Acrylic fabrication questions? I can help!

[bulkhead]

I'm needing a little advice... My choice of acrylic locally is almost nothing, what I can get is 3 or 4 times what others are paying. So, from the advice of others, I ordered material from estreetplastics.com. Their site says you will get one of several brands, plexiglas acrylite lucite chemcast, depending on what was in stock..... Anyway, I tried to contact them beforehand to find out what brand I might get as I didn't want lucite. I didn't get an answer, so I ordered anyway figuring a sump out of lucite isn't the end of the world. But, what I got was Marga Cipta, which I had never heard of before. Of course, the first thing I do is search this thread. I've seen it mentioned a couple times and everything says its not good acrylic...GREAT! Is there any way to make this stuff work? Maybe a different solvent, other than weld-on 4?

My plan is/was to build a 48"x20"x20" sump out of 3/8" front, back and ends with 1/4" bottom and 1/4" euro bracing with a center support.

:headwally:

Ok scratch all this...I should have unpacked all of it, it comes very well packaged and I only looked at the brand of one odd ball sized piece. I unpacked the 3/8" and it has unmarked brown paper and the 1/4" is Astariglas??? <---now someone tell me how awful this stuff is...

 

[adambowersva]

Hey Bud (Floyd) and All! I have been gone and BUSY for quite some time and just getting back up to speed on this thread. Bud, if you still have my number you should give me a call again so we can chat. Many things have changed in my neck of the woods and we can have another little brain pick session with each other . I see you are still contemplating the table rebuild like mine . Only diff is now my router table is a full 4x8, but still has another few feet of in feed/out feed for the really long pieces since my router bit is basically square in the middle of the table (actually prob about 5 feet to the right standing in front). I still keep it about 6 inches in from the front also and it still works a dream. Other diff now though is now I have an 8 foot long, 6" wide 1" acrylic fence HAHAHAHAHAHA. I lost your number though...otherwise I would reach back out to ya.

Bulkhead...The Astari acrylic is an import acrylic from Indonesia. I took a chance on it once for some small projects I was working on and overall was not impressed at all. As James tells everyone...myself included...stick with the known goodies. The problem with the material I found is that it just doesn't weld up that well. For me it was far more prone to bubbling and its certainly not my technique. I can achieve virtually flawless seams with Plex-G and using same method with the Astari would have issues. That being said, there are certainly builders out there that will use it for even large display aquaria. As the only material you have that is that material is for the baffles and possibly the bottom you could give it a go if you can't return it, but you would be better getting a better material for the bottom. The baffles aren't going to cause much issue though.

The unmarked brown paper stuff is LIKELY made by Arkema, same makers of Plexiglas G. It's made in the same plant, but doesn't include any warranty or QC standards. For small sumps and non-display items it should be fine though.

 

[bulkhead]

Thanks for the info. I'm need to turn over a few more rocks to get access to better material I suppose. What do you think about using Acrylite FF for the bottom vs the Astari? Just a thought since I have some old unused FF left over. The rest of the Astari will be used for baffles and such.

 

[adambowersva]

The acrylite FF will be fine for the bottom (better than the Astari IMO at least)...it's extruded though so it will setup quicker than the cell cast would so you just gotta be quick with your solvent run and pin pulls.

 

[Dustin1300]

Ok, I just got off the phone with Bud and spoke to him about this for a bit. Below is a direct copy from my build thread on a dilema I currently have with my overflow box. He believes the best solution he can think of is to buy a bulk amount of Weld-On 40 and pour into the overflow box so it surrounds the PVC and actually bonds to it.

Concerns:

- Would the 40 have a reaction with the epoxy?
- What could be done on the bottom side to give extra insurance?

Thanks in advance. I've got poker night here shortly but will be responding later tonight and first thing in the morning.

After plumbing in the closed loop today, quickly discovered that the overflow box is leaking. The tank has 1.5 fittings glued in (Weld-On) my guess and then has had a layer of epoxy poured into the overflow box that makes about a 1/4" thick epoxy covering which I would guess was insurance for leaks. The epoxy (I'd assume this is what it is) has some cracks in it and a few of the fittings are dripping really fast between the acrylic and the fitting.

That being said, I'm looking to solutions...And think my options are limited to be honest. If I could do it over again I would just buy a new tank but I'm past that point and think I'm best off fixing the leak around the fittings. I believe the tank being in storage might have heated up some and the epoxy shrank/cracked some, which allowed the water to escape between the fittings and acrylic.

