Yesterday was a beautiful 66-degree November day, which I took a half day off work and frantically culminated a couple month push to repair/prepare the interior hull. (yes Eric, sleep was limited) I almost completed all goals, failing to complete the last one which will have to be picked up in the spring. As I continue my journey through re-engineering the boat industry, (thanks Jim A) the next 6 or 7 posts will take you through my experience learning to work with polyester resin, fiberglass, gelcoat, die, and floatation foam.
In a previous post I explained how I removed the cabin roof so I could give everything a good clean and restore the cabin windshield and sliding side windows. Unfortunately, I discovered a few serious sins were committed when the helm/steering controls were fitted.
It looks as if a drill bit was used to chip away and make the opening larger albeit horrifying. The gunwale (or is it gunnel in the mid-west) wooden stringer (if that's a real thing) was cut through and the exterior fiberglass/gelcoat damaged.
The cabin roof did not fare much better
View from under the gunwale. The boat was constructed by laying a fiberglass hull, spraying the whole thing with 1-2-inch-thick floatation foam, with a final layer of polyester resin and chop strand fiberglass shot out of a spray gun. Larson referred to it as "Blue Water Technology"
To start the repairs, I began working with the top. I clamped a straight piece of hardwood down as a straight edge and used a Fostner bit to drill nicely radiused holes in an effort to eliminate future cracking. Placement of the holes was determined by the radius of the existing rough cutouts.
I then cut out the rough material to the edges of the newly cut holes. The Fein Multimaster tool proved invaluable while working on the fiberglass projects. I was able to make clean and controlled cuts easily.
A small sanding drum and drill softened the edges nicely!
I used the same Fostner bit, Fein Multimaster saw, and drill sanding drum combination to clean up the gunwale
The Fein Multimaster and sand paper removed the foam and cleaned up the underside of the gunwale in preparation for repair and strengthening
With the foam removed I was able to see a previously made hasty repair
Additionally, my foam removal work pierced the paper-thin glass in a couple places. The cracked gel coat was part of the previously made repair
After years of watching Andy's Boatworks Today YouTube channel, I decided to try my hand at fiberglassing. I ordered Polyester Laminating Resin, Polyester Structural Repair Putty, Polyester Faring Compound, Wax, and glass matting from TotalBoat. (Jamestown Distributors) I appreciate there may be more affordable options out there, but these products are well documented by Andy, and proved to work well for me.
On the inside of the gunwale, I placed two layers of chop strand, two layers of 1708 and then two more layers of chop strand fiberglass matting. Initially, I was waiting 20 minutes between each fiberglass mat layup. As I got more comfortable with the materials, I was able to apply the fiberglass layers one right after the other. I learned quickly that Polyester Resin catalyzed with MEKP is only workable for ~20 minutes. To get through all my repairs and gelcoating, I needed quite a few chip brushes and disposable measuring cups, which I purchased on Amazon.
Yes, despite my attempting to use a piece of wood covered with packing tape as a backer board, I still ended up with a wavy product on the top of the gunwale. This required some sanding and polyester structural repair putty to smooth it out.
Finished product ready for gelcoat
A small glass and structural putty repair, restored the mating surface on the cabin roof.
Jumping months ahead, this is the finished product as of last evening, just prior to its return to the storage locker for a long winter nap. Keep in mind, the cabin wall and helm mate up against this opening, so I wasn't worried about my gelcoat sanding error....
More on that in the coming posts.
When I originally disassembled the boat for cleaning and repair, I was disappointed to discover the factory chose not to finish the bow deck cross-member. I added it to my to do list. So, why bother fiber glassing/gel coating something covered by padding?
1) Protect the wood and easier to keep clean
2) Add strength to the cross-member - there was some minor flexing leading to gelcoat cracks inside the front of the windshield area
3) Could practice fiberglass layup and gelcoat application in a mostly hidden space
This is what I started with.
I gave it all a good sanding. I feathered the gelcoat on side rails and relieved the edges of the cross-member inside and out. I also softened the port and starboard radiuses of the cross-member
Using CAD (Cardstock Aided Design) I created templates, which were traced onto chop strand and the heavier weight 1708 fiberglass mat.
The cross-member CAD template was a little harder to design properly. I needed to ensure enough glass was cut to allow for wrap around the underside of the cross-member.
For the fiberglass layup, I started by wetting the wood with polyester laminating resin, until the wood stopped absorbing it. (applied with a 2-inch chip brush) Using polyester structural repair putty, I filled the joint on both port and starboard sides where the cross-member meets the gunwale and created a nice radius for the glass mat to lay on through the corner.
