Acrylic fabrication questions? I can help!

[Acrylics]

Ok so I picked up some 1/4 cell cast acrylic last month from a supplier and they said it was Polycast. It came in a plain brown paper mask. Is this how it normally comes?

Just curious if they just wanted to tell me a brand that I wanted to hear...

No, Polycast normally comes with red writing on one side. If there is no writing, I'd be leary and I've never bought Polycast with just plain paper.
Also, Polycast is not all that common in 1/4". It's made, but virtually nobody stocks it due to price.

does anybody know a supplier for acrylite gp in 1" thickness with 72"x120" sheet sizes? or even 48"x120" sheet sizes, everybody local thinks im crazy for a 120" length, it can also be polycast

Any Acrylite or Polycast supplier should be able to get you 10' sheets. Acrylite is 4x10, 5x10, and 6x10, while Polycast is only 6x10. There is an upcharge 'cuz 10' sheets are not the commodity item that 8' sheets are and mfrs have limited number of 10' cells as compared to 8' cells.

Acrylics, have you ever done butt joints in thick acrylic?

Sure

Im contemplating building a bull-nose , i cannot find 120" material at a reasonable price, price per square foot skyrockets over 96" for some reason, i have a shop in town that has an oven to bake the sheet for me and i can build the form for it, so if i go bullnose i can utilize 3-96" sheets , but that brings into the equasion 2 butt joints, i have never done a butt joint but im assuming its as easy as routering roughly a 20-30 degree angle in the pieces being joined and also spacing it .030 and placing a backer and then casting the gap and overfilling to avoid shrinkage, then sand and polish the area?

In theory and in a nutshell, yep, it's that simple. In reality, far different story. I'd highly suggest a lot of practice pieces with various thickness before attempting. It really is not that simple to get the desired results

Since the sheet will be drape formed it will have been heated, will this cause crazing during the casting and bonding process?

It can, but generally not.

HTH,
James

 

[noobtothereef]

yes i will be practicing this method MANY times, this material isnt cheap by any means, what would be the best material to use as the "backer"? Ive read some use a thin piece of acrylic but i would think that would just be more material to remove from the joint when finishing

 

[Acrylics]

yes i will be practicing this method MANY times, this material isnt cheap by any means, what would be the best material to use as the "backer"? Ive read some use a thin piece of acrylic but i would think that would just be more material to remove from the joint when finishing

Personally, I use Teflon/PTFE. But there are many plastics & tapes that would work well Many use a foil tape available at roofing supply houses.

James

 

[noobtothereef]

Well i found a place that has an oven for heating my sheet, its a powdercoating shop with a 12' oven, i gave him the heatup times etc and said hed do it for $100 and he will let me form it there and everything, pretty nice people. The cheapest plastic fab shop wants $2500 to do it..... The only thing im concerned with is anything in the air that might affect the acrylic itself as i know some chemicals will cause crazing but since powdercoating has no solvents that shouldnt be a problem.

My next questions are, i will be making the hieght of the bullnose oversize so i can trim the top and bottom and the butt joing area to the front and back panel, what would be the best way to trim the top and bottom ? I think its going to be pretty difficult to get 100% perfect edge on a radius so i may have to cast the top and bottom seam as well.

And thanks for all of the help acrylics/james!

 

[on the spot]

Yep, 40/42 is not a solvent that fuses the 2 pieces together. It is an actual acrylic resin that fills the void and sticks to the other pieces.

Hi James,

First thanks for answering so many questions.

I want to fill the voids between the teeth of my overflow. The overflow takes up the entire right end (36"), and the teeth are cut really deep, 1 1/4". Would this resin work?

Any suggestions on an easier way? I also thought of making a jig and cutting plugs, but that seems tedious.

Thanks for your help.

 

[jcw]

I'm part way done with my refugium tank and had a question. This is the first time gluing acrylic but i'm in general pretty good with my hands including gas welding sheet metals.

The glued edges at full of bubbles. I think the routered edge wasn't perfectly straight and the glue never fully filled the gap near the center of the panels.

I used the pin method with the copper wire inside automotive wiring. The pins in the center of the panels were smaller than the gap.

I used Weld on 4 and filled the gap, let it dry for about 5-10 minutes than went back in there with another pass until no more solvent wicked into the gap. Even with that, and weights on the tank, it doesn't look good. BTW, it's 3/8" acrylic for a 24"x18"x16" refugium "on display."

