The Planted Tank Forum banner

Resealing tank question

7K views 44 replies 10 participants last post by  Leeatl 
#1 ·
I got a standard 75 gal glass tank and stand for free and I want to set it up , but , it was built in 2003 so I think it may need to be resealed . I have done some research , including utube vids by The King Of DIY , and it is very doable . My question is all the info I have found so far shows the removal of the inside silicone and reseal . What about the silicone between the glass panes ? Old silicone doesn't stick to new very well , and the joint silicone is just as old as the rest , so how does this work ? I am not going to go as far as totally disassembling and reassembling the tank . If I can't get a good answer I will just get rid of it to a snake handler....lol . Thanks for any help .
 
#2 ·
The best answer I can give you is the silicone where the panes of glass meet is not likely to fail structurally. With that said, the silicone on the inside can get beat up from normal cleaning and use. Eventually a leak can develop so it stands to reason the information you got from King of DIY is good.
 
#3 · (Edited by Moderator)
Thanks Immortal1 I do value your opinion . That is what is confusing me . If there is a leak , that means the joint silicone has a "hole" , so is just resealing the inside enough to rely on ? Hope you can see what I mean .

I think I found an answer..."Think of the seam as two parts, the structural part that holds the panes together, and the inner seal that covers/protects all of the structural seams. " I guess you just have to trust the joint silicone is ok . I an going to try it , but it will be a while before I get to it .
 
#4 ·
I can see what you mean. My only comment would be a single minor pinhole fail will not cause the entire joint to fail. I built a DIY 40 gallon rimless tank for the wife and in the process I learned a lot regarding glass to glass joints and silicone. It is amazing how little silicone is actually holding the panels together - really just a film to be honest. I have seem some bad joints on tanks (visible air bubbles in the joint). From what I have learned, a couple of small bubbles in the middle of the joint is not too bad. A whole bunch of tiny bubbles along a single joint and it will fail (to hold the water pressure within the glass box). If you can't visibly see any little bubbles in the glass joint, the mechanically the joint will last a very long time (many tanks out there over 30 years old). Keeping it water tight for 30+ years might be a little more difficult.

If you do reseal your tank, I would suggest razor blading as much old silicone as you can off the interior glass surface without digging into the actual glass to glass joint.

When you apply the new silicone, most people use their finger to smooth out the silicone right to the glass. I found that by using a couple layers of thick tape (duct tape) you can create a better / more durable edge.
 
#5 ·
I resealed a tank a year and half ago or so and left the silicone between the panes. It's been holding fine. After I removed the old silicone I put down blue painter's tape around the vertical corners to ensure a nice clean edge. Then I laid down a nice thick bead of silicone (GE Silicone I) in all the corners and smoothed it out using the back side of a table spoon. Then when satisfied I had enough silicone and it was all smoothed out like I wanted I removed the tape. You don't want to wait on the tape because then it will be trapped under the silicone.
 
#9 ·
I resealed my 72 bowfront 8 years using the above method (GE silicone, painter's tape...) and it's been holding water since. It was my first reseal if that help make you feel more comfortable. ;)

Not sure if the video mentioned it but make sure that glass is super clean before applying silicone. Scrap it with a razor blade and then use rubbing alcohol to remove any residue.

That being said a 13yr old tank wouldn't concern me too much. I have a tank from the late 80s that's never been resealed!
 
#8 ·
Thanks guys . As always the answer is as close as The Planted Tank...lol The bead between the glass looks good and it was filled and in use for a long while when I got it so I am going to go for it . In some places the inside silicone can be pulled up from the glass on the edges . That is my main concern , but resealing will take care of that .It will have to be a fall/winter project .

Bump:

Nice . Where did you get that ?
 
#12 ·
RE-sealed my 80 gal this past weekend, and 55 gal last year.
Can use grout removing tool for around edges of sink's and tub's, and maybe a razor blade, but do not worry bout that silicone in the joint itself between the glass panel's.
I too use the tape to make a clean edge and used my finger to push it into the joint.
GE Silicone I.(24 hrs cure time)
I suggest doing one end at a time to help preserve structural integrity.
I then clean with Windex vinegar formula no ammonia, rinse it out with garden hose and spray nozzle a few times ,and then fill the tank outside and see if it's gonna not leak.
 
