# What am I doing wrong with my sump?



## JerseyBird97 (Sep 13, 2009)

Im building a 10 gallong sump under my new 20 long. I've done alot of looking around online and seen people just put acouple of dots of gel super glue then super glue and done.

I started with 1/8" plexi and that poped right out. I went to 1/4 plexi and that poped right out. I tried a couple of dots of epoxy and that melted. With a last ditch effort I epoxyed the whole thing then siliconed... each time I let the epoxy cure for 2 days and the silicone for 1 and it never holds. Also I clean the edges realy well before resetting and the baffels fit snug.

WHAT CAN I DO!? Everyone makes this look so easy.


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## Mikaila31 (Dec 18, 2008)

Can you tell us what you are trying to do?


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## SinCrisis (Aug 7, 2008)

What kind of plexi are you using? Try sanding the edges a little. Personally, I use Weld-On. It is a bonding agent and works on a lot of different types of plastic, ive been using it for my DIY and its real strong, haven't had it fail me yet. Cures fast and is at 80% strength in 24 hrs. Silicon does NOT bond to acrylic, its basically useless unless you are using it to just coat the plexi to seal in superglue.


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## JerseyBird97 (Sep 13, 2009)

Mikaila31 said:


> Can you tell us what you are trying to do?


sump baffels



SinCrisis said:


> What kind of plexi are you using? Try sanding the edges a little. Personally, I use Weld-On. It is a bonding agent and works on a lot of different types of plastic, ive been using it for my DIY and its real strong, haven't had it fail me yet. Cures fast and is at 80% strength in 24 hrs. Silicon does NOT bond to acrylic, its basically useless unless you are using it to just coat the plexi to seal in superglue.


I just put the first one in secured with marine epoxy... well find out tomorrow if it was strong enough. I've already done the seal super glue in with silicone with no success.


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## bearwithfish (Sep 29, 2009)

not sure of the issue ... what type of silicone? i just cut mine snug (as you did) and simply siliconed them in.... i used 100% silicone 1 from GE and mines been up for 7 months with no issues... did you run the bead on both sides of the plexi?


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## JerseyBird97 (Sep 13, 2009)

Yes I ran beads on both sides. The baffels keep comming comming out of place after a few hours. Same silicone (GE Silicone 1)


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## SinCrisis (Aug 7, 2008)

well if the epoxy fails and the silicond oesnt work for you i recommend weld-on. Its a bit more difficult to get, but its a solvent with some acrylic in it already and it bonds by softening, the acrylic and then allowing them to fuse together, like liquid welding, hence the name. Its also a bit pricey 5 bucks for 4 ounces. Its hardish to work with but it bonds like WHOA. if you have the edges cut just right u can even get seamless bonds which look great


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## bearwithfish (Sep 29, 2009)

ok ..hmmm this one honestly is stumping me and because its something i have a lot of experience with i am very curious as to the issue... after my post last night i contacted all the folks i have made sumps for (about 7) and they all report no issues... so lets start at the begining ... could you post some pix of one that did not hold? in particular the plexi and the placement, also the way the silicone is applied?
i am super intrigued at this point...


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## JerseyBird97 (Sep 13, 2009)




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## bearwithfish (Sep 29, 2009)

hmmmmm it looks good my only recommendation would be to run your seals a little thicker (its not a display so it can be a bit less than pleasing to the eye... other wise i am not really sure..... please forgive me if i sound foolish here but i am simply asking obvious questions to get to the root of the issue.... 
when seting new seal you have emptied, cleaned and dried the tank removed all traces of old seal and cleaned area for new seal with alcohol. then after it dries set new seal and let set for 24-48 hours before adding any water to the system? againi have no doubt in your ability just trying to figure out the issue....


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## JerseyBird97 (Sep 13, 2009)

bearwithfish said:


> hmmmmm it looks good my only recommendation would be to run your seals a little thicker (its not a display so it can be a bit less than pleasing to the eye... other wise i am not really sure..... please forgive me if i sound foolish here but i am simply asking obvious questions to get to the root of the issue....
> when seting new seal you have emptied, cleaned and dried the tank removed all traces of old seal and cleaned area for new seal with alcohol. then after it dries set new seal and let set for 24-48 hours before adding any water to the system? againi have no doubt in your ability just trying to figure out the issue....


 
That is correct. I just talked to someone who does this for a living and he said plexi will not easily adhear to class as Sin was saying I need to use a heavy duty maring adhesive. So I have the Marine Epoxy curing now. If this doesn't work he told me to just use glass and that should be alot easier to make stay in place.


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## SinCrisis (Aug 7, 2008)

OH, your adhering to glass! Haha, maybe i misread but i thought u were doing plexi to plexi. weld on wont work for that, epoxy is the best bet, but there are products out there designed for plexi to glass connection.


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## JerseyBird97 (Sep 13, 2009)

Sin... you didn't mis read. I am using plexi. I used loctite marine epoxy yesterday at 7pm. 3 hour cure time then added heavy silicone on both sides. Cured over night. Let it sit in water all day tonight. I'll give it till this time tomorrow before I try it under the tank again. So far it's holding strong.

Keep your fingers crossed for me!


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