acrylic. anyone build their own sump?

[MPevine11]

Considering building my own sump and water holding tank for ATO out of acrylic.

I plan to buy a small table saw off Craig's list. Nothing expsnive just something I can use to cut straight.

Do I really need to worry about a router to do the edges super good or could I sand it?



Last question, went to lowels and homedepo looking for prices, and seemed crazy expsnive for like .220 thickness. Where do you guys get it at? (and is that the correct thickness)

 

[JohnK]

Router for the edges is definitely preferable. A table saw with the right blade Can work, but I've also seen multiple acrylic tanks fail along seams where you could see the marks left from table saw cutting.

Sanding is definitely a no-no for acrylic work. You don't want to risk creating seams where the edges are slightly out of square / flat.

I would strongly suggest rough cutting with a table saw, then finishing with a router. For the actual building, a router is also essential do doing a nice job. The right way to build an acrylic tank or sump is to slightly overlap the seams, then flush cut them with a router. This makes for a nicer finish on the end result, but more importantly the overlapping edge allows the solvent to puddle up just enough so that air doesn't get sucked into the seams as the solvent evaporates. Without this, air sucks into the seams causing bubbles, weak seams, and an ugly mess.

There are lots of ways to build stuff out of acrylic. Tanks have been built using a table saw, no trimming, and tape to hold things together for bonding. (I don't know how long said tanks held water, but it's been done). I'm giving you cautious and safe advice. I'm sure someone else will post alternative suggestions - take mine and theirs with a grain of salt

*PM me if you want to borrow a router, you've been around long enough, I suspect that a loaner could be arranged but you'd probably want to invest in a fresh flush cut bit*


Seep post #2 for pics of what I'm talking about when I say overlapping and then flush cutting the edges/seams. Look close, the sheets are welded with a lip hanging out on the outside sheet. Once fully set/cured, the lip is cut flush with the router leaving a perfect seam and edge.
http://www.bostonreefers.org/forums/showthread.php?119524-One-way-to-build-a-frag-tank&highlight=


Also see here for building a sump, start at post #18
http://www.bostonreefers.org/forums/showthread.php?102490-57G-Oceanic-build/page2

 

[JohnK]

Oh, and I missed the last part.

Good acrylic IS stupidly expensive. Also, you won't find good quality acrylic at any lowes/HD/local hardware store. You'll need to find a plastics shop, or order from somewhere online. I've gotten OK material from Altec and J Freeman, both in boston. There are several cheaper types of questionably adequate material, but only a couple that really considered appropriate for our uses. I don't recall off the top of my head, but I know the stuff I have used recently was not the best but it worked for my purposes. (see pics in those threads I linked). See the endless RC thread for more specifics.

http://www.reefcentral.com/forums/showthread.php?p=23779521#post23779521

 

[MPevine11]

Thank you for all the help! If I don't end up getting a router I'd greatly apericate narrowing yours. I am in the planning stage currently. But was looking at sumps online and didn't want to dish out all that money. If I could make something even a fraction as nice as your acrylic work I'd be happy! Great work.


So things needed:
small table saww with acrylic blade
Router, for edge clean cleaning (and I assume making the top piece that has the hole, which I want to do)
Acrylic glue
The bottle with the needle to apply it
2(ish) acrrylic sheets



Am I missing anything?

 

[choff]

What size sump are you making? Smaller can be forgiving and larger you may need to look into the pin method.

Use weld on 4 for the initial welds, but I would get some weld on 16 in case you need to fix any issues.

A mapp gas torch if you want to flame the edges clear for a nice finish. Here is a good video about edging/finish work. They (tap) have some other vids that can be very helpful.

http://youtu.be/QhAXbA2lmnE

Good luck, looking forward to seeing your build.

 

[JohnK]

A dedicated acrylic blade costs around a couple hundred $ or more. You can most somewhat fine toothed blades for rough cutting, or skip the table saw completely and do all the cutting with the router.

I would suggest using corner clamps and the pin method even if the sump is on the small side. Solvent will wick into the seams without pins, but without pins you run a much higher chance of having air get sucked in and then bad seams.

I agree on WO #4, but make sure the can is not more than a year old as per the date on the bottom. LOTS of places will have useless, expired weld on on the shelf. Old weldon can easily ruin a project and the expensive material involved.

I wouldn't flame polish for a sump. It looks really nice, but it also does stress the material and can cause crazing down the road which would definitely negate the benefit of a cool polished looking edge. I've done it and nothing terrible happened, but I wouldn't do it again unless I had a darn good reason.

On the router, yes buy one. Super cool tools, if you like tools you need a router. Once you have it you'll start finding new projects because you can If you are going to buy, get one with a regular and a plunge base. Just know that if you're not careful you can easily spend more on bits than you ever will with the tool itself.

 

[choff]

Good tips john.

I use a table saw with an 80 tooth blade that cost be 60 bucks that cuts plexi like butter.

http://www.amazon.com/gp/product/B00004T7AL?psc=1&redirect=true&ref_=oh_aui_search_detailpage

 

[Jeff.:P]

Altec in boston will precut the pieces for you. I forget how much they charged me, might of been free or cheap. Just make sure to mention that you need nice, clean square edges.