Cutting acrylic weir slots longer, preferred tool?

[Hezam]

Water height can be adjusted a small amount by the return pump flow rate. Using a router bit and a straight edge clamped to the box will most likely give you the best results. In addition to a straight edge to guide the path of the router another one, or some kind of stop, to control the length of the slot.

I'd second Ron in regards to drilling holes rather than trying to extend the length of the weir slots themselves. Not a lot of margin for error there and not something i'd recommend trying to freehand with a router.

So I recommend checking out something called a fluted drill bit. This is a company known as Tap Plastics.

Regular drill bits are not the greatest option. They will work, I use them all the time for drilling holes in acrylic. But there is the possibility of cracking the plastic.

Fluted bits, allow the plastic that is being cut to escape upward, preventing any additional pressure being applied to your work piece. It also leaves a rather clean cut.

That being said, I have never seen them at Lowe’s or Home Depot. So you would have to order them somewhere.

Thanks a lot everyone who replied. I went through them all. It seems like the general consensus is that dremel wont look good and the best way to do this is with a router and a jig. OR I can drill just simply holes with a drill bit for acrylic. I am leaning more towards the drill as I have a small fear of routers. I've never used one but I want to learn. Not sure if I want this first project

Both Acrylic and Polycarbonate are "grabby". You are going to split it drilling holes that close to an edge. Save yourself the headache and just order the proper overflow box. The router, jig setup and time is going to cost you more than just replacing it.

Modular marine replied and gave me a $120 for a new box with longer weirs and a little bit shorter top. I will go ahead and order that...

I think I will do both actually, I will order the modular marine replacement for the perfect clean look. I will also satisfy the DIYer in me and try to make bigger slots. If I mess them up Ill just replace overflow box with new when one

 

[Hezam]

So I recommend checking out something called a fluted drill bit. This is a company known as Tap Plastics.

Regular drill bits are not the greatest option. They will work, I use them all the time for drilling holes in acrylic. But there is the possibility of cracking the plastic.

Fluted bits, allow the plastic that is being cut to escape upward, preventing any additional pressure being applied to your work piece. It also leaves a rather clean cut.

That being said, I have never seen them at Lowe’s or Home Depot. So you would have to order them somewhere.

Man I love specific tools. Even though I think I will only use this once or twice I still want it!!

 

[biecacka]

@Troylee
Troy, any input?

Thank you

Corey

 

[Troylee]

You can do it with your miter saw and that’s the cleanest option.. I don’t have a picture on me of my setup I use but it’s simple… when I get home I can snap one for you.. I basically put a strip of wood or pvc in my choice cause I got plenty of scraps lol about 4” wide down and double stick it to the saw and cut through it. Essentially what this does is pushes the material out 4” from the back stop and only allows the outside edge of the blade to cut the plastic… this allows me to bring the blade all the way down and only cut a 1-1/2” slot in my acrylic and keeps it uniform.

You need to bring the blade all the way down and measure in how far you want it to cut like 2” or so.. place a mark on your saw and then measure the space from the back gauge to the mark and that’s the size of spacer you need if ya catch my drift lol…

Edit to add photos… the piece against the back stop is double sided tape down to hold it in place I make a cut through it and then I use that as my back stop to cut my weirs.. it’s much faster than a table saw and I don’t like using a router cause it leaves large gaps in the teeth and I don’t feel like fishing my fish out of the over flow or sump lol.. unless you got a cnc router of course.

 

[mfinn]

You can do it with your miter saw and that’s the cleanest option.. I don’t have a picture on me of my setup I use but it’s simple… when I get home I can snap one for you.. I basically put a strip of wood or pvc in my choice cause I got plenty of scraps lol about 4” wide down and double stick it to the saw and cut through it. Essentially what this does is pushes the material out 4” from the back stop and only allows the outside edge of the blade to cut the plastic… this allows me to bring the blade all the way down and only cut a 1-1/2” slot in my acrylic and keeps it uniform.

Specific blade?

 

[Troylee]

Specific blade?

I prefer these… triple chip and the more teeth the better. I’ve used regular wood blades in a pinch but non ferrous or aluminum cutting blades work best.

 

[mfinn]

I prefer these… triple chip and the more teeth the better. I’ve used regular wood blades in a pinch but non ferrous or aluminum cutting blades work best.

Reasonably priced too.
My saws are all 10", so the 100 tooth blade would be what I would need, at around $50

 

[Troylee]

Reasonably priced too.
My saws are all 10", so the 100 tooth blade would be what I would need, at around $50

I added photos above in my post.. made a jig at work real quick to help you guys out.

