14 replies to this topic

[TAiLsChaser]

I was wondering if everyone who has used CPVC has had the problems I have had with them. It was well apparent to me since I put some in my paintball gun as a barrel that darts don't want to go into it very well. I have to screw darts in. I wanted to put a "real" barrel into my LS but I just don't think it's going to work.

Does anyone know where I can get (I guess) "better" CPVC? I would prefer to not order off the internet but I guess if that's the only option, so be it.

And if CPVC isn't the way to go, what other options would be better for my situation?

I heard of brass and PETG being used. What is better?

Thanks.

[Quilan Fett]

As far as I know, and I might be wrong:

1/2" CPVC had an Inside Diameter of .48
17/32 Brass has an Inside Diameter of .5
9/16 Brass has an Inside Diameter of .53125
1/2" PVC has an Inside Diameter of .62
My 9/16" PETG has an Inside Diameter of about .51 or so.

That being said, CPVC and other materials usually come in the standard size. There is some variation, but not much. For your LS, you want a looser barrel, like brass or PETG. It also depends on your darts. Just go to a hardware store and see what fits your darts. Unless you're using stock darts, that is. With stock darts, I'd use either PETG or 17/32" Brass.

[TAiLsChaser]

Alright. Great, thanks.

[xNFx 37]

My darts are relatively thin, but I find that if you go to Lowes, they have a Thick and thin wall CPVC. Very small deifference, but helps alot. I have frost King foam, and that thin stuff, and I don't have to twist either of them in.

[CaptainSlug]

1/2" CPVC had an Inside Diameter of .48
1/2" PVC has an Inside Diameter of .62

Those are off by a good deal. And you're not even including the specifications that affect the dimensions of the pipe size.

1/2" PVC or CPVC pipe will have a .84" OD unless it's made as conduit for running cables. I don't know what the dimensional specs are for conduit.
SCH40 PVC or CPVC pipe will have an ID around .602"
SCH80 PVC or CPVC pipe will have an ID between .527" and .547" depending on where you get it.

PVC or CPVC material choice has no bearing on the dimensions of the pipe unless you are shopping only by pressure rating numbers. CPVC is denser per cubic inch and therefore will be rated for higher pressures and temperatures than PVC of the same dimensions.

What works with your darts is highly dependent on where you get your foam. My optimal barrel ID is .527" (-+ .005") with preferences given to certain materials based on the power source that's firing the dart.
I get both my barrels and my foam from Mcmaster because the consistency is better than what is available locally.

For spring guns I use mostly medium-walled polyester (ID of .548" OD of .572") because it fits my foam very nice and has the right "grip" for spring guns.

For air guns I'm inclined to use either SCH80 CPVC or aluminum tubing (mcmaster part# 1658T49). Both with a .527" ID.
They may be smaller dimensionally but their surface texture is very smooth. ESPECIALLY the aluminum.

Edited by CaptainSlug, 16 January 2008 - 06:09 PM.

[xNFx 37]

ON mcmaster, the foam they have is 3/8 inch, 5/8 inch and something else.

I didn't see any 1/2. The 5/8 inch OD foam had a 1/2 gap though.

Could you give me a link?

[CaptainSlug]

You may be looking at the wrong material. Foam Backer Rod usable for making darts is polyethylene closed cell.

Search for part# 93295K43

[Quilan Fett]

1/2" CPVC had an Inside Diameter of .48
1/2" PVC has an Inside Diameter of .62

Those are off by a good deal. And you're not even including the specifications that affect the dimensions of the pipe size.

1/2" PVC or CPVC pipe will have a .84" OD unless it's made as conduit for running cables. I don't know what the dimensional specs are for conduit.
SCH40 PVC or CPVC pipe will have an ID around .602"
SCH80 PVC or CPVC pipe will have an ID between .527" and .547" depending on where you get it.

PVC or CPVC material choice has no bearing on the dimensions of the pipe unless you are shopping only by pressure rating numbers. CPVC is denser per cubic inch and therefore will be rated for higher pressures and temperatures than PVC of the same dimensions.

I don't know what you're talking about. 1/2" CPVC has an ID of .48 and an OD of .63 or .64. It is off white and almost fits in 1/2" PVC.

