# Making a wax melter: : is 16NC thread tap equivalent to NPT?



## Ben Brewcat (Oct 27, 2004)

I'm making a wax melter a-la http://www.candletech.com/general-information/do-it-yourself-wax-melter/ presto pot. I went to get a thread tap and all Home Despot had is a "16NC" tap set in 3/8". Will this tap threads for regular NPT fittings like a regular brass plumbing fitting?

Do the compressed-air fittings (there's a nice 3/8" full-port valve with male threads, where most fo the other ball valves have female on both ends) have the same thread count as NPT or this die, or do I need to use plumbing fittings only?


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## deknow (Jul 17, 2006)

I think the NPT is a tapered thread....the NC is not.

deknow


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## deknow (Jul 17, 2006)

I just reread your post...I think I did exactly that a few years ago for a presto pot. My recollection is that it worked, but the fitting didn't thread all the way through...a bit fragile, but workable.

deknow


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## Ben Brewcat (Oct 27, 2004)

Dangit, I figured. Can it be that HD doesn't carry threading taps? I guess I can look around for plumbing supply places, but sheesh this should be easier inch:. 

Wait, I wonder if the bind (we're talking super-thin aluminum wall here) would be OK to seal anyways?


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## deknow (Jul 17, 2006)

...you might check Amazon.

deknow


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## Ben Brewcat (Oct 27, 2004)

This air ball valve for example; is air NPT?

BSP air ball valve


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## odfrank (May 13, 2002)

I see some on EBAy that are JB Welded in. I have the tap I used, I could look tomorrow what it is.


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## Ben Brewcat (Oct 27, 2004)

Yeah, I'm looking at this one but wanted to make it this weekend. Plan ahead right ?


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## waspslayer (Jan 3, 2010)

I believe NPT is National Pipe Thread and NC is a coarse thread and not tapered as a pipe thread is.


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## DarkWolf (Feb 20, 2013)

JB Weld to seal and treat it like a bulkhead? That way you're basically sandwiching the aluminum and not relying on it to hold its thread. Just a thought.


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## DC Bees (Sep 24, 2009)

I made one a few years back. The aluminum Is thin and hard to tap so I packed it with JB Weld and has held up good. When using the wax melter the wax at the end of the ball valve cools and will not flow . I use a propane torch to melt the wax in the fitting, works great ,good luck.


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## ArkansasBK (Mar 5, 2011)

Do you know a machinist? He'll have a NPT tap at home!! Just remember, the size of a standard thread tap is WAY different than the size of pipe thread, and not just because of the taper. For instance, 1/4" pipe is way larger than a 1/4' drill bit. Threads per inch is different also.


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## Ben Brewcat (Oct 27, 2004)

DC Bees said:


> When using the wax melter the wax at the end of the ball valve cools and will not flow . I use a propane torch to melt the wax in the fitting, works great ,good luck.


I've seen that others have experienced this also which is why I was hoping to be able to use the compressed-air fittings; they are male-threaded and eliminate the need for the nipple (keeping the whole fitting warmer).


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## Daniel Y (Sep 12, 2011)

Deknow got it. NPT is not the same. My local Home Depot has NPT taps. I would ask them and if they do not carry them. have them order one.


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## Daniel Y (Sep 12, 2011)

I am thinking this design woudl be much improved with a bulkhead fitting rather than trying to tap thin metal. this one is 1/2 inch but with a bit of searching I am sure you could find a 3/8 version.
http://store.homebrewheaven.com/thru-wall-bulkhead-fitting----brass-12-npt-p728.aspx

Just keep in mind the heat rating for the seals.


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## simplynatural (Mar 4, 2013)

thanks for the link - they had the 15 gal pots I've been trying to find for my wax melting


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## Tallevaguy (Dec 15, 2012)

McMaster and Carr has them. I order from them almost daily.


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## berkshire bee (Jan 28, 2007)

got my pipe tap at Aubuchon hardware when I made my presto pot and one for a friend. As was mentioned, the metal is very thin. Tap carefully and keep checking for fit.


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## mmmooretx (Jun 4, 2012)

This will probably work. It only needs a hole, no welding, and works with boiling water (beer making).

http://www.northernbrewer.com/shop/bronze-cooler-valve-kit.html


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## RonnieS (Sep 12, 2012)

No. 
NC = national couse 
NPT = national pipe thread (which is tapered)


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