek: Can I cut that rivet out, match drill a plate, and rivet it in place with the mfg heads on the outside of the tank rib? I can't believe I did this. :mad: Should I wait a few days for the proseal around it to cure the rest of the way so I dont damage the fillet underneath it?
 
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Daniel...I am going through the same challenges as you at this time, so I must first say that I am NOT experienced and just learning. However, I want to share some input given to me by a friend of mine who works for Ratheon, and has handled proseal alot. He stopped by one day and looked my proseal technique over carefully. He did find a couple places where there were VERY TINY "pinholes" He recommended making sure these were covered with a little dab of additional proseal, as they are a common area of "potential leakage". Easy to do...and may or not have been a source of leak...but merits careful inspection. Also, he told me...as you probably have read...be very cautious with pressure/vaccum amount when testing...excessive air pressure or vaccum can damage the skin. By the way...I also forgot the outboard reinforcement plate. When I discovered this, the proseal was totally dried. I just simply drilled out the rivets and carefully "filleted" the proseal off and the cover plate I used to cover the hole ...buffed the remaining proseal off, and cleaned with MEK...Then a "do-over" to attach the reinforcement plate... Easy stuff, no sweat.
 
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No biggy...

danielhv said:
Oh ****.... :( I thought there was only one (inboard)!.... What do I do?!? :( :eek: Can I cut that rivet out, match drill a plate, and rivet it in place with the mfg heads on the outside of the tank rib? I can't believe I did this. :mad: Should I wait a few days for the proseal around it to cure the rest of the way so I dont damage the fillet underneath it?
Click to expand...

Remove the rivet in the tooling hole. Clean the proseal fillet from the nose on the inside of the rib so you can cut the plate to the shape of the skin, and have it tight against the rib. Cut/shape the plate and match drill to rib, using the plate as a guide. You may need a 90 degree drill/adapter if you have the next inboard rib riveted in place. Rivet and seal the plate. Mfg head on the outside is fine. Shouldn't be a big deal.
 
I've found that a razor blade can be useful for removing proseal. Then use MEK to clean up the small layer left over. Way easier then trying to get MEK to eat through a big glob.

As Nate said, just clean up the area, match drill the plate & rib, and shoot and buck, and seal up with a fillet of proseal around the plate & rivets.
 
K, so I can do this without having to remove the fillet on the rib right? I DO NOT have to drill out the skin to rib rivets correct?
 
I would call Vans and ask them if this part is 100% needed if you already have a real nice fillet and seal up at the tip of that outboard rib.

I would say that the doubler adds some level of protection against the heavy fuel from pushing out that area in flight during hard moves that push the fuel outboard.

Call them before you spend hours digging out all that proseal just to see what they say.
 
Brantel said:
I would call Vans and ask them if this part is 100% needed if you already have a real nice fillet and seal up at the tip of that outboard rib.

I would say that the doubler adds some level of protection against the heavy fuel from pushing out that area in flight during hard moves that push the fuel outboard.

Call them before you spend hours digging out all that proseal just to see what they say.
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I will... thats why I was saying... can I put that plate in place either right over the proseal fillet thats there, or maybe slightly above it? I dunno... I guess I'll see what Vans says and report back.
 
Ok, Vans said to remove the proseal in that area, and put the plate in place. Yippie! :mad: I hate it when I make foolish mistakes... and I'm sure this won't be the last one either. :rolleyes:
 
Bummer,

I would get at it fast before the sealant fully cures!

There is a solvent for proseal, Methylene Chloride. This is the ingredient in allot of paint strippers at the hardware store or you can buy it in bulk on the net.
 
Another question... Is it possible to use pop-rivets here? And if so, what kind? Reason I consider that, is because:

1: The bucking bar is square and the leading edge is round, and this is in the smallest compartment of the fuel tank, thus I'll be bucking with the very tip of the bucking bar, increases the chances of screwing this up (even further!)

2: I am not fond of pounding on the side of the rib while it is prosealed in place...

3: Its MUCH easier that way :D!
 
They are not that hard to do..

I just did these with all the ribs riveted in place. It was really easy with my small titanium bar. I bet you can do it! Pops would probably be ok, but I would call the experts up one more time before I did that. Get 'er done!
 
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