#14 · (Edited)
Ok , I didn't want to start another thread so here is part 2 of this project...the stand . This is an unusual DIY stand . The thing I like the most is the height . The top of the tank sits at about eye level so you can really see what is going on without sitting in a chair or breaking your neck bending over . The first pic is the front . I am going to redo/add doors to give me more storage . The builder used planks for a top and it was too narrow so the tank hung over the front and back . Not good but it did not seem to hurt the tank . I am going to build a 2x4 frame around the top and put a piece of 3/4 plywood on top of that . I will make it so it will be an inch or so bigger than the tank all way around . When done the top will have the same footprint as the bottom . I think I am going to put a couple more 2x4 verticle supports in the center front and back just because . It has 4 2 x 4 supports on each end now going from top to floor , but I am an overbuilder....lol The last 3 pics show this . I won't be able to work on it much till all the fall yardwork and Christmas decorating has come and gone so I will resurrect this thread with updates as they come . Thanks for looking and for any suggestions anyone may have .
 
#15 ·
Nice. I added some extra 2x4 supports to my existing stand as well. It was an older stand and previously I had used the stand and tank for a day gecko. So along with re-sealing the tank I added the extra supports. The peace of mind was definitely worth the effort on both counts. Especially since I keep the tank upstairs.
 
#16 ·
First of all, let me add to the silicone discussion by saying that all of the above suggestions for working with silicone and aquariums are spot-on. I have never had a tank that was properly made (with clean glass and no bubbles inside the joints) start leaking AS LONG AS IT IS SUPPORTED EVENLY. This includes very old silicone/glass tanks. I have repaired larger tanks and even built medium-sized tanks from scratch, and never had a problem with my repairs or builds. (I used G.E. Silicone I at the time, which was common practice then, but I believe that formulation has been changed, and there are better choices for aquariums now, without paying an arm and a leg for the high-dollar aquarium-product name brands, so do your research before buying.) The one tank-killer I am sure of is an uneven platform, especially with larger aquariums (3'-4' long +), and that includes the floor/foundation the stand is sitting on. If there is any unevenness, the tank and stand will settle over time, causing stress on the glass and/or joints which will result in a wet floor and possibly some very sudden heart-racing moments in the future. I currently have an old Hagen 10 gallon that has a build date sticker from 1984, and I expect no problems with it, even though the tank was in storage for 20 years and is built with very thin glass and only 1/16th of an inch extra silicone on each pane in the corners. (The wrought-iron stand it's on was very uneven, so I put a sheet of styrofoam between the tank and stand to absorb the uneven pressure and reduce the stress points.)

That said, I don't think I've ever had a tank that had silicone lifting at the edges (possibly from scraping algae with a sharp metal flat-edge?), so redoing the corners might not be a bad idea, even if it's not already leaking. Of course, chances are that it will go for many years as it is without any problems, but then, "chances are", and we're talking about 75 gallons gushing onto the floor very quickly once a seam lets go. (I've had the corner of a boss's 110 gallon turtle tank let go at work, it's not fun.) So maybe better safer than sorry.

And as for the stand, I have a commercially built stand made for very large tanks (72"x18" footprint) that has two 2"x4" legs on each end and two in the middle (front and back), and it is held together with two carriage bolts connecting each leg to 2"x4" frames (top and bottom) that have one 2"x4" cross-member on each end and two in the center (on each side of the center legs). That simple configuration is plenty to support for a 125+ gallon aquarium, so the two 2"x4" legs in each corner of the stand pictured is waayyyyy overkill for a 75 gallon tank. The homemade stand that I got with my "new" 125 had eight treated 4"x4" posts built into it, and eight 2"x4" crossmembers on each frame (top and bottom), and all that did was make it brutally heavy to move. (You can check out the pics on my tank journal here.) Plus I didn't care for the build-job on it, so I'm probably rebuilding it entirely from scratch, although I might use the upper and lower frames and just redo the rest, I'm not sure yet.

