I have bought a very old rough finished redwood slab to use as a counter top on my wives new island. The slab measures 90"x52"x3" and is rough planed on both sides. It is very dry with some rot on the side that will overhang the cabinets and whilst sanding it last night I noticed that one of the cracks would open slightly when I applied pressure to it. The crack is about 12" in from the edge, it does not run all of the way across. Any idea's on how I can make this crack structurally sound. Once sanded, I am going to oil to bring out the grain and then thought about an ultra clear resin, would the resin provide the strength or do I need to do something like straps underneath? Any help would be greatly appreciated.