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

I'm making a wax melter a-la http://www.candletech.com/general-in...lf-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?

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

deknow

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

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 :pinch:.

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

...you might check Amazon.

deknow

This air ball valve for example; is air NPT?

BSP air ball valve

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

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

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

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.

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.

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.

Quote:

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Originally Posted by DC Bees

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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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).

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.

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...-npt-p728.aspx

Just keep in mind the heat rating for the seals.

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

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

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.

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

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

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