radiator end cap plastic repair

[DGraber460 at aol.com]

In a message dated 1/18/2007 7:44:04 P.M. Mountain Standard Time,  
ttauskey at worldnet.att.net writes:

The  "Snowqueen" - 1993 100CS - has developed a 1 inch long thin crack in the 
 front/middle of the radiator left end cap.   It's easy to get at and  the 
thought occurs to me that a small patch-job (essentially doubling the area  
around the crack) might hold if it was made out of the right plastic and  
adhesive.  Sure there's pressure behind it - but there is a relatively  large 
(although curved) surface area to which the patch could  adhere.

Any ideas as to what material the patch should be made out of  (a scrap piece 
from another radiator should work, no?)- and what adhesive  should be used 
(urethane based)? 


If the plastic is Polypropylene or Polyethylene, there is _no_ glue  or 
adhesive that will stick to it. Both can be welded, but not pressure  rated.
Not sure what Audi radiators are made of, so if anyone has successfully  
repaired one it would be beneficial to post and archive.
 
Dennis
Denver