Testimonials
Epoxy, built 1966
Stuffing Box
The above photo is a view of epoxy's hull with the fuel tanks removed. This was taken half way into the restoration process to give you some perspective as to what you are looking at. The wood was cleaned of oil, dirt and debris so that CPES could penetrate. This step is very important so it was a full day’s work of scraping with a paint scraper and then using TSP with a scouring pad. The photo on the right is wood damaged by rot. This was a doubler for the stuffing box seen below.
The photo of the left is a picture of the stuffing box for the Starboard motor. For those not familiar with nautical terms, a "Stuffing box" is a seal for drive shafts and rudder shafts. Sever corrosion is easily visible here as it’s hard to distinguish the bronze stuffing box from the wood itself. As you will see in the following photo is that a lot of the wood was destroyed and the rot was very extensive.
After I removed the stuffing box and cleaned the area, this is what I was left with. I have to admit it looked pretty bad and I spent some time thinking about how I was going to repair this. It was obvious that I would have to replace some wood. CPES can do a lot but sometimes replacement is your only option. I heavily saturated the entire area to stop the further spread of rot. There was no way I was going to do this repair again. After the area dried I applied a mixture of sawdust and Layup and Laminating resin but with only enough sawdust to slightly thicken the mixture. I still wanted the mixture to flow easily into voids and areas that were not easily visible as seen below.
If you look at the area in the red box you can see how the thin mixture has migrated its way into all the voids and has bonded the delaminated layers of plywood back together.
The above picture is a heavy mixture of Tropical Epoxy adhesive and about 70% fine sawdust. My objective here was to build up the area back to 1/2 inch, which was the original thickness. My only surprise was that it did take a long time to cure. The days were warm but the night cooled off considerably which is why curing took so long. The picture below is what the area looked like after I sanded the cured resin. Because rot had worked its way between the layers of plywood it bulged, the porosity between these was high and this caused extensive rot within the wood itself. The penetrating abilities of CPES allowed the epoxy solvent mix to be drawn deep inside the wood destroying rot and, at the same time, glue the laminated sheets back together. Because I was using 3/4 inch oak as a reinforcement plate I wanted the area to be as flat as possible, this wood will not accept any bending. Once the area was sanded relatively smooth another layer of CPES was applied and then the reinforcement plate was secured in place.
I thought at this point it would be a good idea to give you look at the bottom of the boat. This is a picture of the drive shaft going into the boat via the starboard stuffing box. All the pitting on the drive shaft is electrolysis damage. This was another involved process that caused a lot of my problems. To keep things simple and not to open another can of worms; electrolysis itself is a extensive topic with many different opinions. Some people will over "protect" boats with zinc's (which is a sacrificial metal) this creates currents which will destroy the wood itself. Epoxy was over protected, and many different fastener materials were used i.e. Silicone bronze and Stainless Steel.
This is a photo of the stuffing box removed from the boat.
This is the finished repair.
Here you can see the mixture of sawdust and Tropical Hardwood glue, again this is about fifty percent sawdust to fifty percent resin. I was very generous with this as I wanted all voids to be filled. The bottom hull of Epoxy has a slight curve to it and I wanted the cured epoxy to serve as a transition medium (from a curved surface to a flat surface). I did not want to clamp down with such a force as to push all the resin out. Once the resin is cured, it will have a shape identical to the hull with no voids to weaken the bond.
This is a view of the doubler plate for the stuffing box just prior to securing it down with the four bolts on each corner. The purpose of the plastic is to prevent the resin from sticking to the bronze stuffing box.
The above two pictures are before and after. I was pleasantly surprised when the area was cleaned up that it was not deteriorated to the same degree as the starboard log shaft. There was some missing wood and decay was very evident but not to the point that I had to remove any of the decay. As you can see Epoxy has a very shallow bilge and as a result water mixed with the oil from engines was constantly sloshing around the entire length. This oil also contributed significantly in the deterioration process as seen by the following photo. I would like to stress again at this point how important it is to clean the area that is being restored. In this case it was more work than the actual repair, but a VERY necessary step.
This is an example of what happens to wood upon long term exposure to oil. I do not know if this was marine grade plywood; I doubt it, however the damage is very evident. I have showed this to some people and they were surprised. Most thought the oil would have protected the wood like a preservative, rather than destroy it!
If you refer to the above [After] photo, this is the area that required some strength building. As usual this was a mixture of Layup and Laminating Epoxy Resin with sawdust. When this cured I just went ahead and secured the backing plate in the same manner as the starboard stuffing box.
The mixture is spread over all surfaces and then clamped in place. The only repair left in these areas is two replace some of the reinforcing stringers. In the above "after" photo you can see the stringer I had to cut in order to facilitate the repair. The restoration of these areas will be covered in a later segment.
Port stuffing box final repair as viewed from the inside of the hull.
Port stuffing box as viewed from the hull. The original installation consisted of carriage bolts driven right into the wood. I fabricated some doubler strips from epoxy and cloth.
Directly above is the picture of the boat looking at the stuffing box thru hull for the starboard rudder and directly in front of that is a main cross beam support that has extensive rot and decay. The original owner bolts a very large stainless steel plate over this in the hopes it would strengthen the area, the exact opposite took place. I chose to replace these sections as indicated on the right photo as large bolts go through this beam and support the strut for the drive shafts.