Acrylic fabrication questions? I can help!

What are the differences between Reynolds R cast and Spartech Polycast GP?

Which one machines better? which one would work better with 2 part cement?
 
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I added 1/2 X 1/2 gussets in all joints. [extra precaution] Since I wasn't happy with all the bubbles. Here is a pic. A little fugly I know. But it is holding water so far.

So I may take your advice to rebuild it using cell cast and weldon-4.
What thickness would you recommend.? 1/4 3/8 1/2 ??

010.jpg


Can anybody help with my question. ^^^
I'm referring to just the outer walls and bottem piece.
For the dividers I will use the rest of my 3/8 acrylite FF
 
GrandpaDon,

Your build is fine...as its just a sump and not a display piece, if it were my personal sump I wouldn't worry about it. If it were for a customer...naturally it would then never see the light of day to maintain build reputation. You didn't do a bad job at all for your first build I assure you...I have seen worse and I have had to fix much worse.

Case in point...got an 'H' tank in my shop now that a guy working at a sign fab shop decided to build for a friend. He had all the right tools and then some (access to CNC router for parts machining) but didn't have the foggiest clue about how to make good joints apparently as the think leaked like a pig after a pitch fork stabbing. I have had to go through the thing with a fine toothed comb and gusset virtually all joints in order to properly fix it.
 
GrandpaDon,

Your build is fine...as its just a sump and not a display piece, if it were my personal sump I wouldn't worry about it. If it were for a customer...naturally it would then never see the light of day to maintain build reputation. You didn't do a bad job at all for your first build I assure you...I have seen worse and I have had to fix much worse.

Case in point...got an 'H' tank in my shop now that a guy working at a sign fab shop decided to build for a friend. He had all the right tools and then some (access to CNC router for parts machining) but didn't have the foggiest clue about how to make good joints apparently as the think leaked like a pig after a pitch fork stabbing. I have had to go through the thing with a fine toothed comb and gusset virtually all joints in order to properly fix it.

Thank you for those kind words. And no im not terribly worried about appearance of the sump just function. It is still holding water as a test now for 5 days.

Its a Paletta design with skimmer first then mud/algae [fine sand/algae] then return area.
 
hey James,

sorry to bother you but Im not having luck prepping my edges with my 2 hp Bosch router on a router table with a fluted bit from Vortex tool. Its a 1/2 shank bit but doubled fluted. The tool company told me that its the best bit for acrylic. After a pass It leaves a few spots of ripples. To scape all this material is my last resort due to the amount of pieces.

any info would help. Thanks Bill
 
What thickness material? Are you running it between the bit and a fence? How big is your router table and how big are the parts?

You got bad advice from your supplier. "the best bit" depends on what you are using it for. If you are cutting acrylic on a CNC machine, then yes, a fluted bit is perfect.

ON a router table such as most aquarium fabricators use for edge prep, fluted/spiral bits do not leave the best edges for prepping. They are a little 'grabby' and want to pull the material into the bit, while straight cutters tend to push the material away (toward the fence) - at least that is my experience. So the straight cutter leaves you with the best edge.

For edge prep, all you need is a double fluted straight cutter. I use a Bosch one from Lowe's, 3/4" cutting diameter, 1/2" shank. You can get bigger diameter, and bigger is better because the bit tip speed increase with diameter.

You only want to use fluted/spiral bits for flush trimming, and then you want the ones with the bearing on the end (obviously).

HTH
Bud
 
Hey.

I`m gonna build a tank in
Acrylics with the measures 35x28x18
inches with a top flange.
My question is,can i use
5/16, 4/8 in thickness for
this build or 8mm in my case
since i`m from Norway??
If not, what should i use?
If i read in this tread i would
probably find my answer,
but i try here first.
 
Hey.

I`m gonna build a tank in
Acrylics with the measures 35x28x18
inches with a top flange.
My question is,can i use
5/16, 4/8 in thickness for
this build or 8mm in my case
since i`m from Norway??
If not, what should i use?
If i read in this tread i would
probably find my answer,
but i try here first.

