Is it possible to seperate PVC after gluing?

hoyta

hoyta

New member
Hello all!
I have a Euro-Reef skimmer that has a union glued to the output of the pump (the guy before me did a crappy re-circ mod). I'd like to be able to get it off, so I can make the skimmer stock again. Problem is, it is almost impossible to pull the piece off. Would something like acetone work? I have an abundance of it where I work...
Heres a pic of the bad re-circ mod-
DSCF3125.jpg


Pretty crappy, huh?!
Thanks for your time!-Adam
 
use a torch. I watched guys that were installing my pool pull pieces apart by doing that. Of course I would be very conservative with that approach. But I saw it work.. Good Luck. Mike/KD9RG.
 
PVC glue works by melting the surfaces of the pipe and then allowing them to reharden. "Glue" is sort of a misnomer, since the physical properties are changed. That's what you're up against. I guess if someone saw a torch work then it does actually work, but it's kind of hard to figure out why it would.
 
i wouldnt try a torch...chances are it will end up burning or melting the union or another surface..ive had luck using a heat gun...looks like a hair dryer..but i wouldnt advise using it for that!!! just work the heat arond the joint till it soften..and carefully twist and pull at the same time. Ive done it on pvc sizes ranging from 1 1/2 to 6" , important thing is to take your time and heat it slowly and evenly...as the previous poster mentioned your actually solvent welding the pieces together, the primer softens the pipe and when the glue sets it makes the two pieces as one...now if your lucky the person who made the joint didnt use primer...it will be easier to get the union off... HTH
 
PVC cement is a solvent just like the weld-on products for acrylic. My best guess is the torch example was a slightly different situation. Maybe the joints weren't completely set or were attached with a different type of compound. I would not take a torch to a fully set joint and expect it to do anything more than make a mess.

Hoya, I think your best bet is either a saw, like someone already suggested, or using a primer to gradually soften the pvc around the joint. I've done this before to slightly change pipe's diameter. Just apply primer to whatever you're trying to loosen, give it a few seconds to soften the material, then scrape away what material you can with a knife or razor blade. If you've got a pipe glued solidly all the way into a fitting this probably won't work as you'll never be able to get all the way into the joint, but if it's some kind of makeshift joint he made to attach the pvc to that tube then it just might work. By the way, you can find primers that aren't purple as I'm guessing you don't want to end up with a half purple skimmer.
 
pVC cement is not a solvent...the primer used is an acetone base that is used to soften the polyvinyalchloride, its a 2 part process just like a 2 part epoxy ..one wont work without the other. Hey woz...that avatar is awsome!
 
i found the best way and cleanest way to do this is:
cut the side you can or want to replace
get a dremel and grind one spot slow till you see that you made it thru to the other piece.
then get a flat screw driver and work it into the seam and the whole thing will pop right out
i do alot of diy crap and end up wanting a piece i glued together this works everytime
 
pVC cement is not a solvent...the primer used is an acetone base that is used to soften the polyvinyalchloride, its a 2 part process just like a 2 part epoxy ..one wont work without the other. Hey woz...that avatar is awsome!
Click to expand...

Well, they won't work well without each other. However, both parts are in fact solvents: the primer is more concentrated while the cement itself is a mixture of resin in a solvent solution. Just look at the MSDS sheets here. I should have specified that I was referring to the solvent and cement being used in tandem. I actually had Weld-On #16 in mind which would be very similar in nature to the PVC cement by itself so I really wasn't that far off (obviously though WO 16 being for acrylic while PVC cement is used for PVC). The primer by itself would be similar to say Weld-On #4. In fact you could use just the primer by itself if it was possible to apply it as we do Weld-On (pins method). But, that's just not practical so a heavier, "filler" type of cement is necessary in most applications (sound similar to Weld-On 16 to anyone else?). Definitely not an epoxy, the solvent is not a hardener which would be the similarity to epoxy.

Thanks, Glad you like the avatar.
 
use a hack saw, cut on the side piece that you want to throw away. Then use the hack saw, slide them to many small pieces, use the slot screw driver chisle them out. sand paper the good pieces and reglue. It works.
 
<a href=showthread.php?s=&postid=10792728#post10792728 target=_blank>Originally posted</a> by halcyon_diver
pVC cement is not a solvent...the primer used is an acetone base that is used to soften the polyvinyalchloride, its a 2 part process just like a 2 part epoxy ..one wont work without the other. Hey woz...that avatar is awsome!
Click to expand...

Sorry, but I have to disagree 100%

1) The primer essentialy the same as the glue, but without the solids content (dissolved PVC)

2) The glue may be less agressive as a solvent to help control evaporation and ensure a uniform bond.

They are NOTHING like 2 part epoxy. 2 Part epoxy is resin that forms a polymer (plastic) by the process of polymerization.

PVC pipe is glued by chemical solvent welding. The pipe is literally melted and tightly pressed together where its components intermingle and dry together.