Anyway, good luck with all of it!

Olskule
 
#17 ·
First of all, let me add to the silicone discussion by saying that all of the above suggestions for working with silicone and aquariums are spot-on. I have never had a tank that was properly made (with clean glass and no bubbles inside the joints) start leaking AS LONG AS IT IS SUPPORTED EVENLY. This includes very old silicone/glass tanks.

Olskule
I've got a dozen tanks that I got from a fish farm here that would prove your statement inaccurate at best. Over 200 tanks 40+ years old supported 1/3 the way in front and back on galvanized pipe racks. none of the dozen I bought were leakers. And very few of the ones he was selling ($4 each tank 22 gallon breeders) were leakers. My oldest, bought new tank is from 1980 and still going. And no, it doesn't sit evenly on the steel stand. I've never had a tank leak from that problem. Defects yes.
 
#18 ·
To reiterate what others have already said regarding the joint silicone; If it hasn't leaked before, chances are that youll be good to go. Your point of failure when it comes to joint silicone would be a bunch of tiny bubbles that run from the inside edge to the outside edge, as that would be where the bond is the weakest. Even then, if you seal the inner bead properly, there is still a good chance that it won't leak since the inner bead will prevent water from getting to the joint silicone, and will also distribute the pressure of the water across the weakened joint, making it less likely to fail.
 
#20 · (Edited)
I was tinkering with the stand a little today and it looks like I am going to build a 2 x 4 frame around the top and then 3/4 plywood on top . My concern is that the tank will be on the ply , but the front and back edges of the tank will be on ply that will be overhanging the stand by about 1 to 1.5 inches . Will this be ok , If not I will have to build a wider frame for the top so all the tank and ply are on the frame . Maybe this pic will help...Excuse the poor drawing....
 
#22 ·
Leeatl, what is the exact measurement of the stand width and depth (front to back) as it is pictured above? Also, what is the exact outer measurements of your tank's footprint? 3/4" plywood is pretty stout, so a 1" overhang only supported by the plywood would probably be ok, but it would be better, and look better, if the tank footprint was supported both structurally and visually, as in building out the front and/or back. It might be easier to just add to the back so that the front doesn't look awkward, because you probably won't be seeing the back anyway, right? Anyway, give me the measurements and I'll try to think of a solution.

Olskule
 
#23 · (Edited)
Thanks Olskule ,
The dimensions are 48.5 inches wide x 14 inches deep . The base is 19 inches deep so no problem there . I had thought about your support the back idea , but the damn thing is so heavy now....lol Let me know what you come up with and I will be thinking on it too .

I came up with this idea , put 2 X 4's on the sides extending out the back enough and put 2 2 X 4's in between those on the back held with joist hangers and a 2 X 4 attached to the ends of all 4 . I think this should work , but am still open to other ideas . Here is a drawing of what I mean.....
 
#26 · (Edited)
If the base is already 19", then that's perfect--all you have to do is flip the stand upside-down!:grin2:

No, seriously, if I'm not mistaken in my interpretation, your idea would entail adding 2x4s to each side of the existing stand, which I'm not sure will be easily disguised as an add-on, plus will add 1.5" to each side, which you don't need, so I came up with this alternative:



