Acrylic fabrication questions? I can help!

[Floyd R Turbo]

Okay I've got a question for ya:
What do I do with a 9.5' tank if I suspect I am moving- i.e. If I can't sell it can an acrylic tank be cut apart, refinished and reassembled or modified into a different dimension tank easily enough to justify the effort?

I would not try to cut up and repurpose an old tank unless you are very good with acrylic, and even then, it's more hassle than it's worth. The acrylic will have changed shape and will be very difficult to prepare.

 

[Floyd R Turbo]

Will 1/4" be okay for this low/ small amount of water?
Weld-on 16?

I agree with trinewbie, 1/4" is fine, and no on #16 - go with 3 or 4

 

[saintsnsinners]

Is there a minimum waiting period before filling a vessel with water? I tell my clients a week but I don't think all of them are that patient.

 

[Floyd R Turbo]

Depends on the thickness of the material bonded. I think James posted something along these lines a while back but I'd have to dig it up:

1/4" 5 days
3/8" 7 days
1/2" 10-14 days
3/4" 2-3 weeks
1" 3-4 weeks
etc.

for 1.5" and up I think it was 2 months.

 

[saintsnsinners]

Hey Floyd, have you come across a longer screw-on tip that fits the 16 tubes?

 

[Floyd R Turbo]

No, but I haven't looked. One usually comes with a tube of 16

 

[saintsnsinners]

The place I get mine from don't have them.

 

[saintsnsinners]

Anneal before using wo40?

 

[Floyd R Turbo]

Not sure but I think you want to anneal afterwards. That assumes you have an annealing oven. I don't know anyone that anneal tanks.

 

[saintsnsinners]

"To prevent crazing during bonding, acrylics should be annealed following machining
and forming."

is this done at the manufacturer?

 

[Floyd R Turbo]

I've seen that many times. Ask James if he ever a meals anything. I think it's a CYA statement personally or else you would see "anneal everything" all over this thread. Search it (and the previous splits) for "anneal" and I think you'll find it's not necessary.

 

[Raul-7]

What tool do you use to cut out a Eurobrace?

 

[pandimus]

What tool do you use to cut out a Eurobrace?

Router

 

[jc03]

Hello, sorry if I' duplicating some already answered questions: I'm about to take the plunge and build a 119"x40"x32" out of 1" material.

-will Weld-ON 4 be sufficient, that's what I've been practicing with and have heard 40/42 is tougher to work with
-do I need to use the pins method or will capillary action work?
-how much space do I need to leave along the rim so the solvent is sucked up?
-when you attached both sides to the front do you do them both at once or wait 8 hours in between?

Thanks in advance,
Jonathan

I forgot to add, am I crazy trying to attempt a project like this?

 

[Floyd R Turbo]

Yes, for your first one.

Start on a smaller project like a sump, or even a random cube-shaped build out of scrap material. Learn the process of rough cutting, edge prep, pinning and shimming, solvent welding, etc.

You do not need 40/42. #3 or #4 will work fine.

You need to learn the pins method. Capillary action results in weak joints. if it didn't, then no one would use the pins method.

Not sure what "space along the rim" means. If you are referring to a lip for a fillet to form, and then flush trimming that off afterwards, 1/16" or more.

If you have a workspace that allows you to bond one end to the front panel and leave it in place without disturbing it at all, then yes you can bond both ends to the front one after the other, then leave it for cure time, then flip and bond both to the back (similarly, at the same time). The bigger the build, the longer I wait between steps. No need to rush it.

 

[jc03]

Thanks for the quick reply Floyd. I searched "pins method" and didn't see an exact description. Can you point me in the direction of an article or how to including what sort of pins to use? Thanks again.

 

[saintsnsinners]

can someone explain the science behind the 2" corner radius theory? is there a size of vessel where this theory doesn't apply?

 

[Floyd R Turbo]

jc03 it's on here but it's quite a huge thread.

There's a few good threads:

http://www.reefcentral.com/forums/showthread.php?t=169326

this is one of the better ones

http://www.reefcentral.com/forums/showthread.php?t=390652

Look for the MDF with foam on it, use these, foam on both sides (camper shell foam from Menards) clean all edges with denatured alcohol, blow off with compressed air, set the pieces and shim if needed so the pieces are in full contact with the right angle brackets in place, THEN insert pins, if pins are loose then shim under them, go around a few times and tug on pins to make sure they are all snug, blow out the joint with canned air, apply solvent to entire joint, pull pins, and adjust the joint so that everything is lined up right (and watch for drift). You will have about 30 seconds to adjust the joint after pulling the pins, then it's pretty much set for life. Let sit for 8 hours minimum and then you can handle it. No routing for 20 hours preferrably

 

[Floyd R Turbo]

can someone explain the science behind the 2" corner radius theory? is there a size of vessel where this theory doesn't apply?

I suppose a small frag tank or sump would not need 2' radius on the euro, maybe 1", I've done this.

sharp corners focus the internal stresses of the material. rounded corners spread it out.

Same goes for exterior edges, simply knocking a routed edge down with a razor blade at a 45 degree angle for 4-5 passes removes the point stress inherent in the material once the tank is full. That's why a lot of acrylic tanks have 1/8" rounded outside corners, it de-stresses the tank

Also the 2" radius round is not the only thing that needs to be done, you also need to knock the sharp edges off all surfaces (well you don't NEED to, but it's a good idea, just for not cutting yourself if nothing else)

 

[jc03]

Thanks Floyd. I'll check them out. Gonna pick up some thicker scrap to practice tonight! Sure I'll have some more questions afterward. Thanks again.