Don`t mind this question. I`ve got my answer
 
Help help!!! :)

In Norway we can`t get hold of Weld-on`s products. Instead we got this type called Acrifix. Can anyone help me pick out the right one from the cart i have linked??
I called 2 diffrent suppliers today. The first told me ACRIFIX® 2R 0190 (ACRIFIX® 190) was the best one to use, it was way stronger then other`s and so on. The second one i spoke to told me the ACRIFIX® 1S 0106 (ACRIFIX® 106) was probably the best since it was easier to work with...??? When i read in the weld-on specifications the viscosity says only (water thin). Please sombody help me before i get crazy!!

http://www.acrifix.com/sites/dc/Downloadcenter/Evonik/Product/ACRIFIX/de/191-1%20ACRIFIX%C2%AE_en.pdf
 
2 part cements will produce a stronger joint on thicker material if used properly with good adhesion into the base. Polymerizable cements such as PS30 or #40/42 will produce stronger joints on thicker material. Just too much factual data and tanks out there to even dispute this. If you want to ensure a good bite into the base material then sand parallel groves into the base for the cement to bite into. A perforated surface enables greater resistance to slippage.

Solvent may work well for thinner material but not for the big tanks. You will never see a public aquarium with panels over 2" thick that uses solvent to bond it together. Even Cryo recommends the use of 2 part cement. It sounds like his tank failed due to an engineering design deficiency (eurobrace as mentioned) rather than a material failure. Possibly too close to a metal halide?

Do the research and you will find that each type has it's place. Look around and talk to a lot of builders and engineers and you will see, 2 part cement is indeed stronger in certain applications.
 
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30x48x22

30x48x22

my wife wants a tall fish only tank built into our entertainment center beside the fireplace opposite our reef tank. I tried an acrylic calculator to figure iout the thickness needed and the suggestion was 1 inch thick acrylic. Is one inch overbuilding, can i go with thinner acrylic?
 
If 22" tall then yes you can definitely use thinner material, just make sure you use a top piece. Makes a big difference in structural integrity. A safety factor is built in to these calculators. Here is what I came up with if your using a top section of the same thickness.

22" tall = .5" in

30" tall = 1" is limit for my use although Ive seen 36" with minimal bowing.

48" tall = at least 2" Cryro recommends 2.226" to be exact, not to include sand bed though.

Also depends if you fill to top.
 
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24" high, 1/2" minimum
30" high, 3/4" minimum
36" high, 1" minimum

3" perimeter euro
6" crossbrace for every 24" of length (one cross brace on 48", two on 72", etc)
1.5" radius corners on top euro

At 8' length, jump up one material thickness

Phixer, why would a sand bed presence or absence have anything to do with it?
 
I maintain a 225g tank that is 72 x 24 x 36 tall w/bent front corners, all out of 1/2" material and it bows like a SOB. But it's been in place for 8 years and never moved. I even sanded and polished it because it had big scratches and it's been up and running since then for 3 years, and I just tore everything out and restocked it.

So it's not like 1/2 material won't work. But when you see that bow...it'll give you a heart attack.
 
24" high, 1/2" minimum
30" high, 3/4" minimum
36" high, 1" minimum

3" perimeter euro
6" crossbrace for every 24" of length (one cross brace on 48", two on 72", etc)
1.5" radius corners on top euro

At 8' length, jump up one material thickness

Phixer, why would a sand bed presence or absence have anything to do with it?

Permeability in relation to density Floyd. The greater the density of something the less it will absorb and the more it will displace. When rocks/sand are added they displace a given ammt of H2o depending on their density.
The more something is compacted the more dense it becomes. A thick sand bed composed of tiny grains will displace more water than a bare bottom tank. This affects the height of the water column which directly relates to the ammt of hydrostatic pressure exerted on the walls which in turn determines the thickness of the material.

An example would be, a 48" tall cube tank made of 1/8" material. If this tank was filled with a solid block of lead to within 1" of the top and then filled with water the 1/8" material would be fine. If the block of lead was reduced in size it would then displace less water in turn increasing the volume of H20 and hydrostatic pressure associated.
In a small nutshell.
 
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