(Rot is throughout the frame.)
by Sherwood Heggen
Do you know the condition of the bottom of your boat? Have you ever considered what
is beyond the beauty of the varnished mahogany? What ugly issues do you suppose are lurking within the bilge? If your boat has an original bottom or it is taking on water, you might be interested in digging in to see what the problem is. You might be surprised.
Recently I moved a boat into my shop to repair some damage on the bottom. The bottom appeared to be in sound condition except for the obvious damage that had been poorly repaired. On going is an account of what problems this boat revealed to me. Hopefully this will give you some fair warning regarding what you might expect if you should decide to tackle a bottom repair or rebuild.
To be able to do bottom repairs on this boat, it was necessary to remove the bottom planks. Before I could start that, the boat had to be gutted, meaning the engine had to be pulled, the seats and floors removed, gas tank drained and removed, and anything else removed that would be in the way of getting the bottom off. Often there are parts, such as engine or seat risers, floor supports and rails, steering mounts, etc., that restrict access to the bolts through the stringers holding the frames in place. Remove anything you suspect will be in the way of disassembly.
Bottom removal of the Chris Craft begins inside the boat. There are hundreds of pan head screws holding the inner planking to the outer planking from the inside the boat. To not remove these screws will guarantee great difficulty in removing the outer bottom planks. The screws might be small, but they have amazing gripping power. I found them at the edges of the inner planking strips in a line between the bottom frames. Some of these are difficult to find, disguised well by grime and bilge paint. Once I was satisfied that I had removed every one of those little buggers, I built framework to support the boat while it is upside down and turned the boat over.
With the boat upside down on the sturdy framework, I began removing the putty in the bottom screw holes – all 1800 of them. This went well since the holes were filled with the plaster type putty that breaks up and is easily removed with an ice pick or similar tool. You might not be so lucky if some well meaning restorer had filled the screw holes with an epoxy putty. You are going to be there a while digging those out. Anyway, I kept at it until all of the screws were exposed. Then, I began removing the screws. I find that I can carefully use a variable speed drill with screw driver bit to loosen and remove most of the screws, but at the first sign of the bit jumping out of the screw slot, I change over to a manual screw driver to loosen the screw. It is too easy to damage the screw slot with the variable speed drill because it isnt possible to control it as well as a manual screw driver. Once the screw slot is damaged, the screw can be very difficult to remove. For the stubborn screws, be sure the slot is clear of debris and use the manual screw driver with a lot of downward pressure on the screw to keep the screw driver in the slot. Once loose, use the variable speed drill to spin the screw out.
Speaking of spinning, if you find a lot of screws that just spin in the hole, you have a problem. I found the majority of the screws in the transom base were broken off providing no holding power at all to keep the bottom planks tight to the frame. Other spinners were a sign of something else – either rot or a cracked frame and confirmation that the bottom needs attention. The process went on until all 1800 screws were out and in a bucket, never to be used again. They will go directly to metal recycling where cash is given for the metal.
Time had come to pull the bottom boards. One by one the boards were lifted from the home they had enjoyed for the past 67 years. Yes, this was an original bottom. Occasionally a plank would not pull free only to find that one of those pan head screws was still in place. A pry bar and some grunting noises soon freed the plank. A down side of taking an old boat apart is the smell of oil soaked planks and musty, rotten canvas. The smell permeates my workshop and clothes and hangs with me where ever I go. Everyday spent working on the boat makes me smell musty. It is a great day when the boat gets new lumber, the old boards are burned and the musty stink no longer has to be endured.
The next thing to remove is the inner planking. Just pull and remove the planking, right? No. First remove what remains of the rotten, musty smelling canvas and dispose of it. Then pull the inner planking. Each of these planks is held in place with very small iron nails and many of them have rusted partially away and break off with the activity of pulling the planks. Pulling the planks creates clouds of dust and debris as boards break and remaining canvas parts break loose. Crap flies all over. Wear a dust mask. What remains after the inner planks are off are nails that didnt come loose with the planks. They should be pulled for safety reasons, as they can catch and tear skin if you would brush over them, or if the frames are to be replanked.
Now you have a good look at the bottom frames to see what would be necessary to repair or replace. Being the optimistic type, except for the known damage, things looked pretty good. Closer inspection of the transom base started to clear away the optimism. Besides all of the broken screws in the transom base, someone had previously replaced it, making it only big enough to slide in from the back between the chines. There was no tight fit to the chines and a large void was filled with 3M 5200 or the like. Looks like the transom base gets replaced. Moving forward and cleaning the sludge and grime off the strut frames, I found another problem. The strut frames had a wiggle factor of between nine and ten. That is pretty extreme. The larger of the two was broken in the middle. About this time I decided to remove the keel to free things up and see how loose other frame members might be.
