Newbie, but capable, confirm my gelcoat process?

[btodag]

Got a new-to-me 23 Cat with gouges front to back on the bottom. Looking to make it nice again.
We're not doing bottom paint. This is a trailered boat not close enough to the coast and we're looking for a nice clean gel coat look. I plan to patch, spray gelcoat below the waterline and maybe paint above I think. Still debating my skill-confidence vs elbow grease vs time before summer is here on paint or gelcoat above the waterline.
Asking for guidance on my tentative plan. Thanks for the help!

• Get the boat off the trailer onto stands

• Dremel out the gouges to v-shapes

• Wash

• Acetone clean everything very well

• Patch with 3M Marine Premium Filler. The whole bottom looks like this. Break even on cost for the 3M filler looks to be more than 3 qts ($75) should have been a gallon ($250) buy. I wonder how far this stuff goes?

• Shape/sand smooth to 220 grit? I see lots of different directions here, as coarse as 80 and as fine as 320... what grit should I do before spraying?

• Tack rag?

• Spray FGCI gelcoat w/o wax, maybe 1 coat?? 2 coats? Probably FGCI's Whisper Grey

• Spray FGCI gelcoat w/Duratec, maybe 3:1 gel/duratec?

• Sand/buff as needed, I've read you must still sand to release additional solvent and allow full cure, even if it is beautiful. Starting from 400 up to 1200 or so, probably using a guide coat a good bit to make sure the gouges are blended well.

• Move the boat to different points on stands and repeat from 3-10?

There's a chance I do the whole boat up to the rub rail, debating tinted gel to the rail or just a white bottom and paint above the waterline. We're looking for a "Whisper Grey" color and like the whole hull look better than a white/grey look, but flexible on that. It's a 2015 230 Carolina Cat that is super chalky, so a sand, buff job for sure, but wanting to add a color. How we add that color still to be finally decided.
Considering Whisper Grey gelcoat vs Awlcraft, FGCI has a tinted gelcoat w/o wax. Do I do a coat or two of w/o wax, then a coat w/o wax + Duratec or does every coat have Duratec in it?

Thru-hulls... can I tape them off or need to remove them?

[Jaysen]

Duratec is last coat. No wax. Follow the directions and don’t change the ratio. No wax on coats under duratec. No wax coats don’t sand well so… spray them all.

Base process.

1. Grind out cracks
2. Fill with paste.
3. Fair. If you don’t low spots sand with 80 and paste. No need to go over 120 while your rough fairing.
4. Practice spraying. Unless you’ve done it a lot, you aren’t going to have a good time doing a while hull. Start with a deck lid or something. Spraying should be done with styrene reduced gel and adequate MEKp to catalyze the gel +10%. The styrene will greatly lengthen the catalyst time. Figure it out.
5. No wax no duratec spray till you pass out or complete a coat. Repeat to about 1/8”.
6. Duratec coat. Go light on the styrene as the Duratec thins the gel.
7. Unless you’ve done have runs or want to start over, no sanding. Just course cut through to polish wax.

Or paint it.

[btodag]

Thanks so much! I'm planning on lots of practice before hand.

Just 2 passes, if I'm good, is what you're saying. 1 pass w/o wax and then the finish pass with Duratec. Right?

[Jaysen]

Read #5 again.

A number of thin passes until you get adequate coverage. Over the course of time I try to build 1/8”. Once I’ve got that I shoot duratec.

The trick here is building thickness but wait for just enough cure that bottom layers down sag on you.

There’s a reason these guys make some $$