Acrylic fabrication questions? I can help!
- Thread starter JohnL
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dattack
Active member
I would use 3/8" black if it's a big overflow but 1/4" would work too.
Crazed
New member
Hi! I'm planning on building my own sump (after many years of living with a bad modded glass sump). The design is below (except smaller details like an intake trap and a few probe mounts). Basically, the footprint is 34"x13"x19" and it will be filled to about 14" or about 26 gallons of saltwater (excluding rock, gravel, etc).
My question is do I need to use 3/8" Acrylite FF for this, or would thinner acrylic (with/without a lid/brace) be sufficient? If so, how should I design the lid/brace?
Any other comments on the design are welcome (I'll probably make the return section smaller and do an automatic topoff). Thanks in advance!
My question is do I need to use 3/8" Acrylite FF for this, or would thinner acrylic (with/without a lid/brace) be sufficient? If so, how should I design the lid/brace?
Any other comments on the design are welcome (I'll probably make the return section smaller and do an automatic topoff). Thanks in advance!
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Floyd R Turbo
Either busy or sleeping
With the baffle where they are, you can probably do this with 3/8" extruded with no problems, if you go down to 1/4" it should be OK as well, but the incremental material cost is really negligible to go to 3/8".
A brace is optional, but will really strengthen and solidify the tank, even if it's only a thin perimeter brace. extruded is probably fine vs cast, it will bow more though.
Just make sure you follow good construction techniques: prep edges properly, square the end pieces properly, clean edges before bonding, bond using the pins method and allow for a lip for fillet & flush trim, and allow joints to cure for the proper amount of time prior to handling.
A brace is optional, but will really strengthen and solidify the tank, even if it's only a thin perimeter brace. extruded is probably fine vs cast, it will bow more though.
Just make sure you follow good construction techniques: prep edges properly, square the end pieces properly, clean edges before bonding, bond using the pins method and allow for a lip for fillet & flush trim, and allow joints to cure for the proper amount of time prior to handling.
Floyd R Turbo
Either busy or sleeping
Your reading just about the only place all this information is disseminated. Go back to the beginning of this thread (there are 2 splits, 3 threads) and take a few weeks to read it. Better than any "book"
Phixer
New member
There are a few videos on You Tube about acrylic tank construction using solvent and a few pdfs about plastic fabrication out there but essentially thats it.
Ive found nothing on building big tanks using material over 1" with polymerizable cement but have met several others who build this way. Most fabricators safeguard this information although the processes involved are pretty straight forward.
I had to learn thru experimentation, trial and error and by piecing bits of information together over the years.
As mentioned earlier, if you have questions this is the thread...
Ive found nothing on building big tanks using material over 1" with polymerizable cement but have met several others who build this way. Most fabricators safeguard this information although the processes involved are pretty straight forward.
I had to learn thru experimentation, trial and error and by piecing bits of information together over the years.
As mentioned earlier, if you have questions this is the thread...
Floyd R Turbo
Either busy or sleeping
James will pretty much share any technique on this thread up to bonding very thick material (2.5" and over)
dattack
Active member
Ok I got this quote from reefs dot org where James chimed in 2006 for materials 1.25"
........
You can use either 40/42 or solvent, some of this will depend on how precise you can machine your pieces. If you are able to machine your pieces +/- .005" or so - you can use wires/pins. We use the exact same process for solvent gluing this thickness as 1/2" so that part doesn't change - just the weight and manageability of the pieces.
If you cannot get the pieces machined that closely, then 40/42 is the best method.
If machining is good then between the two above processes, use the one you are most comfortable with. Both will work just fine.
I would *not* use #16 for such a tank at all.
BTW the "pins" method *is* the capillary method - just using surface tension to wick the solvent along, the wires or pins just make for a larger gap.
Out of curiosity, what are the fill dimensions of the tank and what size are the flanges / crossbraces.
HTH?
James
........
You can use either 40/42 or solvent, some of this will depend on how precise you can machine your pieces. If you are able to machine your pieces +/- .005" or so - you can use wires/pins. We use the exact same process for solvent gluing this thickness as 1/2" so that part doesn't change - just the weight and manageability of the pieces.
If you cannot get the pieces machined that closely, then 40/42 is the best method.
If machining is good then between the two above processes, use the one you are most comfortable with. Both will work just fine.
I would *not* use #16 for such a tank at all.
BTW the "pins" method *is* the capillary method - just using surface tension to wick the solvent along, the wires or pins just make for a larger gap.
Out of curiosity, what are the fill dimensions of the tank and what size are the flanges / crossbraces.
HTH?
James
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Floyd R Turbo
Either busy or sleeping
If you want to write out your questions, I'll ding him to jump in and respond. He has a lot on his plate right now. I would probably like to hear the answers as well.
Floyd,
I would like to also hear from Jame regarding bonding two pieces of acrylic side by side. I know two others on this site that did a 12ft tank. They both bonded a 8ft and 4ft piece to form the 12ft piece.
