Acrylic fabrication questions? I can help!

[Acrylics]

Originally Posted by Belgian Anthias

It took some time but we are ready to order the plexi panes now.
Weld-on 4 is not available in Belgium. We think that ACRIFIX® 1S 0117 (agrifix 117) is about the same. It is optimized for capillary effect, can be used without applying pressure to bonded parts and has enough working time. Evonics advices to use it for XT (extruded) only. For GS ( cell cast) they fall back to the reaction adhesives 2 component or 1 component. I have all Acrifix adhesives attached in pdf. As we will have some left overs to practice on we want to try out wich is best for us, unexperienced as we are. We can not try out all of them, so we will limit us to two types of glue. We need your advice here. Panes will be 35mm and 25 mm.
Can not attach file, to big. http://www.acrifix.com/sites/dc/Down...X%C2%AE_en.pdf
Thank You
Belgian Anthias

0117 is their methylene chloride free formula that they are trying to push - IME it doesn't work as well as they'd like. Try to find one that is methylene chloride based. I can't tell from the PDF what is in it - maybe you can look around?
The 1090/0020 2-part formula is a monomer/catalyst (methylmethacrylate/benzoil) peroxide based formula. Very similar to WO 40, if not exactly the same.

As for which to use, up to you - whatever you're comfortable with but I would *not* use the 0117 for aquaria.

Originally Posted by motortrendz

where is a good place to buy tube acrylic? and what is the best way to bond it?
want to make my own reactors.. ive made a few out of pvc they work great but i would like to make them out of acrylic.. any sugestions on good sites or places in the NY/NJ area to buy would be great..

I don't know where to buy it in the NJ area, but the phone book works "plastics, sheet, rod, film" or something to this effect. As for bonding, the easiest method would be solvent. Read through this thread and/or the "Pins Method" thread started by Zephrant IIRC if you want to search for it

Originally Posted by tmcelveen

James - went back to the plastic dealer today to get some 1/4" and all they had was Plexiglas MC? I seem to remember some one a while back asking about the MC but I can't find it now....I don't really have many options the only other plastic dealer is 3 hours away, what do you think?

On a side note, these people are starting to tick me off...it took what seemed like an act of Congress to get someone to tell me EXACTLY what brand and type of acrylic they use and then they act like I'm a pain in their butt for daring to ask such frivolous questions!

MC is simply their extruded Plexi-Glas line (MC=Melt Calendar) and it'll be fine for small stuff. I'd be bent too if they couldn't tell me what crap they're selling. I've got folks around here trained on this. The Plexi-Glas stuff you're looking for is Plexi-Glas G if you can find it in your area.

James

[henrystyle]

check out my self made 41.5 gallon sump.

[marspeed]

very nice sump henrystyle

[henrystyle]

Originally Posted by marspeed

very nice sump henrystyle

Thanks

[chriscobb]

Very nice sump Henrystyle

[henrystyle]

Originally Posted by chriscobb

Very nice sump Henrystyle

thanks bro

[crsaz]

alright, I think I am going to try my hand at working with acrylic.
first I want to try and build somthing like this(link) for holding my 2-part solution. I have 72" of 6" tubing(1/8" wall) I want each cylinder to be 8" tall
My question is how would I router a recess in the lid so it will sit on top of the cylinders perfectly?
http://www.reefconcept.com/catalog/p...oducts_id=1839
and for my second project I want to take the remainder of the tubing and build a dual chamber calcium reactor copying the design of the MTC pro-cal calcium reactor, but with 2 18" tall reaction chambers, me question is will 1/8th" wall tubing be thick enough?

And finally I want to try my hand at building some tanks, 10'x4'x10" euro-braced, what thickness sheet should I use? and what about for a 3'x3'x12" rimless tank 3/4"?

