What should I use

[Folta]

Hello all,

 

I need to glue the overflow box (black acrylic?) to the back of the tank. What product should I use that will hold well and be safe for the tank of course.

 

I have a bottle of 'kitchen and bath adhesive caulk', would that be ok?

[Folta]

This is what I have at the moment:

 

[flowerseller]

No, that is not OK.

It most likely has a mildicide in it to help prevent mildew.

 

Clear aquarium silicone.

 

Use enough pressure to let some ooze out from the contact point while still leaving enough to adheare it to the glass. Take a moist finger and run a bead inside and out after the box dries in place.

[davelin315]

What's the tank made of? If it's acrylic, then use acrylic solvent or PVC cement. They both accomplish the same thing. Solvent is available at hobby shops and will melt the acrylic together. It's not as messy but it's harder to use properly as it's like using water. On the other hand, PVC solvent is much easier to use as it is thicker, but it's also much messier and you can mess up the clarity of your tank if you drop it in the wrong place. That said, if it's an overflow, just brush it on the edges and then push it into place, then apply it to the inside. Once it's dry, use the acrylic solvent which works by capillary action to fill in any remaining leaks.

 

If it's glass, then mount a couple of strips of acrylic in place using silicone and then silicone the overflow in place. It won't go anywhere if it's braced, and probably won't even if it's not.

[xeon]

If the tank is acrylic I would use some Weldon 4 or 16. If it is glass you can get by with silicone. Dave's brace idea sounds pretty good since I experienced a silicone joint semi-failing over a period of time. It is an acrylic to glass application.

 

I would use either epoxy or Weldon 40 for glass to acrylic... make it about as permanent as it could get. The stuff you have is no good, from the fuzzy label I can make out Microban... which is a mildew inhibitor as Chip noted. In general any Window and Door silicone will not have these. Kitchen & Bathroom compounds generally do. I have used GE Window & Door (I & II) for all of my "siliconing".

[Folta]

The tank is a glass tank.

 

Where can I purchase said silicone? Do fish stores typically carry it, or should I head back to home depot?

 

Edit:

 

Will this do?

 

Silicone

[xeon]

The aquarium specific stuff you can find locally in a LFS... my local Wal-Mart has it too. For the GE I or II, you can find that at Wal-Mart, Lowes and/or Home Depot. The specific product I use is the clear GE II Window and Door. I would use the GE II as it will cure faster and supposedly has a little better strength with plastics. To be totally honest, the aquarium stuff is probably the same as the GE I or II. I can't say which since I'm not sure whether it is acid or neutrally cured. Neutrally cured will cure faster... again that is the GE II.

[steveoutlaw]

Find a PetSmart.....they carry it. It's only $5.00 for a small tube.

[ErikS]

Chip is 100% correct - that stuff will kill all the bacteria in the tank "Microban" is a fungicide - you don't want this near the tank.

 

Xeon has it - ANY 100% silicone will work, either GE I or GE II. GE I is cured with acedic acid (vinegar) & I forget what the curing agent is for GE II. You can use GE I sooner in the tank as acedic acid won't hurt anything, just drop the PH (best wait until there's no smell = cured).

 

There is absoultely no reason to waste the $$$$ on the "aquarium use" stuff, silicone is silicone is silicone. The back of the GE stuff will say "not for aquarium use"........but IMHO this is a CYA to protect the interests of the clients who buy GE I/II & re-label it "for aquarium use" - charging 3x the price. GE won't confirm this, nor will they deny it - when asked the reply is "the aqaurium silicone is made to the clients specifications"

 

Just read the label, if it says 100% silicone then its fine. You can pay $5 @ petsmart for a small tube or $1.89 for a full tube @ Home Depot/Lowes.

[Folta]

I found that one of the bulkheads on my sump is leaking, so I'll need to reseal it (or will I need to replace it too?)

 

I'm assuming I can use silicone in this application as well?

[xeon]

You could, but I would try and try to seal it as is. One can actually overtighten and smush the gasket too much or it could not be tight enough. Another scenario is your hole could be a little too large for it to seal easily. I'd mess with it first to see if it can be fixed without silicone... otherwise yes, silicone may help seal it.

