Is there a crossover point where the thickness of the meat section will absorb the brine from both sides well enough to make injecting unnecessary?
"Spray pumping" is preferred over brining a ham for many reasons. Brining a larger piece of piggy may actually require several weeks for the cure to penetrate down to the very center of the meat. During this time, the bone marrow may easily spoil - depending upon how recently the piggy gave up his noble grandeur. Long periods of brining can also strip the meat of protein, causing an undesirable mushy texture. Rytek Kutas took issue with long brining. In the third edition of his book, "Great Sausage Recipes And Meat Curing", he wrote: "These long brining periods also can leach the protein out of the ham and cause it to be mushy around the bone after it is smoked and cooled. There is absolutely no question that spray pumping (stitch pumping) is by far the better process."
Comercially, "Stitching" or "stitch pumping" with gang needles enables Prague Powder #1 to cure ham so quickly that final processing may be accomplished the following day. However, we "home hobbyists" must use a combination of brining and pumping (usually 10 to 15 percent of the ham`s weight) to achieve complete penetration... even in a product as small as pork loins (for Canadian Bacon). Rytek further stated, "For home use, some brining always is required, because a single needle pumping a ham will not do a complete job."
Ross, in "Home Production Of Quality Meats And Sausages, authors Stan and Adam Marianski go into depth in dealing with the subject of brining. Pages 25-30 include photos and graphs explaining the details. On page 28, Stan made a statement most profound. He simply says, "It makes no sense at all to talk about curing time if we don`t specify the strength of a brine". It is absolutely true, yet I see folks making different strength brines with every new batch. I am happy that you have ordered the book and am confident you will find all sorts of answers to your questions. I hope this has helped a bit.