domination2580
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It would be one that is internal that covers holes in the tank. Won't be the total height of the tank but just like a overflow box to cover the holes
Acrylic Fabrication Q & A
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TaylorPilot
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I think it would be fine. Some would say no, but I think if you use a good amount of silicone and you have a nice thick bead around it, then it should be fine. Some of the slim line overflows like the glass holes, are 5 sided, so that the bulkheads actually hold the box in place.
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For what it's worth @domination2580, the five sided box Taylor mentioned is the way I ended up doing it. It is secured to the tank via the bulkheads. You just need an extra bulkhead gasket between the box and the glass on the inside of the tank. It's worked very well for me. Also FWIW, I did my acrylic baffles in a glass tank for my current sump, just as he described. Cut them about 1/8" or so short, and used silicone to hold them in place. It's certainly not pretty though. I'm getting ready to build a new sump, but my current one has been running for nearly two years without issue. I'm not saying it's the correct way, just saying I've been lucky so far.
OP
OP
Seems like a good time for the Acrylic to Glass section
For a pressure baffle in a sump, I would recommend using 3/8" material in lieu of 1/4". Also you can use just about any brand acrylic for this, extruded is game, as well as Lexan (polycarbonate) since you aren't actually bonding it. Another step I recommend is to do this using reinforcing strips that are siliconed flat to the glass on the downstream side of the baffle. Just a 1" wide strip of 1/4" material (again, any material, and it doesn't have to be top-to-bottom, length, but should go to the top of the baffle) and you can silicone this in prior to siliconing in the baffle or at the same time. The reinforcing strip, siliconed flat to the glass, will have much stronger long-term adhesion compared to a right-angle baffle attachment. This way you also don't have to worry about the edge of the baffle taking the load.
In the case of a glass baffle bonded in with silicone, the silicone between the end of the baffle and the glass is taking on the structural load, since there is a physical bond between the glass and the silicone. Since this bond doesn't exist between silicone and acrylic, the silicone "dam" on the downstream side (which is bonded to the tank glass only) is what takes on the load. In essence, it's only a silicone wedge, and since the acrylic baffle can bow under pressure, this can more easily fail. Adding the reinforcing strip will relieve the "duty" of the silicone, transferring the strength load to the strip which spreads out the load quite a bit.
This is really more critical for baffles with a decent level difference between baffles, or a lot of flow.
For overflow boxes (4-sided, open back) @TaylorPilot's advices is pretty spot on. We've all seen the Reef-Ready tanks with an ABS plastic corner overflow, or custom glass tanks with an acrylic overflow siliconed in place. The reason this works is due to pressure along the full length of the box and the fact that the bottom of the overflow is sealed to the bottom of the tank, and also that there usually is a fair amount of water in the overflow tower.
However the thing to keep in mind with a 4-sided overflow is that there can be a level difference between the inside of the box and the tank water level. This creates a buoyant upward force on the box, and that puts a pulling tension along the bottom edge of the overflow box, so that can have a propensity to cause the box to "peel away" from the tank wall if you have a large (wide/long) overflow box, a deep box, or if you run it with a big level difference.
Now, this is not a horrible issue - it just needs to be one of those you are aware of. The second the seal at the bottom edge is broken, water will rush in and fill the box, and then the bulkhead/elbow inside will drain the tank down, worst case here is that your sump fills up more than intended, then if you have a power outage (or a poorly designed sump) you might have an overflow situation.
The fix, for peace of mind, is similar to the sump baffle fix, with one slight difference. Simply take a piece of 1/4" material that is about 3/4" or so wide and about the same length as the bottom panel (it doesn't have to run the full length, it can fall short of the corners by an inch or more) and solvent weld it to the bottom panel of the overflow box, perpendicular to it, flush with the back edge (the edge that will "touch" the glass). Now you have extended the surface area for the bottom/back edge of the overflow box. When you silicone the box in, instead of a 1/4" wide area of acrylic-to-glass, you now have a 1" wide area. This significantly reduces the chances that your overflow box will break away. The solvent weld doesn't have to be perfect in this case either, a rough-cut edge that is nice and straight, followed up by a few scrapes with a razor blade, and capillary welded in place (using the "preferred" capillary method) will work just fine.
