Acrylic fabrication questions? I can help!

[pico-reefer]

They've been there since it was buit.

 

[Floyd R Turbo]

I would not worry then, as long as they don't continue to get worse. It will most likely happen rather slowly vs all at once.

 

[adambowersva]

well, its 3 foot long, so theres alot of pressure along the length of the tank.. exact dims. are 36" long, 8" wide, 6" high

Pico,

In regards to your bubbles I would likely say they were for the most part a result of a minimal "fillet" as the welds cured thereby resulting in a little bit of air getting sucked into the seams. The one running up the corner looks as if the builder (not sure if you built or not) may have actually blown a bit of air into the seam through the needle inadvertently.

As for the pressure due to the length...even though this length would cause some deflection the actual water column pressure is minimal as it's determined by the depth of the water...not the length.

Out of curiosity is the tank rimless? Or is there a eurobrace? In either regard, as Floyd said...absolutely nothing to worry about. With a eurobrace that tank could have been built with 1/4" acrylic and been perfectly fine so you are quite comfortably overbuilt imho...unless you are rimless in which case you are speced out about right...but still fine.

 

[Floyd R Turbo]

I agree with everything Adam stated above. I built a 6' x 4' table would have even done that differently, I sunk a piece of aluminum into the top MDF and since it was 9/16" thick not 1/2 or 3/4 I had to make a push/pull standoff system, which doesn't sit just quite right, but it works for 99% of what I do. If I had to do that over again (and I probably will) the router base will just be bolted direct to the top sheet of MDF.

Also the frame for the MDF top I would make out of fir not pine as it is much better material. My buddy is building a 5' x 10' table after I helped him build his 112 tall.

Things to add:

Clean edges with denatured alcohol
blow off with compressed air
blow pinned joint with canned air

I learned that polishing is a complete snap. Get yourself a rotary buffer from Northern Tool or Harbor Freight like this one

http://www.northerntool.com/shop/tools/product_200442254_200442254

and a couple of polishing pads

http://www.meguiarsdirect.com/product_detail.do?q=4782

hit the routed edges with the ultra-cut compound

http://www.meguiarsdirect.com/product_detail.do?q=4729

Then the swirl-free polish

http://www.meguiarsdirect.com/product_detail.do?q=4754

And man those joints friggin SHINE after only a few minutes of polishing. If you round off the edges with a 1/8" roundover bit, then hit them with some wet/dry sandpaper, then polish them, it comes out looking over-the-top professional.

Here are a few tanks I've built since I read through this entire thread myself a year back and built my router table

30 gallon rimless sump

18g sump/fuge for 29g biocube

40g sump/fuge

30g sump/fuge/ATO

overflow boxes

40g frag tank with internal adjustable overflow fence (notched and weir) and external overflow box set up for BeanAnimal drain sytem

 

[Floyd R Turbo]

I made an 18g frag tank out of some scrap pieces the guy gave me

sanded and polished a zero edge tank

made a couple 30g frag sale tanks

Made a 35g frag tank

Forgot to take a pic after it was polished up

Then I took a tank with a cracked bottom, cut it in half, and bonded a new bottom to it

And right now I'm finishing up this 70g sump for a FW planted tank

 

[adambowersva]

Yes, yes yes Floyd...lest we not forget the edge cleaning part. On tank builds 2-4 I used denatured alcohol and that helped in spades I'm sure. Compressed or canned air is also a must. The amount of dust and acrylic shavings that built up everywhere in my shop (garage) was ridiculous.

As for the table, I'm actually glad I skipped the aluminum plate (at least for the moment...lets see how it does with extended use). Mine is made all from 2x4's for the frame and 3/4" MDF for the top. I even had to modify mine to appease the Miss's. In our case we have a 1 car garage and she usually parks there so I actually bolted the back of my table to the wall and made the front legs hinged to fold under and have a steel cable attached to the wall to hold the table front in position without the legs when she wants to park. In a perfect world I would have my table right in the middle of the garage to allow me to work from multiple sides, but I will have to wait for a bigger workspace. Currently though, I have no problem doing edge prep on table with sheets as wide as 36" and as long as 60".

Ahh, and I worked just off the MDF top for tanks 2 and 3, but added a white formica (not polished as James' is though) top for the 4th and that made a WORLD of difference in moving material across the table.

I also have this magnetic featherboard (embedded steel to the left of router bit to hold) that is a great help when guiding acrylic across the table...it greatly lessens chance of pieces getting pulled into the bit. Best part is when I don't need it then it goes away completely and I don't need a channel in the table to snag up my acrylic.

As for the edge polishing I may check into that in the future. Currently, I used Mapp gas on the 1st tank build and it worked quite well.

 

[adambowersva]

And right now I'm finishing up this 70g sump for a FW planted tank

Holy holes batman! That is a crazy looking sump! Me like, but I feel for you and the labor to drill all of those holes!