[Acrylics]

Originally Posted by crsaz

alright, I think I am going to try my hand at working with acrylic.
first I want to try and build somthing like this(link) for holding my 2-part solution. I have 72" of 6" tubing(1/8" wall) I want each cylinder to be 8" tall
My question is how would I router a recess in the lid so it will sit on top of the cylinders perfectly?
http://www.reefconcept.com/catalog/p...oducts_id=1839

the pics won't come up for me so I'll assume a step or a channel in the lid. For a step in the lid, use a rabbet bit. For a channel, it requires you to plunge route the channel using a guide, if by hand. If you have a router table you can do it on there.

and for my second project I want to take the remainder of the tubing and build a dual chamber calcium reactor copying the design of the MTC pro-cal calcium reactor, but with 2 18" tall reaction chambers, me question is will 1/8th" wall tubing be thick enough?

yep, one would prefer thicker wall simply for the gluing surface but if you do your part - 1/8" wall will suffice

And finally I want to try my hand at building some tanks, 10'x4'x10" euro-braced, what thickness sheet should I use? and what about for a 3'x3'x12" rimless tank 3/4"?

for the big tank, 1/2" will do okay with a crossbrace, 3/4" without. But much of this depends on how wide you want the eurobrace. For the small tank, yep, 3/4" will do nicely.

HTH,
James

[crsaz]

I was thinking 3" or 4" eurobrace and 3 cross braces, I assume that if I go rimless I can use 1/2" for the bottom is my thinking correct? and is it best to place the side "panes" on top of the bottom sheet? what about for glass.

[Acrylics]

Originally Posted by crsaz

I was thinking 3" or 4" eurobrace and 3 cross braces,

then you're good to go

I assume that if I go rimless I can use 1/2" for the bottom is my thinking correct?

yep

and is it best to place the side "panes" on top of the bottom sheet?

yep. With acrylic, you (almost) always want the sides to sit on top of the bottom

what about for glass.

glass can go either way in many cases. Best is to place the sides on top of the bottom with an internal (bottom) euro-brace. This way, you're maximizing tensile and shear strength.

HTH,
James

[A Reef Scene]

What is the best weld on to use?

[TAB]

Thats a depends kind of question. its like asking which hammer is best, it depends on what you need to do.

Generally speaking, #4 for the average DIYer, #3 is also fine, but drys faster.

[jdargonaut]

Originally Posted by jdargonaut

[/IMG]

Does anyone have advice for a beginner for using Weld On 40? I got my acrylic cut, it is now mocked up with tape. Unfortunately, the plastics shop could not route the edges for me, so they suggested to do some light sanding being careful not to round the edges, then use Weld On 40 instead of Weld On 4. My router table is not available right now. They said a sanding block with 600 grit would be fine, but I do have micromesh if that is better.

What should I use to apply the 40? Should I use the "pins" method? A little step by step direction or tips would really help. As mentioned by many others, this is a hugely valuable resource for us rookies, so thanks again!

spent several hours going through the thread, didn't see much on the 40. Did I miss it or is Weld-On 40 a no-no for a beginner? Even if I had my router available I'm not sure it's powerful enough to route 1-1/4" thick material (besides the cost of the bit), so is the Weld-On 40 a viable option?

[bigfalcon36]

40 is easy to use. Mix it and apply it with a plastic syringe without the needle tip on it. I use a 20ml syringe with a 65 gauge opening

[jdargonaut]

cool, thanks. I assume I shouldn't use the pins method then, just apply the 40 to each side, wait a few seconds and put them together? Is squeeze out a problem? Are there any other things to consider to make sure the joint looks nice?

[A Reef Scene]

I want to build a large skimmer, and am looking for the strongent bond I can get

[Acrylics]

Originally Posted by A Reef Scene

I want to build a large skimmer, and am looking for the strongent bond I can get

In reality, WO 3, 4, and 40 are all stronger than we'll ever need on the hobby side. The trick is material, prparation, and technique, (generally) not the solvent/cement you use. So practice with whichever you are most comfortale with, and use that.

Skimmers/fractionators are easy to glue and glue well using any of the above, but you have to hold up your end of the bargain by choosing the correct materials and using proper technique.

James

[Lumpy Gravy]

I've been practicing solvent welding and I can get great joints, but I've come across one issue. In the "ooze" which occurs after pulling the pins (the fillet of melted acrylic pushed out by the weight of the part), I notice what appears as crazing. My first thought was the solvent, so I've tried a number of combinations. I typically use Weld-On 3 with about 5% acetic acid (99.5% purity) added for better flow. I never had good luck with Weld-On 4 (bubbles in the fillet and joint). I've also used straight methylene chloride, with different amounts of acetic acid added (3% to 10%).