My ideal solution would be to try to scrape all the epoxy out, drill out holes bigger, and put SCH 80 bulkheads in place but due to the spacing, is not possible. I cannot just pop the fittings out either as they are held in place with weld on....

My solution at this point is to use Weld-On #16, put around the fittings on the bottomside of the tank, and buy some epoxy and pour it into place in the overflow box so it is about 1/2-3/4" thick. (I've never worked with epoxy and would like to get one that's reef safe, becomes very hard, and is resistant to cracking and sw over a long period of time)

Below are some pictures and would appreciate some feedback if you have any on the subject.

Underside:

Topside:

Drying now.....Ready for a solution that I'm ready to implement ASAP!

 

[jjac]

Hey, I am going to build a 60"x30"x 32" tank. I have access to 3/4" cast acrylic, will it be thick enough for a build this big? Do you have any design thoughts to do a tank of this size as far as bracing? I work with acrylic a lot at work just not the same as you do. I do a lot of thermal forming of mainly 3/16 acrylic for the sign industry. I have glued a lot up, just nothing this big.

Thanks
Jimmy

 

[peppie]

Jimmy, Just be sure you are using Plex-G or Polycast
The material thickness is good for that size tank. 1" would be better, it wont bow as much as the 3/4''
You will need a min 4'' wide euro brace around the top with large radius in the corners.

 

[WmTasker]

Is it possible for me to remove this Triangle bracket and move it a few inches to the left?

 

[Floyd R Turbo]

You can, but does that bracket support the box or hold it in position? i.e. is it a structural element? It looks like it supports the whole thing. More pics would help

 

[WmTasker]

You can, but does that bracket support the box or hold it in position? i.e. is it a structural element? It looks like it supports the whole thing. More pics would help

Yes it is supporting part of the structure. It hold the refugium parallel with the aquarium and supports it vertically. But in order for me to have it on the nanocube and be able to get everything else in and out of the back, I will have to move it about an inch or so.

 

[Floyd R Turbo]

Hmm. Personally, I would have made the thing beefier in the first place - you're supporting what looks to be about 3-4 gallons of water on that little bracket. So the answer is yes you can move it, but no I wouldn't. Because you really need to cut it off with a saw, then to re-attach it, it would have to be perfectly smooth and flat so that is makes full contact and then bonded on with a clean bubble free joint.

Now, if you do move it 1" sideway, you are now putting a torque on that connection/support point as well, or maybe I'm not seeing this thing correctly.

 

[GrampaDon]

Some info....Sump 48X20X16 [run at 10in ] using Acrylite FF 3/8 and some 1/2. [buying scraps cost 1/4 of ordering in cell cast] Weldon 3 [they were out of 4 on that day]
My cuts are using a Freud 84t ATC blade And I do some edge prep before bonding.

Problem im having is when I fill the joint it looks fine. But after 10min I get a lot of tiny bubbles everywhere in the joint.

Whats wrong here ,is it the weldon 3 instead of 4.??
Maybe the Acrylite FF rather than cell cast.

Am I already doomed to get a leak from this.?? And without a doubt need to rebuild it.?? The bubbles dont bother me from a looks standpoint. Its a sump after all.

 

[adambowersva]

Some info....Sump 48X20X16 [run at 10in ] using Acrylite FF 3/8 and some 1/2. [buying scraps cost 1/4 of ordering in cell cast] Weldon 3 [they were out of 4 on that day]
My cuts are using a Freud 84t ATC blade And I do some edge prep before bonding.

Problem im having is when I fill the joint it looks fine. But after 10min I get a lot of tiny bubbles everywhere in the joint.

Whats wrong here ,is it the weldon 3 instead of 4.??
Maybe the Acrylite FF rather than cell cast.

Am I already doomed to get a leak from this.?? And without a doubt need to rebuild it.?? The bubbles dont bother me from a looks standpoint. Its a sump after all.

Honestly would have to see pics of the bubbles to determine whether you should worry about it. Also more info on exactly how you are further prepping the joints after the saw cut and whether you are using any pins or just straight capillary action. My initial thoughts lead towards your questionable edge prep and whether you are cleaning the welding surfaces sufficiently/if at all before welding. Let us know and will see if can help further.