I read both threads and would like more info on this process. Would a 42Gun work better with this type of application or could we use 40? I would think the 42Gun be easier to apply.
I would like to also hear from Jame regarding bonding two pieces of acrylic side by side. I know two others on this site that did a 12ft tank. They both bonded a 8ft and 4ft piece to form the 12ft piece.
I read both threads and would like more info on this process. Would a 42Gun work better with this type of application or could we use 40? I would think the 42Gun be easier to apply.
dattack
Active member
I would love to see how this is done.
Based on the threads that I have read and the pictures (definitely worth a thousand words), it seems fairly simple.
Do a straight cut or a 45 degree cut on both sheets. Make sure they are aligned properly (which i guess is the hardest part and takes the most prep time). Tap up the sides so that not too much 42 leaks out and makes a mess. Apply 42 and let dry. Buff is many, many, many times till clear.
But would like to hear from James on tips and tricks to make it as perfect as possible.
Phixer
New member
Thx Floyd. Id like to hear James advice on this also. Seaming thick material using polymerizable cement seems to be like sorcery (the dark arts) with little to no information out there. Hell..., there's more information on how to build a time machine or light saber. Thank's for asking about it. Hopefully we can all learn more about this from an industry perspective.
Im actually planning this now using the gun to mix 42 to seam two 8x4 sheets end to end to form one 16ft sheet. Each of the ends has been milled 5 degrees using a CNC router. The material is 2.250 thick.
The ends will be butted together leaving about 1/16th gap at the bottom of the V. The void is then cast with 42 and overfilled using aluminum foil tape to form the dams. After the cement is dry, the sanding and polishing begins. Using granite slab lifters, gantry cranes and two 45 degree hinged tables to maneuver the panels. Each weighs around 500lbs.
My question is: Will the small machine marks left by the cutting bit effect the clairity or will 40/42 fill in the irregualities caused by the bit and render these invisible when dry. Since it's cement Im hoping the small ridges will give the cement something to "bite" into and still provide an optically clear joint when dry . Or should I scrape them perfectly smooth? If this was solvent , I know it would need to be perfectly smooth. But its not.
On smaller projects, I've used the gun to squeeze 42 into a syrenge and apply it that way. Have found this helps alleviate some of the bubbles. I've heard of mixing 40 in a small bottle and spinning it with a drill as a centrifuge to remove bubbles also but havent tried it. The applicator gun method works pretty well so far.
dattack:The edges can be kept within those tolerences, however the weight of thick material increases the chances of breaking a wire off beneath a panel in addition to air pockets forming from the greater surface area. Pulling pins on a 16ft section of thick acrylic is tricky business. Im not skilled enough to even attempt this.
Im actually planning this now using the gun to mix 42 to seam two 8x4 sheets end to end to form one 16ft sheet. Each of the ends has been milled 5 degrees using a CNC router. The material is 2.250 thick.
The ends will be butted together leaving about 1/16th gap at the bottom of the V. The void is then cast with 42 and overfilled using aluminum foil tape to form the dams. After the cement is dry, the sanding and polishing begins. Using granite slab lifters, gantry cranes and two 45 degree hinged tables to maneuver the panels. Each weighs around 500lbs.
My question is: Will the small machine marks left by the cutting bit effect the clairity or will 40/42 fill in the irregualities caused by the bit and render these invisible when dry. Since it's cement Im hoping the small ridges will give the cement something to "bite" into and still provide an optically clear joint when dry . Or should I scrape them perfectly smooth? If this was solvent , I know it would need to be perfectly smooth. But its not.
On smaller projects, I've used the gun to squeeze 42 into a syrenge and apply it that way. Have found this helps alleviate some of the bubbles. I've heard of mixing 40 in a small bottle and spinning it with a drill as a centrifuge to remove bubbles also but havent tried it. The applicator gun method works pretty well so far.
dattack:The edges can be kept within those tolerences, however the weight of thick material increases the chances of breaking a wire off beneath a panel in addition to air pockets forming from the greater surface area. Pulling pins on a 16ft section of thick acrylic is tricky business. Im not skilled enough to even attempt this.
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Floyd R Turbo
Either busy or sleeping
super, because if you bond 2 surfaces directly together with WO40 such that they are a "perfect fit" the joint will push out the WO40 and you will end up with a dry joint.
If you read enough of this thread, you will see references to angles on the pieces to create the void. This I believe is the proper method. It is in this thread, you have to really search for it though. Try using the search function on this thread only for the term "40" or "42" and you might find it, also go back to the splits I think it's buried there.
Phixer, in reference to you question here is what James e-mailed me
If you read enough of this thread, you will see references to angles on the pieces to create the void. This I believe is the proper method. It is in this thread, you have to really search for it though. Try using the search function on this thread only for the term "40" or "42" and you might find it, also go back to the splits I think it's buried there.
Phixer, in reference to you question here is what James e-mailed me
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