The basics are that you will be adding another back frame section to the existing stand, held to the stand by three 9"+ carriage bolts (one on each of three 2x4 legs). The spacing of two layers of 2x4 spacers (B=3.5", C=7") between the new frame back and the existing stand will add a total of 4.5" to the existing 14", for a new depth of 18.5 inches, which should be about what you are needing. If you need another 0.5" or more (if your actual tank frame measurement is 19"), then you can add a layer of 1/2" plywood between the spacer "C" and the existing stand, being sure to allow for the added measurement when determining the length of carriage bolt needed.. (Another 2x4 spacer will add another 1.5"). The new back frame piece will be sufficiently supported by the two outer legs plus the one leg in the middle (measure and cut legs to the length needed), and all three legs should be joined near the bottom by an additional 2x4 running the width of the legs' stance, as well as spaced from the existing stand with the same number of spacers as the top back frame extension. (The attachment of the lower frame and spacers is not as critical as is the top since they are merely holding the proper spacing and not actually supporting weight themselves, so carriage bolts are not needed, and simply nailing or screws will suffice.) The spacers "B" and "C" should be lined up to be level with the surface of the existing stand to ensure there is flat support across the old and new structure, and should be attached, either singly or together, with appropriate length drywall-type screws, being sure to allow for the bolt hole that must be drilled through the back frame piece, leg, spacer "C", existing 1/2" (?) plywood, existing frame and leg. Being able to tighten the carriage bolts sufficiently should ensure the rigidity of the existing stand and addition as a unit, without any flexing, and the use of screws instead of nails will help prevent any shifting that might otherwise occur.

Another positive aspect of this design is, since you mentioned the stand is already too heavy, the use of screws and bolts will offer the benefit of being able to take the addition off the stand if you want to move it, and reassembly would be quick and just as sturdy.

I think this design will give you the added depth you want without too much change to the front visual aspect of the existing stand, and you can just add plywood or trim to the sides at the back if you determine it is needed. Hope this helps!:smile2:

Olskule
 
#33 ·
I am in the gathering materials stage for the stand . I got all the bolts , nuts , and washers and door hardware . I am going to use Oskule's idea for a start . I was just thinking . I am going to top it with at least 3/4 plywood and wanted to see if anyone else has used acrylic exterior caulk between the 2 x 4 frame and plywood to smooth out any imperfections . I have done this with foam board for acrylic tanks , but not sure caulk would work the same way in my plan . The type of caulk I have stays flexible for a very long time .
 
#34 · (Edited)
This is for anyone , but I hope Oskule will chime in . I was tinkering with the stand today and turned it upside down for the first time and discovered that the support members go down to a 2 x 4 frame , but that is attached to another 2 x 4 frame that is about a 1/4 inch lower . So the support members do not touch the floor . The 2 bottom frames are glued nail gun nailed and lagbolted together . Is this an issue ? Thanks for any opinions . It shows in the red circled area in following pics....
 
#35 ·
Since they are bolted together, I think it should be sturdy enough, although with this and the stand I ended up with, it makes me wonder of people actually plan these home-built stands and use tape measures or just start building and add as they go. (lol) Luckily, most of them fall into the "overkill" genre, but they sure make it difficult to make it "right". (And to move them!)

And as far as using caulking, that would only serve to adhere the plywood to the frame, and won't add any structural support at all, IF it was needed (which I don't think it will be, considering the layer of strong plywood you're planning on using). Personally, I would just make sure the spacer blocks (and new construction) were all level with the original stand and that the new bolts were tightened well, then add a sheet of 3/4" to 1" styrofoam between the tank and the stand. Styrofoam has the unique ability to hold a lot of weight spread out over a large area yet give easily (and a lot) at small points of pressure, which makes it perfect for absorbing irregularities in the stand/support surface while supporting the overall weight of the filled tank evenly over the support platform. Although you can poke a finger through it easily, you could lay a sheet of styrofoam on a flat surface and put a 5/8" sheet of plywood on top of it, then drive a car over it and it wouldn't crush the foam (except, perhaps, at the edges, where the plywood might give a little bit). But you could put a 1/2" stone between the styrofoam and the plywood (or the flat surface) and drive the car over it, and the styrofoam would absorb the stone, smoothing out the irregularity, just as it does when placed beneath an aquarium. Placing the foam board between the plywood and the frame might absorb any irregularities between the two, but those are not the contact and possible stress points you need to be concerned with; the bottom frame of the tank is where the attention might possibly be needed (if at all), so that is where you would most likely need stress points to be absorbed, and however unlikely that may be, I always prefer to take the precaution. Hope that helps!