Digging for bolts that held the keel in place, I found gobs of caulking filling voids in the keel at the transom. What ever damage had happened to the keel was repaired with caulking rather than with wood as it should have been. Three different colors of paint can hide a lot of problems. The keel eventually was removed and set on the workbench for cleaning and repair. The paint was stripped from it and then thoroughly washed with lacquer thinner. The oil soaked surface was scraped and planed to remove the surface crud. Below was reasonably clean, useable wood. Once the voids are replaced with new wood, the keel will be ready to go again.
Next the chines were loosened by removing the bolts holding them to the main frames. That sounds easy enough except that the bolts had been there a long, long time and didnt want to leave. Often, at the factory when the boat is built, the nuts are tightened down on the bolts and then the excess bolt length is cut off at the nut. This damages the end of the bolt and the nut will not easily turn off. Attempting to back the nut off with a wrench just causes the carriage bolt to turn in the chine. The bolt is buried deep in the chine and there is no way to get a grip on it, so a way has to be made. The easiest way I have found is to drive a narrow bladed screw driver into the hole next to the bolt head. Then while turning the nut off with a wrench, turn the leading edge of the screw driver blade against the bolt head. This wedges the screw driver blade against the bolt and stops it from turning, allowing the nut to be turned off. If that fails, try a hack saw to cut the bolt, if you can get at it.
The auxiliary frames are held to the chines by a large screw which passed through the chine and into the end grain of the frame. But in most every frame, the screw was broken or stripped, so that lessened the disassembly time. That leaves the bottom frames free to move around which does not promote a water tight bottom. Another thing I noticed was that the auxiliary frames were not fit tight to the chines. That is not how the factory built it; the boat had spread over time.
With the chines and keel removed, it was apparent that frames were no longer fastened tight to the stringers. There had to be a reason why. Screws securing the strut frames were made of steel and had rusted away leaving little to hold the frames in place. Some time in the past life of this boat, someone had noticed one of the strut frames was loose. A quick fix was done with a steel lag bolt screwed in from the top of the stringer down through the strut frame to secure it. Over time the bolt rusted, destroying the wood around it. There was no longer anything holding the frame in place. The frame was simply lifted off the stringers to remove it. It is no wonder the frames were easy to wiggle as stated earlier. In many cases, the rusted screw left an oversize hole. To repair the hole and larger hole was drilled and plugged with a mahogany bung and epoxy filler. Now there is new, solid wood for the new silicon bronze screw to hold fast in.
The auxiliary frames were next on my inspection run. Every one of them was oil soaked and/or showed evidence of rot or breakage. Bottom ties also were oil soaked and broken. Every auxiliary frame was loose and free to move up and down. The screws holding them to the stringers were also steel. The steel screws were locked in their holes by rust plus the slot for the screw driver was didnt exist any more. Using a screw driver to remove the screws was not possible. Instead, a chisel was used to open a slot beside the screw, and after the bottom tie was removed, the frame was rolled away from the bolt to remove it. Care was taken to keep the frame intact to use it as a template for its replacement. To remove the screws a vise grip pliers was required.
Each of the auxiliary frames was replaced with new wood and brought into alignment with the existing main frames. I noticed that the keel and bottom was not flat forward of the transom as it should be. In addition to that, the auxiliary frame in front of the shaft hole in the keel stood proud of the rest of the frames by at least a quarter of an inch. This caused a hump on both sides of the bottom. Maybe this accounts for the wedge someone had installed at the transom to make the boat plane flatter at speed. That hump was mistakenly built into the boat at the factory. The keel was flattened and new auxiliary frames were installed correctly this time to flatten the planing surface. The wedge should no longer be necessary to achieve a flatter planing angle.
Problems were also found with the main frames: oil soak, cracks, broken screws, rot, some kind of a brown fungus growing between the chine and the frame. Remember I said the boat was in for bottom damage repair. Well, the damage went a lot farther than just a hole punched in the bottom. I believe the boat was run on a Colorado river when it hit an underwater boulder, sinking the boat. The water was heavy with silt which found its way into the boat and settled in the hollows and cavities in the frame, especially in the frame/chine junction. The silt remained there and held moisture which encouraged rot. There was no hope in saving the main frames. One by one they were removed, copied with new wood and replaced. The bottom ends of a number of topside frames also had to be replaced and held in place with a sister frame.
From the outside, the chines looked pretty good. Inside they were bad news. Rot at the main frame areas and erosion at the transom was obvious. They will be replaced.
Did I mention the stem. No, I didnt. It is not unusual to see the bottom of the stem cracked, dried out, and broken. This was the case with this stem and a new section was scarfed in place and fastened to the gripe. Believe it or not the gripe was in excellent condition. A good cleaning and it was good to go.
So does that give you an idea how beauty is skin deep but rot is throughout the frame. If your boat has an original bottom, I can guarantee there are problems that are compromising its strength and safety. This boat with the good looking bottom will soon a bottom that will be both good looking and sound for safe ride for years to come. Do the same for your boat.
If you are puzzled with how to proceed on your boat project, dont hesitate to call or e-mail me at 715-294-2415 or Heggensj@Centurytel.net. Your questions should have answers so you can get on with your project. I look forward to hearing from you. Now, put this magazine down and go work on your boat.