 

[Floyd R Turbo]

Drilling holes is easy. I had a set of templates CNCd for me, 11 in total, to fit just about every type, brand, and size of bulkhead from about 1/2" to 3". So I just double-stick tape, drill a pilot hole with a 3/8" acrylic bit, then use by 1/4" spiral upcut flush cutter and whip it out either with the handheld base or on the router table. When I do it with the handheld base I drill out the hole to a smaller diameter with a hole saw then use the template and router to trim off the last bit, without being able to put one finger on the cutout piece it goes flying once the router breaks through the cut. I learned that when putting 6 holes in 3/4".

The drip trays...yeah that's going to be a lot of drilling...

 

[adambowersva]

The drip trays...yeah that's going to be a lot of drilling...

This is exactly what I was referring to...yikes :fun5:

 

[LockeOak]

Hi, thanks for answering so many questions for people! I have a very basic question: I have a 4' angled bowfront acrylic tank (from that company that can't be named on RC) and I've just filled it. How level do I have to be on the length of the tank? Right now there's about 5mm difference between the two distant ends, it's level on the short axis. Top and bottom panels are 3/8", the sides are 1/4" (thin, I know, there is some bowing but it doesn't seem out of control).

 

[Floyd R Turbo]

That's strange for even ten e cor to make the sides thinner than the top, are you 100% sure on that?

If the tank is as you say (maybe it's short?) then it's underbuilt as it is, and should be perfectly level all around and completely supported 100% flat surface that the tank is set on. No exceptions.

 

[LockeOak]

That's strange for even ten e cor to make the sides thinner than the top, are you 100% sure on that?

If the tank is as you say (maybe it's short?) then it's underbuilt as it is, and should be perfectly level all around and completely supported 100% flat surface that the tank is set on. No exceptions.

Yes, I just re-measured, it has a sticker from the company on the bottom. Both side panels (the large flat back and the 5-sided front) are 1/4", top and bottom are 3/8", total volume approx. 70 gallons. The top cut-outs are quite small, the bracing is 5" wide on all sides.

I suppose that begs the question, would you feel comfortable keeping this tank in your house with livestock (assuming it's level)?

 

[Floyd R Turbo]

Well the angled bow front tanks have sort of a built-in bracing due to the bends, and I've seen more than one 55g size tank made from 1/4". It will hold, it will just bow more, which means it's harder to keep clean with a scraper, so it's easier to scratch. When I said underbuilt I meant that the big tank builders build the tank to the minimum, which is underbuilt to anyone who gives a damn about anything except making $$. It will be fine as long as it was treated well (seams in good shape) but I would make sure it's flat, level, and fully supported.

 

[jgsensor]

I may have missed this in here already, but tapatalk won't let me do a search. Any way, what is the best way to repair a crack. I have a new sump that got knocked over (I wont go into that) and now has a couple cracks. None of them go completely through and the largest is roughly 1.5". Can I seal them using weldon or would I need to patch them?

Thanks for any help

 

[nivram]

I'd like to make some cylinders come to a cone or point. What would be the best way to achieve this? Can I heat and form the tube? Or would I be better off forming a flat piece of acrylic?

 

[Floyd R Turbo]

I may have missed this in here already, but tapatalk won't let me do a search. Any way, what is the best way to repair a crack. I have a new sump that got knocked over (I wont go into that) and now has a couple cracks. None of them go completely through and the largest is roughly 1.5". Can I seal them using weldon or would I need to patch them?

Thanks for any help

First step is to stop the crack - patching over the top of it may not stop it. Drill a small hole at each end of the crack. Then laminate a piece of acrylic on each side of the affected area. This is where WO16 comes in useful IMO.

I'd like to make some cylinders come to a cone or point. What would be the best way to achieve this? Can I heat and form the tube? Or would I be better off forming a flat piece of acrylic?

Buy acrylic cylinder. Both of the methods you mentioned will be darn near impossible to accomplish and you're waste a ton of effort and end up buying it anyways IMO

 

[nivram]

Buy acrylic cylinder. Both of the methods you mentioned will be darn near impossible to accomplish and you're waste a ton of effort and end up buying it anyways IMO

Thank you. I already have the acrylic cylinder. What would be the best method to have or form a funnel at the end? My goal is to thread a valve at the end of the pointed end.

Another idea was to cut an angle on the tube and then attach a small sheet of acrylic to to it.

 

[Floyd R Turbo]

nivram, what are you trying to make?

 

[vanzea]

Im sure it has been covered however I cant seem to find it. Looking for what is the best, or what people have used successfully with table saw blades. I am looking for a 10in blade. If you could direct me to which name brand and type that would be great thank you

 

[Floyd R Turbo]

Diablo I think 80 tooth blade at Home Depot, there's one that specifically calls out that it's for plastics, about $80