calcium phosphate clogged pipes

Plant has clogged pipes because of calcium phosphate deposits. Preventing will mean an 'ion-exchanger'. But how can the current problem be (dis)solved?

My understanding is that sodium hexametaphosphate (Calgon) was developed specifically for this purpose. (Not to be confused with CalgonITE, which also contains detergents.)

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

Hello,

I am looking for information about making clay pieces that will have accurate dimensions in the finished work. I need about 0.01" tolerance. I have heard that one needs to do the first and second firing at the same temperature, but wonder if there is anything else I need to know.

Thank you in advance for any help.

If you are referring to my advice from the Rec.crafts.pottery NG, then

the critical point is not that the two firings be at the same temperature, but that the clay is not taken too close to vitrification, which causes additional shrinkage. Typically there is no shrinkage in the bisque firing (relative to the bone-dry state), but only in the gloss firing because it takes the body up to or near maturity. So you just have to find a glaze that fits on your body when fired to well below maturity.

But if you are willing to spend some time doing initial tests of fired shrinkage, you can just make all your pieces proportionally bigger. You need to do a certain amount of that even with my approach, since you still have to make allowance for the shrinkage from wet to dry, which is on the order of 5% or so. The advantage is that it's pretty easy to adjust the dimensions of each piece when it's dry, and (assuming you have the right clay body) you can be assured that those will not change in firing.

If you have to get the dimensions perfect in the making, it may be tough to hit 0.01 accuracy unless you are using some sort of molding process with well-characterized clay. You would probably need to make several mold attempts before you got one just right. And even still I wonder how close you could hold your firings so that you got exactly the same shrinkage each time. That's why I favor the low-fired method.

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

"Bob Masta" wrote in:

Thanks, apparently I misunderstood your previous post.