Sealing off the fuel tanks

[RV7A]

I've been fearing this step for a while, but I'm ready to do it! I'm looking for advice/videos/tips/photos on installing, sealing, and riveting the rear baffle of the fuel tanks.

This is a critical step and I want to get it right so they don't leak. What are some ways you spread the sealant on the rivet holes of the tank skin? I know that when I push the baffle into place, it pushes the sealant into a bead inside the tank. How much sealant should I use? Did you put sealant in each of the 13,000,000 holes?

I'm building an RV-7 but this step should be the same for the -7, -8, -9, and I think the -10.

Thanks for any tips and advice!!

[Spike]

There has been a fair amount of discussion regarding sealing the tanks on these RV's here. Try the search engine of the forums.

John

[captain_john]

Mark,

I just checked out your pictures and I dare say that your tanks look great thus far!

I think that you already know many if not all the gotchas people talk about and are hoping to hear a new one before you do the rear baffle.

You are probably at the stage where there is nothing left to it but to do it! Have a go at it!

I used a sealant gun to speed up the application and get lots of product down in a short amount of time.



I also had extra hands on deck to assist me!



Go for it! I am sure that you will be fine!

CJ

[RV7A]

Found a real good thread right here on RB about sealing the tanks.

I think the main reason I'm leary of doing this is because I don't know how to get a nice bead of sealant down the skin holes.

I've seen some people use those little syringes they got from Target, but I have no idea what kind of voodoo magic they used to get the Pro-seal into those syringes!!

It looks like Captain_John in the pics above is using a larger syringe. Is that the one of those pro-seal's that already come in a syringe? It looks like one would be enough to seal one tank plate right?

One other question-should I seal up the rear of the tank before I 'glue' on the round plate on the root rib? (the plate where the fuel sender attaches-sorry no part number handy)

Gonna be a SWEET day when these tanks are done!!

[captain_john]

Mark, yes, that was a tube of pro seal and I used a pro seal gun in order to dispense the goo.

They are expensive especially for one set of tanks but maybe someone could loan you theirs?

I borrowed mine from a local builder.

I left the round plate for last so that I could view into the tank as the baffle was installed in order to observe the application of the proseal on the tank parts.

Let us know how it comes out!

Good luck!

CJ

[bruceh]

Get a veterinary syringe. Local feed store has them for $2 each. I went through 3-4 to do the tanks. If you let the proseal set up long enough you can pull the hardened goo out completely and reuse them. Get some plastic knives from your local fast food store, and some stir sticks from your Starbucks. Those and some paper plates are all you need to do an easy proseal job on the tanks.



Measure up the pro seal on the paper plate with your digital scale. Mix it with the stir stick, and use that to shove it into the syringe. Wear gloves and change them often! Use the syringe to lay out an even bead along all of the flanges, then use the serrated knive to spread the stuff around. The serrations act like a notched trowel and keep the layer of sealant thin and even. Cleco it all up and let it sit and tack up before you try to do any riveting. I waited a day and it worked out perfectly. Load up the syringe again after riveting and lay down some nice fillets and dollops on to each shop rivet head.

[captain_john]

Bruce, I have seen other pictures of yours and know the high quality of your work, but all the rookies here need to know that the picture you have above is of pro seal that is NOT READY to be applied! It needs to be more thoroughly mixed than that! The color should be uniform before application!

...just wanted to add that.

CJ

[BSwayze]

I did mine, too, almost exactly like Bruce described. I had some of the syringes from Target, and I just used a popsicle stick to scoop the proseal up and into them. No special magic there. And like he said, I was able to use them over and over. They really worked great!

[valentind52]

Found a real good thread right here on RB about sealing the tanks.

I think the main reason I'm leary of doing this is because I don't know how to get a nice bead of sealant down the skin holes.

I've seen some people use those little syringes they got from Target, but I have no idea what kind of voodoo magic they used to get the Pro-seal into those syringes!!

It looks like Captain_John in the pics above is using a larger syringe Garde Meubles. Is that the one of those pro-seal's that already come in a syringe? It looks like one would be enough to seal one tank plate right?

One other question-should I seal up the rear of the tank before I 'glue' on the round plate on the root rib? (the plate where the fuel sender attaches-sorry no part number handy)

Gonna be a SWEET day when these tanks are done!!

You are absolutely right, but you should choose the material used to make the tank.