# derimmed a 20g long explosion



## chumlee (Nov 4, 2010)

Hey guys I just about to de-rim my 20g long but I just wanted to see if there were any horror stories from you guys if you've done this before and had a tank explode or something. I would also like to hear the success stories :hihi: Thanks


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## CLASSIC (Feb 25, 2009)

I would be to scared to take anything other than a 10G apart haha. I just couldnt trust the seals on non rimless tanks. Already it seems rimless is beginning to catch on with the masses as i seen some ADA and Do Aqua tanks in local stores here in Portland, soon i bet they will be easier to get a hold of and somewhat cheaper. I would wait hah.


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## Geniusdudekiran (Dec 6, 2010)

Yeah, the general consensus among the forum-goers here seems to be DONT DERIM ANYTHING OVER 10 GALLONS! That's the answer I got at least LOL


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## Geniusdudekiran (Dec 6, 2010)

But you can just cut off the front part of the rim on the top, which can actually look pretty nice.


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## PinoyBoy (Mar 14, 2008)

http://www.nano-reef.com/forums/index.php?showtopic=221692
http://www.plantedtank.net/forums/g...cussion/107817-de-rimming-20-gallon-long.html

2 threads with some nice stories in it, and bad ones.


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## Betta Maniac (Dec 3, 2010)

Lots of people have derimed 20s with no problem.


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## tuffgong (Apr 13, 2010)

I have a 20 long with the top rimmed removed and no problems. I wouldn't take the bottom rim off though.


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## Hoppy (Dec 24, 2005)

Don't you wonder why we don't get threads here about the tank falling apart after being derimmed? Or about the front/back glass shattering after the tank was derimmed? The fact that people are derimming tanks and we don't get those reports of disasters suggests that the procedure isn't nearly as unsafe as rumored.


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## RipariumGuy (Aug 6, 2009)

Hoppy said:


> Don't you wonder why we don't get threads here about the tank falling apart after being derimmed? Or about the front/back glass shattering after the tank was derimmed? The fact that people are derimming tanks and we don't get those reports of disasters suggests that the procedure isn't nearly as unsafe as rumored.


Yes, I agree. Hydrophyte has derimmed a 50g tank and filled it about 80% of the way with water. No problems with his setup! You can derim a 20g long easy as pie. Just research a little on how to do it first! :thumbsup:


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## bigboij (Jul 24, 2009)

from what ive seen you can derim just about any tank under the size to need a center brace.


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## Arctangent (Feb 22, 2010)

Water pressure varies linearly with depth (Pressure = Density X Gravitational Acceleration X Depth). The greatest pressure occurs at the bottom of the tank. The force acting on the walls of your tank is equal to the average pressure times the surface area of the wall, and the location of this "representative force" on any vertical wall is about 2/3rds down from the water level.

So if force causes failure, taller tanks with higher glass surface areas (walls and bottom) are at greater risk. Note however that larger tanks also have thicker glass, which means higher overall strength and larger surface area for glue. So it's a balance between water pressure and both glass and glue strength. If you knew some mechanical properties of the glass you could tell by its deflections how close it was to failure (assuming glass fails before glue).

That being said, I would have no qualms with de-rimming the top of a 20L because the top of the tank experiences little local pressure, and the tank is only 12" tall so the total pressure is limited. In fact I plan to do this myself, I'm leaving the bottom rim on, but it could probably come off safely. I'm leaving it on for the footprint.

Quick calculations for a 20L.

Bottom plate: 
Pressure: 62.2 lbs/ft^2 = 0.432 PSI
Force: 155 lbs

Front/Back:
AVERAGE pressure: 31.1 lbs/ft^2 = 0.216 PSI
Force due to avg press: 77.75 lbs

Side glass:
AVERAGE pressure: 31.1 lbs/ft^2 = 0.216 PSI
Force due to avg prss: 31.1 lbs.


