Acrylic fabrication questions? I can help!
 

This thread was split due to performance issues. You can find the previous portion of the thread here:
[url]http://archive.reefcentral.com/forums/showthread.php?s=&postid=4641089#post4641089[/url]

I keep getting split up!
:)

Acrylics.
Ive been reading thru the previous pages up to 54 .
I have a question...I built a skimmer box about 2 years ago.
i think it was extruded transparent plastic, may be cast, not sure.
The seams are turning white. i used the capillary method
with meth chyloride./craftics brand.
Is there anything to worry about?

ok question 2, when gluing i tend to spill/drip sometimes. again the plastic turns white before i wipe up the spill. is there a way to clean these type areas ? would the denatured alcohol be a good choice?

in the future i will use cast and leave the paper on while gluing.
i think that i will try out the pin method also.
will the pin method produce a stronger joint than capillary method? i currently use the plastics brand MC, not sure if that is equal to weldon # ?
thanks for the insight,
back to the privious pages to read more,
jonboy

how do i drill acrylic for bulkheads can i just use a hole saw or do i need a special bit i bought 2 tanks from glass cages 24X12 1/2X6 H and want to drill 3 holes 1 drain and 2 returns in each they are to be my frag tanks for zoo's and SPS.

Please help me out
Thanks
Kevin

jonboy, if the seems are turning white (and it looks as if two pieces were dry fitted together) then they are failing and eventually the box will fall apart. When there is overrun I tend to just let it evaporate off. Rubbing or cleaning will cause more of a blimish then it would just letting it sit. You should always use cast acrylic when dealing with water applications. The cappillary method makes joins the acrylic and will hold as your current box has, while the pins method allows for a longer reaction time and therefore a stronger joint.


Reeftreasures I just use a regular holesaw for 1" bulkheads and use my circle cutter and the router for the bigger bulkheads. You do not need a special bit for bulkhead holes.

May i know if it is possible to glue up a sump tank using the capilary method?
Dimemsion of the tank is 24"x18"x24" (LxBxH)

Cheers

Summers,
I'm not sure what you mean by pieces looking like they are dry fitting. I will try and post a picture later.
Were there any recommendations on how much time to allow between gluing and routing and flaming the edges?
I usually glue something up and route/flame the next day
Jonboy

Does the joint look as though you just have the two pieces against each other? As if you are rady to apply solvent but have not yet?

I like to let products sit/cure 48 hours or so before routing, and at least 72 hours before polshing. Flame polishing adds a lot of stress to joints, as such there are many other ways to polish acrylic.

As previously stated by Summers There are other ways to polish acrylic that are better suited for the hobbiest. Flame polishing is better left to the profesionals as it requires special equiptment, not something the average hobbiest has or would spend the $$$$ for occassional use. Also as Summers stated flame polishing puts additional stress on the acrylic that should be relieved through the annealing process in which the completed project is gradualy heated to a uniform temp of about 150 degrees the gradually cooled to room temp. Incorrectly done flame polishing can lead to seam failures and inevitable leaks or worse. HTH JJ

Acrylic tube wall thickness
 

I'm in the process of building a skimmer. I have found a source for 12" cast acrylic tubing. They sell tubing with either 1/8" or 1/4" walls. The difference in price for a 5' tube is $300 ($290 for 1/8" vs. $590 for 1/4"). Do you think 1/8" walls is strong enough? The main riser will be approx. 48".

Thanks for your help .....

Can you securely attach an acrylic overflow to a glass tank? What would you use to do it?

what are the ways to polish acrylic? which one produces the smoothest surface?

Normally an acrylic overflow will just be siliconed onto a glass tank. You can use the GE silicone I door and window to silicone it into place. The silicone does not hold the acrylic to the glass very well, but in this case the water will actually push the silicone to the glass harder so the silicone is just a gasket.

