Replacing side panel on 360 gallon glass tank.

[JMello]

I have a 360 gallon glass tank that one side panel needs replaced and I need to replace it with annealed or float glass. It currently has 1/2in thick tempered glass.

I see so many varying opinions on replacing glass in a glass aquarium. I've learned over the year to take peoples opinions online with a healthy grain of salt and remember everyone has their own opinion based off their life experience not mine.

From what I've read I think I have a sound plan but would like feed back from people who have done it, seen it done or have done it and failed.

My side panel sits inside the aquarium inside the front and back panel and on top of the bottom panel. Some say you can't mix silicone, old with new but the only parts that would touch are the two bottom corners of silicone.

My plan was to remove current panel (dis-guard), clean the remaining glass with rubbing alcohol tape off the area that will get silicon and use light sand paper to guarantee flat clean surface then clean with acetone. Put new panel in and let set up over night (24 hours) then remove the sealer silicon inside the tank. Not the silicon between glass but the caulked edge on the inside of the tank and reseal the whole tank.

My skill level of "tank stuff" is I've built a 250 gallon acrylic sump. along with small acrylic over flows and tanks. I've taken tanks apart a few tanks, I've drilled multiple tanks, I built a pond/tank with wood and old piece of red sea front glass. I would also say in general I'm pretty mechanically inclined, I build custom vehicle parts and cars for a living. I only list my skill set because I've had people that may have never left their basement tell me "I'd just buy a new tank". I understand a nearly 400 gallon tank in my house that I "DIY'ed" has a certain level of "that went wrong". But I also have a red sea currently and I don't lose sleep over that one:) That being said It will get water tested out side for a while with a pump flowing water in and out of it just to make sure.

Please let me know what you think> If there is a thread here on this page that I missed about this please link. I read as much as I could before i posted this.

 

[KrisReef]

Are you replacing the glass because the silicone is bad or because the glass is bad?

If you only need to replace the glass, I would carefully remove the silione from the 3 beads holding in the current plate and avoid cutting or scraping around the seals in the rest of the aquarium. Otherwise, dismantle and replace all seals, which might be the best bet but it's a lot, lot, lot more work.

The difficulty I see is trying to get sealant in between the replacement glass and the old tank, where the strength of the silicone seal is most important. The slop over inside the tank doesn't hold the tank together and doesn't help much at all with leak prevention, compared to the silicone in between the glass pieces does.

 

[JMello]

Thank you, the panel is being replaced because I tried to drill it with out checking to see if it was tempered and it shattered. I figured the outcome would be the same. Drill it and it breaks replace it or cut it out and replace it anyways. The rest of the seals in the tank are good (meaning it held water) but I figured if I'm replacing this one panel it would be a good idea to re seal the inside bead. I under the silicon between the glass holds it and mostly water proofs it but the inside seal or "chalk" seal for lack of a better term is there to help as well? Maybe I'm wrong on that. if it was a smaller tank I'd take it all apart and reseal and re stick the whole thing but this is a very large tank and that would be difficult. I think to do it right I'd have to build a temporary bench with carpet top and enlist several friends to move and hold panels while I do the work. If that's the only way to do this I will do that but that's a fair amount of work i'd like to avoid if it's not needed.

 

[KrisReef]

Thank you, the panel is being replaced because I tried to drill it with out checking to see if it was tempered and it shattered. I figured the outcome would be the same. Drill it and it breaks replace it or cut it out and replace it anyways. The rest of the seals in the tank are good (meaning it held water) but I figured if I'm replacing this one panel it would be a good idea to re seal the inside bead. I under the silicon between the glass holds it and mostly water proofs it but the inside seal or "chalk" seal for lack of a better term is there to help as well? Maybe I'm wrong on that. if it was a smaller tank I'd take it all apart and reseal and re stick the whole thing but this is a very large tank and that would be difficult. I think to do it right I'd have to build a temporary bench with carpet top and enlist several friends to move and hold panels while I do the work. If that's the only way to do this I will do that but that's a fair amount of work i'd like to avoid if it's not needed.

That actually make disassembly easier since you have better access to the old sealant.

I would not use sandpaper to remove old sealant. Elbow grease is your best friend. There are solvents for removing silicone, that are supposedly awesome but I would be afraid to get any on the old seals since you just replace the one side instead of a complete reseal.

I suspect that an aquarium shop might have some tricks for the job of getting the sealant in between the glass panels? GL

 

[JMello]

Thanks for your help! Yeah when i've removed silicone before a razor blade replaced often worked fine. I just read for best adhering to use sand paper to scuff and clean the already cleaned glass, not to remove silicone but to make the surface more susceptible to silicone.

 

[KrisReef]

Thanks for your help! Yeah when i've removed silicone before a razor blade replaced often worked fine. I just read for best adhering to use sand paper to scuff and clean the already cleaned glass, not to remove silicone but to make the surface more susceptible to silicone.

