Too much grain question

[goinbroke2]

After adding my drain and screen to the keggle, I decided to do a mash. I put about 12 gallons of water in then when it got to what must of been 130-140 or so (I didn't have my thermometer yet) I dumped in 4 ice cream buckets of cracked barley thinking 5lb's per because I weighed it before. Then I remembered it was cracked corn I weighed so I thought since barley is lighter per volume than corn, I'll throw one more in...ok, two more to be safe.
I used my paint mixer to stir while I heated it up to 150 with the barley getting thicker and thicker. It got to about 155 or so before I caught it so I wrapped it in blankets and let it sit for a couple hours to come back to 150.
After a couple hours I pulled the blankets off and it was dry on top for about 2"!! I added about 3L of water while stirring with the mixer again and once I was sure it was at 150 I added two packets of enzimes. Yes it thinned out but I wrapped it anyway and am going to leave it for several more hours.

So, my question (finally right?) If I add too much barley (or any grain for that matter) what happens? Does the SG go higher or is it just wasted grain? I'm thinking this is WAY more than the last batch and it converted well and the strip run started out around 45% (which seems to equate to about 10% mash for me. But if this is way more than last time...so what? Is it just a waste of grain?

I'm thinking about 12-13gal water and 25+lb's of cracked barley. Hmm, reading it like that, 2lb's per gallon is good so why was it so dried out/filling the keggle so much?

Any idea's?