Connecting a liner pond to a pre-formed fibreglass pond

[SteveC]

I have an existing rubber liner pond and am intending to build a new pre-formed fibreglass pond next to it. I want to connect the two together with a deep channel and I'm wondering how to make the channel watertight and seam it to the two ponds. I thought it might be possible to use a length of rubber/EDPM liner to seal the channel;

has anyone got experience of bonding rubber/EDPM liner material to fibreglass?

 

[Waterbug]

I know I'm probably wasting my time, people love to goop stuff up, but I'll give it another go...

The EDPM only needs to be over lapped by a small amount (4-10"), but a little extra is OK. The overlap of course should be sloped down stream and not be in standing water. The trick is to place a gap between the 2 liners to stop capillary action.

If you use any goop you have to let it dry before laying the top layer. I know that goes against all newbie logic of goop being a solution to all issues but if you read a little about capillary action you'll understand why gooping it up can create a worst leak.

Just to get a little ahead, after you ignore the above and goop it up, your next question will probably be how to fix a leak. You'll be able to fix the leak by removing all the rock and removing all the goop, and doing the above. However there's a very good chance that your leak will be very small and you won't even notice it, so gooping it up does work, by some standard.

Because I know the desire to "stick" things together is so overwhelmingly strong for people new to this stuff I have a compromise. Use double sided foam tape to create the gap...I mean stick the two materials together. Has to be back away from the liner end by at least 2" I'd say. That way you can think the material are "sealed" but still have the gap so no leak, at least from capillary action.

Sorry for the sarcasm...it's meant to make a point. Most people (like 95%) asking questions will choose the most complex, expense, and least effective method they hear in a forum. Not really their fault, impossible to make a judgement call without experience.

Just for background...there is no way to "seal" most dissimilar materials, especially plastics. Professionals call it welding. For example PVC "glue" is more precisely a solvent for welding PVC together into a single piece of PVC. Things that are glued or gooped together remain 2 separated pieces with another material in between. There are some materials that can be glued together to form a long lasting water tight bond, but they are rare cases. Water is very good at getting in between materials.

 

[addy1]

I have had no issues using goop, pl roofing goop, makes a good seal. Have never tried what wb is suggesting above. Have not fought leaks.

 

[Waterbug]

Millions of people goop up all kinds of stuff, duct tape stuff together, and many are very happy with the results. Most homes in the world are built using what we consider substandard methods and many do stand for 100's of years. Just a question of how lucky you're feeling, as Dirty Harry would ask. If you ask people who've never have a problem they will swear some hack is a great and "proven" building method. Ask people who've had a problem and you'll get an entirely different opinion.

I cut corners, but if a better building method exists, doesn't cost hardly anything extra, is easy to implement, I'm pretty likely to go with the better and proven method. I see no benefit to cutting corners just for the sake of cutting corners, or to falsely inflate my ego thinking I know better than the millions of trades people who came before me. I'll save my luck for when I actually need it.

 

[sissy]

leaks are sneaky little things and sometimes you really never know they are there and other times they are in your face types .I have seen a leak in mine in the past that I just put off as evaporation since the water lose was so miner and then when the neighbors dog ripped my liner I found it .I could not repair all the damage the dog did so was easier to replace the whole liner since I had a big piece I got at an auction .I began to think leaks are just a way of life and a pond .Life is a mystery that we take a life time to figure out and never do ,so figure a leak no matter where it is can be a mystery that may or may not be solved .It is a guessing game like hide and seek .The other thing is if you have a rubber liner now why do you want to put in a preformed with it .Preforms are hard to level and keep level ,liner is easier and cheaper .Some preforms being that they are not deep can get water under them in bad rains and float up as there is not enough water in them to hold them down