The sandpaper will scratch the glass. Tank builders do not scuff the glass before adding silicone. They do use alcohol solvent to remove grease, again that's something to keep away from the old seals when you are working next to them.

Wearing gloves when doing the final cleanup prep can help keep the glass clean for bonding.

 

[Aaron Stone]

Thanks for your help! Yeah when i've removed silicone before a razor blade replaced often worked fine. I just read for best adhering to use sand paper to scuff and clean the already cleaned glass, not to remove silicone but to make the surface more susceptible to silicone.

With the old panel out you should be able to carefully flex out the tops of the adjoining panels while you apply a bead.

Sounds like you are fully aware of the risks going into it and probably have a better chance at success then most so I think you will be fine. Following, so keep us updated!

 

[KrisReef]

And just because I'm thinking about this,
Drill out the new holes in the glass before you silicone it into place. Don't forget to leave room for the bulkhead nut & flange.

 

[JMello]

The sandpaper will scratch the glass. Tank builders do not scuff the glass before adding silicone. They do use alcohol solvent to remove grease, again that's something to keep away from the old seals when you are working next to them.

Wearing gloves when doing the final cleanup prep can help keep the glass clean for bonding.

Thank you, i appreciate the input. I won't sand paper then.

 

[JMello]

With the old panel out you should be able to carefully flex out the tops of the adjoining panels while you apply a bead.

Sounds like you are fully aware of the risks going into it and probably have a better chance at success then most so I think you will be fine. Following, so keep us updated!

Thanks, I hope so. It seems so easy to me. But when I mentioned it on a FB group people acted like i was performing open heart surgery and I should just spend 8k on a new tank.

 

[JMello]

And just because I'm thinking about this,
Drill out the new holes in the glass before you silicone it into place. Don't forget to leave room for the bulkhead nut & flange.

This may sound dumb but I was going to do it once in place but you are 100% right! If I screw up I would have to reseal all over again. Now that I type that, I can't believe I even considered that option. thanks for the reminder. haha

 

[BeanAnimal]

I see so many varying opinions on replacing glass in a glass aquarium. I've learned over the year to take peoples opinions online with a healthy grain of salt and remember everyone has their own opinion based off their life experience not mine.

Well. some of us bring facts to combat opinion.

My side panel sits inside the aquarium inside the front and back panel and on top of the bottom panel. Some say you can't mix silicone, old with new but the only parts that would touch are the two bottom corners of silicone.

There is a reason "people" say this. When silicone dries, it forms a single solid mass of cross linked molecules. When you place uncured silicone on cured silicone, there is no cross linked bond. The adhesion is mechanical and in that context, silicone does not bond to itself very well.

My plan was to remove current panel (dis-guard), clean the remaining glass with rubbing alcohol tape off the area that will get silicon and use light sand paper to guarantee flat clean surface then clean with acetone. Put new panel in and let set up over night (24 hours) then remove the sealer silicon inside the tank. Not the silicon between glass but the caulked edge on the inside of the tank and reseal the whole tank.

See above. You are losing a good bit of strength by having two distinct beads of silicone.

Please let me know what you think> If there is a thread here on this page that I missed about this please link. I read as much as I could before i posted this.

Without tank dimensions and bracing specifics, any advice is going to be lacking. That panel may have been tempered to achieve the proper safety factor.

 

[JMello]

Well. some of us bring facts to combat opinion.

There is a reason "people" say this. When silicone dries, it forms a single solid mass of cross linked molecules. When you place uncured silicone on cured silicone, there is no cross linked bond. The adhesion is mechanical and in that context, silicone does not bond to itself very well.


See above. You are losing a good bit of strength by having two distinct beads of silicone.



Without tank dimensions and bracing specifics, any advice is going to be lacking. That panel may have been tempered to achieve the proper safety factor.

Thank you for the response.

Are you saying it's fact that it will leak if you don't take all the panels apart and start over? This was my overall question if it wasn't clear before. I've watched a number of videos where people replaced panels and didn't tear them completely down and had no issues. Even read through comments to see if years down the road it leaked and so far I haven't found one. Again that's just what I found hence while I'm here asking people that maybe have done such a thing.

I have read and heard and understand that silicon doesn't bond to it self well. The only place this would be happening is in the bottom corners as the replaced panel sits inside the glass the new silicone wont touch except those corners. And the "re-sealing" of the whole tank was more of a "while I'm here" lets do this. There doesn't seem to be much dispute over this online. I've watched a number of videos of people cutting off the old interior seal and running new sealant in it's place. I guess that won't bond to the old silicone between the glass very well but it creates a secondary barrier. That being said even if my two corners where silicon will touch approximately 1/8in on each side would then be covered by the "re-sealing" layer over that.

