(build up) adhesives for PVC poly vinyl nylon etc.

[majstersztyk]

Hello everyone
it is my first post so please be gentle on me lol

Nerveless i am in the process of designing custom filtration/ terrarium.
i can go on into explaining details, but this is not the question that i have
(so please dont be like a hardware store guy....what is it for?)

keeping it incognito..

I am fabricating set of fittings, but the problem is that they are out of different materials, I am trying to keep mechanical connections in the most locations (by having compression fittings and o-ring type of seals)
I need to joint water tight and non toxic:
pvc to nylon
pvc to poly

The trick it that these will be not precise cuts
i can keep tolerances to +/- millimeter (1/16-32")
so not only i need adhesive, but a build up adhesive

Can anybody give me a hint of which adhesive i can i use for this project?
or is it even possible to join these materials at all without risks of leaks.
ps: no pressure involved in the flow

[discussmith]

You are going to struggle getting a water tight fit. It is as you're aware the manufacturers do not make the sizes interchangeable with differing materials. I've had some success connecting differing types by using fittings with a male or female thread that is of a common denominator, ie 1/2" mpt (male pipe thread) and coupling them together. I have also been able to find compression fittings that are capable of squeezing slightly differing diameters in some materials.

[majstersztyk]

that is the biggest problem with experimental or non cookie cutter designs

i will thinker a bit about it

One time during high price of gas, me and my friend have build hydrogen cell out of pvc. It was pressurized high temp system. He used some weird marine adhesive which was almost like 2 part epoxy, or 2 part glue used to fix broken automotive bumpers (made out of abs or something like that) which is tough to joint.

Problem is that i bet that those adhesive are probably poisonous so not really good for my application.

Thanx for hint!

[Jhhnn]

Poly and nylon are extremely difficult materials to bond to anything because they're slippery on a molecular level. Mechanical fastening with threads, clamps, flanges/gaskets, or whatever are the norm with those materials...

[roybo]

If you gotta go with some kind of epoxy or other (super glue) type of adhesive to make things work for you. Clean both surfaces thourly first! Let the glued joints air out a day or two in the sun. Rinse with 25% bleach solution. Treat with clhorine / chloramie water treatment. Air out again for 1 day and you should be good to go. most harmful stuff will be disipated by the open air. Also If you have to bond nylon, delron, etc make sure to abrade the bonding surfaces thouroghly with 100-80 grit as these are cousins to teflon and will only stick when your cooking hamburgers or somthing you are really hungry for. Additionally use stainless steel hose clamps on these joints whenever possible for added protection, I've have had steel ones break on my boats plumbing and do not trust them, I now use 2x SS clamps on everything below he waterline. Flooded fishroom recoverable , flooded cockpit could spell serious trouble.

Roybo

[adam_withrow]

another option (provided the PVC is the larger diameter) is to heat the PVC up until its soft, slip the other pipe into it, and then use a screw down pipe clamp to tighten the PVC to the other material. it will create a tight fit. then, allow the PVC to cool all the way off, slip the pieces apart, use regular PVC cement and put them back together.

[rubinsteinnyc]

majstersztyk, Polak?

[jeff@zina.com]

JB Weld epoxy. Works on everything and is strong.

Jeff