Acrylic fabrication questions? I can help!

[Acrylics]

Is there a recommended width for a euro bracing?

On something like this I'd probably do 2" or so. Doesn't look like anything is necessary over the filter sock area - just the main body.

HTH,
James

 

[Webmanny]

I am so happy I found this thread. I have been thinking about building my own sump out of acrylic. The picture below will give you an idea of my design. The issue is that I have never worked with acrylic and I don't have the tools. Buying a table saw, router, etc. would defeat the purpose, as it would cost me a lot more than just ordering the sump custom made.

My question is, are there any reasonably priced builders online that you can recommend or if you think this is a simple enough design, where can I get the acrylic already pre-cut and prepared for welding?

 

[Acrylics]

I am so happy I found this thread. I have been thinking about building my own sump out of acrylic. The picture below will give you an idea of my design. The issue is that I have never worked with acrylic and I don't have the tools. Buying a table saw, router, etc. would defeat the purpose, as it would cost me a lot more than just ordering the sump custom made.

My question is, are there any reasonably priced builders online that you can recommend or if you think this is a simple enough design, where can I get the acrylic already pre-cut and prepared for welding?

I really can't give names out of such fabrication companies. I'd highly suggest making a post in the "Vendor Experiences" forum and ask there.
As for getting material that's cut and machined to size, I'd check the local yellow pages under "plastics, fabricating, finishing, and decorating" or something to this effect. Ask if they'll do it, machined to size, etc. in a high quality cell cast acrylic, namely Polycast or Plexi-Glas G. Do not accept substitutes, all acrylic is not the same. You do not want it polished.
Otherwise, check the local yellow pages for "plastics, distributors, sheet, rod, and tube" or something to this effect. These guys sell plastic but generally don't do the machining - just cut to size. But they'll know who around you can do it.
There are also some online vendors but I'd be careful, and be *very* specific with them.

In the long run, you may find it cheaper to just get it made, but if'n you're up for it...

HTH,
James

 

[pandimus]

Si polycast and plexi-g are the two brands that are good? I have two sheets of 1/4 lucite L in my garage,but know that is probably too thing for my particular project.

Thanks for your time james

 

[Acrylics]

Si polycast and plexi-g are the two brands that are good? I have two sheets of 1/4 lucite L in my garage,but know that is probably too thing for my particular project.

Lucite L is very good material, just not often used for tanks. Lucite was heavily in making acrylic for the bathtub/spa industries and cut production for other endeavors, but the L sheet is pretty good. It's a continuous cast sheet, so much better than extruded but not as good as a good quality cell cast. 1/4" would be fine for baffles and such and glues up very nicely

HTH,
James

 

[pandimus]

Lucite L is very good material, just not often used for tanks. Lucite was heavily in making acrylic for the bathtub/spa industries and cut production for other endeavors, but the L sheet is pretty good. It's a continuous cast sheet, so much better than extruded but not as good as a good quality cell cast. 1/4" would be fine for baffles and such and glues up very nicely

HTH,
James

Yeah plan was to use my lucite L for baffles etc but get thicker 3/8 for the panels. I just got a quote for 3/8 clear he told me 8 dollars a square foot.I suspect that stuff is junk gonna meet with him tomorrow and be more specific

 

[Webmanny]

I really can't give names out of such fabrication companies. I'd highly suggest making a post in the "Vendor Experiences" forum and ask there.
As for getting material that's cut and machined to size, I'd check the local yellow pages under "plastics, fabricating, finishing, and decorating" or something to this effect. Ask if they'll do it, machined to size, etc. in a high quality cell cast acrylic, namely Polycast or Plexi-Glas G. Do not accept substitutes, all acrylic is not the same. You do not want it polished.
Otherwise, check the local yellow pages for "plastics, distributors, sheet, rod, and tube" or something to this effect. These guys sell plastic but generally don't do the machining - just cut to size. But they'll know who around you can do it.
There are also some online vendors but I'd be careful, and be *very* specific with them.

In the long run, you may find it cheaper to just get it made, but if'n you're up for it...

HTH,
James

Thank you for your suggestions. I will look into your suggestions.

 

[RxReefer]

I have an acrylic tank that im putting baffles in. I'm using acrylic sheets I got from lowes. Is there any problem I should worry about using them?

 

[Floyd R Turbo]

for baffles, it's less important but I would still try to use extruded at the least. Also remember that acrylic does absorb water and expands over time, so if you are putting baffles into an existing tank that hasn't been dried out for a while (like many weeks) then the new acrylic will expand while the old acrylic is already expanded, and this has the potential to cause problems. Not saying it will.

The other aspect that makes this point kind of moot is that you will have a very hard time cutting a baffle to fit exactly perfect because you can't "rotate" it into position if it is a tight fit, it would have to be slightly smaller (unless it's rimless) and even then, you will have warping/bowing of the tank walls that will make it an imperfect fit. That's OK because you really don't want that anyways, solvent welding a perfect fit tight joint will only tack weld it in place, it won't hold water usually.

