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View Full Version : How do you add spacers when siliconing glass to get the right amount of silicone in ?


Reefbox
10/23/2009, 09:17 AM
How do the professional tank builders set spacers between the glass panes to get the right amount of silicone in the seam?


Thsanks

tat2shawn
10/23/2009, 07:18 PM
Im on board to hear from the pros.

marc111
10/23/2009, 07:46 PM
Here is what I did when building my 260 gal plywood tank with 3 glass sides. I followed the instructions that were published when they made the big reef tank at the smitsonian.

I made small forms that I could temporarily tape in place to lay down a small bump of silicon in the shape of a line and about 1/8 inch thick. The bump was placed so that it would be totally surrounded by the silicone holding the glass in place. I let the bump fully set up.

I laid down the real coat of silicone and set the glass inplace against the 4-8 bumps ( depending on the size of the pane)I had put in. This worked perfectly, gave me an even seal of silicone and the tank has not leaked after over 15 years.

Hope this helps,
Mark

Reefbox
10/24/2009, 02:31 PM
Mark. You are a genuis. That's exactly how I will build my tank. So you have about an 1/8" of silicone in the seam?


Thanks for sharing.

coralnut99
10/24/2009, 08:18 PM
About a year ago I dismantled an old 125G that was made out of 1/2" glass all around. The manufacturer embedded tiny platic "bumpers" in the silicone bead, for this purpose. I call them bumpers because they were just like the little plastic bumpers on the corners of faceframe cabinet doors to keep them from slamming. They were clear and adhesive. In the coming weeks I'll be assembling a 160G peninsula (if I ever finish the family room remodel!), and I plan on just laying small bits of fishing line (not sure what Lb test yet) horizontally in the silicone bead itself. The silicone bumps sounds like a neat idea, but I would be afraid that they wouldn't be uniform, and may take up too much room in the final silicone bead. Just my two bits here, no real science.

seafloor09
10/24/2009, 10:02 PM
you can make the spacers out of acrylic I would think

uncleof6
10/24/2009, 11:54 PM
you can make the spacers out of acrylic I would think

I wouldn't. The acrylic could act as a point load, and cause you some problems. A rigid spacer might make it impossible to squeeze out all the air from the seam, making a weaker seam.

The silicone spacers are used as a guide to insure the right amount of silicone is in between the panels. Most seam thicknesses are between 1mm and 1.5mm. (~ 1/16) I have seen seams thicker, generally in rimmed tanks, measuring at 1/8". Granted I have not seen every tank ever made. To a point, the thinner the seam, the stronger.

Sometimes the spacers are removed during the application process, for one particular assembly method that I am aware of, and sometimes they are left in place to prevent the larger heavier panels from squeezing too much silicone out. Generally this would be with a sides on top of the bottom construction.

After a while, it becomes second nature-- a matter of "feel", squirt the silicone on, put the panel in place, clamp it and walk away, the specifics of it lost, somewhere along the line. Ya don't bother dragging out a scale to measure the seams.

Jim

Reefbox
10/25/2009, 09:02 AM
Uncle, What type of clamps are you using. I have not used clamps yet. Was looking into setting up a jig or fixture to make assembly easy.

I have been just siliconing two panes at a time but was wondering if it should all be siliconed at the same time?

Thanks for the input.

1DeR9_3Hy
10/25/2009, 09:12 AM
You can do just one or two panes at a time....but it will take twice as long :D

*Time for abbreviations*

FWIW, IME as long as the seam has a nice even, darker green color (take a look at 'uncleof6's' avatar, see the hat? You want a few shades darker) it will have plenty of strength. You can add too much and get away with it through pressure on the seams, but if you dont add enough....you cant fill it back in easily.

marc111
10/25/2009, 11:36 AM
The comment about the acrylic as a spacer is right on point. You want a silicone spacer so that it will flex the same amount as the rest of the silicone.

I was not gluing glass to glass. I, like Dr. Addey at the Smithsonian was putting glass panels into a frame. In his book he had said he used 1/8 inch so I followed his advise.

For an all glass tank they tipically use much thinner seams and I would think that 1/16" would do. Caveate: I have not built an all glass tank.

