Overboard vent construction
 

I guess it was about a week ago, that a question was asked about overboard vent location on a BVM BobCat.
At that time, I submitted a couple of photos of my BobCat XL vent location.

I have made another one for my BVM T-33 that is under construction, and have photographed it so those who haven't made an overboard vent can see one idea of how they can be made.
There are many ways to do this, but this is an easy way to do the job....it took me less than 20 minutes to fab this one up....all of the material was from the scap box, except the screw and the Stay-Brite silver solder.

A short tutorial: Use a 3/4" square maple block 1/2" thick, and 5/32 brass tubing, 1/4" wide brass strip .063 thick.
Silver solder the tab to the tubing.
Contour sand the block to fit the fuselage contour, then install the tubing assembly and drill and install the screw.
Remove the "tubing and tab assembly" from the block, and scuff the fuselage interior with 80 grit.
Aeropoxy the block to the fuselage.

When the aeropoxy has cured, carefully backdrill through the block and fuselage skin.
Bevel the tubing, and install the tab and tubing assembly to the block.
See the photos.
.

RE: Overboard vent construction
 

Clever idea Harley to be able to remove the vent/fuel line. That's always a problem/nuisance whenever working with your fuel system. I guess the trick is locating the vent block where it is accessible and you can get at it with a screwdriver.

Thanks for the tip,

Craig

RE: Overboard vent construction
 

Craig,
I try to use the "KISS" principal.
I made a totally different type of removeable vent line fitting for the Ultra Bandit. I'll post some shots of it next time I take the airplane apart.

RE: Overboard vent construction
 

I have never understood people putting plugs on their vent lines. I understand what its for but how many people transport their planes with fuel in them? I have seen more people burst there tanks because of forgetting to take the vent plug off than I can count. I have never used a vent plug or found a reason too. Harley, do you use one to prevent fuel spillage or for other reasons?

RE: Overboard vent construction
 

I always install a plug before transporting the airplane in my trailer. I like to keep the fuel smell at a low level. I always keep the airplane plugged in the shop to prevent the smell of Jet -A from stinking up the shop.
As you turn the airplane over, a small amount of fuel will spill out of the main tanks through the vent. There will sometimes be a small amount of fuel in the mains, even after defuelling.
I use a start and taxi tank during fueling, so the plug must be removed before hooking up the S&T tank. I use an old RAM fuel pump on my fuel can, on 7.2 volts to keep the pressure down.

RE: Overboard vent construction
 

That was me that asked the question on the vent line. Thanks for more info. I haven't been able to do any building on mine yet.

Graham

RE: Overboard vent construction
 

Graham,
Happy to be able to offer the info.
Start digging through your scrap box, and get going!

RE: Overboard vent construction
 

Ian, I always plug my fuel AND smoke together after a day of flying. I use a RED ribbon on the plugs to warn me of them before fueling. I also use the vent of the fuel or the smoke to allow access liquid to go back in the appropriate tank. This way, there is no spillage or forgetting the plugs. If I leave my jets in my van, I normally leave the window open a liitle and I release the vents to allow for heat expansion....BTW, Most of my jets are in one piece in the van hence no need to defuel in most cases.....

Just my .000001 US cents[8D]

RE: Overboard vent construction
 

Who fills their tanks without using an overflow (taxi) tank? Makes it real hard to forget to remove the vent plug 'eh?

Dave

RE: Overboard vent construction
 

And it keeps the jet fuel smell from wicking into your cool looking chair in the trailer - you got a foot rest for that bad boy? :) Thanks for the vent assembly tip btw.

RE: Overboard vent construction
 

Mike,
That's where I take my afternoon nap. Footrest included.