Short answer, no. The only success that I've seen (long term) for stopping leaks is using either properly compacted clay 18"-24" thick or a liner. All other techniques have failed over time.

Or live with the fluctuating water levels and spend the $$ on electricity keeping it topped off with a well. That's what I'm doing with my pond. No clay in the area, sandy soil. My pond will fluctuate up to 6' depending on the level of the ground water if I don't supplement it with the well.


www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).