How to repair missing cross brace on a 75g?

[Dark River Aquatics]

Hi all! So I found a used 75g where the price was right (traded for fish & plants), but it needs a reseal and a new cross brace. I’m looking at it as a fun challenge and something new to learn as I always just buy new tanks and this will (hopefully not backfire) as both a basically free tank and a new skill set.

 

So the reseal process looks straight forward enough, but the cross brace is troubling. It looks like it was melted off by a very hot strip light, one side is all melty and the other looks snapped off. I’ve done some preliminary research and found several ideas - ordering a replacement frame (but I’m not sure what brand of tank this is), using a strip of glass siliconed or epoxied to the frame in place of the brace, just slapping a clamp across it, or stripping the top frame completely and eurobracing it.  So I guess my question for the collective nerm-mind here is; what do? Please advise 🙂

[Sarina]

So, funny story, I used to be a composites fabricator, and I actually can tell you how to fix it without replacing the entire top frame. Order some 1/8" thick abs plastic online, cut two strips about an inch wide, and use methylene chloride to glue one strip on either side of the damage. If you want, for aesthetic purposes, you can even cut down the melty bits and cut a piece wide enough to cover both strips and glue that on top of the gap to cover it. It probably wouldn't look half bad and it would save you from having to strip and re-silicome the whole top of the tank. 

[Dark River Aquatics]

On 6/26/2021 at 8:40 PM, Nirvanaquatics said:

So, funny story, I used to be a composites fabricator, and I actually can tell you how to fix it without replacing the entire top frame. Order some 1/8" thick abs plastic online, cut two strips about an inch wide, and use methylene chloride to glue one strip on either side of the damage. If you want, for aesthetic purposes, you can even cut down the melty bits and cut a piece wide enough to cover both strips and glue that on top of the gap to cover it. It probably wouldn't look half bad and it would save you from having to strip and re-silicome the whole top of the tank. 

Thank you so much! Would it work to glue the strips to the underside of the frame as well? Ideally I’d like to be able to use glass lids, but structural integrity def comes first

[Sarina]

On 6/26/2021 at 7:45 PM, Dark River Aquatics said:

Thank you so much! Would it work to glue the strips to the underside of the frame as well? Ideally I’d like to be able to use glass lids, but structural integrity def comes first

Oh yeah as long as both sides of the cracked part are supported, you can do it however you like! 

[Dark River Aquatics]

On 6/26/2021 at 8:48 PM, Nirvanaquatics said:

Oh yeah as long as both sides of the cracked part are supported, you can do it however you like! 

Possibly a stupid question but is methylene chloride the active ingredient in PVC cement? Did some googling and that popped up as one of the first things, I already have some Oatey regular clear PVC cement listing methyl ethyl ketone 78-93-3 as the first ingredient, will this do the job?

[Hobbit]

(Ooo I got a tank with the same problem. This is good to know!)

[Spicy Reef]

On 6/26/2021 at 5:40 PM, Nirvanaquatics said:

So, funny story, I used to be a composites fabricator, and I actually can tell you how to fix it without replacing the entire top frame. Order some 1/8" thick abs plastic online, cut two strips about an inch wide, and use methylene chloride to glue one strip on either side of the damage. If you want, for aesthetic purposes, you can even cut down the melty bits and cut a piece wide enough to cover both strips and glue that on top of the gap to cover it. It probably wouldn't look half bad and it would save you from having to strip and re-silicome the whole top of the tank. 

So I have this situation in pic below, can I run a couple of strips, top and side, using ABS glue to keep together or is my situation a possible complete replacement. I already tested, it held water no problem for a month and I did not notice any expansion, THANKS!

 

[Sarina]

On 6/26/2021 at 10:17 PM, Spicy Reef said:

So I have this situation in pic below, can I run a couple of strips, top and side, using ABS glue to keep together or is my situation a possible complete replacement. I already tested, it held water no problem for a month and I did not notice any expansion, THANKS!

 

It looks like the center brace is still intact, so just scab over the cracks with some 1/6" thick abs (you'll save a few bucks with thinner material) and you'll be golden! 

[Sarina]

On 6/26/2021 at 9:16 PM, Dark River Aquatics said:

Possibly a stupid question but is methylene chloride the active ingredient in PVC cement? Did some googling and that popped up as one of the first things, I already have some Oatey regular clear PVC cement listing methyl ethyl ketone 78-93-3 as the first ingredient, will this do the job?

Yes, methylene chloride is basically the super generic version of mek lol I guess I should have said something about pvc cement working just fine for this purpose.