Kim

[QUOTE][i]Originally posted by Rickster88888 [/i]
[B]May i know if it is possible to glue up a sump tank using the capilary method?
Dimemsion of the tank is 24"x18"x24" (LxBxH) [/B][/QUOTE] Sure, just about every sump you'll ever see was made this way :)

[QUOTE][i]Originally posted by Rip Current [/i]
[B]what are the ways to polish acrylic? which one produces the smoothest surface? [/B][/QUOTE] There are 4 basic ways, those 3 are solvent polishing (not recommended), flame polishing, buffing, and Micro-Mesh. Micro-mesh take more time than any other but yields the best results. It is sanding all the way to 12000 grit sand "paper" and then abrasive creams for the final polish.
For reference there are a few machines which will yield polished parts but not after they've been glued.

[QUOTE][i]Originally posted by trapassi [/i]
[B] I'm in the process of building a skimmer. I have found a source for 12" cast acrylic tubing. They sell tubing with either 1/8" or 1/4" walls. The difference in price for a 5' tube is $300 ($290 for 1/8" vs. $590 for 1/4"). Do you think 1/8" walls is strong enough? The main riser will be approx. 48".[/B][/QUOTE] The tube itself is plenty strong, the determining factor is the strength, therefore quality of the bottom glue joint. 1/4" simply has twice the surface area on the ends as 1/8" allowing for ease in getting a stronger bond.

HTH,
James

Thankz acrylics!!!

Cheers :)

ok I ended up getting 1/2 cast for my frag tank and I need to know what the strongest glue to use is. weld #3 #4 #16 what?
the frag tank is 120x 30 x 18 and the top is a single sheet with
a 3 1/2 lip all the way around with two braces in the center.
What I did was take the top and cut out three holes.
(I'm not sure how to post the picture of it) Any help would be
very useful. Thanks

From what I have read this is the method the big boys advocate for us:
 

The strongest solvent is #4
The strongest glue (cement) is #20. #20 is a 2 parter you need to mix. #16 is weaker than #20 but it is easier to use for noobs like me. Use #4 and the pin method for everything you can. Use the "glue" (20 or 16) for stuff you just have to glue to gether and adding extra support to spots that didn't weld well in the first run.

My turn:
So, I get to the bottom and everything goes fine, but the overflow is at a slight angle up. Not ready to dare the #20, I pull out the 16 and cant figure out how to apply it. I put it in the same aplicator bottles I have for my #4 and cut the tip off, shove a turky baster into the neck to give a bigger hole. It's not pretty, but it did the job.
Is there something I can use as an aplicator from the HW store?
If not which applicating tools should I be getting for #16 and #20?

I am planning a sump 30" x 10" x 12" High divided with cross partitions 8" high a 1/3 points. Is 3/16" Lucite satisfactory for this sump? Thanks.

bump

The common thicknesses of Cast Acrylic for tanks are 1/4" 3/8" 1/2"

Lucite is a brand name. I am not sure if they make extruded or not, but be sure it is cast. You could make your sump out of any of the sizes, because it is small. If you find the price nominally different, go with the 3/8". Thicker is easier to work with and more room for bubbles and other errors.

Thanks for the info, Adrinal. Thought for a couple days I scared everone off. LOL

I think the 3/16 threw us off lol :)

Lucite does not make a cell cast acrylic at all. They make Lucite L which is a continuous cast sheet (their best) and then Lucite CP & CPX which are both extruded. Lucite L is okay for small sumps n such though I don't think I'd recommend 3/16" for any pressure vessel.

James

Thanks...The 3/16 Lucite was what was availabvle at local Lowe's. I agree after more research that I should go to 1/4" minimum.

Acrylics is pointing out you should go 1/4" minimum and be sure that it is Cast Acrylic (which you will most likely need to get from a plastic distributer rather than the local hardware store.

There is lots of info here on RC, but basically the cast is ... well... cast into a mold. vs the common stuff which is rolled off machines. The procces of making cast acrylic makes it stronger.

Gl in your search.