View Full Version : PVC glue vs cement?
celliott_sa
Jan 14, 2013, 01:06 PM
I have pvc 4 and I am making a dip bar with it. I told the Home Depot guy Cement, but he gave me glue. I told him there must be a difference and he said no. I am worried my weight with cause it to break, also I did not prime. Is glue sturdy enough and did I need primer? I already glued 3 pieces.
massplumber2008
Jan 14, 2013, 03:07 PM
You need primer and cement. Joining PVC is a WELD process not a glue process! Without the primer you are essentially gluing the pipes together and have weaker joints than if you had used an appropriate primer and cement to weld the joints together. Use the correct primer and cement and you will never have an issue with the dip rack!
I cannot speak to PVC glue... never heard of it, but if it says it is approved for PVC then it is... still need primer!
Mark
celliott_sa
Jan 14, 2013, 04:18 PM
Thank you mark. What if I do not use primer but use cement?
celliott_sa
Jan 14, 2013, 04:21 PM
Can reads cement. Now, if I did not use primer.. can it come apart? Worried here. Lol
massplumber2008
Jan 14, 2013, 05:01 PM
Plumbing stays relatively still except for basic expansion and contraction, but for your application you can expect a great deal of flexing and bending of the piping (as well as expansion and contraction), so if you ask me, you definitely want to use the primer. It is what allows the two parts (pipe and fitting) to premelt so they can be WELDED together when the PVC cement is applied!
A welded joint will never crack or come apart... I promise!
mygirlsdad77
Jan 14, 2013, 05:04 PM
For safety here, I would suggest starting over with primer and cement as Mark already suggested. PVC fittings and pipe are relatively inexpensive, so why not take the safe route? Also, as already mentioned, using the cement without the primer is just gluing the fitting together which is not even close to as strong as priming then cementing, which creates a "weld" of the fitting. If you want to go the extra mile, you could even get a can of cleaner, a can of primer, and a can of cement. This three step process is pretty much fool proof and will give you an overall strongest connection possible.
ballengerb1
Jan 14, 2013, 06:01 PM
Curious, what is a "making a dip bar "
massplumber2008
Jan 14, 2013, 07:18 PM
See image below, Bob... ;) This may not be exactly what Celliott is building, but I imagine it to be something very similar! This device is used to develop the triceps muscles and the lower pectoralis muscles (device design arms should angle in for most effective workout).
massplumber2008
Jan 14, 2013, 07:47 PM
Hey Lee..
You said, "If you want to go the extra mile, you could even get a can of cleaner, a can of primer, and a can of cement."
What are you talking about here? Only thing ever required with PVC is a primer and cement... what is the cleaner for... primer does the cleaning/softening according to every can of primer/cement I've ever read?
Celliott must be double confused for sure now!
Back to you...
mygirlsdad77
Jan 15, 2013, 06:13 PM
All I know is they make a cleaner, a primer, and a cement. UPC says to clean, prime and cement PVC. I have been told that the cleaner and the primer do the same thing, so either is just as good as the other, and using both is a waste of time and money. Thoughts? We use Weld-On. Sometimes our supplier sends us cleaner, and sometimes they send us primer (all clear). I can't tell the difference between the two. Both clean and soften the pipe. Is there a real difference, or just another way for them to make money?
massplumber2008
Jan 16, 2013, 07:18 PM
Very interesting Lee!
I looked at the MSDS safety sheets on these products and found that the PVC CLEANER is primarily methyl ethyl ketone and acetone while the PVC PRIMER is methyl ethyl ketone, acetone, cyclohexanone, and tetrahydrofuran. I didn't really know that there was a difference!
Of interest here is that is that they also make a combination purple primer/cleaner. Guess the chemical composition... Yup! Methyl ethyl ketone, acetone, cyclohexanone, and tetrahydrofuran, same as the primer EXCEPT the ratios are different from the primer!
Anyway, understanding that UPC requires this, and I now appreciate why you mentioned it, but like you said, "Is there a real difference, or just another way for them to make money?"... I can't say for sure!
I know in my state, under my code (and all New England codes that I know of), only need PVC primer and cement!
Thanks for posting Lee!
mygirlsdad77
Jan 17, 2013, 05:54 PM
And thank you for looking into it, Mark. Appreciate that. I can say that I have noticed no difference in the strength of the weld with either primer or cleaner. Both seem to soften the pipe the same, and you can't get either of them apart after a few seconds or so. Even when trying to heat and remove pipe from the fitting, via cutting and prying (you know what Im talking about) I have found that using just the cleaner and cement is just as stubborn as the primer and cement. So I guess in my experience, the cleaner, or primer seem to do the same things. Maybe one for mythbusters?
massplumber2008
Jan 17, 2013, 06:38 PM
Mythbusters! Don't you joke about them/this! I'd say this may actually be one for them! If you don't e-mail them about this I will... :)
Great idea! LOL!!
Mark
mygirlsdad77
Jan 17, 2013, 07:32 PM
I will leave this in your hands. Just make sure to let me know when the episode airs. Ha.
EPMiller
Jan 18, 2013, 05:48 PM
Hah, interesting. I never went that deep into it with the ingredient lists side by side. I thought primer and cleaner were the same. Around here all primer is purple primer. I thought the purple was just so the inspector could tell that the joints were definitely cleaned/primed. I use the clear cleaner on CPVC and pressure (supply) PVC and the purple primer on DWV. I hate seeing purple runs on the side of pipes so I'm pretty careful to only prime only as deep as the socket.
mygirlsdad77
Jan 18, 2013, 09:44 PM
Thanks for your experience EP. I think the color is strictly for visual inspection. The color doesn't add to the integrity of the weld, just a dye. I agree, this is interesting stuff (for those of us that use this stuff on a daily basis). Hope to see some of the other folks here give their input.