Acrylic fabrication questions? I can help!

Lenny,
If I were to use 1/4", I'd use a small perimeter flange (aka eurobrace), maybe 1.5" wide to keep deflection down to an absolute minimum. 3/8" could be used without the flange but may bow *a little*. Personally, I'd use 1/2" and not think about a flange at all. At that size, I wouldn't use a crossbrace at all.
Being cast acrylic is not enough IMO, use a good name brand acrylic such as Polycast, Acrylite GP, or Plexi-Glas G. If someone tells you they have the "equivalent", don't buy it, again IMO, it should *only* be one of these brands. Look in your local yellow pages in the plastics section to see who sells acrylic sheets in your area, there should be a section that reads "plastics, distributors, sheet, rod, tube" or something to this effect, or possibly glass shops as some carry acrylic. There may be some online vendors as well, I don't use them so can't make recommendations in this regard.

HTH,
James
 
So last night I arrived to my destination, Spokane WA. The oversize box with my acrylic tank was not at baggage check, so they said they would deliver it.

As promised, this morning around 9, the oversized box showed up. I opened it up, removed all the 1" polystyrene foam, pulled out the tank, meticulously unwrapped the several layers of bubblewrap, and what do I see?

On both the front and the back of a tank, a giant diagonal crack running from the top to about halfway down, through all 3 baffles. This crack is worse on the front, but its on the back as well. So basically, the tank is completely shot. I now have to drive 1 hour to the airport so I can show them the broken tank, so I can try to get money out of them. I don't have any receipts on me, so it will be difficult to convince them that this cost me ~$500 out of my own pocket to build.

Wish me luck, I'll post back with the results of this fun :P

On the plus side, I'm going to re-make the tank, so that one should have a few less scratches/blotches from extra solvent :) I will still give my sister the broken tank with a kind of "I owe you a not broken one" note.
 
I for one am very sorry to hear that it did not make it through the airlines. Hopefully you will not have to much trouble getting some compensation from them.

Kim
 
problem is large rectangular boxes like that make great stepping stools for workers. Sounds far fetched but I really got into it with UPS and turns out I was right. Surprising what a 300lb worker can do to a sump.

Without wooden crating these things, theres really no way to be sure it will arive ok.
 
Well they filed a claim, and they want me to fax a copy of the receipt for the plastic material costs when I get home. Sounds like they will give me compensation but I will not find out until I can supply the receipt for proof.

Next time I am definitely going to get it crated, these are just way too expensive to take the risk, even if the cost of the materials is insured. Materials aside, a sump could easily be over a week of labor, many hours a day. No way to get that compensated :)
 
I would. Or see if you could get somebody to give you a receipt for a sump, rather than just acrylic. Your time has value and if you purchased the completed sump, you would still be out a sump, not just the material. I don't know if they would consider a labor receipt, but you could ask your acrylic supplier if they could give you something that would include some labor. I just hate to see you loose so many hours rebuilding the sump because somebody was careless.

kim
 
<a href=showthread.php?s=&postid=11431656#post11431656 target=_blank>Originally posted</a> by Jeffrey S.
I am looking at 450-500 gallon tank at moment. I am a carpenter....Would you suggest trying to build one or just buy the acrylic. I have a pretty good selection of tools, not sure of what I would need.
I do have a work area off my garage and have large benches and table as well. Is it as simple as "glueing" the peices of acrylic together as you made it out to be ?
Hi Jeff,

Sorry I missed this.

It's relatively simple in the process itself but I'm not sure I'd want to recommend making a 450-500 on your first try. Many of the tools required are similar to carpentry; saws, routers, clamps, etc. The differences are that the tooling is *generally* much sharper than than necessary for most wood jobs. I have different sets of tooling for working with wood & wood composites as many of them are extremely hard on tooling. Tolerances for fitting acrylic are (IMO) +/- .005-.010". Squareness is absolutely critical in this, even a few thousanths out of square will mean either the tank won't sit flat or has the potential for leaking (or worse). There are no fillers or putties allowed, get a scratch? start over unless you want the surface imperfection, a routed edge that is not perfectly smooth and flat should be re-routed until smooth and flat, sanding (even with a block) has a tendency to round over edges.

IMO at a minimum for a tank that size: 5hp+ panels saw, table saw, router table with 3+hp routers, 1"+ diameter straight cutter (primary smoothing of edges), 1/2" spiral flush cutter (for trimming the "flashing"), 1/4" spiral fluted cutter (overflow slots), trim router, chamfer or roundover bit (for easing edges), large flat gluing table, spring clamps, gluing jigs, solvent, applicator bottles, shims, wires or pins

Material weight will become an issue at some point as well, considering a 4 x 8' sheet of 1" acrylic weighs ~200lbs and most 500 gallon tanks will require 5 of them, possibly more if you want colored acrylic. You can by oversized sheets (5 x 8' and 6 x 8' sheets) but these are not stocked at many places. The tank will have to be flipped several times in the process so you have the weight and space issue.

