Floyd R Turbo
Either busy or sleeping
What speed are you running the router at (RPM)?
Acrylic fabrication questions? I can help!
- Thread starter JohnL
- Start date
brian cummings
New member
Hi, I have been reading through this thread, but it's awfully long, and I just couldn't wait any longer to ask a few questions....
I have done a little bit of acrylic work before, I used to work in the exhibits department of a museum, and we occasionally made vitrines (display cases), object mounts, brochure holders, and the like. We worked in 1/8" up to 3/8", welded stuff with IPS weldon #4, used a plex bender, and flame polished edges...
I would really like to make a small (pico) tank for some temperate water invertebrates, and have toyed with the idea of doing it myself...I was figuring making it one of the nice three cell cast acrylics that have been recommended several times on this thread.
BUT I haven't worked with the thickness of material that I want to make this out of- 1". Also, I keep seeing everyone using "the pins method"-- forgive my ignorance, but I haven't seen an explanation for this, what advantage does this have over no pins, good mating surfaces, and capillary action? (does capillary action not work for the thicker pieces?)
I am looking at getting a router and router table soon, would be necessary for this project, but I am getting one regardless for other things.
It maybe be better for me to just have someone make this, but I was curious about the necessary techniques...
Thank you!
I have done a little bit of acrylic work before, I used to work in the exhibits department of a museum, and we occasionally made vitrines (display cases), object mounts, brochure holders, and the like. We worked in 1/8" up to 3/8", welded stuff with IPS weldon #4, used a plex bender, and flame polished edges...
I would really like to make a small (pico) tank for some temperate water invertebrates, and have toyed with the idea of doing it myself...I was figuring making it one of the nice three cell cast acrylics that have been recommended several times on this thread.
BUT I haven't worked with the thickness of material that I want to make this out of- 1". Also, I keep seeing everyone using "the pins method"-- forgive my ignorance, but I haven't seen an explanation for this, what advantage does this have over no pins, good mating surfaces, and capillary action? (does capillary action not work for the thicker pieces?)
I am looking at getting a router and router table soon, would be necessary for this project, but I am getting one regardless for other things.
It maybe be better for me to just have someone make this, but I was curious about the necessary techniques...
Thank you!
TropTrea
New member
I have no idea. The Router was purchased in the late 70's and is 1 1/2 hp. if that helps.
TropTrea
New member
In my experience the thicker the acrylic is the easier it is to work with. However the cost does go us considerably.
Floyd R Turbo
Either busy or sleeping
I run mine at max RPM, ~23000. If you're running slower (a lot slower) that might explain it.
dahenley
New member
trop,
are the bits your using carbide tip and new/sharp, or are they standard HSS router bits?
i ask, because if they are not carbide tiped, it will dull from the heat and thus melt and not cut/sheer the acrylic.
when i rout things, i look like frosty the snow man and have no melt around the edges....
i just use a 1/2 shank bit from lowes normally. with no problems.
are the bits your using carbide tip and new/sharp, or are they standard HSS router bits?
i ask, because if they are not carbide tiped, it will dull from the heat and thus melt and not cut/sheer the acrylic.
when i rout things, i look like frosty the snow man and have no melt around the edges....
i just use a 1/2 shank bit from lowes normally. with no problems.
Floyd R Turbo
Either busy or sleeping
Capillary action does not allow the solvent to soak and 'bite' into each side. The bond is weak and can / will fail over time. Got a sump in my garage for repair that is cap welded. Seam snapped clean at the joint. Pin welded joints are stronger than the material.
TropTrea
New member
So how do do pin welds? My guess is you drill a hole through both sections then insert a pin with acrylic cement? Details please if I'm wrong.
Floyd R Turbo
Either busy or sleeping
Whoa, way off! You prep the joint as if you were going to to a capillary weld, then use pins to create a separation space at the joint, run the solvent, wait 15-30 seconds, then pull the pins. That is a simplified explanation. There are more detailed descriptions in this thread
brian cummings
New member
makes sense.
Floyd R Turbo
Either busy or sleeping
Here's my latest project. A friend picked up a failed sump for free. 180g, 72 x 24 x 24, all joints were capillary welded and panels were rough cut w/o any edge prep. This is a case for how you should not build a sump.
Euro snapped off in 2 places when he tried to lift the tank by it when he got it - snapped clean off, like it was not ever bonded!
The reason it was free - vertical seam failed, again snapped clean like never bonded
The pressure of the failure cracked the bottom panel, but it doesn't go all the way through the panel (can't feel the crack on the bottom of the bottom panel)
other scary looking welds
Believe it or not, this thing held water for a time and was actually in use!!
The plan is to:
1) drill a hole to stop the crack from progressing
2) re-weld the vertical joint (rough weld)
3) re-attach the euro sections
4) gusset all seams (top, bottom, vertical) with 3/4" triangle rod and square rod in the corners using Weld-On #40
5) patch in missing (cut out) euro sections with 3/8"
6) laminate entire euro with 1/4" strips
I spent a few hours cleaning it all up and prepping the bad corner for re-welding.
