Acrylic wizards, need input on modding a Nilsen reactor

[cr500_af]

I have had it with my old MRC kalk stirrer. Now I see why they changed the design, and I want to mod mine to a "recirc pump" style and get rid of the little magnet-driven stir stick thingy. It's just too much of a hassle to take it apart and fix when the stick jumps off its pedestal, which is quite often.

What I need to do is drill the sides of the body and install fittings so that I can attach a small Mag pump or similar to stir it. I don't know what would be the typical way... pvc fittings in the acrylic tube? There is a Weld On for that, but I've never seen it for sale. I am looking for ideas on an easy way to do it that will also be reliable... in this case "reliable" is simply defined as "it ain't gonna leak".

I had also thought about drilling and tapping the top, and dropping a pipe down from one of the holes on the inside so that the water circulates throughout the length of the body. This sounds easier, but I'd like the top to be easy to remove for cleaning and refilling... and having a pump attached to the top would make that more of a hassle.

I will run the recirc pump and the ATO both on my RKE as multi timers, set up so that the reactor mixes twice a day, and the ATO is shut down for a period of time following each stir... probably stir for two minutes and let it settle for an hour before allowing the ATO to work again.

Any input from any of you MacGuyvers (*cough* Andy *cough*)?

 

[johnr2604]

I'm guessing you are not comfortable with a uni-seal ?

 

[enderg60]

yup uniseal would work. Or you can just seal it up with household goop. I would highly suggest using unions to be able to remove the pump for cleaning/replacement.

BUT, pumps on kalk reactors always go bad and fast. Have you looked at the ones that have the electric motor on top attached to a metal bar that rotates and stirs?

 

[mikesommers]

You can use a MaxiJet they are cheap and work just fine. The pumps last longer if you use aquarium grade Kalk and not pickling lime. The pickling lime is very coarse.

 

[cr500_af]

I don't want to use uni-seals. I don't think they are long-term leak proof.
I was thinking of trying to retro a stirring lid like the one Avast sells on their kalk stirrer, but I understand that it isn't as simple as plunking a motor on the lid. I think the lid has to be made to accept the proper shaft seals.

 

[enderg60]

you can use weldon #16 to bond acrylic to PVC and then just go over it with goop for good measure. Ive dont that a few times.

Also if your kalk reactor is hgher then your sump, you dont need to seal the lid.

 

[rbredding]

cr500_af;554575 wrote: What I need to do is drill the sides of the body and install fittings so that I can attach a small Mag pump or similar to stir it. I don't know what would be the typical way... pvc fittings in the acrylic tube? There is a Weld On for that, but I've never seen it for sale. I am looking for ideas on an easy way to do it that will also be reliable... in this case "reliable" is simply defined as "it ain't gonna leak".

to drill the side, use a drill press if one is available and drill first with a very small (1/6") drill bit to form a pilot hole for the larger bit
weld-on 16 will secure pvc to acrylic (but you don't use it like a caulk, it is used as a glue applied to the contact surface of both pieces)
after drilled, you can either tap it with an IPT tap that matches your "threaded male pvc fitting" or you can drill the hole so that you can weld pvc conduit directly to the acrylic... either way will work.. (the hole would be drilled the exact thickness of the pvc pipe and then use a light sanding around the outside of the pvc so that the fit is snug, not loose)

cr500_af;554575 wrote:
I had also thought about drilling and tapping the top, and dropping a pipe down from one of the holes on the inside so that the water circulates throughout the length of the body. This sounds easier, but I'd like the top to be easy to remove for cleaning and refilling... and having a pump attached to the top would make that more of a hassle.

the easiest way is to attach a "union" to the top, and instead of using the small unthreaded side of the union, just use a piece of 1/4" acrylic as your "cap" it will be held in place with the threaded ring on the union.