I finally freed the boat from storage after one of the worst winters on record in the Midwest. My long list of projects will start with bottom paint. I starting sanding the bottom today in preparation for bottom paint. The old bottom paint was peeling bad and needed attention. I plan to keep the boat on a lift at my lake home when not in use so I thought I would not need to use an anti-fouling bottom paint.
I looked at several different kinds and settled on Interlux VC Offshore Epoxy. It is a two part Teflon bearing Epoxy that has a hard slick finish ideal for powerboats and racing sailboats. Teflon adds lubricity and eases wet sanding and burnishing.
The pictures below show about two hours of sanding with 80 grit paper on my random orbital sander. A few more afternoons sanding and I should be ready for paint. The instructions calls for washing the surface and and wiping down with 202. Complete instructions are listed below.
Preparation:
BARE FIBERGLASS: Begin by scrubbing well using soap and water and a stiff brush. Rinse with fresh water. Wipe with Fiberglass Solvent Wash 202. Sand with 80 grade (grit) paper. Wipe with Fiberglass Solvent Wash 202.
CLEAR EPOXY: Begin by scrubbing well using soap and water and a stiff brush. Rinse with fresh water. Wet sand with 80 grade (grit) paper. Wash down with fresh water. Wipe with Fiberglass Solvent Wash 202.
BARE METAL: Sandblast or grind to bright metal finish. Immediately apply Viny-Lux Primewash 353/354 thinned 25% with Viny-Lux Solvent 355. Allow to dry for 1-24 hours.
Method Apply 3 coats of VC Performance Epoxy. VC Performance Epoxy is designed for spray application but can be applied by brush and rollers.
Hints
Mixing Mix base and curing agent thoroughly at the specified ratio. Allow 45 mins at 50 deg F/10 deg C and 30 mins above 77 deg F/25 deg C for induction.
Thinner Reducing Solvent 2316N.
Thinning Thin, if necessary, after induction.
Cleaner Bare Fiberglass - Fiberglass Solvent Wash 202. Epoxy - Fiberglass Solvent Wash 202.
Airless Spray Pressure: 142-170 bar/2100-2500 psi Tip Size: 0.48-0.53 mm/19-21 thou.
Conventional Spray Pressure Pot: Pressure: 3.44-4.08 bar/50-60 psi - gun pressure; 8-15 psi pot pressure. Tip Size: 1.4-1.5 mm/55-60 thou. Siphon Cup: Pressure: 3.06-4.08 bar/45-60 psi. Tip Size: 1.4-1.5 mm/55-60 thou.
Other If fairing is necessary, use Interprotect Watertite between 1st and 2nd coats of VC Performance Epoxy and then apply 3 coats of VC Performance Epoxy over the Interprotect Watertite.
Some Important Points Product temperature should be minimum 10 deg C/50 deg F and maximum 29 deg C/85 deg F. Ambient temperature should be minimum 10 deg C/50 deg F and maximum 35 deg C/95 deg F. Substrate temperature should be minimum 10 deg C/50 deg F and maximum 35 deg C/95 deg F.
Compatibility/Substrates VC Performance Epoxy can be applied to gelcoat, bare fiberglass, epoxy and properly primed metal. Apply to clean, dry, properly prepared surfaces only. VC Performance Epoxy can only be applied over two component products that are specified for underwater use. If there is any single paint (such as antifouling paint) on the surface, it must be removed and then proceed as with bare surface.
Number of Coats 3-4 as needed
Coverage (Theoretical) - 200 (sq ft/Gal) by spray
Recommended DFT 3.5 mils dry
Application Methods Brush, Roller, Airless Spray, Conventional Spray - Pressure Pot or Siphon Cup
Once the bottom is sanded down to bare fiberglass I hosed the bottom down with water to get all the dust off. Once that was dry I used the Interlux 202 fiberglass wash to wipe down the hull in preparation for painting. Make sure to use rubber gloves when using the 202 wash. It is a really strong chemical cleaner.
I used a 7 inch foam roller to apply the paint. I purchased these from
Jamestown Distributors. They come in 3, 7 and 9 inch widths. Make sure you have some mixing pales because the Interlux VC Performance Epoxy has to be mixed 1:1. After mixing it has to set and pot for about 30-45 minute before you can apply the paint. This allows the curing agent to start reacting with the base. I applied the paint on a day that was about 70 degrees. I thinned it slightly with the Interlux 2316N thinning agent.
When I rolled the paint on and small bubbles appeared. I tried using the roll and tip method but the brush left line in the paint so I just went back and rolled over it again and it smoothed out. I may have needed more thinning agent to allow it to flow out. This process is trial and error until you find the right mixture that works for you. I applied three coats one after the other after the previous coat was somewhat dried and non tacky. It took about a quart of paint per coat on my 22 ft boat.
The final product
Bottom paint job done!
Starboard side
Keel shot, note holes for Depth and Speed transducers
Rear view, note drain scuppers still need paint