[NSRCA-discussion] SODA BOTTLE FUEL TANK

[Rcmaster199 at aol.com]

Stress relief is a time-temp-chemistry sort of thing. Given the chance, PET  
will try to return to near it's original shape which was a thin walled, sealed 
 at the far end, cylinder of plastic. If you weren't careful with the oven, 
you  could potentially bring the thing all the way back. 
 
What Jim is doing is a more controlled shrink down. Working with  the  oven 
will work but takes more care.
 
 It may make some sense to fill the bottle halfway  with water, make sure the 
cap has a hole drilled in it and then stick  it in a pot of boiling water and 
cover but making sure the bottle doesn't  tip over. You want the internal  
pressure build up to be eliminated but you  also want thread protection. Boil it 
for some time and then see how it shrinks.  It will stress relieve and become 
stable quicker probably. Haven't done that  myself but could be worth a try. 
GL
 
Matt
 
 
 
 
In a message dated 2/16/2006 9:54:37 PM Eastern Standard Time,  
brian_w_young at yahoo.com writes:

Could you warm that material in an oven to acheive the same result?
 
Maybe fill it w/ something to hold the shape but let it  shrink.

Rcmaster199 at aol.com wrote:

 
Jimmy, pretty much all of those pop blow molded bottles are made of  PET. A 
fine, very tough and resilient engineered plastic with terrific  memory built 
in (beats heck out of my memory, fer shure). What you  experienced is 
completely expected.
 
Matt
 
 
In a message dated 2/16/2006 5:16:58 PM Eastern Standard Time,  
jivey61 at bellsouth.net writes:

Wayne
 I just flew the coke bottle tank today and I get 15 minutes on  24 oz of 
fuel.It actually draws fuel down to 1 oz in the tank,doing the  Masters pattern.
The upside is I don't have to fill it full to complete the pattern.  The 
weight savings is 2.5 oz using this tank.
 To review...... this was a 33 oz, 1 liter coke bottle' that I  pickled with 
30 % heli for 2 months.
 
Jim  Ivey






 
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