sandwiching acrylic and gluing question

[Anonymous]

If I wanted to glue a couple slabs of acrylic together the large flat side, like if I butted a couple tanks together...

... would I use the same weldon used to butt corners together (ie building a box/tank) I'm curious how I would apply that over a large surface area since I doubt capillary action would pull that across an entire surface

... would laying it flat be necessary? or could I potentially slather up a side with whatever and squish the other side into it?

Since I want to experiment with putting a couple tanks together, the strength requirement would be in the tanks pulling apart (I guess) more so than me just trying to get cheap with acrylic thickness and double up.

 

[Anonymous]

It depends on how well of a job you want. If you don't care about the look/strength, you can do it like an amataur, and end up with a surface full of air bubble, and not transparent.

If you want a clear cement, then you need to do a bit more practice. If you are butting two existing tank together, it is more difficult. but if you have two unglued panel that you want to cement together, it is more workable.

In a nut shell, you put some metal pins between the panels, and clamp the other end. Use paper to protect the panels if you care about appearance. Add solvent cement to the narrow side, and as the solvent move across the space between the panels, move/remove the pin and/or clamp down the other side until the solvent goes across the entire panel. Ensure there is no trapped air, and undo the work of last few seconds if you want to remove the air bubble. It is similar in principle to putting a big sheet of tape on a piece of glass. Good luck.

 

[Anonymous]

Hmmm.. well all I really care about being "strong" or looking good is the outer 2 inches around the paremeter, since the inner side will be cut out. Image a rectangular donut shape if you will.

But can I do the capillary method vertically? or does that always have to be done horizontally?

 

[Anonymous]

Now you tell me what you really want to do.

Suggestions:
1, precut the piece before cementing. Easier to cement, and you may have enough scrap to do other DIY project.

2, for a complicated shape like that, I will do it hori. unless you can't move the pieces from verticle.

 

[Anonymous]

Well I thought I mentiong sandwiching two tanks together in my original post

Precut, never really thought about that, because I figured it'd be easier to cut once they're cemented.. otherwise I'd have to get creative with very big clamps on the outside.

Yah I figured horizontal gluing would be the way to go, just after 2- 4' long tanks all work needs to be done outside since it'll be over 12 feet tall (long) with the next, 16 feet with the one after, and I would be worried about moving these guys into position after the fact.

 

[Anonymous]

If it is any longer than 3 feet, you will need to consider reinforcement on the top AND bottom since any lateral movement may take one of the panel off the tank. 8O

I strongly suggest you consider getting someone else to do this for you for 8ft tanks (16 ft total) so that you have someone to sue when it goes wrong. Unless you can handle the wrath of your angry wife...

 

[Anonymous]

If it is any longer than 3 feet, you will need to consider reinforcement on the top AND bottom since any lateral movement may take one of the panel off the tank. 8O

Out of curiosity.. lateral movement? I mean sure ok earthquake maybe.. but other than that what else? Also is there any reason why say a 1" perimeter that's been bound together would be any weaker than say the joints that are typically done on tanks?

I strongly suggest you consider getting someone else to do this for you for 8ft tanks (16 ft total) so that you have someone to sue when it goes wrong. Unless you can handle the wrath of your angry wife...

HA! As if she would have a say in the matter... not to mention I'm not married, and it's going to be done donestairs on some super crappy laminant flooring that's older than I am, so the only damage would actually be an improvement

 

[Anonymous]

I was thinking about the lever effect if you push the tank sideway. I guess it should not be a main issue afterall, just that I would make sure the top bracket is reinforced.

I hope Acrylics can chime in and let me know if I am off in my comments.

 

[Anonymous]

Let me run another idea by you, or anyone else who feels qualified to chip in (or even if you don't feel qualified ).

How about instead of using acrylic cement to attach a couple tanks making whatever monstrosity I'm thinking up permanent (ie say I had 16 feet worth of tanks, that'll be pretty damn permanent since I most likely wouldn't be able to even angle it to get it out of the door, or worse having to do it on site), what if I use plastic screws to hold them together, sort of like a pressure pipe, then use some silicone or a flange inbetween them and just tighten it up. (see Figure 1 below)

Now from a practicality standpoint this would seem more ideal since
-individual tanks can have holes cut/drilled anywhere and connected later
-if for whatever reason need to move it I can disassemble into individual tanks
-No need to worry about getting a crappy weld because I had to apply the cement to a vertical surface rather than horizontal
-If it did develope a leak, chances are it wouldn't be a catastrophic leak that requires draining the tank, and might be fixable by just tightening the screws a bit more
-Sure screws might look a tad ugly to start, but like everything else in a tank they'd be covered with algae
-Any mistakes in planning (ie it won't fit) can be fixed by removing a single tank rather than having to cut them all apart and start over.

Anyways, if you or anyone else has any ideas on this I'd love to hear them. Specifically I'm looking for things along the line of "This will never work there is a problem with <insert problem here> that'll cause <damaging make me cry thing here>" or even some along the lines of "Wow I never thought of that, and have no idea how that'll work" (although I'd rather some who know what they're talking about say the last one, since just about anyone could say that I'm sure ). I'm just curious because I can try to find an 18g acrylic tank laying around and try it on a small scale first to put theory to test without going through a tremendous amount of trouble.

Also another question, assuming this isn't extremely far fetched already, would I be able to use tanks of different sizes? Since getting all the same exact size of tank might be an issue. I'm wondering how the pressure against the acrylic would pan out, if I had say 55g tanks that were only 16" deep, hooked to a 100g that's 20" deep would the acrylic bow any further? Initially I'd say no since the pressure that's exerted on the walls should be determined by how much water is above it. But again, I'm looking for someone to chime in with something I haven't thought of

Oh yah, I offically name this design/process after myself, incase I am the first loony guy to think it up, and would like full credit if someone with more resources (ie money) whips this up, ie I don't want to see the "Calfo Tank system" or whatever because they happen to write books And in the case it has been thought up, I still want some credit because I figured it out independant of seeing the idea someplace

Alright enough jibber jabber

 

[Anonymous]

>... even if you don't feel qualified

First of all, I am not qualified to even speak for myself...

It is not far-fetched, since these "screwed" together tank is how many relatively large (anything bigger than 8X8X8 for example) fiber-glass tank is being assembled. 6 fiber glass panels screwed together by stainless steel bolts and some fiber glass I-beams for reinforcement.

However, there is some complication with acrylic.
1, acrylic is much more brittle than fiber glass, and bolt hole is prone to initiate a crack.
2, I don't know off-hand any plastic screw that can do the job unless the tank is less than 18 inch deep. Use marine-grade SS (not the regular SS) bolt is better alternative.