 

[WmTasker]

Hmm. Personally, I would have made the thing beefier in the first place - you're supporting what looks to be about 3-4 gallons of water on that little bracket. So the answer is yes you can move it, but no I wouldn't. Because you really need to cut it off with a saw, then to re-attach it, it would have to be perfectly smooth and flat so that is makes full contact and then bonded on with a clean bubble free joint.

Now, if you do move it 1" sideway, you are now putting a torque on that connection/support point as well, or maybe I'm not seeing this thing correctly.

When you torque, you mean having more weight on one side? Then yes.

 

[Floyd R Turbo]

When you torque, you mean having more weight on one side? Then yes.

Well, if that support is designed to not only support the full weight of the box, and it is the only means of keeping the box level, then it's not going to work well!!

But it looks like the intake/return pipes also might sit on the rim of the tank, yes? In either case, you could move the support but you might want to add another small one on the other side of center.

As for moving the support, you would have to carefully cut it off, could use a sawsall but that might get messy. The cut would be as close to the box as possible so you could still use the bracket.

Then sand down the cut side of the bracket, take a piece of MDF and tack glue down a piece of sandpaper (150 grit) and start sanding until you get a flat surface to re-glue. Then switch to 220 or higher and sand more, trying not to sand the tips more than the center. When you can place the piece on a flat surface and see zero gap anywhere, it's ready.

Then just follow normal solvent welding procedure, and even for something this small I would use WO3 or WO4 and pins (maybe just one, on the end of the long tip). Make sure the clean both piece with denatured alcohol and blow them off with canned air first also.

 

[GrampaDon]

Honestly would have to see pics of the bubbles to determine whether you should worry about it. Also more info on exactly how you are further prepping the joints after the saw cut and whether you are using any pins or just straight capillary action. My initial thoughts lead towards your questionable edge prep and whether you are cleaning the welding surfaces sufficiently/if at all before welding. Let us know and will see if can help further.

Edge prep was a router with a flush bit. Then a light sand.
Using straight capillary in the joints.
Welding surface prep is just wiping with a cotton cloth first.

 

[peppie]

The bubbles are most likely the result of your welding method in addition to the cleaning procedure.
The bubble are probably no big deal, but the capillary welding scares me for the fact you may not have had enough weldon in the joint to soften both surfaces properly.
Did you see a filet on both sides of the joint when you applies pressure??

Also you should have use denetured alcohol on your cotton ball.
It is really hard to say if that joint will hold.
IMO you should do it over.

 

[Floyd R Turbo]

G'pa Don - is this joint you show a baffle joint? Maybe a few more pics of the overall tank and the exterior joints, i.e. vertical seams, bottom seam, etc. Also what was your order of welding, as in which joint first, second, etc.

The more info the better. Otherwise we can only draw conclusions about your process that might not be in full understanding of what's going on....

 

[GrampaDon]

.

peppie I didnt get much fillet [squeeze out] because I didnt apply pressure as I thought it was a bad idea but I did use plenty weldon. I just learned I need to precleaning with denatured alcohol.:thumbsup:

Floyd The project is built. I added 1/2 X 1/2 gussets in all joints. [extra precaution] Since I wasn't happy with all the bubbles.

Here is a pic. A little fugly I know. But it is holding water so far.
So I may take your advice to rebuild it using cell cast and weldon-4.
What thickness would you recommend.? 1/4 3/8 1/2 ??

 

[peppie]

peppie and Floyd Thank you both for advice.

peppie I didnt get much fillet [squeeze out] because I didnt apply pressure as I thought it was a bad idea but I did use plenty weldon. I just learned I need to precleaning with denatured alcohol.:thumbsup:

Floyd The project is built. I added 1/2 X 1/2 gussets in all joints. [extra precaution] Since I wasn't happy with all the bubbles.

Here is a pic. A little fugly I know. But it is holding water so far.
So I may take your advice to rebuild it using cell cast and weldon-4.
What thickness would you recommend.? 1/4 3/8 1/2 ??

Glad to hear it is holding water. I dont use clamps for pressure., sometimes just the weight of the panel is enough. Most time I use a 5lb rock or a couple 1 gal. cans of paint. Plexi-g or polycast for water tight vessels.
IMO no shame in the gussets. I used them on my show tank. I made mine in the shape of a triangle to reduce the profile. They are 3/4'' on a 3/4'' panel.