cutting soap..is it too late?

[pau-rosa]

Hi everyone!

2 days ago I made a batch of soap with new reciepe
50% OO, 15% PKO, 10% Babassu, 5% Castor, 20% Red Palm Oil.
7% SF, w(NaOH)=33,33%, 1%SL, 2% SC, 1% NaCl. After molding I put it in hot but switched off oven for gel it.
Yesterday (after 18 hours) I unmolded it. It was very rainy day and soap started to "sweat". So I decided to cut it later and... decided to make another batch with similar but modified reciepe.
40% OO, 15% PKO, 10% Babassu, 5% Castor, 30% Red Palm Oil.
8% SF, w(NaOH)=33,33%, 1%SL, 2% SC, 2% NaCl. And also I put it in hot but switched off oven.

Today after 36 hours I started to cut my first batch and it was cracking on the bottom. I started to search why is it happen and understood that it was too late to cut this soap. So I decided to cut my second batch to avoid cracking. And my second soap was cracking more bad.. (after only 18 hours). I don't have any beautiful soap bar...

Please help me figure out why did it crack? I think that the point is Red Palm Oil and of course I made a lot of other things to make my soap harder. But I live in tropics with high humidity and all-year temperature 30 C.
My ungelled soaps are very soft after unmold and also are difficult to cut. So now I gel all my soap.
When I need to cut my gelled soap?
I use kitchen knife for cut a soap (I attached). Is another cutter will be better option?
I haven't try "normal" palm oil, but I'm waiting for package with it. Is it the same in hardness?

Thanks for attention!

 

[Obsidian]

Your recipe is quite hard, you should cut it as soon as its firm enough to handle. My recipe is hard too, I can cut after just a few hours. If I wait too long, it will crumble like yours.
Regular palm is just like red palm, only the color is different. Next time you gel your soap, try cutting as soon as its cooled down.
For the soap you have now, you can try putting it back in the mold and reheating it just until its slightly warm. That might soften it enough to cut.

 

[Seawolfe]

I've had some luck by swapping out knives - try to find the thinnest, sharpest knife that you can and heat it up a bit in hot water. Oh sure you can do it properly and cut at the optimal time, but where's the fun in that?

 

[pau-rosa]

Thanks a lot, guys! Your replies are very helpful.
I will cut my soaps earlier. Unfortunatly I've already cut my batches experimenting with hot knife and didn't have luck. My only luck is that I make every experimental batch with only 340 grams of oils .
And yes, this knife is a thick.

 

[pau-rosa]

Yesterday I made one more batch using my second recipe.
I cut it after 3 hours when soap was still warm. It was easier, but anyway the bottom little bit crumbled. Next time will try to cut earlier!:shock: And buy new knife...