After Lynn's comment last week about welding together a polypropylene
take, I went looking for what it would take to do such a thing.  The
most innovative thing I've seen in a while was at http://www.powercore.com/

I think it would be fairly easy to seal an aluminum tank by welding together a bladder slightly smaller than the tank 
and then sealing the bladder into the bay.  Bake the wing to bring the temperature up on the bladder (it'll take 320*F), 
then put a few PSI of pressure in it.  The bladder would blow up to conform to the bay's contours.  All the fittings 
would be welded on, and the bay would be guaranteed leak free without ProSeal goo.

Composite planes could do the same, but the heat would have to be supplied internally somehow.  Alternatively, a 
completed, closer fitting bladder could just be micro-ed into place.

They didn't have a price list on their website, so I inquired...

Since the bladder won't actually need structural strength, a much thinner sheet could probably be used.




Ernest,

Thanks for you inquiry.

A 1000 ft spool is US $0.65/ft.

Attached are some pictures of an air bladder made from  two  flat 0.60''
HDPE sheets. it is blown up to 50 psi.

You can weld any shape up to 80 feet long, one continuous weld in about 4
min.

Kind Regards,


----- Original Message -----
From: "Ernest Christley" <ernestc@netapp.com>
To: <info@powercore.com>
Sent: Friday, October 10, 2008 2:35 PM
Subject: Cost

> We're building custom fuel tanks for off-road vehicles.  Each one is a
> custom job made from .060 sheet material.  I would like to present your
> product to our group.  Can you give me a price sheet?