For a pressure baffle in a sump, I would recommend using 3/8" material in lieu of 1/4". Also you can use just about any brand acrylic for this, extruded is game, as well as Lexan (polycarbonate) since you aren't actually bonding it. Another step I recommend is to do this using reinforcing strips that are siliconed flat to the glass on the downstream side of the baffle. Just a 1" wide strip of 1/4" material (again, any material, and it doesn't have to be top-to-bottom, length, but should go to the top of the baffle) and you can silicone this in prior to siliconing in the baffle or at the same time. The reinforcing strip, siliconed flat to the glass, will have much stronger long-term adhesion compared to a right-angle baffle attachment. This way you also don't have to worry about the edge of the baffle taking the load.
In the case of a glass baffle bonded in with silicone, the silicone between the end of the baffle and the glass is taking on the structural load, since there is a physical bond between the glass and the silicone. Since this bond doesn't exist between silicone and acrylic, the silicone "dam" on the downstream side (which is bonded to the tank glass only) is what takes on the load. In essence, it's only a silicone wedge, and since the acrylic baffle can bow under pressure, this can more easily fail. Adding the reinforcing strip will relieve the "duty" of the silicone, transferring the strength load to the strip which spreads out the load quite a bit.
This is really more critical for baffles with a decent level difference between baffles, or a lot of flow.
For overflow boxes (4-sided, open back) @TaylorPilot's advices is pretty spot on. We've all seen the Reef-Ready tanks with an ABS plastic corner overflow, or custom glass tanks with an acrylic overflow siliconed in place. The reason this works is due to pressure along the full length of the box and the fact that the bottom of the overflow is sealed to the bottom of the tank, and also that there usually is a fair amount of water in the overflow tower.
However the thing to keep in mind with a 4-sided overflow is that there can be a level difference between the inside of the box and the tank water level. This creates a buoyant upward force on the box, and that puts a pulling tension along the bottom edge of the overflow box, so that can have a propensity to cause the box to "peel away" from the tank wall if you have a large (wide/long) overflow box, a deep box, or if you run it with a big level difference.
Now, this is not a horrible issue - it just needs to be one of those you are aware of. The second the seal at the bottom edge is broken, water will rush in and fill the box, and then the bulkhead/elbow inside will drain the tank down, worst case here is that your sump fills up more than intended, then if you have a power outage (or a poorly designed sump) you might have an overflow situation.
The fix, for peace of mind, is similar to the sump baffle fix, with one slight difference. Simply take a piece of 1/4" material that is about 3/4" or so wide and about the same length as the bottom panel (it doesn't have to run the full length, it can fall short of the corners by an inch or more) and solvent weld it to the bottom panel of the overflow box, perpendicular to it, flush with the back edge (the edge that will "touch" the glass). Now you have extended the surface area for the bottom/back edge of the overflow box. When you silicone the box in, instead of a 1/4" wide area of acrylic-to-glass, you now have a 1" wide area. This significantly reduces the chances that your overflow box will break away. The solvent weld doesn't have to be perfect in this case either, a rough-cut edge that is nice and straight, followed up by a few scrapes with a razor blade, and capillary welded in place (using the "preferred" capillary method) will work just fine.
The only silicone I use with acrylic is momentive Rtv 100 series. but that's taking into consideration everything that's just been said about using silicone with acrylic.
OP
OP
Yes, and readily available at Grainger and online, in clear (108) black (103) and a few other colors.
Another thing on silicone is also curing time. Many thing that 48 hours to water-test and 72 hours to full strength is good enough, but it's really 2 weeks until the silicone fully cures to the point of not offgassing anything. So IMO it's a mistake to think that you can skip this 2 weeks period, and doing so it likely the main reason why people experience tank crashes and blame it on using the wrong silicone. The whole GE-II vs GE-I argument is based on using regular silicone vs "kitchen & bath", the latter has antibacterial and/or antifungal additives and should not be used, while the former is (likely) just fine, they just haven't paid the extra fee to label it "aquarium safe". It's cutting short the curing phase that still puts you at risk even when using the "correct" silicone.
