De-rimming my 20 gallon long

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gilpi

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So I finally decided to de-rim a 20 gallon long. $1 a gallon sale at Petco.

Got to say the project is a bit tougher than I thought it would be. The plastic rim is very hard and this tank was very well built, I understand now why the rim is part of the tank's integrity.

After a few attempts trying to cut through it I gave up and pulled out my heat gun, I took a few shots hoping I can post them as I go along. Basically I'm melting the plastic and the silicone that holds it right off of the tank and as I heat up a section, it becomes easier to pull away from the glass, so I'm just peeling it as I soften the next section.

I'm pretty confident the tank will hold the water after I'm done, this is not a big tank and the silicone is very strong.

I'll post more as I go along and please to anyone attempting this.... Please be very careful as you can easily chip or crack the glass and also the glass itself has some sharp edges.
 

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So I finally decided to de-rim a 20 gallon long. $1 a gallon sale at Petco.

Got to say the project is a bit tougher than I thought it would be. The plastic rim is very hard and this tank was very well built, I understand now why the rim is part of the tank's integrity.

After a few attempts trying to cut through it I gave up and pulled out my heat gun, I took a few shots hoping I can post them as I go along. Basically I'm melting the plastic and the silicone that holds it right off of the tank and as I heat up a section, it becomes easier to pull away from the glass, so I'm just peeling it as I soften the next section.

I'm pretty confident the tank will hold the water after I'm done, this is not a big tank and the silicone is very strong.

I'll post more as I go along and please to anyone attempting this.... Please be very careful as you can easily chip or crack the glass and also the glass itself has some sharp edges.

I heard that your suppose to reseal the tank...
 
The heat gun is definitely the way to go pulling the rim, was done in just over an hour total.

After it was all done I cleaned some of the remaining silicone and rounded the sharp edges of the glass with emery cloth using a sanding block, being careful not to scratch the glass.

Filled the tank with water and will leave it for a day or two out on the deck. It still has a little bit of silicone residue that I'll clean later on with a bit more time.

I did a measurement filled and there is a bow of just under an 1/8" in the center, I don't think 1/16" per side is a lot, I forgot to take a measurement with the rim on, can anyone let me know what the bow is with the rim when filled?
 

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Sillyfishes, I'm not sure about resealing it, it definitely does not look like it needs anymore than what it already has.

Do you mean remove all the silicone and do it over?
 
The heat gun is definitely the way to go pulling the rim, was done in just over an hour total.

After it was all done I cleaned some of the remaining silicone and rounded the sharp edges of the glass with emery cloth using a sanding block, being careful not to scratch the glass.

Filled the tank with water and will leave it for a day or two out on the deck. It still has a little bit of silicone residue that I'll clean later on with a bit more time.

I did a measurement filled and there is a bow of just under an 1/8" in the center, I don't think 1/16" per side is a lot, I forgot to take a measurement with the rim on, can anyone let me know what the bow is with the rim when filled?

It's bad if there's ANY bow in the tank.
 
It's bad if there's ANY bow in the tank.

True. But without a baseline measurement, it is possible that the extra 1/8" was already present at the center with the frame on. Still, fingers crossed on this.
I have two 20 gallon long tanks. Next chance I get, I will take measurements at the center and the corners and check for differences.
 
Unless there is a center brace, there is always going to be some bowing. Both of my 40 gallon breeder tanks bow around 1/4" total and that is with a rim.
I'm not worried about an eight of an inch bow in the center, just wonder what that measurement is with the rim still attached.
 
Unless there is a center brace, there is always going to be some bowing. Both of my 40 gallon breeder tanks bow around 1/4" total and that is with a rim.
I'm not worried about an eight of an inch bow in the center, just wonder what that measurement is with the rim still attached.

40g breeders are suppose to have center braces... As long as there's bowing, there will be pressure on the silicone. Eventually it's going to blowout. When you de-rim a tank, you want to keep your water level lower then usual.
 
Unless there is a center brace, there is always going to be some bowing. Both of my 40 gallon breeder tanks bow around 1/4" total and that is with a rim.
I'm not worried about an eight of an inch bow in the center, just wonder what that measurement is with the rim still attached.

Its 1/8" ad well. I have the 20g L and it bows witha a brace. Its all fine and dandy
 
Its 1/8" ad well. I have the 20g L and it bows witha a brace. Its all fine and dandy

Thanks for the info, just wanted to compare.

I always wanted to de-rim a 20 long, I have a 20 tall that I de-rimmed a year ago that has been in service since but I remember its was as simple as just pulling on the rim and it came off, not the 20 long, took a lot more work.

BTW, I wouldn't go as far as removing the bottom trim for many reasons.
 
40g breeders are suppose to have center braces... As long as there's bowing, there will be pressure on the silicone. Eventually it's going to blowout. When you de-rim a tank, you want to keep your water level lower then usual.

Appreciate all the input Sillyfishies!
BTW I own two 40g breeders that I purchased new without a top center brace, they do have a center brace on the bottom though. You'll never see me removing the rim on those, that would definitely be asking for trouble!

For sure the bracing adds strength to the tanks, but I also wonder if manufactures use the plastic trim to save on glass thickness and not having to finish the glass on top?
 
Appreciate all the input Sillyfishies!
BTW I own two 40g breeders that I purchased new without a top center brace, they do have a center brace on the bottom though. You'll never see me removing the rim on those, that would definitely be asking for trouble!

For sure the bracing adds strength to the tanks, but I also wonder if manufactures use the plastic trim to save on glass thickness and not having to finish the glass on top?

I wasn't aware you left the bottom brace. I think you should be fine then.

I just personally don't trust the manufacturing silicone.
 
I wasn't aware you left the bottom brace. I think you should be fine then.

I just personally don't trust the manufacturing silicone.

Bad communication on my part, sorry about that.
I don't know if I could trust my silicone job, no matter what silicone I use :(
 
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