Check and see, your main "heavy stuff" will no doubt come in a box "container" if so you shouldn't have many dramas as long as the manifest states what is inside and you have current M.S.D.S. for the products, I would wrap them to protect your other items. I have purchased items, liquid and powder and had them airmailed to me no problems. Surface is less of a hassle if your paperwork is in order.
Hope this helps