Acrylic fabrication questions? I can help!
- Thread starter JohnL
- Start date
Floyd R Turbo
Either busy or sleeping
^ I don't see this weird horizontal "foggy" line in any of the pics below. Just curious if it is a strange reflection or is it really there.
^ I'm interested in the point at the back panel where the side meets the back blue wall and the bottom of the overflow box.
^ is this an optical illusion, or is the material actually thicker at the mid-height point, then it tapers off toward the top??
^ The side panel does appear thinner. Does the other side panel appear thinner as well?
^ Yeah that's not a good sign.
Overall I can tell you that the tank was put together differently than most. Most have the side panels "inside" the front/back so you have a continuous front panel. On this one, the front/back panels are "inside" the side panels. This is needed because the side panel is extended for the overflow box, and the euro makes contact with the side (otherwise you would have more joints to deal with and more stress points).
The euro looks decent up front, but then it's pretty narrow along the back. This means that the load on the rimless back wall get transferred through the overflow box and up to the euro, more points for stress to focus on. So I"m not really sure what it going on with that side panel, but the overall design of the tank is suspect IMO, the crazing is a sign of stress and/or flame polishing (the front seam is definitely flame polished.
That being said, there
Floyd R Turbo
Either busy or sleeping
If it's straight 100% MC, should be fine. It will just have partially evaporated. If it is a mixture, like WO4, then no, it's bad pretty quick because the MC evaps and everything else does not (even in a tightly sealed can)
dahenley
New member
Its straight MC, and a little has evaporated (glad you mentioned that)
Thank you again.
Soon, well be calling you AcryIics 2.0
Floyd R Turbo
Either busy or sleeping
Oops missed an email I guess
Without seeing it, I can't say. When acrylic seam failure happens on solvent-welded seams, you generally will see the tell-tale signs of pending failure. Generally, you only see the catastrophic failure when a 2-part seam gives way, like that cylinder tank in the news recently, and that other cylinder tank in the news before that.
Without seeing it, I can't say. When acrylic seam failure happens on solvent-welded seams, you generally will see the tell-tale signs of pending failure. Generally, you only see the catastrophic failure when a 2-part seam gives way, like that cylinder tank in the news recently, and that other cylinder tank in the news before that.
bulkhead
Premium Member
Great, there goes my 500g beer can shaped tank.... #dreamkiller :fun2:
Floyd R Turbo
Either busy or sleeping
Naw, you can have cylinder tanks cast out of one piece instead of pieced together!
Hey Floyd,
Long time since I posted, busy with testing end to end bonding with weld-on 40. Will be using weld-0n 42 when I do the actual bonding.
Just a quick question that you might be able to help me out with. The bonds fill in nicely after sand, however, I notice that I get crazing on the ends. Almost like small cracks. Don't know if its the cheaper plastic Im testing it with or I didn't clean the ends well enough.
I tried it with a real rough surface to give it extra grip. Im starting to think that a semi-smooth surface would be better for end-to-end bonding. Any inputs as to how I can make sure the middle is clear of defects.
Long time since I posted, busy with testing end to end bonding with weld-on 40. Will be using weld-0n 42 when I do the actual bonding.
Just a quick question that you might be able to help me out with. The bonds fill in nicely after sand, however, I notice that I get crazing on the ends. Almost like small cracks. Don't know if its the cheaper plastic Im testing it with or I didn't clean the ends well enough.
I tried it with a real rough surface to give it extra grip. Im starting to think that a semi-smooth surface would be better for end-to-end bonding. Any inputs as to how I can make sure the middle is clear of defects.
Floyd R Turbo
Either busy or sleeping
Crazing indicates stress. That's all I can tell you though, I've only used 40 for bonding in gussets and other such repairs.
From what I recall, it's advised to rough the bonding surfaces with 400 grit but they don't have to be super rough, but I will have to let others chime in and listen and learn
From what I recall, it's advised to rough the bonding surfaces with 400 grit but they don't have to be super rough, but I will have to let others chime in and listen and learn
I went out of my way to make it real rough, maybe that was what caused it to craze. 400 grit is pretty fine, but based on my test I do believe that smoother surface would have less stress caused by crazing.
I guess I will have to try a smoother surface. Before I go into the 400grit, I think I will give a router surface a try. No sanding or prep, just basic router the edges and see from there.
Seriously thinking of getting the 42 applicator gun so I can squeeze 42 out instead of mixing 40.
