Acrylic fabrication questions? I can help!
- Thread starter JohnL
- Start date
Been practicing on 1" material. Not my first time working with material of this thickness. Running my material through my router table. Actually have a setup similar to James attached to my table saw with a cast iron top. Edges look perfect although not using a spiral upcut bit, but a double fluted flush trim bit.
I've checked flatness of work surface, checked squareness of router bit to table surface which is square. I have noticed that when I square table with one edge of bit it's flush, but when rotating the bit to the other cutting edge it's still square, but doesn't contact square...
What I'm noticing on glue up is what appears to be small bubbles that creep in on the edges?? Initially when applying solvent the entire joint is super clear/clean, but as it dissolves little air bubbles seem to appear along the edges. Currently I'm using 24gauge picture hanging wire for pins...soak time is roughly a minute. I've actually been playing with soak time. Is it possible there's an issue with the router bit an edge prep or the WelOn 4 itself?? Any help greatly appreciated!!!!
I've checked flatness of work surface, checked squareness of router bit to table surface which is square. I have noticed that when I square table with one edge of bit it's flush, but when rotating the bit to the other cutting edge it's still square, but doesn't contact square...
What I'm noticing on glue up is what appears to be small bubbles that creep in on the edges?? Initially when applying solvent the entire joint is super clear/clean, but as it dissolves little air bubbles seem to appear along the edges. Currently I'm using 24gauge picture hanging wire for pins...soak time is roughly a minute. I've actually been playing with soak time. Is it possible there's an issue with the router bit an edge prep or the WelOn 4 itself?? Any help greatly appreciated!!!!
Floyd R Turbo
Either busy or sleeping
First, the bit does matter - for edge prep, you don't want to be using a spiral upcut of a flush cutter, you need something that is beefier. Go for a double-fluted straight cutter like htis
https://www.lowes.com/pd/Bosch-3-4-in-Carbide-Tipped-Straight-Bit/1081969
^^ this is the one I use for everything up to 1/2", I think I used on 3/4" once as well. For 1" you probably want to go up to a higher diameter bit
The spiral and flush cutters will flex more with thicker material. This could be the source of the issue. Only use flush cutters for flush trimming and pattern routing.
As for using the other side of the bit, if I understand you right, you get a square edge when running along one side of the bit, but it's not quite square when you come at the bit from the opposite side of the table? That's very odd, could indicate an issue with the table (hard to imagine)
https://www.lowes.com/pd/Bosch-3-4-in-Carbide-Tipped-Straight-Bit/1081969
^^ this is the one I use for everything up to 1/2", I think I used on 3/4" once as well. For 1" you probably want to go up to a higher diameter bit
The spiral and flush cutters will flex more with thicker material. This could be the source of the issue. Only use flush cutters for flush trimming and pattern routing.
As for using the other side of the bit, if I understand you right, you get a square edge when running along one side of the bit, but it's not quite square when you come at the bit from the opposite side of the table? That's very odd, could indicate an issue with the table (hard to imagine)
Thanks Floyd....Ran out to the local WoodCraft and picked up a new Freud bit. Straight cut 1" diameter and perfect!!!!!!
SFish
New member
Math check please
Overflow box
Two boxes 1/4" acrylic
Outside measurements of boxes
Inside box 7 1/2 x 3 1/2 x 8
Base = 7 1/2 x 3 1/2
Front/Back = 7 1/2 x 7 3/4
Sides = 3 x 7 3/4
Lid = 7 x 3 took off 1/8 for play so 6 7/8 x 2 7/8
Outside box
8 x 4 x 8 1/2
Base = 8 x 4
Front/Back = 8 x 8 1/4
Sides = 3 1/2 x 8 1/4
Lip that would fit inside the box to add 1 1/2 of height
7 1/2 x 3 1/2 x 1 1/2
Front/Back = 7 1/2 x 1 1/2
Sides = 3 x 1 1/2
Lid
7 x 3 so 6 7/8 x 2 7/8
Thoughts
Ideas
Things wrong
Thanks
Overflow box
Two boxes 1/4" acrylic
Outside measurements of boxes
Inside box 7 1/2 x 3 1/2 x 8
Base = 7 1/2 x 3 1/2
Front/Back = 7 1/2 x 7 3/4
Sides = 3 x 7 3/4
Lid = 7 x 3 took off 1/8 for play so 6 7/8 x 2 7/8
Outside box
8 x 4 x 8 1/2
Base = 8 x 4
Front/Back = 8 x 8 1/4
Sides = 3 1/2 x 8 1/4
Lip that would fit inside the box to add 1 1/2 of height
7 1/2 x 3 1/2 x 1 1/2
Front/Back = 7 1/2 x 1 1/2
Sides = 3 x 1 1/2
Lid
7 x 3 so 6 7/8 x 2 7/8
Thoughts
Ideas
Things wrong
Thanks
laverda
Well-known member
Thanks James.