Price out the acrylic you will need to see what it will cost you, then price out a completed tank, compare the differences and then factor in the time, tooling, and the "what if" factor (what if something goes wrong), as well as figure out (as best you can) can you do as good of a job as someone who does it professionally. Compare these and see what works best for you.

Not trying to scare you off as the pride factor is priceless and if you can save $$ - all the better, just that IMO a 500 gal tank is a bit more than I'd recommend for your first try. I'd recommend starting by building a smallish sump or 'fuge then maybe a small (55-120) gallon display tank, then maybe a 250-300 or so, then try the 450-500. At that time, you will have the necessary tooling, experience, and confidence in your abilities to tackle the job.

FWIW if I make it out to be easy, thank you, I had a master craftsman teach me for the first 7 yrs doing this but I've messed up a bunch of stuff over the yrs and still do from time to time (but shh don't tell anybody ;) ). Sux to do it when you have several thousand $$ invested in material and time and have to start over.

HTH,
James
 
James,

I would like to make a 5' vertical sump/water holder.
Do you think a 60"h x 16"l x 14"w would be feasible from acylic?
Would it need additional support along the seams?
 
I'm finally back home :)

I hope everybody had a great Holiday!!

James,

You recommended

"... 1"+ diameter straight cutter (primary smoothing of edges), 1/2" spiral flush cutter (for trimming the "flashing"), 1/4" spiral fluted cutter (overflow slots), trim router..."

Could you possibly clarify what the difference between a "spiral flush cutter" and a "trim router bit" is?

http://www.infinitytools.co.uk/cgi-bin/trolleyed_public.cgi?action=showprod_85921

To me it looks the same as a trim bit except with spiral blades. What exactly is 'flashing' and when would you use a spiral bit instead of a regular straight trim bit?

Also, for your straight bits, are you using 1 or 2 flute?

Thanks!
Ryan
 
BadPacket,

Sure you could use acrylic for that, easy enough. Wouldn't need any additional support on the seams :)

Ryan,
For flush cutting of thicker materials (3/4" - 1"), I do not recommend 1/4" shank cutters at all, too much flex for my taste. So I'd recommend a good 1/2" spiral cutter like the one in your link. I never mentioned a "trim router bit", I do however recommend a 1/4" version of the one in your link for doing 1/4" diameter overflow slots and a roundover or chamfer bit for easing edges. I generally only use the trim router for easing edges, they simply don't have the torque for much else with heavy gauge acrylic.

Whenever (well almost always) I glue acrylic, I leave an 1/8" "lip" on the outside that should be trimmed off, this is often called "flashing". Stuff that is left on for the maufacturing process then trimmed off.

For trim routing/flush cutting, I simply do not use straight trim bits at all, I still have some but prefer to use spiral flush cutters rather than straight flush cutters (aka straight trim bit). Spiral cutters clear chips better than straight trim bits and last longer IME so recommend the same to anyone else.

All of my straight cutters up to 1.5" diameter are 2 flute except some "stagger tooth" bits which are designed for heavy duty "mulching" of acrylic or (usually) polycarbonate.

HTH,
James
 
Hi Bchbum,

I don't use tablesaw blades for finish-cutting per se. For finishing or gluing, I always route the material edges. For the past few yrs, I've been using 10-80 blades by Everlast, run around $100 or so. I have both the blades for plastic (PC-1080) and for non-ferrous metals (NF-1080) and don't have a preference between the two, they both cut through 2.5" easily enough, don't chip, don't melt, and last a good while. PC-1080 blades cost more so if that is a factor, the NF-1080 blades will work well provided you are not stack-cutting much extruded as the hook angle is -2 degrees on the NF blades and +5 degrees on the acrylic blades.
The Forrest blades are fine but don't cut any better IME and for my purposes - not worth the extra $$.

HTH,
James
 
James,
Where do you get your staggered tooth fluted bits? I work w/ acrylic countertop material and haven't really seen any online (not that I've looked very hard). I used my spiral bit that I use for my work on an acrylic project recent and it worked good, but those staggered bits would work better when working w/ my top material. TIA
 
yeah ive been using the forest blades for a couple years now and couldnt help but think there was a cheaper alternative. thanks

oh and were do you get these blades from?
 
That would be great, thanks. I usually get my stuff from www.specialtytools.com, from their solid surface area, but they don't sell the staggered bits like that. We used them in my training class while learning how to fab, and they worked great so it'd be nice to be able to get my hands on one. I'm sure they have a high grade carbide on them too for ease of sharpening if they're coming from your saw blade guy.
 
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