kamkiel wrote:What is the purpose of the p-lip, and is there any special reason for the tenon to have the step in it?
-- It's a 19th century patented design which is still in production because people still like it enough there's a market for it. The main feature that Peterson's focuses on in adverts & promotional materials is how the smoke stream is angled upwards away from the smokers tongue.
-- There's not necessarily any purpose to tenon steps in general, but I HAVE encountered instances where the length of the step (meaning how far past the contact area of the tenon the reduced diameter portion extended into a pipe's "dead air" space, such as Peterson's condensation chamber) made a night & day difference regarding wetness finding its way up the stem's airway. Still trying to figure THAT one out, lol.
caskwith wrote:I warm the stem holding the bowl with the heat gun on high (sorry George)
I guess it depends on the make and model of gun. Mine is over 1000 degrees when set on high, and will boil the surface of acrylic in an astonishingly short time.
People should definitely experiment with their own gear, starting on the low side and working upward. Losing 3-4 hours of work in a flash sucks.
That's a good point, I don't know the temp of my gun but might not be that hot. Also experience plays a lot into it, I have bent hundreds of stems using this gun, I know where to hold the pipe and how to move it. It probably helps as well that Polyester doesn't bubble if you get it too hot. It will snap though if you get the temp wrong so again practise is the key here.
my heat gun caps out at about 500 so george must be running some industrial model
i've actually been thinking about changing to some type of propane setup because i usually bend more than one stem at a time
do you make all of your stems from polyester? I looked at it because for the mid range type market its much easier to get at a good price and in bulk than vulcanite rod
Pretty much all of my stems are polyester. Pen blank poly is cheap, good rod stock is more expensive and is priced in between ebonite and acrylic. Learning curve to work with it though.
I made a device from a fender washer with a hole just big enough for the tenon to fit into. To this washer and using double stick tape I apply fine grit sandpaper. Put the washer sand paper against the stem. Slide stem onto the pipe and either twist washer or stem until the surfaces of pipe and stem are parallel. Or as stated reheat and allow it to straighten on its own. I use a heat gun but it's has a small nozzle and is very easy to direct heat to only where you need it.
Thanks George