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## mindy (Dec 22, 2010)

arctangent, would you think a 20 high is safe to de-rim, top only?


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## Arctangent (Feb 22, 2010)

I really couldn't say for sure. All I can say that it would be a greater risk than a 20 long. My point in the earlier post was that derimming a 20L would pose about the same risk as a 10g, due to dimensions and construction. The only way to really know (without a bunch of work and research) is to try it, or find someone who has. But that can be risky...duh.

I could tell you the pressures like I did for the 20L if you wanted... just post dimensions.


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## mylittlefish (Oct 5, 2010)

chumlee said:


> Hey guys I just about to de-rim my 20g long but I just wanted to see if there were any horror stories from you guys if you've done this before and had a tank explode or something. I would also like to hear the success stories :hihi: Thanks


Just Do It :thumbsup:

Go out on a limb. 


Show some sense of adventure. :bounce:


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## chumlee (Nov 4, 2010)

I did the 20L And it looks awesome. It came out very very cleanly. Ill post some pics later i just got done i need some sleep lol that was a lot of work. I actually set the tank up with water and everything already...


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## VaultBoy (Nov 11, 2010)

If you are talking about removing the plastic rim then i wouldnt think twice as they are simply aesthetic however if it is a glass rim/brace then i wouldnt even think about it as they are a structural element


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## mindy (Dec 22, 2010)

Arctangent said:


> I really couldn't say for sure. All I can say that it would be a greater risk than a 20 long. My point in the earlier post was that derimming a 20L would pose about the same risk as a 10g, due to dimensions and construction. The only way to really know (without a bunch of work and research) is to try it, or find someone who has. But that can be risky...duh.
> 
> I could tell you the pressures like I did for the 20L if you wanted... just post dimensions.


thanks! 

i just measured the tank. the glass is 3/16" thick.

the tank is 24" long, 16 1/2" high, and 12 1/4" wide.

thank you


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## Arctangent (Feb 22, 2010)

20H

*Bottom: *
Pressure = 85 lbs/ft^2 = 0.59 PSI
Force = 173 lbs

*Front/Back:*
avg. Pressure = 42.5 lbs/ft^2 = 0.3 PSI
Force = 116.82 lbs

*Ends:*
avg. Pressure = 42.5 lbs/ft^2 = 0.3 PSI
Force = 59.62 lbs


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## mindy (Dec 22, 2010)

thank you! 

so, do you think it can handle it?


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## Arctangent (Feb 22, 2010)

Well it's a complex problem, and I dont have the glass/silicon/de-rimmed experience to say from my gut. I don't want to say yes and then hear back that it failed on you. I provided the measurements only in an effort to help you make your decision.

I do remember hearing from a civil prof who was a self proclaimed "glass guy" that even a static stress on glass will weaken it over time. So it might work for a couple years and THEN fail. I'm on the conservative side so my suggestion would be to stick to de-rimming tanks with low height to volume ratios.


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## boringname (Nov 11, 2010)

Arctangent said:


> Well it's a complex problem, and I dont have the glass/silicon/de-rimmed experience to say from my gut. I don't want to say yes and then hear back that it failed on you. I provided the measurements only in an effort to help you make your decision.
> 
> I do remember hearing from a civil prof who was a self proclaimed *"gass guy"* that even a static stress on glass will weaken it over time. So it might work for a couple years and THEN fail. I'm on the conservative side so my suggestion would be to stick to de-rimming tanks with low height to volume ratios.


Do you mean glass guy?


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## mindy (Dec 22, 2010)

Arctangent said:


> Well it's a complex problem, and I dont have the glass/silicon/de-rimmed experience to say from my gut. I don't want to say yes and then hear back that it failed on you. I provided the measurements only in an effort to help you make your decision.
> 
> I do remember hearing from a civil prof who was a self proclaimed "gass guy" that even a static stress on glass will weaken it over time. So it might work for a couple years and THEN fail. I'm on the conservative side so my suggestion would be to stick to de-rimming tanks with low height to volume ratios.


thanks  

i still don't know what to do. i have to think about it longer. i would love to have a rimless tank but i don't want to come home to dead fish one day! 

i don't think that i am able to find a rimless tank at my lfs. they don't have much at all. maybe i should look into it though.


