Cutting acrylic weir slots longer, preferred tool?

[Hezam]

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.

 

[Ron Reefman]

A battery powered Dremel with a proper attachment (your hardware should have a wide variety). Another option would be to just drill some small holes below the slots.

Good luck.

 

[Roadkillstewie]

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.

 

[Hezam]

A battery powered Dremel with a proper attachment (your hardware should have a wide variety). Another option would be to just drill some small holes below the slots.

Good luck.

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.

Thanks a lot guys. Drill seems like a good idea, though I would need to drill multiple holes to get the 15mm I need? I am afraid it looking like hackjob. I might test with scrap acrylic first drill and Dremel.

 

[MartyK]

Dremel is probably going to look like more of a 'hackjob' than drilling holes if you're doing everything free hand.

Spend 30 minutes to set up a plywood/whatever jig for drilling the new holes that would be the bottom of the weir slots then build another jig for the dremel cutting part so everything is square and straight.

A router with an 1/4" bit is probably how the original weir slots were cut so that's another option but it's also not going to go well free hand.

 

[mfinn]

Dremel is probably going to look like more of a 'hackjob' than drilling holes if you're doing everything free hand.

Spend 30 minutes to set up a plywood/whatever jig for drilling the new holes that would be the bottom of the weir slots then build another jig for the dremel cutting part so everything is square and straight.

A router with an 1/4" bit is probably how the original weir slots were cut so that's another option but it's also not going to go well free hand.

Yeah, I was thinking this as well. I tried this once, a while back and was not happy with my effort at all.
I really like the idea of a jig to drill holes

 

[The_Paradox]

If all you have is common tools the best bet is a flush trim router bit. You can guide it off a piece of 1x2 clamped flush with the edge of each slot.

 

[mfinn]

Hello everyone,



I can remove the overflow from the tank its not yet filled.

I missed this part.
Since you won't have to work on it while it's in the tank, being able to make a jig for either drilling holes or using a small router with a trim bit seems much more doable.
Myself I would skip the miter saw. Too much potential for chipping and breaking.

 

[BeanAnimal]

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.

 

[esquare]

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.

 

[Patx]

Just i quick idea...

I don't have it in my hand so...
Can you drill a higher hole and patch the rest ?

 

[slingfox]

See this video for one way to approach:

 

[The_Paradox]

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.

Of tools are not readily available he could also just cut 1/4” off the bottom.

 

[Roadkillstewie]

Drill you one row... check the flow/water level, then if you need do another. Time consuming, but safer and less likely to come out looking like a 'hack job' than trying to cut slots. Just measure and use a bit diameter on par with the width of the slots.

 

[Roadkillstewie]

What tools do you current have/own?

 

[LandLockedJones]

Thanks a lot guys. Drill seems like a good idea, though I would need to drill multiple holes to get the 15mm I need? I am afraid it looking like hackjob. I might test with scrap acrylic first drill and Dremel.

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.

 

[LandLockedJones]

check out the tooling section of the website.

Head to the home page, choose “shop by department”-Plastics-fabrication tools.

They have a ton of cool options designed for cutting plastics in various manners.

 

[Hezam]

What tools do you current have/own?

I have a circular saw, miter saw, and your typical drill and dremel. very close to buying a router

 

[Hezam]

Just i quick idea...

I don't have it in my hand so...
Can you drill a higher hole and patch the rest ?

Modular marine design has the threaded part of the bulk head fitted inside the weir, will try to remove but I don't think I can remove it its glued tight

 

[Hezam]

I missed this part.
Since you won't have to work on it while it's in the tank, being able to make a jig for either drilling holes or using a small router with a trim bit seems much more doable.
Myself I would skip the miter saw. Too much potential for chipping and breaking.

Yeah in my head the miter saw Idea looked good but thinking about it more it seems like a definite no.