Outgassing from Sealant on Bonded Acrylic Top

[EricR]

Wondering if I should be concerned about long-term venting/outgassing of the clear sealant I used to bond together some acrylic sheets when I made my lid/top. (Basically cut two sheets of acrylic to shape to act as a frame for regular clear mesh/screen, plus have a set-in feeding door, and then sandwiched the mesh/screen between the two frames/shapes)

Here's what I used (just because it is crystal clear and bonds nicely to acrylic):

Lexel Clear Sealant

*It has warnings about inhalation (mentioning toluene) which I think is for while you're working it (wet).

My assumption is that after full cure, it would be safe, in terms of outgassing/venting toxins into the air (gas exchange at the water surface) but maybe that's not a safe assumption?

Curious what others think. (Not finding any long-term details like that so far)

Aside -- if you have thoughts on a better/safer silicone that is really clear, I'm interested.

 

[MnFish1]

Wondering if I should be concerned about long-term venting/outgassing of the clear sealant I used to bond together some acrylic sheets when I made my lid/top. (Basically cut two sheets of acrylic to shape to act as a frame for regular clear mesh/screen, plus have a set-in feeding door, and then sandwiched the mesh/screen between the two frames/shapes)

Here's what I used (just because it is crystal clear and bonds nicely to acrylic):

Lexel Clear Sealant

*It has warnings about inhalation (mentioning toluene) which I think is for while you're working it (wet).

My assumption is that after full cure, it would be safe, in terms of outgassing/venting toxins into the air (gas exchange at the water surface) but maybe that's not a safe assumption?

Curious what others think. (Not finding any long-term details like that so far)

Aside -- if you have thoughts on a better/safer silicone that is really clear, I'm interested.

I would doubt that long-term there will be a problem - once its cured - that said - I would consider this almost 'under-water' use - and I don't see in the specification where its ok for under-water (but is ok for interior/exterior).

Having said that - I would likely not use the product - as I'm not sure how well it will last over time - and whether something will decompose in a marine environment. Curious - was there a reason you used this instead of regular acrylic 'glue'?

 

[EricR]

I would doubt that long-term there will be a problem - once its cured - that said - I would consider this almost 'under-water' use - and I don't see in the specification where its ok for under-water (but is ok for interior/exterior).

Having said that - I would likely not use the product - as I'm not sure how well it will last over time - and whether something will decompose in a marine environment. Curious - was there a reason you used this instead of regular acrylic 'glue'?

I was basically in a hurry to slap something together (as I was about to do a tank transfer) and was just standing in Lowes staring at the giant selection of silicone/caulking/etc -- this one was crystal clear and said it bonded to acrylic, so I grabbed it.

If you have a specific acrylic "glue" in mind, point me to it, please.

*only reason silicone (or similar) was in my mind was because I have normal aquarium clear mesh/screen sandwiched in between so was just thinking the two pieces of acrylic might have that little space in between them but, after doing it, don't think that's a concern

 

[MnFish1]

I was basically in a hurry to slap something together (as I was about to do a tank transfer) and was just standing in Lowes staring at the giant selection of silicone/caulking/etc -- this one was crystal clear and said it bonded to acrylic, so I grabbed it.

If you have a specific acrylic "glue" in mind, point me to it, please.

*only reason silicone (or similar) was in my mind was because I have normal aquarium clear mesh/screen sandwiched in between so was just thinking the two pieces of acrylic might have that little space in between them but, after doing it, don't think that's a concern

Gee - I wish I knew the name of the acrylic expert here - but here is a question - is it a firm joint or needs to be a bendable joint?

 

[JoshH]

@Elder1945 Knows a little bit about Acrylic. Weldon seems to be the standard for bonding acrylic to acrylic.

One thing that concerns me in the description of the product you used is this...

Typically if a product says this, it contains mildewcide. These chemicals can be incredibly toxic to your reef. I'm not sure on whether or not the same issues will happen with a product that isn't constantly submerged, however it will be exposed to moisture from your tank.

 

[EricR]

Good catch on the "Won't grow mildew" spec.

The sealant is sandwiched in between two pieces of acrylic sheet so not even really touching the air, let alone the water, so I never even thought about that.

...but, now, hmmmmm

 

[MnFish1]

Good catch on the "Won't grow mildew" spec.

The sealant is sandwiched in between two pieces of acrylic sheet so not even really touching the air, let alone the water, so I never even thought about that.

...but, now, hmmmmm

The way it was done - is likely not an issue. BUT - IMHO - every time you have a problem with your tank - you're going to be going 'wow' - is it the top. I would order a custom mesh cover from I think its 'clear view lids'. and forget it - they are not that expensive - and will custom do a lid for you tank - with cords, etc.

 

[EricR]

The way it was done - is likely not an issue. BUT - IMHO - every time you have a problem with your tank - you're going to be going 'wow' - is it the top. I would order a custom mesh cover from I think its 'clear view lids'. and forget it - they are not that expensive - and will custom do a lid for you tank - with cords, etc.

I hear ya ... but I've got extra acrylic sheets (cheap from local OfferUp) sitting in the garage, just itchin' to be cut,,, plus I have extra clear mesh/net.

More fun to make something sketchy than buy something nice -- just kidding

I did pull it off the tank for now and will probably make a quickie window screen frame for the time being.

*long-term, I am still interested in hearing specific suggestions for CLEAR silicone or acrylic "glue" that would be SAFE to use for bonding acrylic (for aquarium lid)

 

[JoshH]

I hear ya ... but I've got extra acrylic sheets (cheap from local OfferUp) sitting in the garage, just itchin' to be cut,,, plus I have extra clear mesh/net.

More fun to make something sketchy than buy something nice -- just kidding

I did pull it off the tank for now and will probably make a quickie window screen frame for the time being.

*long-term, I am still interested in hearing specific suggestions for CLEAR silicone or acrylic "glue" that would be SAFE to use for bonding acrylic (for aquarium lid)

Weldon is the more popular solvent for bonding Acrylics.

You can buy it in different viscosities "16" being the more common type. Hopefully Kyle (Elder) chimes in in a bit for a better description of your options.

 

[MnFish1]

I hear ya ... but I've got extra acrylic sheets (cheap from local OfferUp) sitting in the garage, just itchin' to be cut,,, plus I have extra clear mesh/net.

More fun to make something sketchy than buy something nice -- just kidding

I did pull it off the tank for now and will probably make a quickie window screen frame for the time being.

*long-term, I am still interested in hearing specific suggestions for CLEAR silicone or acrylic "glue" that would be SAFE to use for bonding acrylic (for aquarium lid)

I believe the answer you already got - weldon - is the answer.