Main Discussion Area > Flintknapping

Getting ready to put together a kiln

(1/5) > >>

Huntrick64:
Hey all, my first post here.  I've been building and hunting with selfbows since 1991.  The last few years I have been wanting to hunt with stone points, but want to use my own.  I have tried knapping off and on since I was a kid, but never stuck with it long enough to make a decent hunting point.  I am now breaking rock a couple times per week and finding the need to heat treat a little more than what my turkey roaster has been doing.  A friend of mine and I just secured an old pottery kiln with inside dimensions of 17.5" diameter by 18" deep.  That works out to almost 19 gals of volume (or 4 buckets).  I recently ordered all the stuff from Auber's to build a ramp/soak PID using a SSR and "K" type thermocouple.  I'm going to try to use some of the existing coils to get to enough resistance to generate 1200 watts on a 120V circuit.  I'm hoping to get two wraps around the inside of the kiln with the proper resistance.

My question is, do you think 1200 watts will be sufficient to heat this thing full of spalls, or will I need to cut the kiln down in size?  I want to stay with a dedicated 15A 120V household circuit.   Most of my rock with be Kay County (550), but I can see wanting to get some novaculite as well (850-900).

thanks,
Rick

iowabow:
How many ramps or segments can your program into the pid

Huntrick64:
This particular one has 30 programmable steps some have 50 steps.  You would use about 5 or 6 steps for each recipe so I could basically keep about 5 recipes stored.  You can start at any step you want so here would be an example:

Step1  200 degrees soak for 24 hours
Step2  Ramp 200 degrees to 550 degrees over 10 hours
Step3  550 degrees soak for 8 hours
Step4  Ramp 550 degrees to 200 degrees over 10 hours
Step5  shut off
Step6
Step7  Another recipe

Let's say that step1 is for Kay County, I could start at step one and it would stop at Setp5.  Novaculite could start at Step7, etc.  The really cool part in the ramp feature is that it calculates and uses a linear progression for the increase in temp over whatever time you put in.  So you don't have to use up steps for each hour if you wanted to raise the temp 30 degrees per hour, just put in beginning temp, ending temp and the duration of the ramp.

Anyway, this is how I'm hoping it works.

iowabow:
You will need to program rate/ hour up and down

iowabow:
Pm your number and we can talk

Navigation

[0] Message Index

[#] Next page