Acrylic fabrication questions? I can help!

[kaserpick]

Fluid dynamics...thanks for pointing me in the right direction. I've got a large Mechanical Engineering book a friend gave me; I got my degree in Mathematics and wanted to branch out. Now I've got some research to do! Thanks again!

Floyd, what thickness do you think the overflow box should be? I was thinking either 1/4" or 3/8".

 

[Floyd R Turbo]

Hey James, there are several posts way back that reference pictures of tape blocks, and pictures in your album. But I think in the server transition back them they got lost or something. Do you have pictures of those that you can post again?

Thanks

Bump for pics from James...

 

[Acrylics]

I sincerely doubt I have any of those pics. Most of my stuff was lost in the great hard drive crash
there are a few in here that might be relevant...
http://www.reefcentral.com/forums/showthread.php?t=390652

 

[peppie]

James seen this on my tank. I built it. Been full for 4mos. It grew 1/4'' in the past 24 hrs

Thanks James

 

[peppie]

Thought this may also help you. This is a pic of how the top of the tank was const.

The tank is 36 x24 x22 high. Made with 1/2" cell cast

 

[TheFishMan65]

I am thinking of doing a sump. I have done a little work with Acrylic. A fellow reefer decided not to use some Acrylic that they got at Home Depot (1/4 inch). So a few questions if you don't mind.

Can I use this for a 14x48x14(high) sump?
I really don't want to Eurobrace it. Will a baffle (13.5 inches) at the halfway point be enough? If not how often could I use a 1 inch strip front to back? Any other options?

Thanks

 

[Acrylics]

James seen this on my tank. I built it. Been full for 4mos. It grew 1/4'' in the past 24 hrs

If it's growing that fast, I'd take it down

Doesn't matter how the top was constructed, the seam itself is failing

..and being cell cast ain't good enough, has to be good cell cast. There are far too many variables in the mfg of acrylic to just use any "cell cast" - I know everyone says just use cell cast..but they be incorrect. IMO the material needs to be either Polycast, Acrylite GP, or Plexiglas G, and in this order of preference.

Wish I could tell you something different, but if it is indeed growing that fast, I'd take it down now to avoid something real bad happening.

James

 

[Acrylics]

I am thinking of doing a sump. I have done a little work with Acrylic. A fellow reefer decided not to use some Acrylic that they got at Home Depot (1/4 inch). So a few questions if you don't mind.

Can I use this for a 14x48x14(high) sump?
I really don't want to Eurobrace it. Will a baffle (13.5 inches) at the halfway point be enough? If not how often could I use a 1 inch strip front to back? Any other options?

People get away without top bracing, but I wouldn't recommend it, especially with that material.

Using that material, your best and safest bet is to eurobrace it.

James

 

[peppie]

Thanks James.
You most likely save me a whole got of greef and a very large mess, and cost for a new floor.
I tore it down. and set up a temp 40gal. I will build another very soon.

Thanks again for the quick reply.

 

[TheFishMan65]

Thanks James.

..and being cell cast ain't good enough, has to be good cell cast. There are far too many variables in the mfg of acrylic to just use any "cell cast" - I know everyone says just use cell cast..but they be incorrect. IMO the material needs to be either Polycast, Acrylite GP, or Plexiglas G, and in this order of preference.

Reading the your post above you recommend 3 types of cell cast. I couldn't remember the types (I have read several posts and your tank thread). Sorry for the double check (but I want to be safe). Is the Home Depot going to be OK? How wide of a top brace do need?

 

[reeferstricken]

James, sir, sir James?

I'm planning for a "drop-off" tank, and saw in another diy thread, troylee?, that you wouldn't' have built it the same way he had. Have you built these, would you advise against it completely?

Plan: parallel to the ground - (upper portion) 48x22" then perpendicular with the same sized sheet to create the deeper section, making the depth difference 26". 3/4" thickness

 

[Floyd R Turbo]

Thanks James.

Reading the your post above you recommend 3 types of cell cast. I couldn't remember the types (I have read several posts and your tank thread). Sorry for the double check (but I want to be safe). Is the Home Depot going to be OK? How wide of a top brace do need?