Hello, I am having some trouble making a euro brace for a small tank I'm making. I had the piece cut out and I tried to double side tape a template down just made out of MDF pieces. I drilled a hole for the router bit to go in, but the router would just jump around and knock the template from the double sided tape. I don't know if I'm doing this the correct way or would you have a better solution. Thank you and I'm enjoying this thread very much.
TaylorPilot
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What type of bit are you using? It sounds like you may be traveling the wrong direction. It may seem counter intuitive, but you need to be feeding the bit into the acrylic. Does that make sense?
yes I know what you mean. I have used a router quite a bit. I am using a flush trim bit, or template bit as some people call them.
You will need to use firm steady pressure when routing acrylic, which means you might have to clamp the lid/template to a flat work surface.
Oh don't get me started. lol. what about a certain tank manufacturer that re-packages junk silicone and call it "aquarium" silicone. then says it's safe to use after 24 hours.
TaylorPilot
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Yea, my rule of thumb was always, if I can smell it at all, then it is releasing chemicals. I can usually smell silicone for about 10 days, so the 2 week period is probably a very good idea!
TaylorPilot
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yes I know what you mean. I have used a router quite a bit. I am using a flush trim bit, or template bit as some people call them.
That looks like a nice bit. I use Diablo bits and saw blades sometimes and they cut really nice. What is your feed speed? I very rarely experience a bit chattering or bouncing around. You say the jig is made up of multiple pieces? How small are they. Maybe get some wooded pieces to run along the side to screw it together, so it acts like it is one piece. It would probably be more secure and not move as easy.
OP
OP
FWIW you can use a laminate trimmer (that's what that bit is) for flush trimming, it won't leave quite as nice of an edge as a spiral upcut flush cutter, but it will do.
Personally, I was using a 1/4" diameter laminate trimmer in place of by 1/4" amana spiral upcut (which finally gave out after 3+ years) to cut out a part using a template and the bearing flew apart in seconds. And that was an Amana bit, which are like $45 minimum. So if you're gonna use a straight-flute trimmer bit, I would definitely rough-cut the hole using a jigsaw first.
The tricky part is starting. #1 your pilot hole has to be really big, so that you can either start the router up with it in the hole, or start the router then place the material w/template over the spinning bit. If on a router table, your material travel will be clockwise, going the other way will "pull" the material into the bit. When in a table (bit up) the bit will spin counter-clockwise, so you need to have your leading edge (template) on the left side of the bit and push into it. If that makes sense.
The thing about double-stick tape and MDF templates is that they break free easily. Any dust decreases the adhesion, which is why you want to rough cut the hole first, if you feel the template moving you need to have an "out", and without the center cut out, you don't have one. You have to hit the e-stop (if you have one) and pray the bit doesn't grab the material and go flying, or try to route out a small hole to free the bit and hope it doesn't grab it as you freehand and spray you with hot acrylic shavings (and potentially snap the bit). As you can imagine, these are extremely dangerous situations. I have been sprayed by hot acrylic shavings on more than one occasion, which is why I use a full facemask whenever I am template routing. I've also had my hand pulled into a 3/4" diameter 2-flute straight cutter spinning at 23,000 RPM (I should have known better w/r to what I was doing). I haven't had the pleasure of experiencing a broken bit, but a buddy of mine has, twice. He found one embedded in his drywall 30 feet away 2 months later, the other one he has yet to find. Bottom line is, be careful and plan ahead, and don't be stupid.
Regarding templates, the tape you want to use is Intertape brand, I use 591 which is 3/4" wide. It is like plain masking tape so it's thin. You need to clean off the MDF surfaces with a tack cloth, and then just wipe off the paper mask surface. Stick the tape to the MDF first then use a paint scraper or anything with a hard plastic edge and swipe it across it several times to "push" the tape onto the surface. You will be able to see the difference in the tape backing as you do this, you can use the knob end of a screwdriver, anything hard (but not metal as this tears the backing). Then take off the backing and lay the template on the acrylic, and push down hard all around to make sure it's on there good. Route your part and then peel the 2 piece apart, if they don't come apart easily then just pick up parts and slam then down flat on the router table and they will pop apart. That's a little trick you wouldn't think works, you'll laugh the first time you do it.
