Acrylic fabrication questions? I can help!
- Thread starter JohnL
- Start date
TheGrog
Member
OK, problem.
I am building a calcium reactor. Everything was going great. Got all the parts cut out, drilled, tapped, cleaned, sanded (saw edges) and ready to assemble.
On my top cover--the removable one that screws on so I can get to the media--I have a 3" hole in the center, covered by a 4" disk and the return line is tapped in the 4" disk. This will help remove any CO2 accumulation at the top. I have a hole tapped on the main cover, about 1/4" from the edge of the 4" disk for my effluent return. My plan was to lay the disk on top of the main one and run some #4 in there to seal it down.
Well, when I ran the #4 in there, the lower disk cracked!! It cracked where the tap hole is with the JG fitting in place and the cracks go towards the center (3") hole!!!
I had no idea that weld-on could do this! I it because the acrylic was under some stress to begin with and the solvent simply weakened it enough to cause it to crack???
The majority of the crack is under the top disk, which I put a small bead of #16 around the inside and outside edge so I don't think it will leak (hoping it won't).
Did I do something wrong by using #4 on a peice under some stress??
I know it is hard to visualize, but I don't have the digital pics on my computer yet.
Any help or suggestions would be appreciated. I worked for hours getting these peices just right and I could have cried when I saw them break in front of me for no apparent reason! :sad1:
Thanks and I'll post some pics soon when I get the on my puter.
I am building a calcium reactor. Everything was going great. Got all the parts cut out, drilled, tapped, cleaned, sanded (saw edges) and ready to assemble.
On my top cover--the removable one that screws on so I can get to the media--I have a 3" hole in the center, covered by a 4" disk and the return line is tapped in the 4" disk. This will help remove any CO2 accumulation at the top. I have a hole tapped on the main cover, about 1/4" from the edge of the 4" disk for my effluent return. My plan was to lay the disk on top of the main one and run some #4 in there to seal it down.
Well, when I ran the #4 in there, the lower disk cracked!! It cracked where the tap hole is with the JG fitting in place and the cracks go towards the center (3") hole!!!
I had no idea that weld-on could do this! I it because the acrylic was under some stress to begin with and the solvent simply weakened it enough to cause it to crack???
The majority of the crack is under the top disk, which I put a small bead of #16 around the inside and outside edge so I don't think it will leak (hoping it won't).
Did I do something wrong by using #4 on a peice under some stress??
I know it is hard to visualize, but I don't have the digital pics on my computer yet.
Any help or suggestions would be appreciated. I worked for hours getting these peices just right and I could have cried when I saw them break in front of me for no apparent reason! :sad1:
Thanks and I'll post some pics soon when I get the on my puter.
ouch, if it were mine, id have to remake the part to sleep at night. WO 4 causes alot of stress, on top of that drilling also does. WO 4 can crack acrylic easy if given the chance to but it was def the combo of the 2 cause look at how its fanned out around the drill hole.
Are you using an acrylic drill bit? Normal bits do alot of damage which might be responsible.
Are you using an acrylic drill bit? Normal bits do alot of damage which might be responsible.
TheGrog
Member
Thanks for the input guys.
It is extruded plate that I drilled through with a standard bit.
Did a test on it today and it seems to hold water. Whether it holds up under pressure, I will not find out until this weekend when I get the pump for it.
Since it is the one detachable part to the assembly, I can remake it if necessary.
The rest of the reactor seems to be coming together just fine. Still getting little micro-bubbles in the base parts (flat plate to flat plate at 90 deg angles), but they have held up well. They don't need to hold water anyway. With more practice, that will get better (I hope)
slavearm
New member
What is the best way to prepare an acrylic tube for gluing up.
I made a v-shaped jig for my tablesaw to deal with the 12" acrylic, so I could basically set the fence, and then spin the tube. I am using a 200 tooth blade.
Normally before joining pieces of wood (heh) I would run it through a joiner to get a super clean edge to work with. I have been running some ideas through my head, but the only thing that seems even slightly feasable, is to take my jig over to the router, hook up the router with a down spiral cut bit, and set the fence to basically allow me to remove about 1/32" then spin the tube.
Is that necessary, or is there a quicker easier way.
Gracias in advance.
I made a v-shaped jig for my tablesaw to deal with the 12" acrylic, so I could basically set the fence, and then spin the tube. I am using a 200 tooth blade.
Normally before joining pieces of wood (heh) I would run it through a joiner to get a super clean edge to work with. I have been running some ideas through my head, but the only thing that seems even slightly feasable, is to take my jig over to the router, hook up the router with a down spiral cut bit, and set the fence to basically allow me to remove about 1/32" then spin the tube.
Is that necessary, or is there a quicker easier way.
