Tank baffle screw up

[rv9aviator]

I had a big brain fart last night and dimpled all the rivet holes in the right fuel tank. The problem is the spanwise row of rivets that attach the rear baffle are supposed to be machine countersunk to allow the baffle to slip down in place making it easier to install. I did the left wing the right way and everything went pretty smooth. I'm wondering how difficult it will be to get the baffle over the dimples without wiping off too much Proseal. I think if I get a couple of people to help spread the tank skin I will be able to get it in OK. Anyone else been there done that?

 

[scard]

I agree that you'll probably be alright if you take extra care by adding more proseal and more assembly help.

 

[dan]

Not a big deal

You don't need to add any additional proseal imho. The proseal sits FORWARD of that rivet line anyway. Any additional proseal is likely to clog up the little holes in the lower aft corners of the ribs that allow fuel to pass when the fuel level drops.

Sure, it might take a little more force to get the baffle in there, but once it's in it's in.

Just my 2 cents -- press on, and it's a good lesson learned that shouldn't affect anything. You won't make the same mistake on the 2nd tank (unless it's intentional this time).

)_( Dan
RV-7 N714D
http://www.rvproject.com

 

[Mel]

Keep plugging away. All RV tanks used to be built this way.
It's not a problem.
Mel...DAR

 

[alpinelakespilot2000]

The only disadvantage I can see is that at the wing root, some of the dimples and shop heads are likely going to rub against the main spar doubler bars. I followed the plans and countersunk, but even a couple of my rivets almost touched the bars. You'll just have to make sure you address any interference and rubbing here. I know at least one or two other builders just chose to dimple, and it worked out fine in the end after they'd rounded off the shop heads and/or took a little material off the doublers. I would check with Van's though if you do need to do this. Good luck.

 

[Jamie]

I agree with Steve. I think it's definately doable, but I had a problem with a little extra sealant on my -7 tanks interfering with the doubler at the root. I'm not sure how the dash niners look in this area...but I assume it's very similar. I think if you avoid that issue you'll be OK.

 

[rv9aviator]

Thanks for the advice everyone. At least the left tank is already finished so I can't make the same mistake twice. I think the biggest lesson I've learned is don't build one tank, aileron, flap and them wait 6 months to build the other one. It's like starting over. Well maybe not if your 25 but when your 55 it was. But I sometimes wash my hair in the shower twice cause I can't remember if I did it the first time.

 

[mlw450802]

Thanks for the advice everyone. At least the left tank is already finished so I can't make the same mistake twice. I think the biggest lesson I've learned is don't build one tank, aileron, flap and them wait 6 months to build the other one. It's like starting over. Well maybe not if your 25 but when your 55 it was. But I sometimes wash my hair in the shower twice cause I can't remember if I did it the first time.

At least you still have hair!

 

[plaurence]

I had a big brain fart last night and dimpled all the rivet holes in the right fuel tank. The problem is the spanwise row of rivets that attach the rear baffle are supposed to be machine countersunk to allow the baffle to slip down in place making it easier to install. I did the left wing the right way and everything went pretty smooth. I'm wondering how difficult it will be to get the baffle over the dimples without wiping off too much Proseal. I think if I get a couple of people to help spread the tank skin I will be able to get it in OK. Anyone else been there done that?

Jim,
it's OK. The only holes that need to be countersunk are (as I recall)
The first 18. The rest can be dimpled. The first 18, if dimpled, will interfere with the spar cap , but the rest are clear. Also, a dimple is stronger that a countersink.
On my 6A I dimpled all the holes and slightly beveled the spar cap corner to clear the shop heads. This will not harm or weaken the spar. I had forgotten to do this on my 9A which I had already primed. Yes, It would not have been a big deal to alodine the corner and re spray-- but I was lazy at the time so I countersunk the first 18.

Have someone help you to spread the skins while you place the baffle. It'll position itself easily. I've done four thanks this way and it works out well.

Did you use Tank dimple dies?. If not, the rivets may end up a little proud.

Hope this helps.

Peter
RV9A wings

 

[rv9aviator]

I did use the tank dimple dies ad I'll check on interference with the spar cap on the first 18 rivets.
Thanks everyone!