 

GE I uses acetic acid and GE II is neutrally cured using alcohol. The alcohol cure happens a lot faster.

[davelin315]

On the bulkhead, I'd remove it and remount it. Clean off the seal and the hole, make sure you've got the flush side to the water with the gasket on the inside of the tank and then hand tighten and then use a wrench to tighten it about 1/2 to another full turn.

[fishface]

FYI, in general silicone doesn't bond plastic to glass well. It isn't really load bearing. For the overflow, it's acceptable, but not great, and still can leak.

 

This is just gossip, but I talked with Glass cages at MCNA, and they only sell a glass overflow because they had reliability trouble with the acrylic over the years. Anyone else see their tanks there?

 

They mentioned that a major manufacturer is changing over to glass overflows too for the same reason. So if you're going to fix something...I'd look to doing it the best way possible.

 

FF

[dchild]

I use Marine Goop - very strong and IME perfectly reef safe. Not trying to hijack, but I have a question on the bulkheads - will it work to turn the bulkhead around so the long part is sticking into the tank if you use teflon tape and if the gasket is still on the inside? I'm trying to plumb 2 Rubbermaid containers together and minimize the required distance between the tubs.

[davelin315]

Use a lot of teflon. The problem is that the threads themselves may not be the problem. Many bulkheads I have seen have a line that runs perpendicular to the threads from the casting process for them, and this is what seems to cause the problem with leaking. It's not significant and salt creep will seal it up in the long run, but it will leak, and if it's under pressure, the leaking will be greater. It can be done, but I would make sure you use more than a couple of wraps of teflon tape and also try and find a bulkhead with very little evidence of the casting process.

[xeon]

This is just gossip, but I talked with Glass cages at MCNA, and they only sell a glass overflow because they had reliability trouble with the acrylic over the years. Anyone else see their tanks there?

 

They mentioned that a major manufacturer is changing over to glass overflows too for the same reason. So if you're going to fix something...I'd look to doing it the best way possible.

45667[/snapback]

They should look into using Weldon 40 since they are manufacturers of a lot of tanks. Next time I talk to the guy at Glass Cages, I might suggest that. Acrylic overflows IMO outclass the glass overflow if for nothing else... you can add overflow teeth which are invaluable. Doing teeth in glass is a major operation IMO.. or adding acrylic faceplates with teeth would look cheesy IMO.

[ErikS]

GE II is neutrally cured using alcohol. The alcohol cure happens a lot faster.

Thanks for the reminder/correction - I always seem to forget the curing agent in GE II

 

It matters not which way the threads go - inside or outside the tank. What does matter is that the gasket goes in the flange side whether it be the dry or wet side.

[Folta]

Ok, so I went to home depot and picked this up:

 

 

 

I was wondering, if I find a leak around a seam of one of my pvc pipes (I used all solvent connections with the excepton of the threaded connections to the pump), can I use this stuff to seal around the seam?

[ErikS]

can I use this stuff to seal around the seam?

Yep, kinda of a kludge but it will work (I know this for the very same reason ) Just make sure the joint is dry & not under pressure when you silicone it.

[flowerseller]

Timothy,

 

Next ride to HD, look for Rain-R-shine solvent. (baby blue container)

It's used on pool and spa stuff, it's a blue solvent and easier to see your joint while gluing. I switched to it more than a dozen years ago and never looked back.

Get the little containers because they have a smaller swabby.

 

Erik's on about the BH- IME

[Folta]

I'll have to look out for that rain-r-shine stuff. How is it better than the purple primer + pvc glue?

 

 

I siliconed the box up last night. I ran a bead of silicone on the edges of the overflow box, then stuck it into position. I then used a clamp to hold it firmly in place. I took more silicone on my finger, and ran it in the corners both inside and out of the box, where the box meets the glass.

 

Will that be enough, or should I use more and go over the seams again?

[flowerseller]

I like the Rain-r-shine better because I can see the glue joint better while I'm gluing.