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
4) Wax
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)
No luck.
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.