Should I just pitch the tank and start over? If this was a metal weld, it would likely fail with time. :sad2:

How long to wait before filing it with water and testing it? I was planning on 12 - 16 hours. maybe tomorrow am I'll post some pics.

 

[jcw]

Well, it leaked, but not at the spots I was really worried about.

It's at a spot with a bunch of bubbles though. Can I seal this with weld on 4?

 

[Acrylics]

My next questions are, i will be making the hieght of the bullnose oversize so i can trim the top and bottom and the butt joing area to the front and back panel, what would be the best way to trim the top and bottom ? I think its going to be pretty difficult to get 100% perfect edge on a radius so i may have to cast the top and bottom seam as well.

Shouldn't need to, just build yourself an overhead router base. This will enable you to get all edges to within a coupla thousanths with very good edge quality

James

 

[Acrylics]

The glued edges at full of bubbles. I think the routered edge wasn't perfectly straight and the glue never fully filled the gap near the center of the panels.

I used the pin method with the copper wire inside automotive wiring. The pins in the center of the panels were smaller than the gap.

I used Weld on 4 and filled the gap, let it dry for about 5-10 minutes than went back in there with another pass until no more solvent wicked into the gap. Even with that, and weights on the tank, it doesn't look good. BTW, it's 3/8" acrylic for a 24"x18"x16" refugium "on display."

Should I just pitch the tank and start over? If this was a metal weld, it would likely fail with time. :sad2:

No reason at all to leave the joint 5 minutes, for any material or thickness. For 3/8" material, I usually let it sit for 15-20 seconds or so. Once the joint is wired up; apply solvent, wait 15 seconds, pull wires, shim as necessary, that's it. Reapplying solvent doesn't help, at least nothing beyond a negligible effect. What brand and type of material is it? this will have a huge effect on joint quality and long term strength.

HTH,
James

 

[Acrylics]

I want to fill the voids between the teeth of my overflow. The overflow takes up the entire right end (36"), and the teeth are cut really deep, 1 1/4". Would this resin work?

Any suggestions on an easier way? I also thought of making a jig and cutting plugs, but that seems tedious

I'd probably opt for just cutting a strip of 1/8" or 1/4" black acrylic and gluing it across your overflow, or silicone it if you want the option of changing your mind You *might* be able to "plug" it using 40, but might also look like crap and would take a bit of work and money to do it.

James

 

[jcw]

No reason at all to leave the joint 5 minutes, for any material or thickness. For 3/8" material, I usually let it sit for 15-20 seconds or so. Once the joint is wired up; apply solvent, wait 15 seconds, pull wires, shim as necessary, that's it. Reapplying solvent doesn't help, at least nothing beyond a negligible effect. What brand and type of material is it? this will have a huge effect on joint quality and long term strength.

HTH,
James

I got the plastic locally at ET plastics. They say it's cellcast acrylic they didn't give me the brand. They said it's made to their specs. <shrug>

It's got their own stickers on the paper.

http://www.e-tplastics.com/

I ended up mixing up weld on 16 and some plastic shavings and patching the place where the leak was as a last ditch effort to save the thing. If this doesn't work, I think I'll get it professionally cut next time.

The leak was a slow drip if it matters...

I'm bummed. But thanks for the recommendations.

 

[levischilz]

I have a question. Does weld-on bond acrylic and the black frame around glass tanks together? The corner of a tank I just purchased have a fine crack and I was going to brace it together with a corner L shape of black acrylic and weld-on glue. Thanks Levi

 

[James983]

James, I just filled my acrylic 180 and only now see that it is approx. 1/4-3/8" out of level.

I did check it prior to filling but didn't notice it with a 6ft level. Don't know why. Either way. Do you think that this is a crucial difference?

It took me 4 day four days to fill with RO water and don't really want to strat over.

 

[blackizzz]

Hey, i got some material questions for you James. You recommend plexiglas g and similiar but whats the difference between plexiglas g and plexiglas gs? could i use plexiglas gs (10mm) to build a quite small tank (14 inch high)? then is it any easy way to see if the acrylic is cell cast or extruded? do you know any place in europe that sells weld on if not, what is the best substitute for it. i want to use as good materials as possible but living in sweden i'm quite limited. Do you know any acrylic seller in US that have international shipping?

(i have used a glue, thats named akrifix 116 but thats not like weld on, it is very hard applied and the rests doesnt evaporate. so i would like something more like weld-on?)