Olskule
 
#38 ·
Yea I am 100% confident in the top . You got me to thinking about the depth of the stand . I had thought about the tip over concern before , but I can't rock it front to back without picking up the front edge so I figured it would be ok . After looking again the bottom is just a tad narrower than the top so I am going to put a piece of plywood on the bottom and extend the footprint 3 inches each way...front and back . That coupled with the weight of the stand should be enough to keep it from tipping unless an NFL lineman runs into it full speed ...lol
I don't have any large pets or children around so I think it will be fine . Glad I gave you some ideas . Sounds like a unique design . On a side note , where are you in Miss ? My wifes people are in Natchaz and Macon/Tupelo areas .
 
#40 ·
I, too, suspect it would be extremely difficult to tip an 18" deep tank over backwards if the stand footprint is as deep as the tank. However, I was thinking further about what the absolute requirements of a stand actually are, if not a base with the exact same footprint as the tank's, and placed immediately beneath it at all points, and I've realized that what we all commonly think of as a "proper" aquarium stand may not be required for "proper" support. In thinking about my 125, with a 72" X 18" footprint, I realize that, as long as the material of the stand is strong enough, and the design and weight distribution is equally distributed across the footprint of the tank, then the legs and feet of the stand don't absolutely have to be at every corner or midway along the front and back, either. For instance, a tank the size of mine could be supported merely by one foot in the middle (front to back) of each end and one foot midway along the front and the back, with just four feet placed in a sideways diamond pattern. And actually, if you get right down to it, even the legs at each end could be moved in a foot from each end (just four feet apart) without being unstable, because from end to end, something would have to pick up one whole end of the filled aquarium a few feet high to get it to the sideways tipping point. Heck, as long as the material and bracing design were strong enough, you could probably safely bring them in to only three feet apart. However, I do think it's a given that the back and front legs should be the full 18" directly beneath the front and back of the tank. I used to have a stand for a 55 that appeared to only have four legs (one at each corner) that held the cabinet about 5" off the floor, and it looked very nice--very "furniture-like", but it actually had a fifth leg right in the middle, directly beneath a center divider inside that partitioned the two shelf areas and supported the center of the stand top; this same five feet configuration could be used on much larger tanks just as well. I'm working on some of these, what might be considered "radical" designs, for my new aquarium stand, and I have to admit that it is a little exciting getting away from the everyday "big box beneath the aquarium" design and looking at the bare essentials of what is actually required. I'm finding, of course, that the more radical the design, the more "utility space" is lost beneath the tank. It is interesting to look at it differently, though.

And as far as that "100 gallon" tank on the table goes, it might would work just fine IF the tank footprint was properly supported and the little legs were braced sufficiently, but if that thing ever even starts to lean sideways, it's ALL coming down fast and it ain't gonna be pretty! lol :eek5:

edit: (On second look at that 100 gallon on the "table", now I see that it looks more like it could be an older TV stand or some other box-shaped piece, which might would suffice for the weight, but then there's the unsupported ends hanging off.)

I used to live in Natchez when I was a kid and one summer during college (when I used to hang out with Greg Iles a little, playing music), and I still have some relatives in that area, but now I'm in Philadelphia, NW of Meridian. Do y'all get over this way and visit much?

Olskule
 
#41 ·
I like some of your stand ideas . Hope you try one so I can copy it if it works....lol Not much done on mine last couple days . Life gets in the way sometimes . I know where Philadelphia is . We had to go over a lot a couple of years ago due to funerals , but have not been since X'mas of 14 when we stopped in Tupelo for a night on the way to Christmas at Graceland in Memphis .
 
#44 ·
I like what you've done to the stand. Funny you should put angelfish on the doors like that, because in thinking about stand designs, I had also thought of a design similar to that, with angelfish facing each other, but in an Art Deco stylized version made with different veneers (marquetry), but I like the way you applied the cut-outs, good job! I'm anxious to see your tank set up and stocked; do you plan on putting other fish in with the angels?

Olskule
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top