Does a Norton 4k swell after proper soaking?

A few days ago I was in a rush to get a couple blades honed and I only soaked my 4/8 Norton for four or five minutes before lapping it. My thinking was that I didn't see air coming out so I must be good. So i lapped as usual using wet/dry on a flat surface (I really need to get a dmt). I buy eBay blades to restore and I had two of them with bevels set ready for the 4k. A couple strokes in and it's clear that there's a high spot in the middle of the stone. Now I just lapped it and checked it and it was good. Put it back in water for 15 min and lapped it again and it stayed flat this time. The 8k side was lapped good the first time and stayed flat.

So here's my questions.
Does the 4k swell when fully soaked to the point of such an obvious high spot being formed.
Did I just not chech my work close enough the first time?

From now on the Norton will get a twenty minute soak before I do anything with it.

Thanks for any helpful replies

Mine has never swollen, and I've never heard of one that has.

I agree with holli never saw a Norton swell. They are one of the most stable rocks out there. Mine are usually swimming in the pool non-stop. Unlike the Naniwa's that can crack.

No, Nortons don't change from soaking or humidity the way polymer based binders do. Probably needed to be lapped more than it was.

+1 on the nortons not swelling, the naniwas are good for that!

If they did swell the amount would be so small I doubt any of us could measure it without highly specialized and expensive equipment.

Thanks for all the replies. Must have been a poor job of lapping it on my part. I use sandpaper and my counter is no the flattest. I've been thinking about getting a DMT for a while so I think I'll go ahead and order it. Thanks.