threaded fittings offer more restriction than slip fittings..avoid unless necessary.

what glue you use is up to you..i use oatey's clear primer and grey cement, haevn't have a problem...if you do get a small leak, just clean off with a damp cloth (after the cement is dry) and just put another coat of cement over the fitting..has always worked for me

I agree.
I just learned, last week, that the only reason purple primer is purple is so that building inspectors can see that a plumbing contractor has been using it. They see the purple all smeared on the pipe were the joint(s) is/are.
The clear stuff is essentially the same...just not dyed, so you won't get the purple mess on your piping if you use clear primer.
If you don't need your work "inspected", I'd go with clear primer.

Cheers,

pvc
 

Hi all ,Johnny reefer wrotedoes'nt everyone get there piping inspected :biggrin: about threaded fittings i found that it is good to use them on the unions,I had a union split at the ring and if it was not threded i would of been cutting and glueing.Paul

all good info I used the stuff from home depot but now would have left more space and some threaded parts too.