I've read this question several times in the thread. The types of acrylic that you get from Home Depot or Lowe's (if they are indeed acrylic, and not polycarbonate) are generally extruded, and a cheap one at that (probably import). If it were me, I wouldn't make anything from that stuff that is meant to hold water. That's my personal opinion based on advice given throughout this thread. It may be fine, you would just want to watch the seams over time for signs of degradation, like crazing or cloudiness.

I fall back on the Chemcast issue. That's a cheap cell cast material that was used a lot at first, sometimes it worked fine, but in many cases 6 months down the road tanks started falling apart. One company made all their tanks out of Chemcast and they ended up going out of business after tanks started failing.

I've seen if suggested that Acrylite FF or Plexiglas MC extruded materials can be used for sumps and such, again with a eurobrace, and proper construction techniques (pins method and flush trimming, etc). But even then it might be a good idea to bump up a thickness since those products use metric thicknesses, so 1/4" is actually 0.236 and 3/8" is 0.354. And you still want to watch for signs of degradation.

Plus I would build the tank according to the strength requirements needed without the baffles. That way it will be overbuilt. The material cost difference is really not that much if you can find a good local supplier.

 

[collie man]

I have a question:

How can i go about making a dosing container with 3 compartments for my 3 part dosing schedule. I also want to make a 5 to 10 gallon reservoir out of acrylic, how would i go about it? dimensions? type of acrylic to use? im totally lost. i have woodworking skills so i know i can cut and glue. what type of glue to you use...ive heard of weld-on but which kind.

 

[Floyd R Turbo]

I would suggest if you're really serious about doing it right, and you've never worked with acrylics before, go back and at least read all of this part of the thread. It may take you a while, but it will likely answer most of your questions. This thread has 2 splits (3 parts) and goes back to about 2003. Actually the first about 2-300 posts of the original thread are very informative, then you get into a lot of repeated questions and you have to pick out the good tidbits of info here and there.

 

[collie man]

okay thank you, any specific tools i should look into getting? polisher? saw of some sort?

 

[Acrylics]

James, sir, sir James?

I'm planning for a "drop-off" tank, and saw in another diy thread, troylee?, that you wouldn't' have built it the same way he had. Have you built these, would you advise against it completely?

Plan: parallel to the ground - (upper portion) 48x22" then perpendicular with the same sized sheet to create the deeper section, making the depth difference 26". 3/4" thickness

can you post a drawing of some sort? I don't advise against them, but if you're not real familiar with acrylic work, might not be the best first project

James... just James

 

[Acrylics]

Reading the your post above you recommend 3 types of cell cast. I couldn't remember the types (I have read several posts and your tank thread). Sorry for the double check (but I want to be safe). Is the Home Depot going to be OK? How wide of a top brace do need?

Only way I could see doing it safely from HD material (if) would be a 2+" eurobrace and a 4-6" centerbrace as well. All acrylic available at HD/Lowes is essentially low grade extruded. If you want to buy good cell cast, then the brands are Polycast, Acrylite GP, and Plexi-Glas G, in that order of preference. You will need to go to a plastics supplier to get these though and they will probably cost more than the HD material.

James

 

[reeferstricken]

can you post a drawing of some sort? I don't advise against them, but if you're not real familiar with acrylic work, might not be the best first project

James... just James

James!

Thank you, I've built a few sumps, similar dimensions (48x24) but with baffles and overflows, so i have some experience with acrylic.

Here is a mockup slightly different dimensions than originally stated, mostly to get the most out of a sheet 4'x8'. This mockup shows 4" euro, and 6" middle bracing.

 

[Acrylics]

Thanks for the dwg I'd probably increase the thickness to 1" but other than that - no problem. Tanks like this are prone to cracking at the lower inside corner(just to the left of the arrow above the 2' marking. Imagine it's 2 different tanks; the 6' x 2" tank and a 2' x 4' tank. Draw a point at the load center of each, and connect those dots. The corner will just about always crack such the crack will intersect that line at a perpendicular angle. Seen it a lot. Hence my recommendation for thicker material, plus - 3/4" is too thin IMO for a 4' tall tank of that span. Making the stand accommodate the tank so that the panes sit flat is of paramount importance

James

 

[reeferstricken]

Great to know! thank you, could you please recommend a height you would use with 3/4" thickness, also is 1" solid or just doable, i'm hoping to keep this for a long time.

Additionally, is this correct image for the crack you described? and is there additional bracing I could put here to help, like 1" strip across the side/touching the bottom?

Thank you very much for your time.