RV-3A Fuselage Fuel Tank

Anyone have experience building the RV-3 fuselage fuel tank? Starting to cut out bulkheads and and side panels and take to machine shop for welding.

Everyting is pretty straight forward execept the baffle plate which runs down the starboard center of the tank.

Is there more than one baffle plate?

The baffle plate corners are cut 2"x 2" at 45 degree angles, I assume to allow fuel to transfer from port and startboard sides of the tank. Seems like the baffle plate would add some vertical rigidity to the tank so the sling staps do not crush it.

KattieB, I think you said you had a fuselage tank, maybe you could shine a flashlight inside and see what the baffle plate looks like.

Any help always appreciated.

tank

On my Rv-3 the baffle runs from top to bottom on the left side of the fuel fill cap, gap at the top and at the bottom. Weld are only on the front and rear, none on top or bottom, I did not build the tank and dont't know who did, bought it used.

I will suggest that you cross break the baffle for stiffness before you install, keep from oil canning. Also bend the top and bottom for stiffeness.

Perry

Perry

Welds on forward and aft bulkheads make sense to help with construction and hold the baffle plate in place. Understand hem at top and bottom of
the baffle plate.

Could you explain "cross break the baffle"?

Not sure I understand this fabrication technique.

Thanks

Mark

cross break

Cross break (if I am using the term correctly) just means a slight crease with a sheet metal break, Crease the metal from corner to corner (all four corners) prior to bending the edge bends. It stiffens the metal and stops tin canning effect. You will find an example oif this in your home heating ducts if you have forced air heat.

Use just a slight crease, don't need much if needed at all.

My tank does not have the cross break and has broken the welds on the rear that I have had to have rewelded. The welds are rosette type welds held in place with pull rivets and then welded over the rivets after other weld were finished.

Perry

Cross Brake

Perry,

Understand this suggestion and will fabricate the cross brake into forward and aft bulkheads in my tank. Great example regarding forced air system.

Thanks a bunch for your help, I believe I have enough info to fabricate the tank.

Mark

gross break

Not sure I wouild cross break the front and rear of tank, may lead to the bends on the baffle being not firm against front and rear. Only the baffle may need it.

Perry

Cross Break

Perry,

Understand, will only cross break the baffle and not forward and aft bulkheads. With the baffle welded to the forward and aft bulkhead that should provide plenty of rigidity to these bulkheads.

Thanks sooooo much for your help,

Mark