What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

QB Safety Alert

Caveman

Caveman

Well Known Member
Guys,
I was getting my QB 7's right wing tank ready for installing the senders and fuel pick ups and found my vent line was plugged. I tried blowing (by mouth) through the line by attaching a Tygon tube to the AN vent fitting. No go! I removed the fill cap and drain valve so as to not overpressure the tank if something broke loose and used compressed air. Still no go... even with 90 psig. I couldn't get a good look at the open end of the tube by the fuel cap even with a mirror. After much deliberation, I reluctantly used a piece of bent hinge pin and pulled the open tube end over to where I could examine it with a small mirror. It was plugged with PROSEAL! I was able to use various picks and bent awls and dig the Proseal out. I then blew through the line with compressed air to ensure it was clear and then bent it back into position. I had to be careful not to kink it.

This being a quick build tank, I have to guess that this happened accidentally in the Philippines. All is well. However, I thought I should get the word out. If someone doesn't check their vent lines for obstructions, or use this AN fitting to leak check their tanks, they could be in for a rude awakening. One thing I learned is that Proseal is a very impressive sealant to withstand that much pressure in that big of an opening.
Here's some before and after pics. Click 'em for more detail.



 
Good Job you checked

Not wishing to second guess you but could you not have cut the end off with a small tube cutter or even a mini air saw...Vacuum the shavings out after?

Frank 7a
 
Here's what I was dealing with.

frankh said:
Not wishing to second guess you but could you not have cut the end off with a small tube cutter or even a mini air saw...Vacuum the shavings out after?

Frank 7a
Click to expand...

No offense taken. Here's another pic of what I was working with. I deliberated the same things you mention and even tried to come up with alternative methods. Perhaps you guys know of a tool that might have worked, but these wouldn't. (Except the hinge pin). Do they make a tubing cutter smaller than the one pictured by the hole? I'm not sure I know what a mini air saw is. Got a pic? If you are refering to a die grinder with a cutoff wheel... no way.

The vent tube is tucked up to the top of the tank and held in place by a clamp at the bottom rivet below the filler neck. The filler neck extends down into the tank just over 1/2" and hides the tube from view. I couldn't even see the open end of the tube with a mirror, (tried two different ones), until I pulled it into view with the hinge pin wire.

Do they make a right angle adapter for those Dremel tools with the flex shaft and remote drive motor? Something like that might have worked but only after I alread pulled the tube over. I was very afraid of kinking the tube due to the riveted clamp holding it in position and dared not bend it anymore than I did.

If the picks didn't work my next thought was to try a hacksaw blade with tape wrapped around it for a handle to saw the end off the vent tube. I was concerned about the tube moving up and down while I was sawing though.

The right angle drill even with a shorty bit wouldn't fit to drill the plug out. There isn't much room to work, as you can see by the rule I laid across the opening.

 
Good post, I'll check all mine here today. I've found more than a few missing rivets, bad rivets, missing countersinks etc. so far on two QB kits. Take the extra time to check out closed structure with a dental mirror and flashlight. Don't assume all steps have been completed properly on a QB.
 
You must log in or register to reply here.
Back
Top