HELP! Should I be worried about this acrylic aquarium?

[GoldsteinReef]

Hey Everyone-

I really need your advice on a new acrylic tank I recently purchased. It was made custom by a really good shop in LA. I am new to acrylic tanks so I am not sure what is normal and what isn't in terms of crazing and bubbles.

The tiny bubbles you see in the seams have been there since day 1. Now I'm noticing what looks like strips of air or glue along the seam. I am not sure if this was there already, or its recent. Is this sort of thing normal? I am going to contact the manufacturer tomorrow.



Thanks,

Brian

[Floyd R Turbo]

So the bubbles in pic #2 - those have been there since day 1 I'm guessing

The air gap along the seam in pic #1 - was that there initially or did those show up after you filled it?

If the bubbles in pic #1 were there from day 1, that means they either didn't have the prepared edge flush with the panel (creating an angle in the gap) or they didn't allow for overage create a fillet on both sides of the joint, and air entrained into the joint as it cured. It's also possible that it looked fine when you got it and the water pressure is causing the joint to separate, if that's the case, it could be a bad weld - like maybe the material didn't dissolve well enough (depends on the material and the solvent mix used).

However you cut it, that's not something I would say is acceptable. For a display tank in particular, your seams should be clear and bubble free for pretty much the lifetime of the tank.

[GoldsteinReef]

Originally Posted by Floyd R Turbo

So the bubbles in pic #2 - those have been there since day 1 I'm guessing

The air gap along the seam in pic #1 - was that there initially or did those show up after you filled it?

If the bubbles in pic #1 were there from day 1, that means they either didn't have the prepared edge flush with the panel (creating an angle in the gap) or they didn't allow for overage create a fillet on both sides of the joint, and air entrained into the joint as it cured. It's also possible that it looked fine when you got it and the water pressure is causing the joint to separate, if that's the case, it could be a bad weld - like maybe the material didn't dissolve well enough (depends on the material and the solvent mix used).

However you cut it, that's not something I would say is acceptable. For a display tank in particular, your seams should be clear and bubble free for pretty much the lifetime of the tank.

Thanks so much for your reply.

The small bubbles you see sort of embedded in the black acrylic all around the tank have been there since day 1. These weren't a concern of mine untill I noticed the larger bubbles started appearing after water had been in the tank. These could have been there, but I honestly didn't notice them. Just an dyi, this tank was not cheap. I payed top dollar.

I've posted some pictures. I went ahead and emptied the tank.

[GoldsteinReef]

Originally Posted by GoldsteinReef

Thanks so much for your reply.

The small bubbles you see sort of embedded in the black acrylic all around the tank have been there since day 1. These weren't a concern of mine untill I noticed the larger bubbles started appearing after water had been in the tank. These could have been there, but I honestly didn't notice them. Just an dyi, this tank was not cheap. I payed top dollar.

I've posted some pictures. I went ahead and emptied the tank.

fyi***

[Floyd R Turbo]

Honestly....that's pretty bad craftsmanship. JMO. I would have never considered that seam work acceptable enough to deliver to a customer.

[GoldsteinReef]

Originally Posted by Floyd R Turbo

Honestly....that's pretty bad craftsmanship. JMO. I would have never considered that seam work acceptable enough to deliver to a customer.

That's disappointing to hear.. I've reached out to the owner of the company. Very curious to hear the response.

[GoldsteinReef]

Honestly, this is why I never post on Reefcentral... Feedback from the community here is slim to none

[PCguy21]

Bubbles here and there are fine... but that first none blue light pic where the seam from top to bottom is one big air bubble.. thats poor craftsmanship..

The other pics i was going to say itll be fine ive seen worse.. but that one pic is pretty crappy. Id return that tank if you can. Thats a really big gap


If it were an older tank like 5-10 years old thrn i wouldnt worry because if it lasted that long thrn nothing will hsppen usually... but a new tsnk... you either return it or keep an eye on it.

Crazing happens later on.. usually if the acrylic is too thin it causes the panels to buldge out and stretch the plastic.. Which causes crazing.. and crwzing can actuslly increase the strength of the acrylic... yea it sounds weird but a study done by some scientists i found on a pdf from some big company showed crazing increased strength.

I have a 55g hexagon with crazing all over the edges and corners ect.. worried me at first but it hasnt done a single thing to the tank... Id be more worried about ny glass tank leaking then it.


My acrylic tank also has bubbles all over the seams like yours does.. but not nearly as bad as that one picture of yours where its litterally top to bottom air gap.


Air bubbles are fine... what you dont want to see are the seems turning white or cloudy... that means they are seperating..

[Floyd R Turbo]

Originally Posted by PCguy21

crwzing can actuslly increase the strength of the acrylic... yea it sounds weird but a study done by some scientists i found on a pdf from some big company showed crazing increased strength.

Never heard that one before, do you remember where you saw the study?

Originally Posted by PCguy21

Air bubbles are fine... what you dont want to see are the seems turning white or cloudy... that means they are seperating..

