Acrylic Sump Adhesive?

[NeuroticAquatics]

I plan to convert a 90 gallon acrylic aquarium into a sump/refugium by adding acrylic sheets/panels to form the various chambers. Will super glue be okay long term or should I use an acrylic adhesive?

 

[Finhead]

I plan to convert a 90 gallon acrylic aquarium into a sump/refugium by adding acrylic sheets/panels to form the various chambers. Will super glue be okay long term or should I use an acrylic adhesive?

Use acrylic solvent is the best. If you can cut the panels for a nice snug fit you can use Weld-on 3, it is a solvent weld not a glue so it will be permanent as it bolds the structure. IF you can't get a tight enough fit you can use Weld-on 16 but it will cause slight crazing the more you use so you would want to use it very sparingly.

 

[redfishbluefish]

Another option is to use a silicone specifically made for plastics. I've used this before and you won't believe how it sticks to acrylic. You can find it at HD where they sell acrylic sheets. (You won't find it in the Paint Department, where they have all the other silicone caulks).

 

[NeuroticAquatics]

Thanks for the feedback. I will see how snug I can get things.

 

[pdxmonkeyboy]

i would highly advise against using any type of silicone. There are many many threads about how to get silicone to stick to acrylic do to the fact that it is a very oily material..

maybe the poster above found some new product, but standard 100% silicone will NOT work.

 

[Jeepguy242]

use acrylic solvent

 

[hybridazn]

For sump baffles silicone will work just fine if in a pinch. I built my sump out of a 40b and used acrylic baffles with ge1 and each chamber is still water tight. I built the sump back in early 2016

 

[pdxmonkeyboy]

For sump baffles silicone will work just fine if in a pinch. I built my sump out of a 40b and used acrylic baffles with ge1 and each chamber is still water tight. I built the sump back in early 2016

im sorry, but that will not work in this case. Your acrylic baffles are being held in place because the thick bead of silicone is chemically bonded to your glass aquarium.

The OP here has an acrylic aquarium. Silicone will not bond to acrylic. I promise you it will not bond to the acrylic.

I had a similar glass and acrlylic sump. when I took it down i just wiggled the acrylic baffles and lifted them right out.

 

[cilyjr]

@Finhead said it best. use sci-grip {used to be weld-on) 3 or 4 if the panels are cut properly. These solvents are about the consistency of water so they are a bit tougher to use for those not used to them. 16 can also be used and is more the consistency of superglue gel but can cause crazing and ugly edges. there is also an argument to be made that 16 bond may not be as strong as the 3 or 4 bond but for this purpose it will be fine.

If you are inexperienced with acrylic work consider reading @Floyd R Turbo thread about acrylic fabrication and buy some extra to practice. Its not hard once you get used to it. I've found good tools make life much easier ( I pretty much only use end mill cutters for acrylic anymore). Good luck with your project!

 

[NeuroticAquatics]

I will use the solvent and see how snug I can get the panels to edges of the aquarium. I did this sort of thing for my 60g cube sump (just used super glue) but this is larger and will be very different. Those edges were a little bowed, but I was able to get enough touching to get it to hold. I guess we shall see. I will post pictures once I get it all done...

Thanks for all the feedback!

 

[cromag27]

how did this turn out? the big problem is that your tank could be warped by now from holding water. this will make it difficult to properly weld baffles.

 

[NeuroticAquatics]

I’m going to throw it together this weekend. I’ve been busy with other things lately but I’m hoping to get the 240g replumbed and the sump set up by bedtime Sunday. The acrylic baffles seem pretty snug...maybe not top to bottom but my guessing enough that some bonding will make it hold. I will update once I’m done...

 

[cromag27]

i would use sci grip 3 with the pins method. secure the bottom first then each side one at a time. then to make things water tight use momentive rtv 100 series silicone.

 

[NeuroticAquatics]

I’m reviving this as I finally got everything bonded (after life caused some unfortunate delays), but hit a snag after water testing last night...

I have my drain pipes split...one to the left that will go into a sock and skimmer chamber. That was supposed to overflow (an over and under) into a chamber that has the return pump. The other drain pipe goes into a refugium chamber to the right side. With my pump going full (Jebao DCP8000), there is not enough flow to get water going up and over from the left (sock/skimmer) chamber. That is due to small spots where the acrylic could not bond allowing water to the sides of the baffles. The baffles are in tight, so can I just use the Home Depot 100% Silicone Sealant (mentioned earlier) to fill those leaks?

 

[Pelagic One]

May we ask which solvent you eventually used to hold down the baffles? Assuming you used the Weld-On line or a similar product, couldn’t you just use more of that to fill in the gaps?

As others above have said, you probably don’t want to use silicone. I’ve plugged a hole (divot) in my damaged acrylic QT with Weld-On 40, and truly believe it’s now the strongest part of that tank.

“WELD-ON 40 is especially formulated to bond extruded, cast, and cross-linked acrylic sheets. It will also bond acrylic to polyester, butyrate, polycarbonate, PVC and other materials.”

 

[NeuroticAquatics]

I used this and like it says, is is “water-thin”. No way that would work to fill gaps.

The baffles are on tight though. I tried pulling pretty hard and they weren’t going anywhere. I figure if the silicone is just being used to fill tiny gaps, it should work and should come lose, but that’s just me guessing.

 

[Jeepguy242]

I used this and like it says, is is “water-thin”. No way that would work to fill gaps.

The baffles are on tight though. I tried pulling pretty hard and they weren’t going anywhere. I figure if the silicone is just being used to fill tiny gaps, it should work and should come lose, but that’s just me guessing.

try laying the sump down on on the side that has the seam you are trying to fill.... use a syringe to push the solvent into the seam and let it sit for 5 to 10 minutes like that..

wicking action should take the solvent into the seam and melt the acrylic and create a watertight bond

 

[NeuroticAquatics]

It is in the stand and that was rebuilt (had to pull pieces off to get it under). My fix has to be done with that in mind.

I have a little of the SciGrip left...was thinking of maybe cutting acrylic and doing a layer of that at the seams. Still doesn’t guarantee a watertight seal though.

Maybe superglue gel?

 

[Pelagic One]

Weld-On 40 is a much thicker version of (SciGrip) Weld-On 4, and will fill the vertical gaps. My nearest plastic fabrication company (Tap Plastics) recommended I use some acrylic shaving in the mix to strengthen it even more. 'Hope that helps...

As an FYI, reefer friends of mine in the Palm Springs area have visited Regal Plastics in Cathedral City for their acrylic repair and fabrication needs.

 

[NeuroticAquatics]

I will look them up tomorrow and see if they have that weld-on 40. Thanks.

I filled it again today and think that the gaps may be more on the bottom. I held the hose against the sides and did not see water going through.