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## Arctangent (Feb 22, 2010)

boringname said:


> Do you mean glass guy?


 Nope, a flatus connoisseur....Yes GLASS. lol.



mindy said:


> i have to think about it longer.


:wink:


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## chumlee (Nov 4, 2010)

Yeah my tank is still holding water and it's been about 24 hrs. 

BTW I would think this guy knows something about math/physics lol his name is arctangent afterall.


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## mindy (Dec 22, 2010)

i think that when i read your post, arctangent, i skipped over the bottom part that said that i should stick with a less deep tank. :redface:

i am not going to do it. it makes me sad because it would look SO much nicer. maybe i will try my 10 gallon instead.

thank you.


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## chumlee (Nov 4, 2010)

just buy a 20 long


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## mindy (Dec 22, 2010)

i would love to but i am trying to keep the costs low. also, there isn't much choice for me at my lfs. i would have to get something shipped to me. and, if i am going to go that route then i am getting rimless and big and expensive. it will have to wait a while for that. hopefully by next fall...


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## chumlee (Nov 4, 2010)

If you wait for a petco 1$/gal sale u can get a 20g long for 20 bucks


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## kevmo911 (Sep 24, 2010)

I believe PetSmart has 20L's for something like $32 regularly. Here, anyway.


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## yikesjason (Jul 2, 2008)

Check around some of your LFS for Mr Aqua tanks. They make some nice rimless tanks for great prices.


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## meowfish (Jan 5, 2011)

chumlee said:


> I did the 20L And it looks awesome. It came out very very cleanly. Ill post some pics later i just got done i need some sleep lol that was a lot of work. I actually set the tank up with water and everything already...


Have you taken your pictures yet? I have a 20L I need to drain and move, after seeing this thread I'm eager to see photos of the finished product!


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## mindy (Dec 22, 2010)

chumlee said:


> If you wait for a petco 1$/gal sale u can get a 20g long for 20 bucks





kevmo911 said:


> I believe PetSmart has 20L's for something like $32 regularly. Here, anyway.





yikesjason said:


> Check around some of your LFS for Mr Aqua tanks. They make some nice rimless tanks for great prices.


thanks for the suggestions guys. i would love to get one of those tanks but unfortunately those stores aren't even in my province. 

there is only one lfs and it is 2 1/2 hours away! i will check but i can guarantee that anything there will be drastically over priced. i guess he can do that being the only pet store around and being an @$$. 

i will keep looking though!


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## mindy (Dec 22, 2010)

meowfish said:


> Have you taken your pictures yet? I have a 20L I need to drain and move, after seeing this thread I'm eager to see photos of the finished product!


yes, i am eager to see it too!


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## chumlee (Nov 4, 2010)

sorry you guys ill go take them now haha i had to charge my camera


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## chumlee (Nov 4, 2010)

for some reason when i uploaded it really reduced the image quality...that never normally happens

sorry for the tank looking so bare it was just set up and the angelfish is leaving shortly, and an iwagumi scape is moving in.


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## orchidman (Dec 15, 2010)

Beautiful! I just de rimmed my 20 long as well. I only did the top rim though. Can't wait to set mine up!


You can call me Bob


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## Aubzilla (Mar 2, 2008)

Looks good- I can't see any bowing. :thumbsup:


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## chumlee (Nov 4, 2010)

I only did the top rim as well


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## meowfish (Jan 5, 2011)

WOW! That looks amazing! Ok, I'm sold, will do mine this week lol


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## Green024 (Sep 19, 2009)

chumlee, which DIY de-rimming thread did you use? Is there anything you would do differently if you were to try again?


