My boat had "sprongs" (oil canning) in the floor on either side of the helm station. This is a common problem on any aluminum boat, and can carefully be repaired. My decision was to bring the boat to Jack Winninghoff on the N. shore of Boston in Rowley Mass. I met with his welder Bill Stone who in detail went over the repair, what they have encountered, and the best approach at the repair. He was able to score the floor across the sprong but not thru. He went about .150 deep leaving a thin skin of material between the floor sheet and the bilge. He then inserted a 6" blower hose into the floor hatch located above the fuel cell to extract any potential fumes. When all potential fumes were evacuated he layed a bead of weld along the score in the floor thus pulling the two sides of the sheet together and eliminating the sprong
Now here is the most important part
He decided to remove the boat from the trailer to do the additional work I wanted done. Cell phone rings "we got problems" Where the boat sat on the front bunks/carpet it had begun to corrode the under skin of the boat about the size of a softball on either side and about 1/8" deep 
Not Good!! He then took a small grinder and ground out all the corrosion and began to fill, grind, fill, grind until the void was full of new weld. Then he ground it smooth again to match the Hull bottom. I have never really heard of this potential problem with bunk trailers from ANYONE I am writing this to inform all of you to check the hull sections you never see....between the bunks and the hull 
Had I not brought the boat to Winninghoff Boats this problem may have not been caught until the hole was completely thruAt the same time I always liked the looks of the rub rails that many builders install sown the sides of the hull. We cut 2" schedule 40 alum pipe in half using a skill saw and installed, welded, & capped the rails on either side
I also installed a couple front mounted rod holders which I whipped out at the shop in the front roof area for spinning rods while tossing plugs at Charlie. And the big change in an effort to knock down spray while 30 miles out we installed a reverse chine spray rail along the bow of the boat. It will be interesting to see the effect it will have and how functional it will be (test result will follow ). I plan on running here today Picked the boat up last night. Jack, Bill, and I shot the breeze for hours
He ran back and forth pulling out blueprints of boats he's built, and told all his "war stories" of things he's built and projects he's worked on.....quite interesting to say the least. I thank them for finding the potential future issue the most with the bottom corrosion. This is the difference in using a builder for a repair and just any welding shop. Next will be adding starboard to the front bunks, maybe with carpet over them.......re-applying non skid on the floor repair sections, applying Nyalic to the new rails and where the welding burned the existing....then getting her bloody It's your investment....protect it
It's only money SL Dave....just start up the printer and make more 
Thanks for the info