Acrylic fabrication questions? I can help!

[Acrylics]

More info on why I had asked about laminating thinner material to thicker material. The idea would be to overlay an 1/8" piece over a 1" thick clear piece to avoid the expense of buying a full sheet of black. The laminated piece would be the back wall of the tank blocking out the overflow. That was my intention for wanting to know.

Painting isn't really an option due to the overflow being external, so the water would be in contact with the paint.

Call around to plastic fabricators and ask if you can buy a smallish chunk of 1" black? You won't have to buy a full sheet this way

If I want it permanent, do I use Weld-on 4 with wires/pins OR Weld-on 16 (or 40)? Or is that a two part process?

Sorry...total acrylic newb.

Either/or, both are permanent. If you lack the experience, perhaps you have a friend or member in a local club that can help? it's really only a 5 minute process, but if messed up - can turn into a big ordeal.

I have an internal glass overflow box that I want to black out and the consensus was to us a piece of black acrylic. The only problem is that the overflow is a coast to coast and I need to figure out how to affix the acrylic to the glass.

So far I have thought of using rare earth magnets, fabricating a lip that could latch to the glass, superglue or epoxy.

I would prefer to affix the acrylic directly to the glass with magnets being my second favorite option. I really don't want to fabricate a lip just because of the length 65" and the very slim width 3/8".

Thanks for the help.

Safe to assume you want the black acrylic inside the tank? Personally, I'd get a tube of black Dow Corning 795 (neutral cure silicone) and just silicone it in. Let it cure for a coupla weeks and you're good to go. Can also use GE 1200 series silicone in black - also sticks well to acrylic and doesn't take so long to cure. Spooge some onto the black acrylic, put into place, silicone around it.
The silicone will stick to both the acrylic and the glass well enough for cover-up but not well enough for a structural application.

If I misinterpreted the question, please lemme know

James

 

[chriscobb]

Thanks James!!! Been calling all day long, and all will only sell a full sheet.

 

[mitchwelt]

Ok I build my sump which is 72x24x24, made from 3/8 acrylic, we used Weldon 4 on all joints, 24hr later I went over all joints with Weldon 16, is this safe and OJ, been reading 16 weakens joints.
I know the 16 makes ugly bubbles but it's just a sump

 

[Acrylics]

Thanks James!!! Been calling all day long, and all will only sell a full sheet.

Best I could say is look at aquarium manufacturers, lots of 'em use 1" black

Ok I build my sump which is 72x24x24, made from 3/8 acrylic, we used Weldon 4 on all joints, 24hr later I went over all joints with Weldon 16, is this safe and OJ, been reading 16 weakens joints.
I know the 16 makes ugly bubbles but it's just a sump

hehe, in your case, a sump is a tank that holds ~180 gallons of water and when the power goes out - not the time to be hopeful. 16 *can* stress the material. It won't *necessarily* weaken joints, but over-stressing acrylic certainly can cause the material to fail. The amount of latent stress in the material depends on many factors and not something that can be determined by an internet forum post.

If you don't see any crazing in the affected areas, don't worry about it too much.

If you don't mind me asking; why did you go over the joints with 16?

James

 

[mitchwelt]

Best I could say is look at aquarium manufacturers, lots of 'em use 1" black

hehe, in your case, a sump is a tank that holds ~180 gallons of water and when the power goes out - not the time to be hopeful. 16 *can* stress the material. It won't *necessarily* weaken joints, but over-stressing acrylic certainly can cause the material to fail. The amount of latent stress in the material depends on many factors and not something that can be determined by an internet forum post.

If you don't see any crazing in the affected areas, don't worry about it too much.

If you don't mind me asking; why did you go over the joints with 16?

James

We used 16 to basically seal the 4 and have no leaks

 

[dlp211]

James,

Yea, it is a coast to coast overflow and I just want to hide the glass with a piece of black acrylic. The acrylic will be super light, only 1/16" thick, so I appreciate the advice. Yes it will be in the tank and you answered my question fully.

Thanks again
Dave

 

[noplay180]

What does the pin method do and is it needed for a sump 48x24x16 3/8 thick acrylic with baffles. and where do you get the right pins from

 

[noplay180]

Also I had my material cut exact and after reviewing this great forum I realized I should have made made the a little bigger do you guys think I will have a problem with this any tips

 

[noobtothereef]

Reynolds Polymers in Grand Junction, CO has 6' x 15' sheets made, industry termed "RPG Asia." However, all joints with this material must be cast as it doesn't solvent bond well at all.

How does this material compare to polycast? Ive never heard you talk about this material. Would you use it?

 

[Acrylics]

What does the pin method do and is it needed for a sump 48x24x16 3/8 thick acrylic with baffles. and where do you get the right pins from

Here's the thread Zeph wrote for it way back when:
http://www.reefcentral.com/forums/showthread.php?t=169326

In a nutshell, all it is is placing pins (I use wires) between the horizontal piece and the vertical piece to allow for solvent to flow freely between the two pieces. Is it needed? not as an absolute, but I wouldn't build a tank without using similar techniques.

My take on it is here:
http://www.reefcentral.com/forums/showthread.php?t=390652

Also I had my material cut exact and after reviewing this great forum I realized I should have made made the a little bigger do you guys think I will have a problem with this any tips

IMO, you'll have to make the tank a little smaller as flushing gluing is simply a PITA

How does this material compare to polycast? Ive never heard you talk about this material. Would you use it?