If you use an acrylic template, the process is the same, except acrylic-to-acrylic (paper on both) is a much stronger tape bond. If you peel off the mask on one side (usually your template) then the tape will almost always stick to the non-masked acrylic, and very well (to the point where you have to use denatured alcohol to remove the residue after removal)
Personally, I was using a 1/4" diameter laminate trimmer in place of by 1/4" amana spiral upcut (which finally gave out after 3+ years) to cut out a part using a template and the bearing flew apart in seconds. And that was an Amana bit, which are like $45 minimum. So if you're gonna use a straight-flute trimmer bit, I would definitely rough-cut the hole using a jigsaw first.
Are you using a router table (router in table, bit sticking up, template on top of work material) or handheld?
The tricky part is starting. #1 your pilot hole has to be really big, so that you can either start the router up with it in the hole, or start the router then place the material w/template over the spinning bit. If on a router table, your material travel will be clockwise, going the other way will "pull" the material into the bit. When in a table (bit up) the bit will spin counter-clockwise, so you need to have your leading edge (template) on the left side of the bit and push into it. If that makes sense.
The thing about double-stick tape and MDF templates is that they break free easily. Any dust decreases the adhesion, which is why you want to rough cut the hole first, if you feel the template moving you need to have an "out", and without the center cut out, you don't have one. You have to hit the e-stop (if you have one) and pray the bit doesn't grab the material and go flying, or try to route out a small hole to free the bit and hope it doesn't grab it as you freehand and spray you with hot acrylic shavings (and potentially snap the bit). As you can imagine, these are extremely dangerous situations. I have been sprayed by hot acrylic shavings on more than one occasion, which is why I use a full facemask whenever I am template routing. I've also had my hand pulled into a 3/4" diameter 2-flute straight cutter spinning at 23,000 RPM (I should have known better w/r to what I was doing). I haven't had the pleasure of experiencing a broken bit, but a buddy of mine has, twice. He found one embedded in his drywall 30 feet away 2 months later, the other one he has yet to find. Bottom line is, be careful and plan ahead, and don't be stupid.
Regarding templates, the tape you want to use is Intertape brand, I use 591 which is 3/4" wide. It is like plain masking tape so it's thin. You need to clean off the MDF surfaces with a tack cloth, and then just wipe off the paper mask surface. Stick the tape to the MDF first then use a paint scraper or anything with a hard plastic edge and swipe it across it several times to "push" the tape onto the surface. You will be able to see the difference in the tape backing as you do this, you can use the knob end of a screwdriver, anything hard (but not metal as this tears the backing). Then take off the backing and lay the template on the acrylic, and push down hard all around to make sure it's on there good. Route your part and then peel the 2 piece apart, if they don't come apart easily then just pick up parts and slam then down flat on the router table and they will pop apart. That's a little trick you wouldn't think works, you'll laugh the first time you do it.
If you use an acrylic template, the process is the same, except acrylic-to-acrylic (paper on both) is a much stronger tape bond. If you peel off the mask on one side (usually your template) then the tape will almost always stick to the non-masked acrylic, and very well (to the point where you have to use denatured alcohol to remove the residue after removal)
someone wants me to build a rimless frag tank 36 x 24 x 10, so i used this handy little calculator to find out what thickness of acrylic i would need to buy. came out to be .316, so rounded up would be 3/8". i was actually going to use 3/4" so this is sweet! save me lots of money.
OP
OP
I would highly recommend you use 1/2". The calculator is wrong. I've built about a half dozen 36x24x 8" tall sale-frag tanks, the first one or two I built with 3/8" and they bow. You can't use them for permanent use, only for temporary IMO. So go 1/2" and they are pretty solid. Still a bit of bowing over time, but no where near the 3/8". Price difference is worth it.
And honestly, 3/4" for 10" tall rimless and the tank will be an absolute rock.
And honestly, 3/4" for 10" tall rimless and the tank will be an absolute rock.
Yes, for certain situations. Especially rimless. This is where experience factors in with how acrylic reacts in different situations. This calculator is a basic tool to help guide you, but isn't by any means set in stone.
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