I have the WO40 and 8 pieces of 6 foot 3/4" triangle rod. This should be fun!!
Euro snapped off in 2 places when he tried to lift the tank by it when he got it - snapped clean off, like it was not ever bonded!
The reason it was free - vertical seam failed, again snapped clean like never bonded
The pressure of the failure cracked the bottom panel, but it doesn't go all the way through the panel (can't feel the crack on the bottom of the bottom panel)
other scary looking welds
Believe it or not, this thing held water for a time and was actually in use!!
The plan is to:
1) drill a hole to stop the crack from progressing
2) re-weld the vertical joint (rough weld)
3) re-attach the euro sections
4) gusset all seams (top, bottom, vertical) with 3/4" triangle rod and square rod in the corners using Weld-On #40
5) patch in missing (cut out) euro sections with 3/8"
6) laminate entire euro with 1/4" strips
I spent a few hours cleaning it all up and prepping the bad corner for re-welding.
I have the WO40 and 8 pieces of 6 foot 3/4" triangle rod. This should be fun!!
TropTrea
New member
So then this is not a long way off of my system. I simply run the welding solution on both parts to be joined then wait 10 to 20 seconds before I put the two peices together.
Floyd R Turbo
Either busy or sleeping
I suppose, but how do you keep the solvent from running all over the place? Are you holding the pieces close together, like at an open angle, so that the joint is in close contact? That's how the pins method works. You prepare the joint such that it is in it's "final position", i.e. the joint is flush and in full contact all the way along, then you insert the pins into the joint and get them all snug (this is where boards w/foam and shims come in), blow the joint out with canned air, then run the solvent.
With very large builds, I can't see how you can do this without pins.
With very large builds, I can't see how you can do this without pins.
TropTrea
New member
The biggest difference is I do not trust the catyylist idea to fill in all the holes. Basicly I have a two peices of plywood creating a big V where each piece is going to be on a 45 degree angle. Then apply a beed making sure covers the entire area that is going to be bounded on both peices. Then after a few seconds simply drop the second piece into position. The two "cement" areas then come into a complet bond together. Yes you do get a little excess seaping out around the joint. But this can usualy be scraped off afterwards and no one will detect the joint. Then a final sand with 1200 grit sand paper and a little buffing makes the joint basicly invisable. After about 12 hours dry time I put the next piece on simularly. Sure it not the fastest method but it has always worked for me so far.
My biggest fear is that some side is not cut perfectly to fit. So far I have been lucky that way thanks to prefitting everything first.
Floyd R Turbo
Either busy or sleeping
I'm not picturing your method. Are you saying that then the joint is in "position", that each piece is sitting at a 45 degree angle from horizontal, and the joint is at the "V"?
James (Acrylics) has been using the pins method, as well as just about every other fabricator out there, for decades. It takes a little practice, but for the most part, it works extremely well.
What do you mean by catalyst? And filling all the holes? Which holes are you referring to?
James (Acrylics) has been using the pins method, as well as just about every other fabricator out there, for decades. It takes a little practice, but for the most part, it works extremely well.
What do you mean by catalyst? And filling all the holes? Which holes are you referring to?
TropTrea
New member
Perhaps this will help.
The two acrylic pieces are in blue and the plywood frame is in brown. A small bead if the acrylic catalist is applied to the surffaces to be jointed together before they are allowed to touch. Then I apply pressure to the joint by pushing down on the top piece. This speads the acrylic out slightly on the sides of the joint.
Keep in mind that my projects are small compared to what some others build. My largest build was a betta display tank, 7" tall, 6" deep and 48" long with 6 compartments in it. 6 of those tanks have been running since 1997 without a major issue. I did used a dark gray acrylic for the dividers rather than clear.
I also built two of them with polycarbonate that were 8" tall, 24" deep and 72" wide that had 27 compartments. But those tanks had a water flow issue between compartments and were abandoned after about two years.
The two acrylic pieces are in blue and the plywood frame is in brown. A small bead if the acrylic catalist is applied to the surffaces to be jointed together before they are allowed to touch. Then I apply pressure to the joint by pushing down on the top piece. This speads the acrylic out slightly on the sides of the joint.
Keep in mind that my projects are small compared to what some others build. My largest build was a betta display tank, 7" tall, 6" deep and 48" long with 6 compartments in it. 6 of those tanks have been running since 1997 without a major issue. I did used a dark gray acrylic for the dividers rather than clear.
I also built two of them with polycarbonate that were 8" tall, 24" deep and 72" wide that had 27 compartments. But those tanks had a water flow issue between compartments and were abandoned after about two years.
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Floyd R Turbo
Either busy or sleeping
What are you using for bonding? I now understand your use of the term catalyst, but (and forgive my analness here) it is not technically correct. A catalyst is something that speeds up a chemical reaction. Solvent bonding is not a catalytic reaction. Solvent just chemically "melts" each side so that 2 pieces can be joined and then "harden" together (not the technical terms but I'm short on time). So just substitute "solvent" for "catalyst"...
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