It's not bad material, just doesn't solvent bond well, so every joint must be cast - esp if you want it to look half-decent. In that sense, there is no comparison, Polycast wins easily.
That said, like with most things - there is a trade-off. The mole weight of RPG material is much higher so less apt to craze. Higher the mole weight, the less apt to craze, but also harder to solvent bond which works by means of stressing the material *just enough.* This is why extruded material (which has a low mole weight) glues extremely easily but also crazes real bad.
Would I use it? hmm, maybe on some things, but as a generality - no, my show is not set up to do 15' long tanks... not anymore anyway..

James

 

[noplay180]

@ James in your method do you only use the pins on the top and the bottom. what about the sides

 

[noobtothereef]

wow Reynolds Polymers in Grand Junction is crazy high on theyre price, $7k per sheet at 144x72....

 

[Acrylics]

@ James in your method do you only use the pins on the top and the bottom. what about the sides

every joint on every tank

wow Reynolds Polymers in Grand Junction is crazy high on theyre price, $7k per sheet at 144x72....

captive audience - where else you gonna get a sheet that size? only 2 mfrs in the world that make them.. Reynolds and Nippura in Japan.

James

 

[chriscobb]

Is it acceptable to mix Plexiglas G with Polycast during a build?

 

[Acrylics]

Is it acceptable to mix Plexiglas G with Polycast during a build?

yup

 

[Andrew17030]

I have some questions and have found some answers from reading here but think it would be easier to ask then read through 100's of posts.
I want to build my own sump. I don't have the tools to cut the acrylic so I must buy it cut. How should I go about locating a place that will not overcharge me and will also cut the material for me? I read about variances somewhere regarding acrylic fabrication. What do you recommend is acceptable? My project will be a sump and its dimensions are 42.5"L x 29.25"D x 16" T with 0.5" thick material. There will be a divider 13" in from the inside dimension of 41.5" it will also be 0.5" thick. This 13" x 29.25" area will be baffled, four baffles total. How would you recommend someone with no acrylic fabrication experience construct this? I was thinking about using your method with the pins and the bonding liquid. Then going over the inside seams with something for good measure. What solvents should i use and what weldon should i use to go over the seams? Also, when i am solvent bonding how long should I expect hold a vertical piece in place to allow for bonding to take place to the extent that it will not have to be held in place any longer?

 

[Andrew17030]

I have some questions and have found some answers from reading here but think it would be easier to ask then read through 100's of posts.
I want to build my own sump. I don't have the tools to cut the acrylic so I must buy it cut. How should I go about locating a place that will not overcharge me and will also cut the material for me? I read about variances somewhere regarding acrylic fabrication. What do you recommend is acceptable? My project will be a sump and its dimensions are 42.5"L x 29.25"D x 16" T with 0.5" thick material. There will be a divider 13" in from the inside dimension of 41.5" it will also be 0.5" thick. This 13" x 29.25" area will be baffled, four baffles total. How would you recommend someone with no acrylic fabrication experience construct this? I was thinking about using your method with the pins and the bonding liquid. Then going over the inside seams with something for good measure. What solvents should i use and what weldon should i use to go over the seams? Also, when i am solvent bonding how long should I expect hold a vertical piece in place to allow for bonding to take place to the extent that it will not have to be held in place any longer?

 

[Xolsiion]

Andrew, I'll let the experts answer most of those questions - but they just answered one of them for me here: http://www.reefcentral.com/forums/showthread.php?t=2039385

 

[Acrylics]

I have some questions and have found some answers from reading here but think it would be easier to ask then read through 100's of posts.
I want to build my own sump. I don't have the tools to cut the acrylic so I must buy it cut. How should I go about locating a place that will not overcharge me and will also cut the material for me?

figure out the material you want, the dimensions you want, and the finish quality on the edges you want and call around. IMO you want either Polycast or Plexi-Glas G and a smooth routed edge and all gluing edges. Tolerances on those pieces +/- .003-.005" - should be easy for anyone that's any good.

I read about variances somewhere regarding acrylic fabrication. What do you recommend is acceptable?

what variances are you referring to?

My project will be a sump and its dimensions are 42.5"L x 29.25"D x 16" T with 0.5" thick material. There will be a divider 13" in from the inside dimension of 41.5" it will also be 0.5" thick. This 13" x 29.25" area will be baffled, four baffles total. How would you recommend someone with no acrylic fabrication experience construct this?

I wouldn't. I'd recommend making a few smaller boxes first and get the hang of it before attempting a pressure vessel.

I was thinking about using your method with the pins and the bonding liquid. Then going over the inside seams with something for good measure.

this, to me is a mistake. If you do your part well, "going over" it will do nothing good and may in fact hurt your finished product.

What solvents should i use and what weldon should i use to go over the seams?

Weld-on 4 is cheap and common, so that's what I'd say. "Good" solvent requires more money and knowledge to get right.

Also, when i am solvent bonding how long should I expect hold a vertical piece in place to allow for bonding to take place to the extent that it will not have to be held in place any longer?

2-3 hours minimum IMO. Moving it too soon can lead to problems.

IMO; while I understand the want to build this yourself, I would recommend having it made for you, or practicing a good bit first. This is not a big sump and you should be able to have it build for you for just a little more than you can buy the acrylic at retail prices. But again, JMO

James

 

[noobtothereef]

Hey james, ive noticed you mentioning "stressing acrylic" when bonding, im assuming that you mean the solvents stress the acrylic, which stresses the acrylic less, casting or solvent bonding?