Suggestions for Fixing Tank Seepage?

I have a poly tank that is seeping (water) from a couple of places near the bottom (probably at the edge but not sure). I can't see any visible
cracks or holes and don't want to drain/remove the tank if possible.
Was wondering if anyone could suggest a non-toxic material that could be stirred into the water (maybe a clay material of some sort?)that might stop the seepage?
TIA for any suggestions.......
Laurie Forbes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Seeping or condensing? This time of year, condensation is a problem in a lot of areas. Only insulation can help with that.
For leaks, polyethylene is kind of nasty stuff to try to patch with anything sticky because not much sticks to it. If you can't see holes or cracks, not much point in it, either. Anything like radiator stop- leak needs heat to set it up and it isn't non-toxic.
HF sells a couple of plastic welding kits, if you DO drain and remove the tank so you can see holes and cracks. Uses hot air to do the job. I've done that job with a big soldering iron and some spare plastic film, wasn't pretty when I got done but the crack didn't leak. Very stinky and kind of messed up the iron's tip until I could clean it off with a file.
Stan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Seeping or condensing? This time of year, condensation is a problem in a lot of areas. Only insulation can help with that.
For leaks, polyethylene is kind of nasty stuff to try to patch with anything sticky because not much sticks to it. If you can't see holes or cracks, not much point in it, either. Anything like radiator stop- leak needs heat to set it up and it isn't non-toxic.
HF sells a couple of plastic welding kits, if you DO drain and remove the tank so you can see holes and cracks. Uses hot air to do the job. I've done that job with a big soldering iron and some spare plastic film, wasn't pretty when I got done but the crack didn't leak. Very stinky and kind of messed up the iron's tip until I could clean it off with a file.
Stan
--
soldering irons elements are plated. you don't want to file through that to
get to the copper underneath, or you'll wind up replacing it in pretty short
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@prolynx.com wrote:

Thanks to all for your help. Now that you mention it, condensation is certainly possible as the water used to fill it (recently, for the first time) was colder than ambient. The "seepage" looks pretty localized however and some is around a banjo fitting on the bottom. OTOH, it appears the volume of water under the tank (you can see it from the open top thru the poly) has not increased since yesterday so maybe the source, whatever it is, has stopped. The suggestion of bentonite sounds worth trying if required. If that fails I guess I'll have to drain the tank and try JB weld or heat welding if I can find the crack(s).
Thanks again guys - this is a great news group IMO (if one can get by the dreary political and other OT BS that plagues it).
Laurie Forbes
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I might try Billy Mays "Mighty Putty" (As Seen On TV) - might be the one job it's perfect for and worth a try since it'll do no harm.
http://www.wndu.com/specialfeatures/headlines/15296246.html
As for welding poly, it's more like a high temperature wax than anything. Just enough heat to do the job and no more is the method, with more poly as filler.
Beware: if you stick molten poly to flesh it hurts like hell and only cold water will help you!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Bentonite. A powdered clay used in the oilfield to make "gel" and to line new ponds
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Bentonite. A powdered clay used in the oilfield to make "gel" and to line new ponds
--
which is clumpable cat litter.



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
mattathayde had written this in response to http://polytechforum.com/metalworking/suggestions-for-fixing-tank-seepage-195562-.htm :
------------------------------------- Laurie Forbes wrote:

i would really just try to find the leak (colored water even would work to help isolate it maybe. depending what its going to be used for it might not be good to put anything in it. jb weld will work though to seal a crack IIRC it is food safe when cured
-matt
##-----------------------------------------------## Delivered via http://www.polytechforum.com/ Metalworking Forums Web and RSS access to your favorite newsgroup - rec.crafts.metalworking - 169901 messages and counting! ##-----------------------------------------------##
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

More information is alway nice. Does the tank hold potable water? Is the water in the tank always changing. Is the water in the tank colder than the room temperature? My guess is that you have condensation on the outside of the tank. Right now my cold water pipes seem to be leaking, but it is just condensation. Dan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Laurie Forbes wrote:

To repair leaks in the old galvanized tanks if the leak was in the bottom we used cement just tip a bag of portland cement into the the tank and stir it up ,in a few days it will settle out and harden.
--
Kevin (Bluey)
"I'm not young enough to know everything."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Kevin(Bluey) wrote:

That's clever! Must have been a "stock" tank, i.e., water filled & open at the top. Not a fuel oil tank nor potable water tank (!).
Bob
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.