Building acrylic sump

imustbenuts · Jun 9, 2016

Yes, another DIY sump thread. So, I finally got the nerve up after purchasing acrylic almost a year ago. Thanks to @Floyd R Turbo acrylic fabrication thread. I'm about half way through so far.

This is a rough draft. I'm going 23x23x18. The dimensions on the draft don't take into consideration the material thickness. So the exact size of some of the chambers are adjusted. I should have used 3/8 stock but bought 1/4 and will have to use it. All my pieces have been cut on a table saw. I made a sled for the saw and was able to dial it in to .0005 over a 20" run. I think that's pretty square! After completing the cut list. I routed all edges down to exact fit. However, the top, bottom, front, and back panels are over sized 1/2" where a lip is needed for proper bonding of the material.

I am nearing the last baffle and am creating a shelf to drop in media bags similar to synergy and trigger sumps. I am wondering. With this being the last baffle it leaves a 6x12 chamber for the return pump. I'm wondering if I should add one more baffle at the end so the water has to rise one last time. Please post you opinion on adding one last baffle. It would leave about 5" for the return pump.

hybridazn · Jun 9, 2016

Looks like your off to a great start!

imustbenuts · Jun 9, 2016

hybridazn said:
Looks like your off to a great start!

Thanks! What's your opinion on the final baffle? Should water flow over or is under just as good?

imustbenuts · Jun 15, 2016

Update on the sump progress. The top is being glued on now. I plan to to cut out all the chambers before I glue up the bottom. Things seem to be moving along well.

Turbo's Aquatics · Jun 15, 2016

imustbenuts said:
cut out all the chambers

What do you mean by this?

Drauka99 · Jun 15, 2016

I think he is planning to glue the top on then route out all the opening on the top and leave a euro-brace

Turbo's Aquatics · Jun 15, 2016

He's bonding the top on in that pic and you don't (or shouldn't) cut out the euro after bonding it on. It needs to be open so that when you bond the bottom on it it can breathe.

Also a hint, not a big deal, but when bonding the euro on it's a good idea to leave the bottom panel off and use planks of wood for a place to set your weights, per the reason above

imustbenuts · Jun 15, 2016

Floyd R Turbo said:
What do you mean by this?

I have attached the top panel. I did this because I was thinking it would be easier to attach the wood trim I'll be using to guide the flush trim bit during routing. I was thinking if I attached the bottom first, I wouldn't be able to glue the top on because I wouldn't be able to reach inside.

I don't remember reading in your thread to use boards instead of the acrylic for the weights to lay on. I must have missed that part. Now I know for future builds.

Turbo's Aquatics · Jun 15, 2016

imustbenuts said:
I did this because I was thinking it would be easier to attach the wood trim I'll be using to guide the flush trim bit during routing.

What wood trim are you describing? When I do flush trimming, I just run blue tape where the bearing will ride on the acrylic, make one pass, take off the tape, and make a fast second pass to get that mil of extra material.

imustbenuts said:
I don't remember reading in your thread to use boards instead of the acrylic for the weights to lay on.

I don't recall ever saying to lay a sheet of acrylic on there but also don't recall saying specifically not to, or specifically to only use boards. Maybe I said that in my head, but how would you know that. If you were the NSA or Facebook, you might know what I was thinking. So I can't fault you.

Most of the time I use a random 2x4, MDF strip, a 12-pack, etc, then put the weight on that.

this was a particularly difficult joint to get in full contact. Hence the multiple types of soda, which have slightly different weight properties (right)

imustbenuts · Jun 15, 2016

Floyd R Turbo said:
What wood trim are you describing? When I do flush trimming, I just run blue tape where the bearing will ride on the acrylic, make one pass, take off the tape, and make a fast second pass to get that mil of extra material.

Yeah, that's how I do it for the outside. I'm referring to the inside cuts. My flush trim bits have the bearings on top. So I can't create a pattern to use from the top. I have to creat a pattern for the bit to follow on the inside of the panel. I plan to use wood pieces I'll cut to size and use double sided tape to secure it in place. Actually I don't use double sided tape. I use masking tape on each surface and superglue the tape together. It works great. I'll snap pics of it while I'm making the pattern.

Turbo's Aquatics · Jun 15, 2016

Oh - so you didn't do your euro cutouts before bonding the top on?

imustbenuts · Jun 15, 2016

Floyd R Turbo said:
Oh - so you didn't do your euro cutouts before bonding the top on?

Correct

Turbo's Aquatics · Jun 21, 2016

Not sure how I missed the reply...

It's definitely a good idea to do the euro cutout before bonding. The reasons are:

1) it reduces weight when you flip the tank over to bond on the bottom - the panel is not sagging in the middle, which can push out the edges at the bottom joint
2) when you have the cutout there, and flip the tank over to bond on the bottom, it provides you with access to the other side of the joint so you can add solvent if needed
3) also it provides for quicker curing of the joint because the inside of the assembly is ventilated

These all are also why you bond the top on first and then the bottom. If you bond the bottom on first, then flip it to do the top, you have no access and are trapping the air inside (but to a lesser extent)

Also as you now know, it's rather difficult to route a cutout with a flush trim bit when your template has to be on the other side of the piece. Template bits with the bearing at the bottom are available but I've never used them

imustbenuts · Jun 24, 2016

Floyd R Turbo said:
Not sure how I missed the reply...

It's definitely a good idea to do the euro cutout before bonding. The reasons are:

1) it reduces weight when you flip the tank over to bond on the bottom - the panel is not sagging in the middle, which can push out the edges at the bottom joint
2) when you have the cutout there, and flip the tank over to bond on the bottom, it provides you with access to the other side of the joint so you can add solvent if needed
3) also it provides for quicker curing of the joint because the inside of the assembly is ventilated

These all are also why you bond the top on first and then the bottom. If you bond the bottom on first, then flip it to do the top, you have no access and are trapping the air inside (but to a lesser extent)

Also as you now know, it's rather difficult to route a cutout with a flush trim bit when your template has to be on the other side of the piece. Template bits with the bearing at the bottom are available but I've never used them

It just seemed it would be just as easy to cut out and route my holes after it was bonded. I only say this because I didn't plan on making a reusable pattern. I could be wrong. Either way it's turning out ok. Here are some pictures of the progress. Unfortunately life is getting in the way of my build and I wasn't able to work much on it last week and won't be able to this weekend.

So, I drew the interior baffles and where I wanted holes on top. Then, I rough cut the acrylic with a jig saw. I used masking tape on the acrylic and the wood pieces and superglued the masking tape together. I could have used double sided tape but didn't have any and didn't want to buy some since I had masking tape and superglue already. I used a scrap piece of 1/2" thick MDF, 1/4 ply, and paint stir sticks to make the pieces to use as a guide for the router. It's all in place and ready to route the top.