[CaptainSlug]

I don't know what you're talking about. 1/2" CPVC has an ID of .48 and an OD of .63 or .64. It is off white and almost fits in 1/2" PVC.

If you go to the hardware store and ask for "1/2 CPVC" you're going to end up with one of three things.

1/2 Schedule 40 pipe (ID around .602, OD .84")
1/2 Schedule 80 pipe (ID around .53, OD .84")
1/2 conduit pipe (same measurements as SCH40 but has no pressure rating and may have one flared end)

Pipe sizes are NOT based on exact fractional dimensions. If you want pipe that has the dimensions you are talking about you are actually buying 3/8 size Schedule 40 pipe.

The pipe size gives you the outer diameter of the pipe, so that all of the fittings for that given size will work with it.
The pipe schedule gives you the wall thickness, which then affects the inner diameter measurement. But there is variability in the ID by up to .015" between suppliers.

Whether the pipe is made from PVC or CPVC has no bearing on the dimensions of the given pipe. The material used only affects the maximum operating temperature and pressure of the pipe. And for our application it affects the surface finish on the inside of the barrel.

Edited by CaptainSlug, 16 January 2008 - 06:34 PM.

[jwasko]

Unless many people (and hardware stores, for that matter) have been sorely mistaken, I'm gonna have to back up the Fett.

1/2" CPVC (unknown schedule...I don't have any with me to read the labeling) has a much smaller outer diameter than 1/2" PVC.

I'm not sure about the ID, except that it is too small to fit over 17/32" brass (about .531" OD)

Edit: Just remembered... my brother once used brass as a CPVC coupler. I think the brass size was 5/8," or maybe 21/32."

Edited by jwasko, 16 January 2008 - 06:39 PM.

[Quilan Fett]

But I heard CPVC is based off of copper pipe and PVC is based off of steel pipe. 1/2" Copper pipe has an OD of .625. I say CPVC has an OD of .63 or so. Logical, isn't it.
I am not trying to get in an argument with you, I just think that we must have different CPVC or that you are mistaken, because I know I bought 1/2" CPVC and it is as I described and most other members of the NIC seem to have CPVC that is like mine.

For example:

Cpvc >>>>>>>>Need to twist darts in.
17/32"brass>>> Need to twist darts in but not as hard.
OMC's petg.>>> May need minimal twisting.
9/16" brass >>> No twisting required.

[CaptainSlug]

I don't think any of us are wrong. It's more the fault of the hardware stores and plumbers for adding confusion to an already overly confusing system of nominal (not representative) sizes.

They're using an existing acronym (CPVC or chlorinated polyvinyl chloride) to describe something that is actually National Pipe Standard 3/8 Size Schedule 40 PVC pipe.

"1/2 Copper Pipe" or 5/8" OD with varying IDs between .527 to .569 is also not sized to representatively match its name.

"1/2 CPVC" is the same thing dimensionally as 3/8 size Schedule 40 PVC pipe.

Edited by CaptainSlug, 16 January 2008 - 07:01 PM.

[Kabuki]

Oh good, it's not just me that can't seem to find suitable CPVC. My town also seems to have an astounding lack of brass and PETG tubes available. I've not had a chance to head in to the locally owned Plumbing and electrical supply house, but none of the four Lowes or Home Depot locations in my immediate vicinity stock a suitable pipe in their respective plumbing or electrical sections.

[jwasko]

Oh good, it's not just me that can't seem to find suitable CPVC. My town also seems to have an astounding lack of brass and PETG tubes available. I've not had a chance to head in to the locally owned Plumbing and electrical supply house, but none of the four Lowes or Home Depot locations in my immediate vicinity stock a suitable pipe in their respective plumbing or electrical sections.

Pretty much the only way to get PETG of the proper size is to order it. And who better tho order it from than the One Man Clan?

As far as brass, I suggest looking for a hobby shop. There is actually a hardware store near me that sells brass, but it's much more likely that you'll find it in a hobby shop. Or, you could order it from somewhere online.

[Quilan Fett]

You can also get PETG from fish and pet stores.