Wow that became more questions than intended, sorry for that, but i guessed that when im asking someone that knows his stuff i can aswell ask =)

Thank you very much // Blackizzz

 

[Acrylics]

James, I just filled my acrylic 180 and only now see that it is approx. 1/4-3/8" out of level.

I did check it prior to filling but didn't notice it with a 6ft level. Don't know why. Either way. Do you think that this is a crucial difference?

It took me 4 day four days to fill with RO water and don't really want to strat over.

Sometimes it'll be okay, sometimes not so ok No way for me to tell, or anyone else for that matter. It could be okay for a year and then pop all of a sudden or it could last forever..just too hard to tell.

IMO siphon the water out and level the tank. Best I could say

James

 

[Acrylics]

Hey, i got some material questions for you James. You recommend plexiglas g and similiar but whats the difference between plexiglas g and plexiglas gs? could i use plexiglas gs (10mm) to build a quite small tank (14 inch high)? then is it any easy way to see if the acrylic is cell cast or extruded? do you know any place in europe that sells weld on if not, what is the best substitute for it. i want to use as good materials as possible but living in sweden i'm quite limited. Do you know any acrylic seller in US that have international shipping?

(i have used a glue, thats named akrifix 116 but thats not like weld on, it is very hard applied and the rests doesnt evaporate. so i would like something more like weld-on?)

Wow that became more questions than intended, sorry for that, but i guessed that when im asking someone that knows his stuff i can aswell ask =)

Thank you very much // Blackizzz

Plexi-Glas GS is Acrylite GP, Evonik has the European rights to use the name Plexi-Glas. So if you have this material...good stuff

You can use 10mm to build the tank 14" high, the need for a top flange (aka eurobrace) depends on the other dimensions, but would be recommended regardless.

No real easy way for a novice (sorry, but best term) to tell if it's cast or extruded, but if you have the Plex GS - you have cell cast.

I don't know anyone in Europe or Sweden that carried Weld-on, you might wish to ask them yourself for a recommended distributor.. www.ipscorp.com best I could say on that. I don't think any distributor transships these as they can't be airfreighted at all, would have to be by sea in this case, but IPS would/should know

I don't have any Acrifix 116, I have 117 but I think it's different. Acrifix 117 is methylene chloride free and IMO/IME doesn't work as well, but isn't bad. Just not sure I could recommend it for tank construction. Acrifix 120 is okay but messy, very similar to Weld-on 40 here in the states. If you want a solvent similar to Weld-on 4, you need to find one with methylene chloride/dichloromethane as a primary ingredient.

HTH,
James

 

[blackizzz]

thanks for the quick reply! i have planned for a brace so no problem, thanks for the link and i'll defenetly ask them.

Thanks // Blackizzz

 

[noobtothereef]

james or others, im looking for a video or a tutorial for doing "butt" joint casting acrylic,

 

[noobtothereef]

building a tank, 36" depth for 96" and then the end 24" will be 54" deep, i am wanting to build the entire tank out of 1", will that be sufficient for the 54" depth on the end "step" of the tank? all bottom seams on the tank will be double seamed with an additional 1"x2" strip on the bottom inside corner for added bonding area, the jump in cost from 1" to 1.25" acryic is huge, the end that is 54" deep will be a drape formed bullnose so no corner seams, am i crazy??

 

[noobtothereef]

Also, i will be cutting my own sheets as the plastic shop doesnt want to fuss with cutting it for any less than $1000 in case they mess it up, so ive been searching for a good saw and blade, i have a 7 1/4" circular saw but its too small for the blade im looking at. The blade im looking at is an amana 8" circular saw blade for cutting acrylic found here
http://www.amanatool.com/circular-saw-blades/non-melt-lb86401.html
heres the saw im looking at
http://www.dewalt.com/tools/saws-circular-saws-dw384.aspx
the saw is 15 amp but im not sure if it ill be powerfull enough to cut 1" acrylic and might have to look into a more powerfull saw, but then again im used to rough cutting acrylic ith a wood blade and expierience melting to some degree and drags the blade , the ne blade should take care of this.

heres the router i am debating on getting
http://www.milwaukeetool.com/tools/...eed-feedback-circuitry-and-soft-start/5625-20
3 1/4hp so it should have plenty of power to route the 1" and thicker acrylics
now i need to find the best router bits, i will need a bit for trimming the saw cut edges and also a bit using a bearing to trim the edges once assembled, both being capable of cutting the 1" thick material. Any ideas?