pvc primer question

[jimmy101]

I think BC Pneu is right. Though acetone and MEK may dissolve PVC somewhat they both evaporate so quickly as to be ineffective at doing what primer (or glue) is supposed to do. Acetone brushed on a piece of room temperature pvc will evaporate almost instantly. MEK isn't much better.

THF and cyclohexanone are both higher boiling and will hang around long enough to actually dissolve significant amounts of PVC.

Besides, if cleaner and primer are basically the same thing then why is priming (1) required by most building codes and (2) only acceptable if done with primer and not cleaner?

(ya, I know, code acceptable primer has dye(s) in it. A joint must show the dye to be "up to code" even though the dye itself does absolutely nothing for the strength of the joint.)

EDIT: Too much Engrish, even for me.

[dongfang]

Hi,

I have never seen a PVC primer in here (Denmark, Switzerland). Just the cleaner (and there appears to be only one brand on the market, Tangit).

So, I use cleaner, then cement. Works great. The cleaner softens the PVC a little. As far as I understand, the cleaner is 100% solvents, a primer it a lot of solvents with a little cement, and the cement is lots of cement in solvents.

It seems to me to be just a different approach. I never had a failure with it so far....

Regards
Soren

[jimmy101]

Dongfang: There is really no such thing as "cement" in PVC glues. The "cement" is just dissolved PVC. Perhaps the fomulas are different in Swittzerland, but in the US primer does not contain PVC ("cement"), only glue does.

[meatballs]

here's an idea. try putting some cleaner and primer in glass jars and then drop in some pvc and see what happens. if the cleaner and the primer do the same thing to the pipe (dissolve it) then that would suggest that either works to prime the pipe. if the primer dissolves the pipe faster, but the cleaner also dissolves the pipe well, then it could be concluded that say a double or triple application of the cleaner might be equivalent to the single application of primer.

and has anyone ever tried using tape or anything to protect pipe/fittings from primer while gluing? it works with painting, and i dont see why it wouldn't work here, if your careful and used tape to protect vulnerable areas it would be possible to make a nice neat joint using purple primer. its the stains on the pipe/fittings that are ugly, but i at least dont mind a little ring of purple just where you can see the cement, and where some may have been squeezed out.

[BC Pneumatics]

There is no need for all of this guys. Just do things they way you are supposed to, the way it is safe. Is anyone here really that concerned with saving a few bucks?

[singularity]

meatballs i did that they both dissolved it but the primer did it a little faster ( i thought i posted that earlier....) and bc im going to buy the primer and a stun gun from you anyway (just got to wait till my friend gets back)

[jimmy101]

and has anyone ever tried using tape or anything to protect pipe/fittings from primer while gluing? it works with painting, and i dont see why it wouldn't work here, if your careful and used tape to protect vulnerable areas it would be possible to make a nice neat joint using purple primer. its the stains on the pipe/fittings that are ugly, but i at least dont mind a little ring of purple just where you can see the cement, and where some may have been squeezed out.

This not only works but is really the preferred way to glue PVC.

The tape does two things, one very important for the structural integrity of the gun, and the other for purely aesthetic reasons.

As we all know a piece of pipe should be inserted to the full depth of a socket. Usually, you measure the depth of the socket then make a mark on the pipe to show how far the pipe needs to be inserted into the socket. Only problem with making a mark is that primer (or cleaner) removes and/or obscures the mark. (And, of course, everyone always uses primer on their joints.)

What I do is;
1. Make a couple pencil marks at the proper distance from the end of the pipe.
2. Wrap a layer of painter's tape (great stuff, leaves no residue behind when removed) around the pipe.
3. Prime then apply glue to both pieces.
4. Insert the pipe into the fitting, with twisting, until the fitting reaches the tape. Hold in place for ~30 seconds. (if the pipe is released to soon it has a tendency to push itself back out of the fitting.)
5. Remove the tape. Depending on where you placed the tape, and how far you got the pipe into the fitting, there will be a nice straight purple line around the joint.

Usually, the line is so crisp it looks like you did it on purpose (which of course you did), much nicer than purple streaks, blobs, smears …

[Velocity]

PVC Cleaner > Nothing
PVC Primer > PVC Cleaner

PVC Cleaner will slightly soften the PVC pipe, but not nearly to the extent that PVC Primer will. I am not really sure why we are arguing about this, because Clear PVC Primer is the best of both worlds...

Jimmy- why is it that Clear PVC Primer cannot be used in building?

[singularity]

it can its just harder to find... and were pretty much done arguing the end result was i should just i buy some clear pvc primer from BC

[clide]

Jimmy- why is it that Clear PVC Primer cannot be used in building?

Because the inspectors can't tell whether it has been primed or not if there is no dye. If primer was not used then it is not up to code and they will make you rip it out and do it over again. Primer is absolutely necessary for a proper bond.

[jimmy101]

Like clide said.

Code requires the use of primer.
The dye in primer does nothing except prove that primer was used.

No purple stain = failed inspection (regardless of if clear primer was used or not)