The PRIMER helps to break the surface sheen on the pipe and is therefore a stronger solvent. The glue is a lesser solvent with solids to help fill any gaps due to the socket not fitting tight enough around the pipe.

The larger the pipe, the more solids the "solvent cement" will have. The solids help to fill the gaps as well as slow down the evaporation of the solvent.

The sockets are tapered. As you twist and press the pipe into the socket, the soft pipe and socket walls are pressed tightly together.

Acetone is one possible solvent, but most modern PVC glues have the following:

PRIMER is the same STUFF as CEMENT without the fillers. That "stuff" would be the SOLVENT. The CEMENT is SOLVENT with PVC fillers added.

Please look at the ingredients:

Oatey Purple PVC Primer:
Methyl Ethyl Ketone 25 - 80%
Acetone 0 â€"œ 40%
Tetrahydrofuran 5 - 30%
Cyclohexanone 10 - 20%

Oatey Medium Bodied PVC Cement:
Methyl Ethyl Ketone 10 - 50%
Tetrahydrofuran 25 - 50%
PVC Resin 12 - 20%
Acetone 0 â€"œ 20%
Cyclohexanone 5 - 15%
Amorphous Fumed Silica 1 - 5%

Notice that the ONLY difference between the PRIMER and CEMENT is the PVC RESIN (AKA FILLER) and the fumed SILICA (another filler that makes the cement more thixotropic). Of course we can split more hairs about the percentage of each ingredient... but that would be REALLY splitting hairs. The only major percentage difference is the Acetone. I will leave it to you to determine why...

So both the cement and primer are solvents. The Cement has PVC resin in it with a thixotropic agent to keep it from running.

So please lets not split hairs here. The primer and the cement are the same. There is no polymerization or glue. We melt two objects, cram them together and let the melted components mix and dry. We add a little bit of melted PVC to help fill any gaps due to imperfect sockets.
 
hey guys,
im not trying to start a debate...what i can offer is 27 years in the pipe trades, ive experienced every type of piping materials that are out there and am just offering the experiences ive had in regards to the original posters question...i have removed PVC piping that has been WELDED together and would offer the same advice to anyone who would ask the same question. Although im a newbie in the salt water aquaria world...im a well seasoned professional in the pipe trades...
BEAN Anmal...not trying to split hairs at all...just looking to help this guy get his question answered and hopefully resolve his issue...ever wonder why primer is colored??
 
Basically what I said, much better wording. And those % that Bean listed are maximums, each ingredient has a surprisingly large range.
 
Halcyon, we're trying to help too. The fact is I said it's a solvent and you disagreed. It is a solvent, that's all there is to it.
 
hey woz,

i conceed..i did take a look at the 4 cases of glue i have in my shop...and yes...it does contain solvent...bottom line is....the method i reccomended to the original poster works...
 
<a href=showthread.php?s=&postid=10794064#post10794064 target=_blank>Originally posted</a> by halcyon_diver
hey guys,
im not trying to start a debate...
But your comments DID/DO deserve attention :)

what i can offer is 27 years in the pipe trades, ive experienced every type of piping materials that are out there and am just offering the experiences ive had in regards to the original posters question...
Click to expand...
 That still does not make "PVC SOLVENT CEMENT" glue or epoxy, it is a solvent with some dissolved PVC solids to help fill the gaps :)

i have removed PVC piping that has been WELDED together and would offer the same advice to anyone who would ask the same question.
Click to expand...
 The key word here is WELEDED. The "weld" does have different physical properties than the two components that form the weld. It is possible that SOME may be disassembled. In theory it should not be possible, in reality it is. SOLVENT WELDING is exactly what we are doing. A proper joint should NOT be reversible.

Although im a newbie in the salt water aquaria world...im a well seasoned professional in the pipe trades...
Click to expand...
 Glad to have you in the hobby! I am not discrediting your time in your trade. I am just pointing out how PVC "cement" works and that it is not a "two part" glue. Many of us have spent many accomplished years at a trade, that does not mean we have all the answers, even if we are good at what we do :)

BEAN Anmal...not trying to split hairs at all...just looking to help this guy get his question answered and hopefully resolve his issue...ever wonder why primer is colored??
Click to expand...
 The primer is colored so that the inspector can SEE that it was used. I pasted that stuff from another PVC thread that I participated in... the hair splitting was there :)

I am not trying to beat up on you either... I am just a stickler for getting the details right!
Click to expand...
Click to expand...
 
You must log in or register to reply here.

Similar threads

L
Adapting a Venturi to old reef octopus skimmer
Replies
2
Views
1K
wvned
wvned
G
Back after 20 years - cycling advice
Replies
4
Views
143
Guygettnby
Guygettnby
D
Which sump would you choose?
Replies
5
Views
335
Devilphish
D
S
Tank is not cycling
2 3
Replies
44
Views
821
wvned
wvned
E
What's Old is New Again
Replies
2
Views
481
Uncle99
Uncle99
Back
Top