RPE Liner - Seaming Two Pieces

[Wildneg]

So, after some long thinking, I've decided to put an intake bay on the opposite side of the pond. I'll run the pumps from here and hopefully draw all the floating debris over to that location. I have some ideas to keep the opening shallow so I can create that surface pull as needed.

So RPE liner is reinforced polyethylene and is some strong stuff. It dulls my razer blades very quickly. So does my underlayment. I have some scraps from the original liner and need to seam it up to the main pond. I've already pulled the tractor out and dug the intake bay. I've placed some wood boards to prop up the current liner so it doesn't fall in and fill my hole I dug either. I'll remove this once I can make that seam and test it.

So the question becomes, does anyone have experience seaming RPE or any kind of polyethylene liners? I read to heat weld it. I've got a heat welder and have actually tried on some scratch pieces. My god... its damn near impossible. I'm a pretty steady handed person but I do great and then melt some other parts. I tried different heat settings including the specific temp recommended by BTL liners. I just do not feel comfortable doing a 7' long seam. I do not have much room for failure/melting through.

I've found some 'RPE' liner seam tape that sounds like it would work. It isn't as involved as the EPDM tape since I do not need any 'glue' or solvent that they require. I'm just not sure how well the tape will work. I've even seen some stuff with good reviews on Amazon called 'Tite Seal' Ponder Linder Seam Tape. It is butyl rubber based and have seen this stuff before.

So my options are ... and I'm not sure what would be best so any input would be greatly appreciated it
1) Heat weld as best as I can with hopes I do not melt through and then place a strip of 3" 'single sided butyl pond seam tape' over the entire weld for extra hold ...
2) Use double sided butyl pond seam tape between the two layers (no heat welding) and then lay a strip of single sided butyl pond liner on top (similar to the way epdm is done)

 

[fishlips]

I have bin playing around with this for a few weeks. I also find a heat gun is to hot. I have had some promising results with a iron (like you use on your clothes) you will need parchment paper on both side sides of your seam to stop it from sticking or melting to the iron. Time and temperature is still a little try and fail so start with temperature set between synthetic fabric and natural for about 10 seconds is some where to start.

I have not tried this myself on any thing larger then scraps. I also never did any seaming of pond liners.

If you decide to try this I would like any tips you learn.

 

[Wildneg]

I'll keep you posted.

Plan on doing something today or tomorrow to get the leaves and debris in check!

I may test the iron theory. I think they only get 500 degrees max. Wonder if that's enough heat.

I thought blt liners said for the rpe liners it has to be like 800 or something. I may be making this up... Can't tell what I read or made up these days (busy life with kids!).

Worth a shot though with the iron. Feel like low and slow may be safer. They did recommend putting some of the gorilla tape over it. They sent me a specific product. So will do that in top of whatever I can get to work best, without melting hole through the liner.

 

[GBBUDD]

Here is a quick detailing of seaming using a heat gun

 

[Wildneg]

I've watched the video so many times. And even started watching roofing videos. It takes a lot of practice! Haha....

 

[GBBUDD]

I've watched the video so many times. And even started watching roofing videos. It takes a lot of practice! Haha....

LESS THAN YOU MAY THINK

 

[Wildneg]

Maybe less for you! Stop by, you can seam mine! I'll pay in beer and maybe a few free baby fish. Haha...

I did end up trying. It held pretty well. I learned lower heat then what BLT recommended helped me go slower and control it. I still put the recommended tape on the seam too... better safe then sorry.

 

[GBBUDD]

i have heat shrunk polyethylene, and seamed edpm and know the tricks and i will still do a double seem when the seam is buried under tons of stone and gallons of water

 

[combatwombat]

Like you, I tried about 100 times with a wagner heat gun and a flat-fish tip + rubber roller and had very little success. Got close, but never made a seam I felt good enough to rely on long-term. I just bought a cheap-o roofing membrane welder on Amazon like the one in the video above to test with, but haven't gotten to it yet. Will report back when I do. I was advised to thoroughly clean the seam area w/ xylene prior to attempting a weld.

Failing that, I think the butyl tape is a good option, and the one I will pursue if I can't get a good heat weld.

