Acrylic Tank Design Question
- Thread starter Phixer
- Start date
This tank had some .5 square stock that was horribly glued in with weld on 16 from a previous owner. With 40 i was able to melt over the entire piece creating over a 1" seam. Same method for a reg seam. It takes about a week to get all the seams including the sides, front and back, top and bottom. Anywhere wherea theres a corner even upside down lol. Alot of flipping the tank and patience but well worth every step.
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Conclusion lol... solvent seam is only as thick as your material.....#40 seam can double/triple the bonding area inside the tank 
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Forgot to answer ur vacuum question. Removing bubbles from a mix does not require a vaccumm.... i have made many molds from silicone to plaster and cast with all types of resins. You can tap the side of the mixing cup with your finger, use vibration or even place your mix on a chair and shake it. Ive had better results with homemade vibration tables then vaccums for air removal of mixes. Nothing to b afraid of.
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Those pics are a big help, if you had to do one from the beginning would you use an outside bevel/fillet?
Those edges look pretty stout with a lot of surface area also. Darn near bullet proof actually. So thats what #40 looks like? It's that clear? If I understand correctly your talking about tilting the tank and pouring the #40 along the seams to form the inside fillet right? That would utilizing the properties of the 2 part best by allow more contact area. Have to say it looks pretty good.
Im finding out that most people who use the 2 part stuff do not anneal tanks this size either. Just wondering if it would still be safe, am finding out that it probably will be. I'll probably forego the torch, me with fire near plastic havent worked out well in the past.
Have seen ply tanks built this way with the epoxy poured in and was thinking about this but what concerns me is that Id have to make several pours, one for each side instead of one continous bead all the way around the perimeter. Do you think this would affect the integrity of the cement or would it be an issue?
Narrowing in on it now.
I read that when using the 2 parts stuff that a small gap about .015 between panels is a good idea with a fillet on each side? like the attachement, What do you think? as this would provide one continous piece of cement after it dries, still dont know if I should bevel the edge slightly or not but am quite sure that without annealing more surface area either way for the cement to hold on to is a good thing.
Gluing up the bottom and sides is whats confusing me now. The best way I can think of to maintain a gap and have a continuous bead would be to suspend the tank .015 with suction cups attached to the vertical surfaces. Then pour the cement.
Or do two seperate pours by first shimming the sides .015, pour the long ones for the front and back and then when thats dry remove the shims under the side panels and then pour the edges under the side panels. Really considering the suction cup suspension but dont know if they would be able to hold it in place long enough for the cement to dry.
And it's in Colorado where the air is thinner, this too could affect how well the suction cups hold a vacuum.
Those edges look pretty stout with a lot of surface area also. Darn near bullet proof actually. So thats what #40 looks like? It's that clear? If I understand correctly your talking about tilting the tank and pouring the #40 along the seams to form the inside fillet right? That would utilizing the properties of the 2 part best by allow more contact area. Have to say it looks pretty good.
Im finding out that most people who use the 2 part stuff do not anneal tanks this size either. Just wondering if it would still be safe, am finding out that it probably will be. I'll probably forego the torch, me with fire near plastic havent worked out well in the past.
Have seen ply tanks built this way with the epoxy poured in and was thinking about this but what concerns me is that Id have to make several pours, one for each side instead of one continous bead all the way around the perimeter. Do you think this would affect the integrity of the cement or would it be an issue?
Narrowing in on it now.
I read that when using the 2 parts stuff that a small gap about .015 between panels is a good idea with a fillet on each side? like the attachement, What do you think? as this would provide one continous piece of cement after it dries, still dont know if I should bevel the edge slightly or not but am quite sure that without annealing more surface area either way for the cement to hold on to is a good thing.
Gluing up the bottom and sides is whats confusing me now. The best way I can think of to maintain a gap and have a continuous bead would be to suspend the tank .015 with suction cups attached to the vertical surfaces. Then pour the cement.
Or do two seperate pours by first shimming the sides .015, pour the long ones for the front and back and then when thats dry remove the shims under the side panels and then pour the edges under the side panels. Really considering the suction cup suspension but dont know if they would be able to hold it in place long enough for the cement to dry.
And it's in Colorado where the air is thinner, this too could affect how well the suction cups hold a vacuum.
As others have mentioned, the top is the most important sheet of a tank and under the most stress.
My tank is 120"x36"x48"H. It is 1.25" all the way around, except for the bottom piece which is only 1" thick.
I personally don't like how much it bows (I think it is underbuilt...they should have used at least 1.5").
