Potter 23 Hull's second chance at life (Rebuild Thread)

[flyingfrizzle]

To start off, this hull was one of mine but sold to a friend after his quest to find an 23 for his family. I will be doing the rebuild for him and thought I would share the build up here. That way the new owner (a state away) can watch progress and we also will be able to get help or support from everyone up here. Also it may help others get ideas on how they may want to go about doing their hulls. Something different that may show to be helpful to others on this thread we will be documenting my time spent as well as the build pictures and descriptions. One of the most asked questions up here is "How much time dose it take and cost to redo one of these hulls?" and hopefully this will give people and idea of the massive amount of time going into these builds. We wont be listing cost but you can multiply the hours by your shops local rate to figure cost as well price out the materials and get an close estimate, but you get the idea. One thing that always seems to be certain is that it takes twice as long to build and cost twice as much as you expect so hopefully this will take out some of the grey area around a SeaCraft restore. The hull we are building is a 74-75 era potter 23 sceptre or tsunami which will be converted into a center console with forward seating. Most of the time is better to start with a cc but with his wife wanting the forward seating it was better to start with the sceptre liner lay out. The cap will be modified or completely redone but the cabin section will give us a head start on the basis for the forward seating. Any how please advise if you see a better way or see something I missed during the process as we may can figure better ways on doing things during this build. Also like to thank the fine folks of CSC in advance for all the support, knowledge and friends this site has provided me.

The hull going under the knife:

[flyingfrizzle]

First off the trailer we are using to move the hull around needed some work. I installed four new springs, hangers, u bolts, equalizers and all new stainless steel bolts under the suspension. The old springs were broke and rusted badly. The frame is in great shape and once the boards are replaced, some of the rollers, new bearing's and tires it will be good as new. I have about 8-10 hours changing out the springs and hardware but will not be including that into the rebuild accumulated build time. The hull was unblocked from where it was sitting in my yard then lowered onto the trailer for ease of mobility during the build process.
To start on the hull, the deck was already rotted and out. The transom is rotted and needs cutting out. The engine blocking is rotted and needs to come out. We will be going to a big single on a bracket for this build so the engine bedding is not need. There is a ton of trash in the bottom of the hull that needs to be cleaned. There is a ton of Potter putty on top off the stringers that needs chipping off or removed. The cap is coming off to do the transom as I always change the transoms from the inside. I feel it is much stronger when done that way but from the outside still works if you like sanding you brains out. I just like to keep the hull shell in tack and rather not seam new glass to old on the outer shell if possible. From the inside also allows me to add thickness easier plus I can radius the corners and do a better job with the tabbing.
First days work will be removing some of the trash and top cap from the hull. First off is the rub rail. Then out comes the hundreds of ss screws that holds the base on. I run a scraper around the edge to find the bonded spots. I take the sawall to the spots I find where the potter putty or glass work is holding the cap on and cut it free. Due to weight, I cut the windshield off and into two pieces. Once the cap is all free and lifted it up then recruit the kids and old lady to pull it off.


Cap removal:








Hours:16

Total Hours: 16

[flyingfrizzle]

Next comes cutting out the transom. The more rotted the better. Part of this one is pure mush and part is still in tack. Looks like water worked its way down from the core from the top as the bottom area and around the outdrive is still fairly solid. I can use a scraping knife to take a lot of it off but the rest will have to be pried off with a bar or sanded down with 80 grit. Once I remove all I can I take a 4 inch grinder with a 4.5" sanding pad and cut the wood down till I can see the base of the skin. I change out to 120 grit and go over the entire skin to give the old glass some tooth to bite into. The wood at the base and around the stringers was hard to remove so I cut the stringers back and center keel board so that I can grind the old tabbing back to a good point for re-glassing new back.

Old Transom wood:







Prep the skin:





Prep the base:








Hours: 13

Total Hours: 35

[flyingfrizzle]