SFish
New member
Floyd R Turbo
Either busy or sleeping
If using pins method, remember that you will leave a lip to trim off. This means if you want the box to be 7.5" long finished, then you need to rough cut the piece about 7.75 to allow for 1/8" on both ends for flush trimming. Same for the bottom, except in all 4 directions. 1/16" is actually enough (so 7.625")
Just a personal preference, but I make the outside boxes out of 3/8". It's just a bit beefier and gives me warm fuzzies. 1/4" can bow. You can add a little brace to the inside very easily to prevent that (eases stress on the outer corner seams significantly when bowing can't as easily occur) but then again your box is only 8" long, probably not a major concern.
If the lid is made to fit inside, make that after the box is completely done, things rarely fit like a glove. Also a flat acrylic lid with no bracing will eventually warp. I found that laminating a piece of gray sheet PVC eliminates that. To do that, I cut the PVC smaller (so that it fits inside the inside dims of the box) then use primer on the PVC only, then solvent on the acrylic (squeeze bottle, apply right to acrylic in a line) and then sandwich them together, press down (careful, it will slide) and progressively apply more and more pressure as it sets up, after about 30s it should start to get set up, then put on a flat surface and put a brick on it for an hour, good to go. That will never warp.
Floyd R Turbo
Either busy or sleeping
MC bond has acetic acid in it, big difference.
Sci-grip 4: http://www.scigrip.msdss.com/DocumentCenter.aspx?did=f0fb26c6-c00e-4f79-ab3c-d3967e35e2d8
Methylene Chloride*# (dichloromethane) 30 - 60
Trichloroethylene*# 40 - 60
Methyl Methacrylate Monomer*, Stabilized (MMA) 0 - 1
MC Bond: http://www.polysciences.com/skin/frontend/default/polysciences/pdf/16752.pdf
Acetic acid 6 - 10
Methyl methacrylate 11 - 20
Methylene chloride 81 - 90
SFish
New member
Not going to use pins. I've had good success using capillary action. If I go 3/8 thick for the outside box then I should be
8 x 4x 8 1/2
Base = 8 x 4
Front/Back = 8 x 8 1/8
Sides = 3 1/4 x 8 1/8
Is this right?
SFish
New member
Is this the PVC stuff u are taking about? Am I supposed to laminate it first before bonding it?
Thanks Floyd.....
They're not the same, and IMO MCBond is a *much* better solvent, just harder to find in smaller quantities. TCE is utter garbage for acrylic and has zero place in an acrylic solvent.
If you can get the MCBond - do it
James
They're not the same, and IMO MCBond is a *much* better solvent, just harder to find in smaller quantities. TCE is utter garbage for acrylic and has zero place in an acrylic solvent.
If you can get the MCBond - do it
James
Thanks James....
Floyd R Turbo
Either busy or sleeping
No, that's foam PVC. You want Type 1 PVC sheet...sorry I should have been more specific
http://www.eplastics.com/pvc_type1_sheet
https://www.usplastic.com/catalog/item.aspx?itemid=23056&catid=733
Floyd R Turbo
Either busy or sleeping
Looks right. Remember 3/8" =/= 0.375, it's 0.354 so there will still be a lip in some places. You don't have to use the pins method to get the same fillet effect as you do with pins, and for a small box like this, you can get away with capillary on at least some steps.
The internal box, no worries. you will want this sealed so that the joints don't leak (which could excessively drain down your tank) but other than that, water pressure is external on that.
But, here is what I would do on the external box. When you bond the end to of the sides, hold it at an angle to create the void. Fill it, but wait 15-20 seconds before moving it to the final/perpendicular position. Keep it in from the edge slightly to allow the fillet to form. After getting it in final position and it has stared to firm up, run a quick bead of solvent on either side of the joint. This helps to prevent air getting in from the edge. Do this to both end pieces.
For bonding this assembly to the other side panel, you can do the same for one of the joints but the last joint you will need to use a pin. Just one. It's not going to kill you bro! And it will make the joint that much better. You need that soak time, no matter how you do it. No matter what you've heard about instantly formed capillary joints with no soak time, on youtube or wherever, it's very very weak compared to any other joint with at least 15 seconds of soak time, and these are joints that are under some strange torque and pressure not normally associated with an acrylic box sitting on a shelf. It's one critical piece of the entire system that you need to ensure does not fail. Sorry if I'm being pushy, that's just the way I feel....do it right, no regrets.
As for the bottom joint, same thing - 2 pins under each side (long) panel will form your void, run solvent, 15-20 seconds then pull them and align, done. You don't even need to flush trim if you don't want but that will be a knockout strong box/joint by adding those pin steps.
Cammunoz
New member
Acrylic fabrication questions? I can help!
Hello just found this thread! and wow awesome i need help! I just picked up a shallow 150g 5ftx3 ft . I noticed it does not have a center brace? i can see a bit of a bow on it( it is empty as of now. Should I add one?
Sent from my iPhone using Tapatalk Pro
Hello just found this thread! and wow awesome i need help! I just picked up a shallow 150g 5ftx3 ft . I noticed it does not have a center brace? i can see a bit of a bow on it( it is empty as of now. Should I add one?
Sent from my iPhone using Tapatalk Pro
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