I sent you a link to a thread you might find helpful. Looking forward to seeing your progress on this build....sounds like you have a real monster in the works!
My tank is 120"x36"x48"H. It is 1.25" all the way around, except for the bottom piece which is only 1" thick.
I personally don't like how much it bows (I think it is underbuilt...they should have used at least 1.5").
I sent you a link to a thread you might find helpful. Looking forward to seeing your progress on this build....sounds like you have a real monster in the works!
Yeah, thats the whole reason I decided to go with 1.5" and limit the height to 36". I dont care much for the bowing either. Will probably either sell the 1.25" panels if I do decide to go with 1.5 for the top. Im still thinking about using thicker for the top as you mentioned but Polycast only comes in 120 X 72 at that length so Id be left with an extra 120 X 36 after cutting it down, not to mention the material for cut outs.
Your diagram pic looks like ur heading in the right direction . As for multipe pours, its easy to mix small batches and do one seam at a time during the "tipping method" when the initial structure is complete. The #40 bonds to itself very well and all becomes crystal clear. As for the initial assembly start with the back panel laying flat and glue the two sides vertically. Next flip this 3 piece section and glue on the front panel (both sides as once). Then glue the 4 pieces (walls) to the bottom in one shot. You can pretty much pour the glue on your bottom piece and set the walls on top. Finally flip the tank upside down and do the top as you did the bottom. Id say a 4 day process to get the tank and another week to tip and glue each seam on the inside. Long process to flip the tank around that much and for your size your gonna need some helpers
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. As for multipe pours, its easy to mix small batches and do one seam at a time during the "tipping method" when the initial structure is complete. The #40 bonds to itself very well and all becomes crystal clear. As for the initial assembly start with the back panel laying flat and glue the two sides vertically. Next flip this 3 piece section and glue on the front panel (both sides as once). Then glue the 4 pieces (walls) to the bottom in one shot. You can pretty much pour the glue on your bottom piece and set the walls on top. Finally flip the tank upside down and do the top as you did the bottom. Id say a 4 day process to get the tank and another week to tip and glue each seam on the inside. Long process to flip the tank around that much and for your size your gonna need some helpers Sent from my SAMSUNG-SGH-I747 using MonsterAquariaNetwork App
The front/outside fillet your referring too is usually ground smooth/flush when the tank is complete. Its more or less glue that squeezed out. Not really structural or necessary imo. I like to butt my pieces all the way to the end of the bottom sheet to eliminate the grinding/sanding. To make edges of material clear i use flame polishing. Havent buffed too many tanks but this is the step that will give you a show quality tank. More time is spent on treating the edges of material with sanding and buffing than actually glueing the tank together. Not hard, just time consuming to go through diff. Grits of sand paper and novus polish kits. Flame polishing gives almost as good clarity as sanding in less than half the time. Im not saying the flame is better just quicker. For a material thickness of 1.25-1.50 i think your going to have to buff your outside edges clear with polishes/sandpapers.
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Feeling a lot better about using the #40 now. Yeah I thought about how hard it's going to be to move, my basement may end up looking like a shipyard with all lifting and pushing methods Ive devised. The latest is a rotisserie jig made by modifying two engine stands with cross member and sections of removable steel square tubing to flip it when necessary. Looks kind of like a chassis jig with a cage in the middle.
Today I heard back from a tank MFG that dosent anneal either. Am finding that most do not. He said that if you can prevent the acrylic from heating up to much during machining then you dont need to anneal it. Annealing is mostly done to prevent crazing.
He even goes to the extent of wiping the edges with alcohol prior to bonding them with the 2 part cement (which I though alcohol & acrylic was a big no no). He does this because if the panel was over heated during machining process it will instantly show up as crazing after the alcohol hits it and then can shave off the crazing with a router. A pretty good preliminary test actually. Im going to test this out on some scrap material.
The moral of the story he wanted to impart was to keep the acrylic cool when machined.
Today I heard back from a tank MFG that dosent anneal either. Am finding that most do not. He said that if you can prevent the acrylic from heating up to much during machining then you dont need to anneal it. Annealing is mostly done to prevent crazing.
He even goes to the extent of wiping the edges with alcohol prior to bonding them with the 2 part cement (which I though alcohol & acrylic was a big no no). He does this because if the panel was over heated during machining process it will instantly show up as crazing after the alcohol hits it and then can shave off the crazing with a router. A pretty good preliminary test actually. Im going to test this out on some scrap material.
The moral of the story he wanted to impart was to keep the acrylic cool when machined.