Gracias in advance.
This works, but you will probably want to make a taller fence. Clamp a larger piece of material to the fence that will make full contact with the tube. Hmm, how to say, if the tube is not completely flat on the fence side, it won't spin true - making an irrefular cut. Make sense?
Give it a shot if you want, if the ends are flat and true - you can always simply use a 1/2 sheet sanding block of maybe 220. Sand lightly going around the tube ends. There are easier ways but requires a jig which would take a day or so to build ans relatively worthless for anything else.
De nada
HTH,
James
A friend of mine just purchased a 600 gallon acrylic tank and wants me to make it look new again. Its about 4 yrs old and was in a fish store to give you an idea of how worn it is.
I know how to polish small areas, but what about such a large area, what would be the fastest way? What would be the best way?
I have a buddy who paints cars, was thinking about having him take his air tools and go at it. Works great for making seams clear, but Im not so sure about how it would do on the viewing areas.
I know how to polish small areas, but what about such a large area, what would be the fastest way? What would be the best way?
I have a buddy who paints cars, was thinking about having him take his air tools and go at it. Works great for making seams clear, but Im not so sure about how it would do on the viewing areas.
anupam_gupta87
New member
hey guys,
well i m a new member here, anupam from inida.
i wanna built a 3x1x1.2 m tank for a college project(me dng engineering btw)
i just wanna know hw thick shud be my acrylic sheet coz i need to be holding abt 3000 litres or 800 gallons of water in it...so if u guys cud help me out in this it wud be a great help..
thanx in adavnce...
well i m a new member here, anupam from inida.
i wanna built a 3x1x1.2 m tank for a college project(me dng engineering btw)
i just wanna know hw thick shud be my acrylic sheet coz i need to be holding abt 3000 litres or 800 gallons of water in it...so if u guys cud help me out in this it wud be a great help..
thanx in adavnce...
anupam_gupta87
New member
hey thanx for d really fast reply...actually i dnt hve to build a top...coz its an open tank...need it for an event i have to host in our technical fest ..u knw hw dese things go at clges man...
one more question...how should i support it???i ws thinking of a basic framework of alluminium channels into which i can insert the sheets...but i guess that wud be too weak to hold the joints together right???
one more question...how should i support it???i ws thinking of a basic framework of alluminium channels into which i can insert the sheets...but i guess that wud be too weak to hold the joints together right???
You *need* to have a top on the tank, or else it will fail. If you need a fully open top - I'd go with 2.5" acrylic (62-63mm) for the vertical panels which will get *very* expensive.
Correct, you'll need to glue the panels together, advise Weld-on 40 or 42 for that thickness.
James
supersaltlick
Member
I posted this as a new thread earlier and then found that this may be the more appropriate place to ask my questions. More basic than most of the other subjescts on this thread.
I am getting ready to build my own overflow out of an acrylic sheet. I'm sure this has been addressed on this site before but I have not been able to find it. Basically I just need to know the best way to bend this stuff. I imagine just heating it and bending over a rigid surface would work. Are there any specific techniques that need to be followed? Are there any threads or websites that I could visit that would give specific instructions?
thanks
shawn
I am getting ready to build my own overflow out of an acrylic sheet. I'm sure this has been addressed on this site before but I have not been able to find it. Basically I just need to know the best way to bend this stuff. I imagine just heating it and bending over a rigid surface would work. Are there any specific techniques that need to be followed? Are there any threads or websites that I could visit that would give specific instructions?
thanks
shawn
Shawn,
Do a search here on RC for "Strip heater" with "acrylics" as author, and "any date". There was a DIY strip heater a coupla yrs back, better than anything else on the market, dollar for dollar. You could also just buy a cheapie strip heater from TapPlastics.com
Rich,
It's just a fixture in which the router is mounted horizontally. You can slide the height up and down and set it with screws. Basically, you just set the height and turn the tube under it to get a good, routed edge.
Don't have pics anymore, next time I use it - I'll try to remember to take new pics. I had posted a pic of it some time back, may be able to search around for it though I wouldn't know how. I believe it was in this thread but may be a coupla yrs ago.
James
Do a search here on RC for "Strip heater" with "acrylics" as author, and "any date". There was a DIY strip heater a coupla yrs back, better than anything else on the market, dollar for dollar. You could also just buy a cheapie strip heater from TapPlastics.com
Rich,
It's just a fixture in which the router is mounted horizontally. You can slide the height up and down and set it with screws. Basically, you just set the height and turn the tube under it to get a good, routed edge.
Don't have pics anymore, next time I use it - I'll try to remember to take new pics. I had posted a pic of it some time back, may be able to search around for it though I wouldn't know how. I believe it was in this thread but may be a coupla yrs ago.
James