Now that the old wood was removed and the fiberglass tabbing was ground down we are ready to prep the core to re-install. The owner decided to go back with marine grade ply as the composites are just so high. I am taking two 3/4" plys and bonding them together with epoxy and if sealed up 100% it should last 30 plus years. I use the us composites 635 thin resin normally as it is thin enough the wood with absorb the resin and the glass wets out much faster with it. I mark the wood plys by tracing around the back of the hull and then ruff cut them to shape. For in between the cores I am using something new this time to help the wood absorb up more resin. I have found that the more resin the wood has absorbed and the better it is sealed the longer it survives. The material I am using is a fine felt with long strand fibers on each side. Its kinda like csm but with no binders in it and the fibers are more spread apart and longer. The felt helps hold resin between the plys so that when the dry wood soaks it in there is plenty to pull from. I have seen where the wood draws so much resin out of csm it left the cloth between it dry. Polyester or ve resin will cure fast and it dose not have as much time to soak in as the epoxy. I am using a slow cure that takes 24 hours to fully cure when spread thin so it will have plenty of soak time. I also pre wet the plys first just to give them a head start soaking in resin. Once I get the felt/glass wetted on one ply I roll all the air bubbles out and carefully put the other piece on top. Once it is lined up I screw the two pieces together so that it forces the plys tight and forces pressure on the resin to help push it into the wood. I take any resin that pushes out the sides and spread it on the ends of the ply to help seal them up as the end grain is where most of the water soaks in from. Once the resin set up I pulled the screws out and then cut a piece of 1708 to lay up on the face of the core. It is easier to lay it up and roll out while flat vs in the boat. The next layers will be done in the boat as I like to tab to the sides with one full piece with out seams. The screw holes left will allow resin to draw down to the other side of the ply so when flipped over and the back side done it will lock the two sides together with epoxy binding threw the pulled out screw passages. One other thing I have learned to do is cut the edges of the core on angles. With the transom on a 13 degree angle, if you cut the edges on 30 degrees you will have a tighter fit and the roll in the back corner will not hold the core from sitting all the way down. I also cut the top edge on a 45 degree angle then round it with the grinders sanding pad so the cloth will follow the edge all the way to the top and keep you from having to try and fold it around a had 90 degree edge.

Core cut to shape:



Core soaked with thin resin:





Core bonded together:





Core screwed together:



1708 cloth cut to size:



1708 cloth glassed down:



Radius cut on the top edge:





Hours: 8

Total Hours: 43

[flyingfrizzle]

Due to the weather coming in and the slow dry time of the epoxy I decided to hold off on installing the transom core into the hull. I tried to make the best of my time and did a few other items and some cleaning in the hull. After cutting the stringers and engine bedding back I noticed the wood in the bedding was half rotten. I cut the tops of the boxes off and pulled all the rotten wood out of them. Looks like the water got into the front side of them and couldn't drain out. The tank platform was also half rotted out on one side as well. Like most of these hulls they laid the board on the center keelson and glassed just the top side. The wood rotted out as all the bilge water could get right to it. The port side had started to pull away from the stringer so I cut most of it out for now. There is a ton of potter putty on the stringer tops that bonded the old deck down that is very thick. Looks like some spots didn't even touch the deck where it was so far apart. I took a pull bar and hammer and chipped most of it off and sanded down the rest. I did notice where someone had took the deck out cut threw the top of one of the stringers. That will need to get repaired latter on. Also the holes the factory poured the two part foam into didn't get sealed back off. Plans are to raise the deck just an inch or so to ensure it will self bail later on if the owner goes with a heaver four stroke or twins. Plans for now are a single 3.0 Mercury under 500lbs but one day it may see something heaver. I will have to raise the stinger tops up slight to bond the deck back to them if we raise the deck any and probably would of needed to do so even if we didn't due to the gap there now. I did some final fitting of the transom core to make sure it fit tight. The edges where the steps are for the VDR are a little snug not letting it drop all the way down. I pulled it back out and trimmed it down just an hair so that it would fit like a glove once I bonded it in permanently.

Engine Bedding:





Gas tank shelf:



Stringer tops with potter putty:


Attachment 16088


Fitment of the core:






Hours: 7

Total hours: 50

[flyingfrizzle]

With a nice weekend with out rain I decided to get the transom core installed in the hull. I cleaned the back of the hull as well as I could and prepped it for the thickened epoxy. There was a bit of water running from one of the cut off box stringers so I had to stop the water from coming out of it and getting on the core untilled it was set and cured. I took some clear silicon and built a bridge stop behind it to catch any water trying to run out and also dropped the nose of the boat down with the trailer jack. I mixed up some epoxy with cabosil until it was thick enough to spread and not sag. Some what thicker than mayonnaise and used a notched spreader to cover the inside of the hull back. I used to use a masonry trawl but found it to big to work well. The smaller plastic card works much better and also flexes to the shape needed. Once I got the entire back covered I thickened it up a little more and then laid it across the bottom to bed the base in. Me and my son sat the core into the rear of the boat in the bedding and slowly applied pressure pushing all the air out the top. Once in we took my famous Deep Throat Clamps and clamped her down till a little epoxy started to ooze out the top and edges. I got my fillet tool and ran it around the edge of the core after adding a little more thickened resin to the edges and rolled out some nice fillets so that the nest layer will transition smoothly to the hull sides. Once this sets up I will install another 1708 layer on top of the core with 6 inch tabs on the same piece and then add additional tabbing on top of that full layer.

Thickened resin:



Epoxy Resin on hull:




Leaky stringer Damn:




Clamps on Transom:





Fillets pulled around the core:




Hours: 8

Total Hours: 58

[erebus]

I LOVE your giant transom clamps.
I know I've seen them before on some of your previous posts, but then I always forget about them.
Need to cobble some up for myself!


Maybe if you get a chance post some detail pics of them?
Whats the screw/t-handle part made out of ?

[drtyTshrt]

Great stuff.

[FAS]

and in record time! great thread, will be following this one.

[Eric B]

Very good stuff. The master at work!