 

[Hezam]

I added photos above in my post.. made a jig at work real quick to help you guys out.

Appreciate the help! The pictures made it clear for me. I am thinking of attempting this solution this weekend. I will try all the tools and report on what worked best for me. As I will sacrifice this overflow box for testing purposes as I already ordered the replacement. (Maybe not full sacrifice but you get the meaning)

 

[ShakeyGizzard]

Best option would be a router table with up spiral router bit. But if you don't have one now very pricey to get. If your not worried about professional look, Dremel type tool can be used but mark desired cut area. The right tools can make a frustrating job easy. video below of me cutting my sump baffles with router table and up spiral bit.

Cutting slots in acrylic

 

[mfinn]

Best option would be a router table with up spiral router bit. But if you don't have one now very pricey to get. If your not worried about professional look, Dremel type tool can be used but mark desired cut area. The right tools can make a frustrating job easy. video below of me cutting my sump baffles with router table and up spiral bit.

Cutting slots in acrylic

Great video. Shows that even a cheapo harbor freight router table/combo would do light duty cutting like this.

 

[ShakeyGizzard]

Great video. Shows that even a cheapo harbor freight router table/combo would do light duty cutting like this.

don't know, never used a harbor freight router table, but more than likely they will be ok for basic projects

 

[mfinn]

don't know, never used a harbor freight router table, but more than likely they will be ok for basic projects

I was kind of referring to it being a light duty and fairly inexpensive tool that would be enough for small diy projects like this.

 

[KrisReef]

Hello everyone,



Hope everyone is doing well. So my water level in my 200g in just a smidge higher than I would've liked. I need to lower it by just under an inch. I am using a modular marine overflow box. I've already contacted them and waiting for a reply. But I suspect that they will tell me I have to get a full overflow box replacement. I don't think it's worth for just 1 in difference for the level.



So plan B would be to drill the slots just a bit lower. What would be the best tool for the job. I can remove the overflow from the tank its not yet filled. I have a miter saw. Can I use it to make the tiny slits longer? I can use a Dremel also. I don't have a router but I am willing to buy one if it gets the job done. I've read a thread here talking about melting the acrylic longer with a soldering iron, will that work also? There's a couple of options here just wondering which one will get the job done cleaned and without cracking the acrylic.

I would purchase a new facepiece and use the jig idea to cut lower slots in the new material. Then I would dremel/ hacksaw, sawsall, (carefully) rip out the portion of the old face that needs deeper holes so that the new face can be glue welded over top of the old face that had a hole cut in it to allow water to flow unobstructed to the proper level as directed by the new face. The hole needs to be cut away from the face edges so that there is an old edge to glue too and hide the ugly hole you ripped in the face you covered.

Plastic surgery and teeth replacement.

 

[ShakeyGizzard]

I was kind of referring to it being a light duty and fairly inexpensive tool that would be enough for small diy projects like this.

go for it

 

[Kfactor]

router on a bench table

 

[ShakeyGizzard]

Great video. Shows that even a cheapo harbor freight router table/combo would do light duty cutting like this.

will say router table may be cheap, but the actual router may cost, I do have a harbor freight palm router for trim work. they would be great if you can mount them into a harbor freight table

 

[reef’r]

Appreciate the help! The pictures made it clear for me. I am thinking of attempting this solution this weekend. I will try all the tools and report on what worked best for me. As I will sacrifice this overflow box for testing purposes as I already ordered the replacement. (Maybe not full sacrifice but you get the meaning)

I used a modular overflow for my cube. Didn’t pay attention and drilled it at the level of a tank with a trim piece so like you my water level was way high. I sent them my internal weir and they drilled the holes out as long as I wanted them, and they only charged me $30 bucks for it. Sent them my box, they extended the weirs and sent it back, not sure why you got a price of $120

 

[LandLockedJones]

Specific blade?

If you are routing the edges the specific blade doesn’t matter. Even a wood cutting blade “can” cut acrylic. It just does a very bad job of it.

But I fell in love with Diablo blades cutting hardibacker for a shower project (which is still incomplete)

But their aluminum cutting blades are incredible for cutting acrylic. They are fairly expensive though. And as stated above, likely any blade stating it’s designed for aluminum will work well. These cut like butter and leave a nice clean edge. But then I drag it across the router and destroy it anyways, so the extra funds for the fancy blades may have been for naught.

Also look into using mapgas torches to polish edges. Pretty wicked.