[Ltspd]

I am in process of making my new sump out of acrylic. I am glueing the acrylic with no.3 first then I plan on going back and using a bead of no.16 then laying a 1/2" x 1/4" acrylic rod into that bead and then beading around that pc. This will be at the 4 corners and the bottom corners (structural points). On the inside things I will not use the 1/2 x 14 unless I got some left over.

My question is should I go back and silicone the joints? Would it hurt? I am not creating this for looks, functionality only. The Engineer part of me says I should run a bead of silicone around everything after the acrylic glueing is done and cured.

[golfish]

Paul,
I have never used silicone on acrylic (never needed too) I think you'll be fine the way your doing it.

I seem to remember reading silicone won't work on acrylic??

Mark

[eses]

Silicon won't work to bond the two together, but if you coated the seams, in theory it would help hold back water from leaks. I wouldn't bother though. As long as you glue the acrylic right it shouldn't leak, and if it does, you don't want to repaire it with silicon; use acrylic glue.

And it wouldn't hurt anything, just look worse..and if a leak does spring up, it may hinder your efforts to fix it as you'd have to remove the silicon.

[myreef]

I agree with the above posts Paul, I wouldn't bother with silicone either. The Weldon #16 will act as silicone, just non removeable. A friend of mine built a Nurce top off system and put silicone on the seams and I went in and said watch this. It pealed off easier than I had even thought. It was just a waste of time, IMHO.

[organicreefer]

silicone works fine on acrylic,i cant beleive poeple on the boards always say it doesnt work?!?how are youre acrylic overflows attached to youre glass tank?silicone,regular ge silicone.ive built alot of things (parts of a wet /dry,my baffles in my glass sump are acrylic)using silicone to bond acrylic and its very strong.
if it peels of easily the acrylic wasnt dry or clean.as long as it is dry and clean it bonds very well.

[golfish]

I can't believe Organicreefer doesn't agree

[organicreefer]

just spreading some knowledge to the less fortunate

[myreef]

Originally posted by organicreefer
silicone works fine on acrylic,i cant beleive poeple on the boards always say it doesnt work?!?how are youre acrylic overflows attached to youre glass tank?silicone,regular ge silicone.ive built alot of things (parts of a wet /dry,my baffles in my glass sump are acrylic)using silicone to bond acrylic and its very strong.
if it peels of easily the acrylic wasnt dry or clean.as long as it is dry and clean it bonds very well.

I don't have a glass tank. Well a friend of mine built a Nurce system and before he even leak tested it the silicone peeled off way too easily. So it was not a matter of it not being dry...it was never wet to begin with. Sounds like everything you have built involves acrylic and glass....so I respectfully disagree. Although, it may depend on the silicone that was being used.

[golfish]

Organic,
You old news doesn't help here Everybody knows the acrylic overflows are set with silicone on glass tanks (just reach in and grab a hold. Now pull and watch your overflow come apart) What does that have to do with Pauls post. Unless Paul is writting in secret code again, I see no mention of glass so why would he want to use something that WILL NOT bond acrylic near as well as the Weldon. Sure, silicone will bond it but so will bubble gum. You meaning of "bond" may be different then others. Weldon will make it into one piece.

[Ltspd]

Ok Guys. I am now better than 1/2 way done with the sump. Best stuff out there is to glue it with no.3 then after it dries lay a bead of no16. Its working great. No need for silicone, the no16 makes the engineer in me happy I am using the 1/4 x 1/2 rect acrylic pc's to beef up the joints where I think they need them. I will also add gussets in stragic location to further strengthen the sump and probally comb brace it all around where applicable.

Pictures at 11.

[golfish]

See,see it knew you were writting in secret code Glad to hear its working for ya.....

How are the frags doing?

Mark

[Ltspd]

Mark,
Lost the acro frag (brown) but all the rest are doing well. I just moved them up 1/2 way in the tank yesterday as I aclimate them to the light.

Gotta get rid of the urchins, they keep knocking over all my frags I havent epoxyed to the LR and pusing my Maximum clam off its perch.

[organicreefer]

Originally posted by golfish
Organic,
You old news doesn't help here Everybody knows the acrylic overflows are set with silicone on glass tanks (just reach in and grab a hold. Now pull and watch your overflow come apart) What does that have to do with Pauls post. Unless Paul is writting in secret code again, I see no mention of glass so why would he want to use something that WILL NOT bond acrylic near as well as the Weldon. Sure, silicone will bond it but so will bubble gum. You meaning of "bond" may be different then others. Weldon will make it into one piece.

OLD NEWS you still dont even know you can pull my overflow apart dont know who built youre tank but mine is plenty strong.and what do you mean what does it have to do with pauls post?he wasnt planning on it being structural ,just another leak protection(the way i read it),and it would work obviously if its holding the overflows in place(quite strongly i assure you ,have you ever given them a pull?i drilled through mine i know how strong they are)
and myreef ,next time you happen upon a tube of GE silicone,give it a read,i beleive acryilic is one of the things mentioned that it adheres to even the oil from youre hands can prevent silicone from getting a good grip on acrylic,it has to be clean.
and oh yeah ,silicone is silicone is silicone.its all the same.

[golfish]

Yep, with one little jerk I could yank your overflow out like it wasn't even siliconed in That's one little JERK

[Ltspd]

Yes, organicreefer was correct in the fact I was NOT using it as structural. But as a added leak protection. Now that I am constructing I realize I dont need it.

Any rate, you cant use silicone to make something sturdy when using acrylic. The stuff just doenst stick. I know I would list that as one of the newbie DIY rules. "Dont use Silicone to join Acrylic"

But Hey some of us are just Lucky!

[organicreefer]

im not gonna argue this one ,this isnt about opinion,this is about fact.silicone does stick to acrylic,and i have joined acrylic to acrylic with silicone and it is pretty strong.is it the best way to join acrylic,no ,but it does work.practically all glass tank makers use silicone to attach acrylic overflows,that right there should tell you.

[golfish]

I think all those glass tank builders are LUCKY......sure am glad my tank has glass overflows

Hey, I know....how about you go do some intense research on this, I'm sure you'll find somebody to agree with you

[organicreefer]

hey golfish, did that" intense research",looked at a tube of GE silicone i have in the garage,it says it has an adhesive rating of 3(on a 0-7 scale)on plastic

[Ltspd]

Originally posted by organicreefer
hey golfish, did that" intense research",looked at a tube of GE silicone i have in the garage,it says it has an adhesive rating of 3(on a 0-7 scale)on plastic

Well 3 makes me more confidant of silicones ability on acrylic.

[golfish]

Paul, I just read the back of a Bozoka bubble gum wrapper...its also a 3