Thank dems are 96x30x29.75 It has glass top center brace of 24in and two side braces over each side panel of 3in. all with a black plastic frame top and bottom. The glass on all sides .5in thick and now I assume that it's all tempered. I'm aware of the thickness calculator for aquariums, I've used it on plywood builds. If it was a front or back panel I would be worried about the thickness but being a side panel of only 30in I would assume that the thickness is less of an issue than the front. I still plan to run at least 1/2 but in float glass where as the rest is tempered and stronger. If I have to go up to 5/8in that's an option as well. Kinda a secondary part to my question.

Again thanks for your input. I appreciate it all.

 

[BeanAnimal]

Thank you for the response.

Are you saying it's fact that it will leak if you don't take all the panels apart and start over?

I can't say that for a fact. I can say for a fact that there is a real world difference in seam strength.

Ignoring that for a moment:

You said that the side panel sits "inside" the aquarium. The bulk of the strength in the joints comes from the thin layer of silicone sandwiched between the panels -- not the protective bead on the inside.

I think you are severely underestimating the ease of getting a clean and even undisturbed layer of silicone sandwiched back in there -- whilst supporting the panel and keeping it aligned.

This was my overall question if it wasn't clear before. I've watched a number of videos where people replaced panels and didn't tear them completely down and had no issues. Even read through comments to see if years down the road it leaked and so far I haven't found one. Again that's just what I found hence while I'm here asking people that maybe have done such a thing.

There are a LOT of variables. Tank size of course being one of them. Depth creates the static pressure, but panel size creates stress as well. Larger panels bow more and the bowing creates a peeling effect on the seams. Silicone is not good at that type of resistance to delimitation.

So ignoring the strength issues with regard to adhesion new to old and the act of actually getting the panel in place.... This is not a trivial size tank and there is far less margin for error. That somewhat begs the question if the type of bracing. It adds safety factor, some styles more than others.

I have read and heard and understand that silicon doesn't bond to it self well. The only place this would be happening is in the bottom corners as the replaced panel sits inside the glass the new silicone wont touch except those corners. And the "re-sealing" of the whole tank was more of a "while I'm here" lets do this. There doesn't seem to be much dispute over this online

I would, under no circumstances cut the old silicone bead away from the entire tank and replace it with a new bead. While the primary component of strength is the sandwiched layer -- that layer being monolithic with the bead does add measurable strength. This is more of a concern than the small interface in the corners. It is another variable but this size tank amplifies the risk. There are no shortage of videos and conventional wisdom that is wrong or poor practice -- especially when those instructions disregard the actual physics at play -- lucky outcomes or not.

Thank dems are 96x30x29.75 It has glass top center brace of 24in and two side braces over each side panel of 3in. all with a black plastic frame top and bottom. The glass on all sides .5in thick and now I assume that it's all tempered. I'm aware of the thickness calculator for aquariums, I've used it on plywood builds. If it was a front or back panel I would be worried about the thickness but being a side panel of only 30in I would assume that the thickness is less of an issue than the front. I still plan to run at least 1/2 but in float glass where as the rest is tempered and stronger. If I have to go up to 5/8in that's an option as well. Kinda a secondary part to my question.

Again thanks for your input. I appreciate it all.

You tank, as built, ignoring the bracing has a safety factor of 2. That is pretty low, and why what braces have been added. Most builders shoot for 3+

In this case, they braces and tempered glass are what adds the extra margin of safety. Granted, the front bowing is the largest concern, not the side panels. Note that aside from preventing bowing thicker glass has more bonding area in the joint, adding significantly more strength.

Removing the plastic trim and braces adds more work. I am sure you have considered that already.

So - all in, I am not sure sure that a tank this size is a candidate for a first time DIY panel replacement. In my honest opinion, given the variables above -- I have a decent amount of experience and If it were my tank, I would hard pass. I just wouldn't sleep well at night. You may very well be successful, but there is certainly risk.

@Joe Glass Cages - care to add anything pro or con to a DIY panel replacement in a tank this size?

 

[JMello]

You said that the side panel sits "inside" the aquarium. The bulk of the strength in the joints comes from the thin layer of silicone sandwiched between the panels -- not the protective bead on the inside.

I think you are severely underestimating the ease of getting a clean and even undisturbed layer of silicone sandwiched back in there -- whilst supporting the panel and keeping it aligned.