 

[Wildneg]

@combatwombat - Good luck! If you lived close, you could have come borrow mine! I probably could have mailed it and when you were done, send back. I bought the exact same one in the video. It did help with controlling the weld though. I found going lower heat made it easier for me, but I had to move slower. But allowed me for human error. If I had it too high, I couldn't react quick enough if it was getting too hot. With it being lower, I was able to re-act quicker but just required longer time as I worked to seam it.

I'm not sure about any leaks as I can not get under the liner now. I also added a piece of PVC to my 'dock' I built. I measured off some lines so I could keep an eye on it. It went down about a 1/4" in the past 3 days. But I don't know how much evaporated prior since I just put this PVC pipe in after I did this. I'm not sure if water evaporates quicker in colder dryer weather or not. I would assume not since the cold air can not hold anywhere near as much moisture. It is 36 out currently and the pond water is maybe 40? My floating sender unit is too far away for my receiver to pick up. I put in a intake bay (the main reason I had to seam the two pieces) and now the sender unit finds its way in there daily. I have to get it tied down to something so it doesn't drift over there.

Let me know how it goes for you though, using that heat welder/heat gun!

 

[combatwombat]

@Wildneg: What did you end up doing here? I never got comfortable with my heat welds and ran out of time to practice, so I just went for it with 2 fat beads of loctite marine adhesive sealant applied to cleaned liner with a rubber roller and clamped overnight.

It worked! For a few months anyway. It's leaking now. Inspected the edges of the seam the other day and found the sealant easily separated from the liner. Darn. I think I forgot to scuff the area to be seamed first, which might have something to do with it.

Anyway, it's not the right solution—I just tried it in a pinch. So back to the drawing board for me. Would really like to pull off a welded seam, but it is so much harder than it looks in the youtube tutorials to get a reliable weld.

 

[Wildneg]

@combatwombat
Same boat as you. I tried the heat weld a few times... practiced a bunch and before fall last year tried to do it. I also put some gorilla tape someone recommended on a site somewhere. It held up for a few months but then it started leaking pretty much the worst time (late fall into winter). I kind of placed rocks and anything I could to keep the water in as much as possible.

Come the first few warm days in late winter/early spring, I tore that extension (intake bay) out and removed the attached liner. As of today, I never tried again.

The videos online make it looks so easy. I couldn't get the heat weld to work right at all. It was either melted through or not hot enough to melt together. Just couldn't get it. Probably takes soooo much practice and I just didn't have the spare pieces/time/skills to learn it.

Wish I could be of more help! But sounds like I am in the same boat as you.

 

[GBBUDD]

@combatwombat[/ USER]
Same boat as you. I tried the heat weld a few times... practiced a bunch and before fall last year tried to do it. I also put some gorilla tape someone recommended on a site somewhere. It held up for a few months but then it started leaking pretty much the worst time (late fall into winter). I kind of placed rocks and anything I could to keep the water in as much as possible.

Come the first few warm days in late winter/early spring, I tore that extension (intake bay) out and removed the attached liner. As of today, I never tried again.

The videos online make it looks so easy. I couldn't get the heat weld to work right at all. It was either melted through or not hot enough to melt together. Just couldn't get it. Probably takes soooo much practice and I just didn't have the spare pieces/time/skills to learn it.

Wish I could be of more help! But sounds like I am in the same boat as you.
[/QUOTE]
I have not done so myself but I have seen pros use epdm seam tape and primer on hdrpe. Gorilla tape would never be an option in my book..

It is tricky to heat weld but once you have the temp and timing you can move along.

 

[combatwombat]

Aw shucks. Sorry to hear that. I am probably going to have a go with seam and cover tape this fall. Lucky for me, my seam is pretty easy to get to and not in a critical location.

 

[Bluerooster]

First of all, I would never try to seam a liner of any kind below the water line. The only seams that my ponds have are at the falls, or in the stream bed, with the lap going with the flow. Water doesn't (willingly) flow uphill. If I can't get a liner big enough for a pond, (and that would be one huge pond, way bigger than the average back yard pond) I'll break it down into two or more ponds, or go a different route.