How to fit John Guest to PVC

[Shoelace]

I've been reading up on doing my BeanAnimal.  I have never tapped a PVC to add a John Guest fitting and can't seem to find detailed instructions.  Can anybody give a summary of how do this?  I understand I need to get a tap and die (which is hard to find locally).  Is it as easy as drilling a hole and creating threads with the tap and voila?  Thanks.

[Der ABT]

best way to find the tap locally is go to a hardware store. lowes etc does not have the correct thread well ive never found it there.

 

basically drill a pilot hole designated by the tap size, tap hole....use teflon tape....1 min later all is done.

 

Put your location in your signature, if your anywhere near Falls church i would be happy to help, i have a tap

[Coral Hind]

It's as easy as drilling a hole and cutting threads. You can also just drill the hole and glue in the fitting with 3M 5200 Marine Sealant. There is really no pressure on this fitting since it is a drain.

[Shoelace]

Thanks for the info.  Sounds pretty straight forward.  Thanks for the offer, but I'm up near Columbia.    I'm hoping the Harbor Freight near me has a set.

[Der ABT]

i found mind at the local hardware store (the mom and pop version) they generally have a much better "specialized" section

 

i think its 1/4-20 npt that yuo need (ive heard of harbor frieghts npt tap sets having it.

 

but save a trip and just drill and glue as coralhind said

[Shoelace]

Thank you, both.  I'll look around for the tap, if it's a pain to find, I'll drill and glue.

[Coral Hind]

Where about are you located? Maybe a local reefer has a set you can use.

[Nytelighter]

I went thru the same deal when I built my bean animal.  Never could find the right size tap so I drilled a pilot hole like Der ABT said earlier, fitted the john guest in snugly and then sealed with teflon tape on the threads and a little silicone around the base.  Worked like a charm.  I just started my build thread yesterday and you can see my bean animal build on there.

[Enkay]

Hmmm, not sure what a John guest is but I have a bean animal and I did not have to do this. But then, mine is not very sophisticated. Its the bare minimum which does the job.

[Marc Weaver]

You need a 7/16" drill bit and a 1/4" NPT tap.  My lowes had the tap, but that's way out here in Hagerstown, MD.  Maybe sears?  http://www.sears.com/shc/s/p_10153_12605_SPM2675956702P?ci_src=184425893&ci_sku=SPM6299307603&sid=IDx20130125xMPTLSx025&s_tnt=48014:0:0&executed=true&PDP_REDIRECT=false

 

EDIT: I hate it when national stores sell other people's stuff too, that link is not for Sears, but you get the idea.

Edited October 30, 2013 by Marc Weaver

[AlanM]

I have a tap and die set here, but not anywhere near you.  Often you can buy a set which includes the correct drill bit plus the tap and the handle that lets you turn it into the hole. 

[BowieReefer84]

I have a tap and die set here, but not anywhere near you.  Often you can buy a set which includes the correct drill bit plus the tap and the handle that lets you turn it into the hole. 

I can get it from you and be the middle man...

 

You two figure it out if you want me to hand it off, I don't mind at all.  I drive through Clarksville on my drive from G-burg to HOCO.

[Shoelace]

Mike, thanks!  That's very kind of you, but I wouldn't want to bother...

 

But I did find this that I probably can pick up for $15.  Should do the trick, right?  They don't seem to have individual pieces, unfortunately.

 

http://www.harborfreight.com/40-piece-sae-carbon-steel-tap-and-die-set-39391.html

[monkiboy]

if you plan sufficiently and dry/friction fit your design ahead of time you can get it just right so you don't need the fitting or hose/tubing and it looks a lot cleaner. you just need a hole in that pipe and have it higher than the emergency drain pipe. look to the reefsavvy overflow for inspiration of in the bean animal thread for a few photos. you can also look at my bean animal drain system in my thread for images of how piping may look under this arrangement.

[Marc Weaver]

1/4-20 and 1/4" NPT taps are different.  The NPT taps are tapered which allows the pipe to tighten before bottoming out, allowing for a water/air tight seal.  The NPT taps also have a different thread pitch (18 threads per inch vs 20 for the 1/4" size.)  A 1/4" pipe fitting can probably be forced into a 1/4-20 tapped hole, especially since PVC fittings are thin-walled plastic, but I would not try that in metal or thicker-walled plastic.

 

Standard taps like the 1/4-20 are not tapered, which is why a screw will not stop turning until the head bottoms out.

 

Sorry for the long "lesson" but that harbor freight kit does not have a 1/4"NPT tap in it, but it does have a 1/8"NPT.  Maybe you can try and find a John Guest to 1/8" fitting?  

[Shoelace]

That is really useful info. I appreciate the short lesson!!!

 

I think the JG fittings at HD are 1/4-20. Is that ok to use or should I try to find a tapered NPT fitting. I guess if I Teflon or glue it in, it won't make a difference?

 

Monki, good ideas. I got me some research to do!

Edited October 30, 2013 by Shoelace

[Der ABT]

my 1/4-20 NPT (which is printed on it) is tapered for the first 1/2 or more so as long as you dont go all the way thru your fine.

 

the stuff i found at Home depot was always 15 or 18 count and did not match the john guest fittings which is why i went to the local mom and pops and they had ANY and EVERY type of specialty tap it seemed...and it wasnt a big store at all.

had called another locally owned and they carred it as well.

Edited October 30, 2013 by Der ABT

[AlanM]

Marc is right.  You want 1/4" NPT.  I have that, or I think I still do.  I at least have the work tap set that I used for my own.  I work at the same place as BowieReefer84 and can easily pass one to him to lend to you if he wants to drop one off to you.

[hypertech]

For threading something relatively soft like PVC, couldn't you just use a brass fitting as a tap?

[Shoelace]

Ooh, good idea. What say the experts?