sealing pvc threads and acrylic tubing

[georgeortiz]

Hi,
I was wondering if anyone could tell me the best way to seal a pvc fitting to an acrylic tube. I am using acrylic for a Calcium Reactor housing that I built and I was about to declare victory when I noticed a pinhole leak appeared. I am using a 90 degree street l with the threaded end penetrating the acrylic housing at the base. This leak went un noticed since my wet testing did not duplicate the pressure experienced in the housing when it was full. I have enough material to make another reactor but, before I do I want to get some advice on making that connection leak proof at the base.

[LoneStar]

Weld On #40

http://www.craftics.com/products.cfm?Category=80

[georgeortiz]

Lonestar,
Thanks! Let me mention that I used weldon #40, marine goop, for this part already. Is there a good technique or other tip or trick to use these to make sure the joint holds watertight?

[Darth-Tater]

Hey George, ask Ace (Hobogato) he is the man when it comes to acrylic

David

[matt]

I'm not sure exactly how you made the joint, do you have a photo? The way that I do it is to use a female fitting adapter, female threads by spigot fit (it's a hard fitting to find) so that I'm not "threading" the PVC into the acrylic. I use a router and template to rout a hole the exact size for the spigot fit adapter, then coat the fitting with weld-on #40, then push and twist into the hole, so the weld-on #40 really fills the joint. Still, I've had some leaks at those joints before, usually because I either didn't get enough #40 in the joint as opposed to on top of it, or I used weld-on #40 that was getting close to the expiration date. Your best option at this point, assuming you can't get it apart, would probably be to use a dremel and small file to get as much of the adhesive off the top of the joint as possible, really clean it up, and spread a thin layer of new weld-on #40 right around the joint. It would be helpful to use an aspirator (that's a syringe without the needle) to get the adhesive right where you want it. You also have to be very careful to make sure you get an accurate 20:1 ratio of resin to activator when mixing the #40. I've found an old salifert test kit that has the 5ml and 1ml syringes works well to get the measurements right.