What you do instead is get 2 gusset strips and bond those on the down-pressure side (lower water level side) and then fit your new baffle against those and just silicone it in place to seal it and keep it from moving. If it has to be sealed against the bottom, put one there too. You can try to get the corners of the gussets to meet up so that you can reduce the amount of silicone you need to use. Also remember that silicone takes a while to cure up to reef safe, usually 2 weeks is recommended. Use Momentive RTV silicone.

 

[ReefPharmer]

Hopefully it's good acrylic? good brands are Polyone/Polycast or Plexiglas G, other than that, perhaps Cyro or RPG if casting the joints, but everything else that I've seen is pretty much garbage for tanks.



That said, you can bring the water height up to full capacity provided it's braced well. 3" perimeter flange/eurobrace and (3) 5" cross-braces yield 4 top openings, each measuring ~18 x 16". Orrrr, 4" perimeter flange and (2) 6" cross-braces should yield you something like (3) 14 x ~25" openings.



Personally, I think that would be pushing it a little much. With a single 6-8" wide cross-brace, you could do a 4" perimeter flange and while you'd have the cross-brace to work around, the narrower flange would make the tank more easily serviceable as a whole.



HTH,

James

You feel a 6 inch center brace w a 4 inch euro (so really it's 3 inch euro into the tank since the wall thickness is 1 inch) is pretty strong? I'm in Cali w the earthquakes and such...)

 

[Acrylics]

You feel a 6 inch center brace w a 4 inch euro (so really it's 3 inch euro into the tank since the wall thickness is 1 inch) is pretty strong? I'm in Cali w the earthquakes and such...)

Absolutely, without hesitation.

James

 

[paphater]

Could I get some thoughts on my practice edges? I'm taking exactly 1/16th off using a 1/2 inch whiteside spiral upcut bit and I'm still able to feel ridges on the edge. The raw cut edge actually feels smoother in some parts. :hmm2:

Edit:

I threw on a cheap mlcs double flute straight bit and I was able to get a much more uniform cut but the acrylic is now opaque. It does feel smooth though.

 

[paphater]

I just went back through my "notes" that I've made reading through the thread and I see that straight cutters are the preferred cutter for the edges. I guess that's what happens when you slowly make notes over the course of a year! I ordered a new 3/4" straight cutter and will give it a try next week. I am still a little curious though on why the straight cutter produced that opaque edge.

 

[dattack]

I just went back through my "notes" that I've made reading through the thread and I see that straight cutters are the preferred cutter for the edges. I guess that's what happens when you slowly make notes over the course of a year! I ordered a new 3/4" straight cutter and will give it a try next week. I am still a little curious though on why the straight cutter produced that opaque edge.

You are correct. The straight cutters produce a much smoother edge vs the upcut.

 

[speedyron]

where to get an 8 foot x 3 foot x half inch sheet for a tank front reasonably cheap

 

[paphater]

Google local plastic companies. My local supplier normally sells an 8x4 half inch sheet for $300. No idea if that is around the normal going rate.

 

[Acrylics]

I just went back through my "notes" that I've made reading through the thread and I see that straight cutters are the preferred cutter for the edges. I guess that's what happens when you slowly make notes over the course of a year! I ordered a new 3/4" straight cutter and will give it a try next week. I am still a little curious though on why the straight cutter produced that opaque edge.

Coupla possibilities. One is simply that you got a grain of "stuff" in the collet. Pull the cutter, blow everything out and replace. But before you tighten the collet completely, turn the cutter in the collet a little. I have this issue at times as well.

The other possibility is cutter flex, though the above is more likely? Long thin cutters have a tendency to flex a little more under torque. This is one of the reasons I like to use big fat 1.5" diameter cutters for edge prep. The Whiteside solid carbide spiral upcut is a great router bit, but best used for mulching through material or simply flush-cutting.

HTH,
James

 

[OhMatic]

Hello,
I need some input on drilling and tapping acrylic (cell cast sheets)
I want to Tap some acrylic sheets for use with nylon thumb screws
Is any tap ok to use? Are there Taps made/designed for acrylic?
Any recommendations for thread count 10-24 or 10-32 for a 3/8" thick sheet of acrylic?
thanks

 

[Floyd R Turbo]

There are drill bits made for acrylic (Craftics) and I would definitely use those for the hole. But use standard taps.

FWIW I knock these out quick. For 1/4-20 thmbscrews, I drill a 3/16" hole then use a 1/4-20 tap with an electric drill on high speed (not high torque) with no lubricant and just do one squeeze (full speed) to pop the hole in, then flip to reverse and back it out. If you don't feel ballsy you can use the high torque setting. But there is zero need to hand-tap acrylic.

 

[OhMatic]

Thanks Bud you the man...
I knew about the acrylic drill bits, even though I have always used regular drill bits to drill my acrylic projects.
Do you use 1/4-20 thread taps to tap 1/4" acrylic sheets? like the thumb screw on your ATS Rev3 which holds the light in?
Is 24 or 32 thread too fine for acrylic?