How To Repair Smooth And Paint Your Boat Bottom

Typically fiberglass boat bottoms after severalare using their fast drying Copper Teflon.
years of use become scratched and gouged from 
rocks, grounding, and flotsam. A one-inch scratchWe are using a 3/16-nap "mohair" 9-in. roller for
can produce turbulence for 12 to 18 in. down yourapplication. The hardened spots are brushed in
hull. Turbulence interrupts smooth flow producingwith a high quality brush to help avoid brush
drag which need more power to over come.marks. It is important with urethanes not to
Your boat bottom may also have a few gel coatintroduce air into the urethane during application as
patches where rock impact has flexed theit can leave bubbles in this quick drying finish. You
bottom creating weak spots that were repaired.can spray on the finish as you would car paint
But the gel coat used may not be flush with thewith an air type or airless sprayer and a rather
bottom.fine tip. Now be sure to remove the masking
 tape while the boat bottom paint is still wet. You
The techniques discussed here will help yourdon't want to glue it onto the bottom making it
application and results on both displacementhard to get off.
sailboats with keel and a canoe. The systemsUsing a rag with epoxy thinner on it we now go
employed can be applied to all fiberglass boataround the boat to wipe off any drips that made
bottoms and can be seen in video form at:it past our masking tapes. But the job is not over
(youtube address when found)yet. Once the first coat of bottom paint is dry.
The first step is to wet sand the bottom with aWhich can be in just an hour or two we can
60 to 100 grit 3M type sanding sponge. Purple orcheck the bottom for scratches we may have
green sponges work well. Wet sanding will removemissed. Once the bottom is sporting new paint
any burs of fiberglass along with any marinethose scratches we missed will show up and can
growth or wax buildup that may be on thebe dealt with.
bottom. Next, wipe the bottom with a damp ragUsing the same glazing compound we can catch
to remove any dust which remains.those few imperfections that remain. Next a light
Using glazing compound you can now squeezedry sanding can remove any small bubbles, brush
filler into these gouges and scratches. Because themarks, drips and new glazing overlap. You then
canoe bottom is riddled with scratches I justneed to be very careful that you wipe off all of
squeeze some premixed glazing compound out ofthe dust particles as you are hoping this is your
the toothpaste type tube. I then pull a plasticlast coat of bottom paint.
bondo blade over the hull flexing it to contour theNow, before you coat your entire bottom it is
boat bottom shape. For the keel or rudder of aimportant to "strip the boat bottom". Go over all
boat you can do the same thing but may be ableyour new repair areas with a brush and fresh
to just hit each of the divots and gougesbottom paint to give them some coverage. When
separately.you "strip the boat bottom" you are in effect
Because this glazing compound is soft it sandslaying two coats over the repaired areas. The
quickly with the same sponges which can now bestripped areas will start to set up while you are
used dry. Don't worry about the soft nature ofcoating the bottom from stem to stern. When
this type of filler because the boat bottom paintyou do your final coat you can get more
applied towards the end of the project will sealconcealment over areas that may have been
the boat bottom and harden the surfaces.repaired earlier. Remove your masking tape,
The trick with this process is to repeat it two orcheck for drips and take steps to prevent dust
three times. Each time you will get closer andfrom blowing on to your finish before it sets up.
closer to the "faired hull" you are looking for. OnceA note about support points. If you are using a
you have completed your final sanding be sure toproduct like the Smooth Sailing copper Teflon
rinse the hull off with a hose and wipe dry toproduct you can just touch in the support points
remove any remaining dust. Use blue or greenas the boat is picked up by straps for your boat
tape to mask off your water line and your arelaunching. This product dries in minutes. If you are
ready to apply your boat bottom paint.using the Urethane as we did you will need to hold
For the canoe we have chosen a "non-stick"the boat with the straps for about an hour
anti-fouling urethane Teflon boat bottom paintbefore launching.
made by Smooth Sailing at For the keel boat we