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## mindy (Dec 22, 2010)

that looks so great!


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## chumlee (Nov 4, 2010)

I didn't use a diy thread and I wouldnt change anything if I did it again. I took a metal putty knife thing with a sharp edge on it and slipped it under the rim until the rim was loose. It wouldn't come off so I took a heat gun soldering iron thingy and melted the corner of the plastic which made it peel off nicely. I scraped the remainder of the silicon off with a razor blade. It took like 3 hours to do. 

Sent from my DROIDX using Tapatalk


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## orchidman (Dec 15, 2010)

good idea melting the corner! it was hard to cut through. i used a box opener, but the blade wasnt long enough, so i got a little chipping in one spot, because i didnt completely separate the the silicone from the glass in some spots. so i got a little but of chipping in a few spots. but it will be easy to disguise


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## cervantesmx (Feb 16, 2011)

chumlee said:


> for some reason when i uploaded it really reduced the image quality...that never normally happens
> 
> sorry for the tank looking so bare it was just set up and the angelfish is leaving shortly, and an iwagumi scape is moving in.



I just purchased this 20g tall for $10, I really want to derim it, what do you guys think?


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## meowfish (Jan 5, 2011)

Ah yes, so I'm following in your footsteps... Sort of. I started last night but here are my results:










Finished removing the rim this evening but needless to say this will slow up my progress lol


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## chumlee (Nov 4, 2010)

OUCH are those stitches?


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## tuffgong (Apr 13, 2010)

meowfish said:


> Ah yes, so I'm following in your footsteps... Sort of. I started last night but here are my results:
> 
> 
> 
> ...


Ouch! U OK? What happened?


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## meowfish (Jan 5, 2011)

Yeah, 22 stitches on top, Lord knows how many underneath. I kept the pic small to minimize nightmares lol!

I was trying to emulate chumlee and derim my 20g long... Box cutter snapped just as I moved my right hand in its path and what was left of the blade got me pretty good. I guess I received a good lesson on why you should practice safe cutting techniques and not take shortcuts.

I got the rim off tonight though! roud: Just need to finish scraping the leftover silicone and clean 'er up.


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## chumlee (Nov 4, 2010)

bloodshed over the hobby..now that's what im talking about


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## riddik1 (Sep 4, 2010)

ohhhh maaaaannn... hoow many stitches?? i did almost the same thing on my left but i didnt manage to get my thumb too.


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## meowfish (Jan 5, 2011)

chumlee said:


> bloodshed over the hobby..now that's what im talking about


Hooyah!


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## 1clean4runner (Mar 7, 2011)

meowfish said:


> Yeah, 22 stitches on top, Lord knows how many underneath. I kept the pic small to minimize nightmares lol!
> 
> I was trying to emulate chumlee and derim my 20g long... Box cutter snapped just as I moved my right hand in its path and what was left of the blade got me pretty good. I guess I received a good lesson on why you should practice safe cutting techniques and not take shortcuts.
> 
> I got the rim off tonight though! roud: Just need to finish scraping the leftover silicone and clean 'er up.


Now that is dedication! Good man! :bounce:


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## cervantesmx (Feb 16, 2011)

meowfish said:


> Ah yes, so I'm following in your footsteps... Sort of. I started last night but here are my results:
> 
> 
> 
> ...


Holy crap man, how the... my... that looks horrible. Best of luck. BTW, how big was the tank you were de-rimming?


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## mindy (Dec 22, 2010)

oh my gosh! ouch!


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## g33tar (Jan 8, 2010)

Blood is the secret to making your shrimp dark red. Little protip. :icon_wink


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## orchidman (Dec 15, 2010)

Filled mine yesterday so far so good. It looks like it's gonna be safe ( knock on wood!)


You can call me Bob


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## chumlee (Nov 4, 2010)

my tank is still running strong


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## mindy (Dec 22, 2010)

wooooo!


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