Im going to look into getting scraps of polycast to test. Anyone got some polycast laying around they need to get ride off. :lol2:
TriNewbie24
Member
Sand with 320grit per IPS prior to bonding, although i've used 42 on a routed edge with no issues. It will be ALOT cheaper to get 40, although you might need to look into a vacuum chamber to pull out all the bubbles to the top before applying it.
reefboarder
Intelligent Donkey
I am looking to build a custom sump to replace a 125 long to add room for a calcium reactor and leave a little space under the tank for any future upgrades i may want to do. Im sure its posted somewhere in the 900 pages but what type of plastics are recommended if you are not concerned about viewing pleasure, and what is the best way to go about cutting so that the edges are clean? also what solvents/adhesives would i need? Thank you in advance for any help and sorry if im being too lazy for not reading this entire thread.
Floyd R Turbo
Either busy or sleeping
For cell cast acrylic, Plexiglas-G and Acrylite GP, or Polycast ($$).
For extruded, which you can do, it bonds the same but might bow more over time, Plexiglas-MC or Acrylite FF, or any domestic equivalent (stay away from import, if possible).
You can also try to find something called PMACS which is Plexiglas' cell cast product to complete with the imports, it's generally the same as the G stuff and that's what I use for sumps.
For rough cutting, I use a plastic cutting blade, Diablo, at Home Depot (triple-chip blade) and you could do this and then manually scrape with a razor blade to get bondable edges, or use a jointer or router table for the best edges. Squaring the ends or keeping them equally "off" is probably the most important step IMO
Bond with weld-on #3 or #4 and use the pins method in conjunction with foam-covered boards and shims
Clean edges with denatured alcohol and blow off with compressed/canned air before setting the joint
use 90 degree angle brackets to hold parts in place and let joints sit overnight or longer before touching.
That's the quick and dirty. There are a lot of details to fill in but that's the basics.
For extruded, which you can do, it bonds the same but might bow more over time, Plexiglas-MC or Acrylite FF, or any domestic equivalent (stay away from import, if possible).
You can also try to find something called PMACS which is Plexiglas' cell cast product to complete with the imports, it's generally the same as the G stuff and that's what I use for sumps.
For rough cutting, I use a plastic cutting blade, Diablo, at Home Depot (triple-chip blade) and you could do this and then manually scrape with a razor blade to get bondable edges, or use a jointer or router table for the best edges. Squaring the ends or keeping them equally "off" is probably the most important step IMO
Bond with weld-on #3 or #4 and use the pins method in conjunction with foam-covered boards and shims
Clean edges with denatured alcohol and blow off with compressed/canned air before setting the joint
use 90 degree angle brackets to hold parts in place and let joints sit overnight or longer before touching.
That's the quick and dirty. There are a lot of details to fill in but that's the basics.
dahenley
New member
is there anything other then AA that i can add to my MC to slow the drying/curing time?
my local acrylic place has tons of MC so thats not a problem, but they don't have AA or anything for slowing the curing time.
i also hate buying weldon because after you open it, you might as well throw it away because of how fast it evaporates….
my local acrylic place has tons of MC so thats not a problem, but they don't have AA or anything for slowing the curing time.
i also hate buying weldon because after you open it, you might as well throw it away because of how fast it evaporates….
Floyd R Turbo
Either busy or sleeping
Yes, you can add Ethylene Dichloride but it is like $140/gal and is pretty nasty stuff, chemically speaking.
James' mix I believe is 80% MC, 15% EDC, 5% AA. I've spoken with him about EDC and it as well as AA causes the mixture to flow more smoothly. MC alone tends to "jump around" and this can lead to bubbles in the seams. I think you can actually bond with 100% EDC so there is no limit to the % you can mix up to.
Also adding EDC removes the humidity factor, so you can bond in high humidity conditions without getting whitish seams. I think it may allow for a wider range of temperatures as well but I can't remember what James told me about that.
I get the 8oz brown jars with the green lids (teflon lined) and mix the MC with about 7% AA and cap it tight, I've let this mixture sit for a couple weeks before using it all but I usually 'top it off' with a little MC just in case if it's been more than a week on the shelf.
James' mix I believe is 80% MC, 15% EDC, 5% AA. I've spoken with him about EDC and it as well as AA causes the mixture to flow more smoothly. MC alone tends to "jump around" and this can lead to bubbles in the seams. I think you can actually bond with 100% EDC so there is no limit to the % you can mix up to.
Also adding EDC removes the humidity factor, so you can bond in high humidity conditions without getting whitish seams. I think it may allow for a wider range of temperatures as well but I can't remember what James told me about that.
I get the 8oz brown jars with the green lids (teflon lined) and mix the MC with about 7% AA and cap it tight, I've let this mixture sit for a couple weeks before using it all but I usually 'top it off' with a little MC just in case if it's been more than a week on the shelf.
Floyd R Turbo
Either busy or sleeping
The AA you want is "glacial" and a little goes a long way. I got a 4L jug of it 2+ years ago and I still have 3/4 of it left.
Floyd R Turbo
Either busy or sleeping
Looks right
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