Well, my first try was a failure for several reasons.
1) I cut the cross-member glass mat at one piece which was too large for me (an amateur) to handle
2) I performed my layups in the mid-day sun on a warm day which dramatically cut my laminating resin working time
3) I ended up with numerous air pockets and failed radiuses
I had to grind it all back and start over. This actually proved to be a blessing as I discovered further manufacturing imperfections. Turns out the top of the cross-member was not laminated to the bow deck. There was a 3/8" gap across the majority of the cross-member. (red circle) I cleaned the area out with screw drivers and compressed air and then using a tongue depressor (went through a hundred of those for mixing etc.) troweled my new friend, polyester structural repair putty, into the void. Once dry, I radiused the edge with a sandpaper block and set off to layup fiberglass again.
This time I achieved much better results. 5 layers of chopped strand mat installed one right after the other. The cross-member was divided into two pieces. I did a better job overlapping the port and starboard pieces with the cross-member pieces in the corners and my chip brush wetting/tapping air bubble technique greatly improved. I was more delicate when saturating the mat layups with laminating resin and thus didn't distort the fiberglass mat. Additionally, this helped me more successfully transition the air pockets out from under the layups leaving a solid bond between each layer.
I didn't have a lot of sanding to do once the second attempt was complete. The one main area was the center of the cross-member where the port and starboard layers overlapped. A long sanding block with 80-grit successfully leveled it while causing me to break a good sweat.
Once I was happy all was leveled, including a couple resin runs, I applied a layer of polyester fairing compound, which I hand sanded using a sanding block and dowel for the corners. I then set my sights on spraying gelcoat.
As I made my way through September, the pressure to spray gelcoat mounted. Like my experience with laying fiberglass, I unfortunately had to do the job more than once to get it remotely right. As you'll see, Mother Nature ended up leaving a mark on my project.
On 18 September, found a nice afternoon and spent a couple hours masking the hull (inside and out) to spray gelcoat.
I had done my share of study and had all the components I needed from TotalBoat.
1) wax free white gelcoat (Polyester)
2) MEKP Catalyst
3) Styrene (to slightly thin gelcoat for spraying)
3) Blue, Yellow, Brown and Black die
Disposable paint suit with full face respirator
Anest IWATA KIWAMI4-13BA4 1.8mm HVLP Spray Gun with 3M disposable cups (1.8mm needle/cap a little on the small side)
As the professionals know, I struggled to properly mix the dies into the gelcoat to get a close match the blue hull.
The best way I found was to initially mix some black into the white gelcoat to get grey. Then a fair amount of blue and once close, some yellow to shift the color slightly to the green side. I was pretty close!
Well, the disaster of inexperience struck again. I read numerous posts on gun pressure settings, which technically is unique to each gun. As gelcoat is thicker than automotive paint, more pressure is required. I set my gun pressure at 25lb (regulator on the gun) and shot some cardboard which looked okay.
When I hit the boat, I quickly learned the pressure was too high. The orange peel as bad as it looked could be managed but the pin holes, could not be overcome. I lowered my gun pressure to 15 - 17 lbs. and completed 2 more coats 15 minutes apart hoping for some self-healing. (3rd coat had wax mixed in)
I had to sand it all back. The one piece of good news was my color match was acceptably close.
A lot of sanding and some re-masking was needed to ready for another attempt
After sanding everything back, the weather started giving up on me.
I found another nice afternoon early October and did a much better job of spraying the gelcoat this time around.
In my haste to get done though, my color match was horrible, particularly inside the cabin area.
Once sprayed, the boat was moved into my garage. Without the cabin roof on, it barely fit length wise and had just enough ceiling to work.
Too much yellow, not enough black in the die department.
My weather window had gone, so I had to live with what I have for now.
Padded upholstery covers/hides this area, but I wanted better.
Started by gently using 220 grit paper on a random orbital sander to knock down the high spots
Over the course of a couple nights, wet sanded progressively through 320, 400, 600, 800, 1200, and 1500 grit paper, rinsing frequently. Finished up by working through aggressive to fine polishes, using a random oribital automotive polisher and foam pads. This left me with gelcoat as smooth and soft as a baby's bottom with beautiful, deep shine. I just fell short on the color match.
This is where the professionals like Nautilus are worth their weight in gold.
Due to the mess made by all the sanding, I couldn't take finished pictures until I removed the boat from the garage for a wash. Results will be shown in later posts.