Set quite a few hours aside for this (4 hours(?)). Try to get the soap as fine as you can, IE, grating it, use a wood planer or crumble it as best you can.

Then mist it with water and leave it over night. I always do this in a crock pot (I have a dedicated crockpot) then turn it on med(?) depending on how much soap flakes you have.
The soap will get very very hot (too hot to handle)Find a way to mush or break down the soap lumps when hot. Stir every once in a while.
You may have to add more water, but not too much water (this is the real trick in rebatching soap), try adding only a few tablespoons at a time, and not too often.

Before putting into molds, let the hot soap cool, then add scent if desired. Too hot soap will burn off the scent.

Have some molds ready to pour or lump the very hot soap into. For example, 500 ml milk cartons or wooden molds. Don't forget to lube or line whatever molds you use.

hth

I just signed up on this site and noticed your post. If you use a microwave the ivory soap will expand becuase hte soap had many air pockets. I used the double broiler method and it worked great:

Get a double broiler or a large pot and fill with enough water so that a small pot can float and fit with the lid of the bigger pot on (avoids the need to put something in the bottom to prevent the smaller pot from touching the bottom).

While the water is boiling, grate 1 lb of soap finely and add 1tbsp of milk or spray with a little water. You won't need to much liquid because water condenses on the lid and drips into the soap.

When the water has boiled, add the soap and cover, lower the heat to low. It should take about 10 min to turn to mash potato consistency. Check about every 5 min and stir.

This worked perfectly for me!

Hope this helps.

I am not sure that you are aware that the post you responded to is dated 2006, and I doubt that the OP will read your response.

I know it is an oversight, but the vessel you used is a doubleboiler, vice doublebroiler.

I have not used the doubleboiler method, probably due to the amount of soap trimmings I have to do and the frequency (or lack of, lol) resulting in quite a bit to do at one time.

Welcome to our little community.