Hope this helps,
Mark

uncleof6
10/25/2009, 01:50 PM
Uncle, What type of clamps are you using. I have not used clamps yet. Was looking into setting up a jig or fixture to make assembly easy.

I have been just siliconing two panes at a time but was wondering if it should all be siliconed at the same time?

Thanks for the input.

It can be done either way, depends on how fast you can work, silicone adhesives skin rather quickly, if they skin before a panel is in place, you are done.

This should help on the clamps:

http://i655.photobucket.com/albums/uu274/uncleof6/clamping.jpg

Jim

uncleof6
10/25/2009, 01:52 PM
You can do just one or two panes at a time....but it will take twice as long :D

*Time for abbreviations*

FWIW, IME as long as the seam has a nice even, darker green color (take a look at 'uncleof6's' avatar, see the hat? You want a few shades darker) it will have plenty of strength. You can add too much and get away with it through pressure on the seams, but if you dont add enough....you cant fill it back in easily.

Hat? @@!!##!!*@@!!!, :blown:

ahmedess
10/25/2009, 04:11 PM
I m building my own glass tank with dimensions 40"x20"x24"h and i m using 0.4" thick glass. I will be building the sides on top of the bottom glass. i would like to know if i will be needing to put spacers or not. This is my first diy glass aquarium and i want to make sure i do everything the right way to save my self trouble later on. I would really appreciate learning from your experiences.

uncleof6
10/25/2009, 04:32 PM
I m building my own glass tank with dimensions 40"x20"x24"h and i m using 0.4" thick glass. I will be building the sides on top of the bottom glass. i would like to know if i will be needing to put spacers or not. This is my first diy glass aquarium and i want to make sure i do everything the right way to save my self trouble later on. I would really appreciate learning from your experiences.

.4" (10mm) is too thin, and 11mm ( .43" ) would be very marginal for this tank with the silicone in compression (a metal rimmed tank.) 12mm would be ok for a tank with a eurobrace top and bottom, and 15mm would be a marginal rimless, with 16mm being best, with the least bowing. Standard glass sizes: 6mm, 9mm, 12mm, 15mm, 19mm.

Spacers are not a requirement, and I would not recommend you build this tank as a first glass and silicone experience. Start small, and work your way up, unless you want to redo this tank several times before you get it right.

Regards,

Jim

ahmedess
10/25/2009, 06:53 PM
The reason i thought of using 10mm thickness is because of a glass thickness calculator i found online. It uses a safety margin of 2.5. So you were saying 12mm with a eurobrace would be okay, no bowing. How do i do a eurobrace top and bottom and what thickness for the eurobrace should i use?

uncleof6
10/25/2009, 07:19 PM
OK, this thread is going way off topic now. However, this is what I am talking about. Euros should be the same thickness as the side glass. 12mm.

http://i655.photobucket.com/albums/uu274/uncleof6/der-wille-1.jpg

Jim

dattack
10/26/2009, 12:37 AM
I have seen a square 1/8" thick black spacer on all the LeeMar tanks here in southern california. It doesn't span the entire width of the glass thick, maybe 1/2 of it. It doesn't look like silicone to me. Looks like a solid piece of material. Maybe it's glass? not sure.

impur
10/27/2009, 05:55 PM
Another thing you can do, and the acrylic spacers would work here, is get the tank all taped up with spacers between the panes and as you are squirting the silicon into the seem remove the spacer as you come to it. Then clamp er all together tight.

Reefbox
02/04/2010, 12:31 PM
Uncle,
In that pic u provided did u silicone and clamp all the seams at one time?

I'm finally getting this project going again and wil b ordering glass soon.

24"x24"x20" high rimless tank
1/2" glass. All sides polished.
1/16" seam gaps

Still debating if i should or shouldnt use 1/16" silicone spacers in the seam??? Any advise.


Thanks for all the help. Greatly appreciated.

cnbridge
02/04/2010, 09:15 PM
I just broke down a 120gal tank (perfecto ar AGA)and there were small acrylic/plastic spacers in between the front/back and sides.They were circular and just a little smaller than the width of the glass. There was one at the top and bottom. There were none under the glass sitting on the bottom. I save them to use them when I rebuild the tank.