Another thought was that perhaps the acid is causing the crazing, yet I have noticed it with even small concentrations. I prefer to leave it in there, as it helps avoid any hazing due to evaporation of the solvents. I do notice more crazing with higher amounts of acid, but it still occurs down to 3% (although, to a lesser extent). It could be that the additional acid allows the "ooze" to flow further when the pins are pulled.

I'm using Plexiglas G (the only cast acrylic available around here), 1/2" and 3/4" thick. My pins are 0.015" and I typically pull them after 30 seconds (never more than 45 seconds, or the pins leave voids).

Is this simply an issue of too much solvent action, combined with too large of pins? I'm assuming a smaller pin would result in much less "ooze", but is strength affected with the use of smaller pins?

Thanks in advance for any advice. I'll be sure to post some cool images after I get this issue nailed down.

~Lumpy

[Acrylics]

Originally Posted by Lumpy Gravy

It could be that the additional acid allows the "ooze" to flow further when the pins are pulled.

yep, you got it

I'm using Plexiglas G (the only cast acrylic available around here), 1/2" and 3/4" thick. My pins are 0.015" and I typically pull them after 30 seconds (never more than 45 seconds, or the pins leave voids).

Is this simply an issue of too much solvent action, combined with too large of pins? I'm assuming a smaller pin would result in much less "ooze", but is strength affected with the use of smaller pins?

Strength itself is not affected provided you get adequate coverage of the joint and sufficient "soak time." One of the issues is that for long runs - you need the solvent to stay in solution until the joint is complete and that often requires the larger wires.

As with most things, it's a compromise

James

[rEd86]

Greetings.

I am interested in bending some 1/2" acrylic and was wondering what the tightest radius I should account for in the bend. (my assumption is if the bend doesn't have a rounded corner, the acrylic will stretch and/or form a weaker corner) My geometry skills are very rusty, otherwise I am sure I could figure out a formular that would give me the right curve...

I plan on routing the edge of a piece board to form the jig that would give me a nice, controlled line for the bend.

TIA!

--Ed

[RokleM]

One thing they'll need to know is... for what? Are you bending a corner for a rounded corner tank, or are you building something like a frag rack? Two different setups that will require completely different strengths.

[rEd86]

I am considering doing this for a tank. (a frag rack built out of 1/2" acrylic would be a pretty impressive frag rack! )

--Ed

[RokleM]

Originally Posted by rEd86

I am considering doing this for a tank. (a frag rack built out of 1/2" acrylic would be a pretty impressive frag rack! )

--Ed

All depends on what you have handy and/or find as scrap. We have a local place here you can get scrap by the lbs, even up to 1". Perfect for things that don't matter as much.

That being said, I've never researched the stress on heated/curved acrylic, so will default to the experts like acrylics

[troylee]

Rounded corners are weaker than a glued joint... The heat from the bending it puts a ton of stress on the material.... Do you want to do it for looks or do you not trust your welds???

[Acrylics]

Originally Posted by rEd86

Greetings.

I am interested in bending some 1/2" acrylic and was wondering what the tightest radius I should account for in the bend. (my assumption is if the bend doesn't have a rounded corner, the acrylic will stretch and/or form a weaker corner) My geometry skills are very rusty, otherwise I am sure I could figure out a formular that would give me the right curve...

I plan on routing the edge of a piece board to form the jig that would give me a nice, controlled line for the bend.

It doesn't really work that way. The radius is controlled by the temperature at which you heat, and the area you heat - usually a heat channel made by a strip heater. Narrow heat channels and cooler bending temps provide a tighter radius that a wide heat channel and higher temps.

In other words, if you heat a 3" wide area, you'll have a larger radius than if you heat a 2" wide area. IMO you should never heat an area less than 3x the material thickness, and that's pushing it.

Additionally, when material is slightly cold-bent - it will yield a tighter radius than material that is brought to full temperature.

IMO forget making a "form" to bend the piece around, the mark-off that you'll likely get from this will not look nearly as good as a bend without the jig.

And yeah, as a generality; line bent materials have far more stress on them than glued joints.

James