Bubbles do weaken the joint, but generally they are more of an eyesore. Usually you can remove bubbles before the joint sets if you catch them, but if you pull the pins before removing them, it's a done deal. The pic showing the bubble going into the joint at a right angle might be caused by letting the joint set too long before pulling the pins - the solvent might have set up too much and there was not enough "squish" when they were pulled (which should have pushed that out)

As far as white joints go, that's typically caused by not waiting long enough before permanently filling the tank. When you solvent weld, the thicker the material the longer you have to wait for the joint to fully cure. Some ignore this rule of thumb. You need to let a tank with 1/4" material sit for at least a week before filling (beyond a leak test). Then for every 1/8" additional thickness, wait another week. 3/8" = 2-3 weeks, 1/2" = 3-4 weeks, 3/4" = 5-6 weeks, 1" = 2 months. I might have that off a bit, it might be 1 week for every 1/4" (which would put 1" at 1 month). The point is that the solvent in the middle of the joint needs time to evaporate out and fully set so that the material in the joint adsorbs water at the same rate as the panels. If you don't wait long enough, water adsorbs into the joint more easily, which causes it to expand at a higher rate. This continues for 12 weeks on the panels until equilibrium is reached, but could continue longer at the joints. You won't see the effects of this right away, but a couple years down the road as the constant pressure of the filled tank is applied to the joint, it will slowly work away at that joint.

I've seen tanks that have been set in place for 10+ years with joints that would make you shudder. My LFS has one tank in particular that is 6' long, 30" tall and 36" wide with a white gap joint 6-12" long that is only in contact for maybe 1/8" of the panel....

[GoldsteinReef]

Thank you gentlemen for the responses; noted and much appreciated.. I reached out to the owner of the shop yesterday. Hoping to hear back tomorrow.. I can update if you guys are interested in hearing what he has to say.

Best,

BG

[GoldsteinReef]

I don't claim to be psychic or anything like that, but when I arrived at the shop, I got weird vibes like something was wrong or off. The 2 guys were kind of strangely staring at the tank as if something was off. (just the feeling I got) I know its not a big deal, but they also forgot to put their company logo/sticker on the tank, which is sort of like the final touch. It's the little things.

[Floyd R Turbo]

I've learned to trust my gut. I've gone against it before and it almost always comes back to bite me. Then when I trust it, it turns out that was the right move more often than not.

[PCguy21]

Originally Posted by Floyd R Turbo

Never heard that one before, do you remember where you saw the study?



Bubbles do weaken the joint, but generally they are more of an eyesore. Usually you can remove bubbles before the joint sets if you catch them, but if you pull the pins before removing them, it's a done deal. The pic showing the bubble going into the joint at a right angle might be caused by letting the joint set too long before pulling the pins - the solvent might have set up too much and there was not enough "squish" when they were pulled (which should have pushed that out)

As far as white joints go, that's typically caused by not waiting long enough before permanently filling the tank. When you solvent weld, the thicker the material the longer you have to wait for the joint to fully cure. Some ignore this rule of thumb. You need to let a tank with 1/4" material sit for at least a week before filling (beyond a leak test). Then for every 1/8" additional thickness, wait another week. 3/8" = 2-3 weeks, 1/2" = 3-4 weeks, 3/4" = 5-6 weeks, 1" = 2 months. I might have that off a bit, it might be 1 week for every 1/4" (which would put 1" at 1 month). The point is that the solvent in the middle of the joint needs time to evaporate out and fully set so that the material in the joint adsorbs water at the same rate as the panels. If you don't wait long enough, water adsorbs into the joint more easily, which causes it to expand at a higher rate. This continues for 12 weeks on the panels until equilibrium is reached, but could continue longer at the joints. You won't see the effects of this right away, but a couple years down the road as the constant pressure of the filled tank is applied to the joint, it will slowly work away at that joint.

I've seen tanks that have been set in place for 10+ years with joints that would make you shudder. My LFS has one tank in particular that is 6' long, 30" tall and 36" wide with a white gap joint 6-12" long that is only in contact for maybe 1/8" of the panel....

No i didnt ssve it..but its a pdf downloadable and done by some company.. they did like microscoping tests on the acrylic peices with crazing and found fibers formed in the plastic once they craze which actually increased bending strength of the acrylic.

Its 2am now and i cant sleep cause im figgity from work yesturday... but if you do some research on google itll pop up im sure. I know it sounds weird youd figire crazing reduces strength but after reading that 3 or 4 page pdf on their findings it makes senss

[Floyd R Turbo]

It doesn't surprise me actually - most of the experts I've talked to have described crazing as a "reaction to stress", usually meaning, there is some kind of focused point or joint that is higher stress/strain than adjacent areas - but they usually fall short of saying "it's going to fall apart at that joint" because crazing is not a good predictor of failure.

I could envision the mechanism around crazing that could increase bending strength. Essentially, crazing is an result of the material's need to relieve stress. The point there is: stress is present where it ideally should not be.

I don't know if crazing "increasing bending strength" would translate to a stronger solvent welded joint though.