sump

[silent saab]

hey there so im sorta new to SW fish tanks and i had a sump givin to me and its made out of acrylic, and it was to long to fit in my cabinet.. so i cut it down about 3 inchs on one side and that side had a crack, so i couldnt find any place that carries ips weld on... soooo, i used the all glass aquarium silicone and cleaned the pieces that i was going to silicone with isoprohpal alcohol, and siliconed it with really thick beads... i was wondering if this is going to hold? i tested it for a couple days with water in it and there were no leaks, am i ok to use this or not such a good idea? can i get some feed back and let me know what you guys think i pulled on it and its super strong... but jus let me know

[sjm817]

[welcome]

I would get some weld on. Silicone doesn't stick real well to acrylic.

[silent saab]

ok cool well do you think that it will hold up for a couple months till i can buy the parts to build another sump? i cant find any place here that has weld on so it jus needs to hold up for a month or 2

[vader88]

<a href=showthread.php?s=&postid=12486839#post12486839 target=_blank>Originally posted</a> by silent saab
ok cool well do you think that it will hold up for a couple months till i can buy the parts to build another sump? i cant find any place here that has weld on so it jus needs to hold up for a month or 2

NO, it's not going to hold on. Silicone does NOT bond with acrylic. The acrylic cements actually bonds the two pieces of acrylic together. If you willing to make a 30 gallon mess on your floor, use the silicone. It would be worth your while to order it online and have it in a few days if you can't find it locally.

Check your LFS's, some will stock it. Your not going to find it at your local home improvement stores.

It's just not worth rushing.

[silent saab]

um, alright then well then i guess i will jus wait on the sump, thanks it has been sitting with water in it since friday so im going to see how long it holds.... guess im jus going to start over and build a whole new sump outta new acrylic

[andyman159]

When you go to weld it back together, it's a must to take some 220 or finer sand paper and run it along the edges to be welded, unless you've got a jointer you can plane the edges clean with. You need to get those edges free from the sawcut lines you see on it. It will be super smooth when you're done. Put the sandpaper on a sanding block so that there is even pressure on the whole edge. Also, only sand in one direction, no back and forth motion. This smooth surface will allow that weld on to contact 100% of the surface and not leave cavities or possible leakage points. Do this, and you'll be happy you did.
There are some good pointers on www.melevsreef.com . He uses acupuncture needles to set the acrylic apart for the 40 sec. soak time, I use the smallest needles that my wife uses at the vet. Trust me, this makes it all much easier. Welding acrylic is not a race. Be patient and you'll be much happier in the end. Give it 24-48 hrs. to cure before water testing it. Then fill it and let it set for a couple of hours. This will give any voids time to leak water out.

Good Luck!!!!

[silent saab]

thanks andyman im gunna order the weld on #40... it is going to be here on monday so ill update then...

[silent saab]

hey all i got the weld on # 40 ordered it should be here on mon-tues, a pint was only 15.00 dollars, so my sump should be repaired the end of next week and filled up...