polyethylene calk

[fish]

I used uniseal for the tank/dura skrim, and it was leaking.
This is my very first system I made. When I started adding water with excitement, 5 out of 6 holes were leaking! (used uniseal only)
So, I decided to use Bulk head for at least wood/liner tanks. Before set up bulk head, I need to seal between wood and dura skrim liner.(LDPE)
I heard that Polyethylene calk is safe/good for it. But I can't find a product name of it.
Can anyone help me on locating a product name and where I can buy?

Also, what can I do for the leak between uniseal and bucket? (I made the hole smooth, but it didn't work. It seems the hole was enlarged. I tried tape, it didn't work.)

[dead_sled]

LDPE is difficult to seal. I found this "caulking" that may work for you. I am not sure about your exact needs for this product, but I am sure you will be able to figure that out. 8-)
http://www.stealth316.com/2-dp8005.htm

[fish]

Thank you so much for the info!
This is exactly what I was looking for. I'm trying use it for sealing the bulkhead fittings where they go through tanks and trough liners. One thing is that it requires 3M™ Scotch-Weld™ EPX™ Plus II applicator and it is very expensive...

[dead_sled]

Yes, I agree, the applicator is expensive for a one time use.

You may want to try the 3m fast cure 4000 or silicone. These may be a more economical solution, if they work. I have heard about some hydroponics people who have used these products to seal a uniseal leak. Good luck. :)

[fish]

Thanks for the great info again!

[dead_sled]

I hope you let us know which way you chose, and the results.

[Aloha Don]

Any pics of your system so the rest of us can see what is happening?
Thanks

[fish]

After I searched more, I got so confused and couldn't decide. so, I went back to PETE tape and redone. 2 of the uniseal in buckets and 1 bulkhead recovered. But still 2 more uniseal in buckets and 1 bulkhead are leaking.

Then I've searched sealant/caulk/glue again again...
3M 4000 has Diisodecyl phthalate 10-20%. I don't know the chemical, but "phthalate" made me worry.
Some website says that someone got organic certs with 3M 5200Polyurethane. but MSDS says stay away from food.
Some people said that silicone is easily break.
Sikaflex291, Superglue, Gorillaglue, Black fish safe glue, DAP® All-Purpose 100% Silicone Adhesive Sealant, and lots of marine and aquatic sealant/glue... I don't feel confident on those.
Many of them said that those are fish safe (like Dap website says 'fish safe'). but looking at msds, I'm not really sure.) When I was looking at data, I saw one glue said fish safe and written about 2 fish names that they experiment with. But I forgot the name of the glue...
So, I'm going to buy more PETE tape (I used up 2 rolls yesterday) now.

[fish]

Surprisingly PETE tape worked! No leaking anymore.
For bulkhead, I used some brown rice glue(diy) between wood and liner, grind the hole little bigger and cut the excess liner around circle. Then bunch of PETE tape.
For uniseal, PETE tape only. When I pulled the pipe, uniseal was pushed to the bucket face and leaking was stopped.

Thank you so much for the info and concern though.

Now I got another issue (flow is too slow). I will create another thread for it.