# PVC question (no.....not about grounding)



## big treble (May 10, 2012)

I saw a video of a guy installing a PVC DC system, and while he was on video tapping joints and dust gates with a rubber mallet, nowhere did I see him using cleaner and/or cement to install.

I'm in the process of reconstructing my DC System with PVC and would have uses cement to connect the pipe. Is there a reason not to glue the pipe and fittings?


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## SteveEl (Sep 7, 2010)

Yes, you can take them apart and rearrange them or clear a clog. If you seat them well dry you won't lose any noticeable pressure


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## Fred Hargis (Apr 28, 2012)

I also highly recommend you do not glue them together. If you have a joint that has a load on it (like a ceiling drop) use 1/2" sheet metal screws through the thick part of the fitting. But I do suggest you seal the seams with silicone. I have a guage on my system and could actually see the increase in air flow when I sealed mine....it also eliminates that really annoying whistle some leaks can make. Back to the not using glue part: there will come a time when you need to take things apart...DAHIKT!.


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## SteveEl (Sep 7, 2010)

I've never noticed whines on mine... if they were there, the shop vac must have drowned them out. Interesting bit with the pressure gauge. Had you noticed performance difference before the gauge gave you a number?


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## FrankC (Aug 24, 2012)

You can also seal the joints with duct tape which makes it easy to take them apart if you have to.


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## Fred Hargis (Apr 28, 2012)

Absolutely. The gauge is fastened to the DC plenum, so it was in place when I first fired it up with the new ductwork. The way this one works (it's a Magnehelic on the discharge plenum to monitor the filter) the less air moving, the lower the reading. Before I sealed the ductwork, I was reading almost 3/4" of H2O, after sealing it read 0" H2O (with all the gates closed). This is on a 5 HP cyclone with 6" PVC.


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## big treble (May 10, 2012)

Awesome, tips guys thanks. 

I'm not to that point of hooking my DC Back up yet, but I would have glued it simply putting a wye on the end if a run with a clean out at that point where I could run the tape of a fat max down should I have a clog.

Still will put the clean outs in, but won't cement and will seal with some type of caulking.

Thanks.


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## big treble (May 10, 2012)

So after looking at all the PVC, It looks as though schedule 40 is the only type that I can buy adapters for that I can hook standard DC accessories and hoses to, is this correct?



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## Fred Hargis (Apr 28, 2012)

I don't think so; I don't believe there is any pipe you find that will accept "standard" DC fittings (whatever they are :laughing. The first rule of DC ducting is that nothing fits anything perfectly. You will have to have workaround for just about everything. This will include, but not be limited to, slits in the end of the pipe to allow you to squeeze it down, a heat gun to warm it up enough to stretch it out, wooden donuts that fit between to different size, lots of duct tape (for obvious reasons), and if you have any metal at all a pair of crimping pliers is handy. At least that's how it has always worked out for me. You will find that 6" flex and 4" flex can be squeezed into female drain pipe fittings with a lot of effort. Also it seemed to me that a 4" port from one company was a little different than a 4" port from another company. You really don't want schedule 40 pipe, it's too heavy and it costs more. What you want is thinwall, soil pipe, DWV, or most correctly: ATSM D2729 (it will be printed on the side of the straight pipe).


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## woodnthings (Jan 24, 2009)

*I would not caulk or silicone*

A few wraps of electrical tape, it comes on 1" and wider, will seal off any leaks AND it will be easy and very clean to remove if necessary.

You can use couplers, double females, rather than the bell ended type that fit to eachother. A little bit $$ more initioally, but you can have a more versatile system that way.

These fittings are a slip fit, almost leak free, into the couplers, and available using the part number JW1047 in the photo from Woodcraft:


 

I use them as a quick connect right to the dust collector and to the machine.


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## big treble (May 10, 2012)

I appreciate the responses, I did get a couple of these...
I'll try tog gets couple of the ones you suggested woodnthings.

Probably just try a coupled pieces of PVC and take back what won't work.


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