I may be underestimating that difficulty level. I appreciate you mentioning it. When I built my 250 gallon acrylic sump it was keeping the edges even that was very difficult but fixture it out made it go much smoother. The harder part was making sure everything was sanded and flat perfectly. I know it's different. BUT that was from scratch. Looking at this tank I thought that part would be easier. since there is a fairly large gap where the silicon goes between the two pieces of glass. Acrylic imo is way more difficult as that gap needs to be very well done and clean or it won't melt and stick and create a bond. Where as silicone has a little more forgiveness in that sense. I assumed build a fixture for the glass to rest up against. that blocked off the silicon on the outside. I would only apply the bottom line of silicon, put the glass in from the inside tilt it up into place (thinking I could leave the top brace on as well as an alignment tool. Then once in place and even side to side there was a good gap where the silicone is now at least 1/8in but haven't measured it. I would shoot the gap full of the silicone which would push against the fixture on the outside. using a hard plastic tool on the inside to evenly push the silicon in-between the two pieces of glass. later i would go over it with the "sealing" layer on the inside. Maybe I'm still "not grasping" the amount of work here.

 

[JMello]

I would, under no circumstances cut the old silicone bead away from the entire tank and replace it with a new bead. While the primary component of strength is the sandwiched layer -- that layer being monolithic with the bead does add measurable strength. This is more of a concern than the small interface in the corners. It is another variable but this size tank amplifies the risk. There are no shortage of videos and conventional wisdom that is wrong or poor practice -- especially when those instructions disregard the actual physics at play -- lucky outcomes or not.

Hmm this is interesting, I thought resealing a tank is a common practice in this method. I haven't found many counter points arguing against doing this? maybe I'm not explaining it well.

 

[JMello]

So - all in, I am not sure sure that a tank this size is a candidate for a first time DIY panel replacement. In my honest opinion, given the variables above -- I have a decent amount of experience and If it were my tank, I would hard pass. I just wouldn't sleep well at night. You may very well be successful, but there is certainly risk.

@Joe Glass Cages - care to add anything pro or con to a DIY panel replacement in a tank this size?

Thanks for the input, i will take it into consideration. at the very least my water test will be much longer than I previously planned. Given what i paid for this (nothing) and the cost of the panel I'm getting 130-330 depending on thickness. I think that's a fair gamble to wage on this project. At the extreme very least I would use the front glass from this to make a plywood aquarium and those have a way way higher failure rate. The potential for failure is always an option with any tank. I've seen dozens of red sea seals fail and I still have one of those in the fish room. Along with a 180 fresh that I have no idea on it's age. Although having 400 gallons emptied out on the floor is a bit intimidating it's part of the risk with this hobby, well I will say that till it happens then I'll be on here telling everyone to buy a new tank every 5 years JIC....haha

 

[jsmkmavity]

Any update?

 

[JMello]

Any update?

My glass should be ready tomorrow. I went with 5/8in instead of 1/2in tempered that came out. I pulled out the old panel this weekend, it wasn't too hard some of the bottom plastic trim broke but it's not a huge deal. I got the top one mostly in-tack off. Cleaning the silicone with the proper tools wasn't hard at all. I even used an old razor. BUT I need to get a new one just to make sure I get it super clean. So far it's been easy. The more important part is silicone in the new piece. I think while I have the panel off I'm going to slide in my new reef structure I've been working on. It's two large pieces that will be very difficult to get in through the top due its weight and it would be way safer to slide it in from the side I believe. I also spoke to my local fish store (reef lounge norco) He's been in the hobby for 40 years. He said it's easy and just take your time. He pointed out to several tanks of his in his store he's had for years that he replaced panels on and never had an issue. His comment was "let me guess you went on line and everyone told you to buy new, I laughed and said that was repeated a couple times, He said good send them to me, i'll be happy to sell them new and I'll keep selling you coral and fish instead of new tanks..haha"

 

[JMello]

My glass should be ready tomorrow. I went with 5/8in instead of 1/2in tempered that came out. I pulled out the old panel this weekend, it wasn't too hard some of the bottom plastic trim broke but it's not a huge deal. I got the top one mostly in-tack off. Cleaning the silicone with the proper tools wasn't hard at all. I even used an old razor. BUT I need to get a new one just to make sure I get it super clean. So far it's been easy. The more important part is silicone in the new piece. I think while I have the panel off I'm going to slide in my new reef structure I've been working on. It's two large pieces that will be very difficult to get in through the top due its weight and it would be way safer to slide it in from the side I believe. I also spoke to my local fish store (reef lounge norco) He's been in the hobby for 40 years. He said it's easy and just take your time. He pointed out to several tanks of his in his store he's had for years that he replaced panels on and never had an issue. His comment was "let me guess you went on line and everyone told you to buy new, I laughed and said that was repeated a couple times, He said good send them to me, i'll be happy to sell them new and I'll keep selling you coral and fish instead of new tanks..haha"

Got the glass, drilled it last night. going to install the reef I built first by sliding it in through the missing panel. I think I will use the tile that came with the used tank and put it back down on the bottom. Put the reef work on it and slide it in. Maybe using a towel to keep it from scratching the bottom of the tank. the two large reef pieces I made are pretty heavy with built in plumbing for lots of flow in-between the structure.