SpudFiles

If you dont use primer it will still glue the parts together, and if the pipe is not pressurized you dont need primer, but in a connon, you deffinatly need the primer. If you dont use it the parts will just pop off and you will have to do it all over again. Its best to do it right the first time that way you dont have to go back and do it again.

Thats what I thought, but why would they put a pressure rating of 150 on it if it was going to pop off easily?(I dont plan on going past 125)

the primer and cement combo in effect "welds" the two pieces of pvc as one.

Also, would softening the pvc with heat rather than chemicaly have the same effect?

im guessing no, but even if it is, why would u go trhough all the trouble to heat the pipe when primer is so much easier.

Should I just buy primer anyway?(I currently dont have any)

in aus, it costs like 6 bucks for a can of primer that will last u a lot of cannons. go buy some, trust me.

Don't soften it by heat. You will either mess up and melt your gun (I've done it...don't ask) or the bond will be significantly weaker. The chemical method is the best way to go.

If you are making a combusion, primer isn't such a big deal (you should still use it though). For pneumatics, primer is a must. It strengthens the bond by alot.

make sure you get pvc glue and not abs glue because they don't work together . if you use abs pipe and pvc pipe on the same gun you need an all purpose plumbing glue. 8)

Dont give people the idea of using abs and pvc together

what about a PVC chamber, and an ABS barrel? What would be wrong with that?

@pyrogeek

PVC and ABS don't bond well, so if you fire anything that makes friction with the barrel, you'll just shoot your barrel off.

@anyone who is wondering

Always use primer on PVC NO MATTER WHAT. I think "primer" is a misleading term. It is a solvent. PVC is a polymer. The primer softens the pipe (chemically, you can't use heat), and then the glue is applied. This depolymerizes (A polymer is a molecule that can bond with itself and make a long string of molecules, so depolymerization separates some of the strings from one another.) the PVC temporarily, and then the polymers get tangled. This means that the two separate pieces literally become the same piece of pipe, and they are therefore able to withstand at least the pressure rating of the weakest component.

Correct me if I'm wrong, but I'm pretty sure about this.

You are correct.

You can do a PVC/ABS cannon- just connect them with threaded fittings.

I never trusted that "transition" cement.

multipurpose cement works fine. At first, I also thought it was a little sketchy, but it works ok.