600 gallon acrylic tear down and rebuild or roll the dice?

[wednesday13]

I absolutely agree with you on the overflow. I already removed it, it was actually two overflow boxes that had been poorly glued together. Thank you so much for the advice and help, till now I have not had much experience with acrylic but I figured it was well worth $700 especially when most of the plumbing including all the bulkheads were included, also 2 Jebao return pumps and 4 36" Fluval led lights that is all in good shape. Oh yea plus the two sump tanks.

Here are a couple of the seams but I'll get some better pics when i get this mess of a seal job cleaned off

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View attachment 1545292

Bottoms dont look all that bad so far… when u get a pic of the side seams go from the front of the seams so u can see better what were lookin at. If the tank was full and holding with silicone they cant be all that terrible either or it would have let loose. Personally i like using weld-on #40 for repairs like this. Its like a 2 part epoxy that is the same chemical make up of the acrylic itself. Since u have all that extra material to make rods from thats a pretty good option tho. You can cut it just like wood. Table saw, skill saw or even a router. Ive ripped 1” on a table saw np. Since u have a decent amt of it you can try those few options and see what is the easiest/best for u. You might even have enough to make a center brace with that 1 1/4” also. Should b able to double it up to span the 5’ gap.

 

[bluehand]

Bottoms dont look all that bad so far… when u get a pic of the side seams go from the front of the seams so u can see better what were lookin at. If the tank was full and holding with silicone they cant be all that terrible either or it would have let loose. Personally i like using weld-on #40 for repairs like this. Its like a 2 part epoxy that is the same chemical make up of the acrylic itself. Since u have all that extra material to make rods from thats a pretty good option tho. You can cut it just like wood. Table saw, skill saw or even a router. Ive ripped 1” on a table saw np. Since u have a decent amt of it you can try those few options and see what is the easiest/best for u. You might even have enough to make a center brace with that 1 1/4” also. Should b able to double it up to span the 5’ gap.

After getting all the silicone cleaned off I noticed that most of the joints look almost like they have had super glue applied to them, alot of it chipped away as I was scraping but I didn't go overboard trying to get it off. Also the one seam that had been repaired externally is completely separated, I could shove my razor all the way through it in spots if i tried

 

[wednesday13]

Def. Needs some TLC… nothing outta the ordinary tho for older tanks. Weld-on #40 works very well on older acrylic. You can sand down the areas where its going to be applied to give it a good bite. The only down side is it can cause cosmetic crazing from the glue heating up during the cure. You also need to tip the tank at 45 degree angles to puddle the glue across the seams ur working on one at a time.

2nd option is the rod as mentioned before. You can put that in with #40 also or with solvent. The solvent is a but trickier IMO but theres no threat of crazing and its cheaper since u have material to make rods out of already. Have to deciede which is worse to look at really lol… a 1/2-3/4” fillet of glue with a bit of crazing on the acrylic or a 1” rod in the corners. Either method will essentially give u brand new seams on the tank.

 

[bluehand]

Def. Needs some TLC… nothing outta the ordinary tho for older tanks. Weld-on #40 works very well on older acrylic. You can sand down the areas where its going to be applied to give it a good bite. The only down side is it can cause cosmetic crazing from the glue heating up during the cure. You also need to tip the tank at 45 degree angles to puddle the glue across the seams ur working on one at a time.

2nd option is the rod as mentioned before. You can put that in with #40 also or with solvent. The solvent is a but trickier IMO but theres no threat of crazing and its cheaper since u have material to make rods out of already. Have to deciede which is worse to look at really lol… a 1/2-3/4” fillet of glue with a bit of crazing on the acrylic or a 1” rod in the corners. Either method will essentially give u brand new seams on the tank.

I have ordered a pint kit of the #40 and I think I will use that on the bottom seams. I do plan on having substrate so the bottom seams won't be visible at all. Reading up on the #40 it mentioned an optional #3061 to be used as a thinner. Is that something you would recommend or do I need it at all?

I think I will go with the rods on the sides because I think those joints are in much worse shape also it would give someone additional strength. The tank will be going in between two separate walls and I will easily be able to hide all four corners and still have full view of 3 sides of the tank.

 

[bluehand]

Also, should I attempt to remove the material in the corners ( whatever it may be) it seems to chip away relatively easily and seems to be quite brittle, before applying the #40 and rods?

 

[bluehand]

Ordered some #4 solvent for the rods but will be experimenting on some scrap pieces before attempting the rods being as i have never done any acrylic welding but I am quite optimistic. Thank you Wednesday for the insight and advice. I will definitely be posting pics of the finished product here soon as possible

 

[wednesday13]

Also, should I attempt to remove the material in the corners ( whatever it may be) it seems to chip away relatively easily and seems to be quite brittle, before applying the #40 and rods?

Yes, for the best chance of a clean/bubble free seam the surface will need to be sanded down flush so the rod fits in snug. Corners with rod and solvent are a bit tricky. Ull have to test on scrap like ur saying to get the feel for it. Theres a certain amount of pressure needed for the solvent to work properly. Too much and the solvent wont penetrate, too little and its bubbles everywhere. Worst case scenario if u dont trust the rod and new seals with solvent you can go right over it with #40. I did a tank in my early days of learning with #16 and rod. It failed after a few yrs. I went over with it #40 and its been good since.

 

[bluehand]

One last question before I dive into this project this weekend. On the seam the is mostly separated, should I attempt to weld it back together with the #4 before doing the rod in that particular corner?

 

[wednesday13]

One last question before I dive into this project this weekend. On the seam the is mostly separated, should I attempt to weld it back together with the #4 before doing the rod in that particular corner?

Yup, i always start with #4 solvent to try and fill in any seperation 1st before moving onto #40, rod or patch work. I did a full seam separation like ur doing before also. Ratchet straps worked well to bring the panels back together flush. Dont need to be super tight or anything. Just enough to get er back into place. The 4 should take fairly well and enough to hold it back together to move forward.

 

[bluehand]

Ok, one more last question lol. Should I polish the acrylic in the corners prior to doing the rods? Or will the solvent address imperfections?