Recoating a Driftboat Bottom
For all the benefits offered by an aluminum drift boat, there is only one main drawback, and that is the fact that operation in very shallow waters will only be as good as the bottom coating. Bare aluminum “sticks” very well on rocks, and that grabby nature can get bothersome when low water conditions make frequent bottom contact a fact of life.
Bottom coatings like Gluvit and Coat-It keep aluminum drift boats operating at peak levels. Trouble is these products wear, and over time will require maintenance, or the boat’s performance will suffer.
Redoing a drift boat bottom is not hard work. It is however, loud, messy and generally not fun. Because of this, you’ll want to make every effort to get the best adhesion (and resulting longevity) when you do take the time to redo your boat.
Optimal time of year for this project is the heat of summer. The main reason for this is the ability to work outdoors. First, the dust created in this process is a mess and will permeate every corner of an indoor environment. Secondly, the epoxy bottom coatings benefit from summer’s heat in the curing process. Schedules and available time being what they are, I took on my drift boat’s bottom in December’s cold. This does provide some challenges, but they are not deal-breakers.
If you want to power this project out, the work can easily be completed in a day (allow more time for the epoxy to cure). If you work at a leisurely pace, a weekend is an easy deal.
-60 Grit Flapper Wheel
-1 Qt. Acetone
-Masking Tape and Newspaper
-1 Gallon of Gluvit or Coat-It
-Cheap Plastic Trowel
-Cheap Paint Brush
-Propane Heater (winter only)
ONE: Empty the Boat
TWO: Roll the Boat Over
*POUNDING OUT DENTS-When you roll the boat over, you may be surprised at the wear and dents your boat has accumulated. Unless there’s a random, dramatic dent in a low wear area, I leave all the dents and depressions alone. The reason is that the bottom coatings do not flex well as the bottom dents (they all say they do, but they don’t) and as a result, the bottom coating separates from the metal. A pre-dented bottom will hold the coating better in the second round than one that you pound out, only to push in again under normal use. If you’ve put a few “tunnels” in the bottom between floor supports, don’t sweat it.
Photo 1 shows the worn bottom. Not horrendously bad, but the remaining Gluvit is doing little as the main impact area has been worn away.
THREE: Scrape Loose Material
PHOTO 2 shows just how much material you can remove by working at it a little bit with a scraper.
FOUR: Grind Off Remaining Material
*PROPANE TORCHES- I’ve often removed epoxies and varnishes by heating the material with a propane torch until it softens (and loosens), then scraping it off. This is not a good option for aluminum boats. The heat-treated alloys in aluminum boats require extreme caution in the application of heat. If misused, excessive heat can damage your hull integrity.
Photo 3 – You’ll need a grinder with flapper wheel, safety glasses and dust mask.
Photo 4 is the boat bottom with grinding complete. All remaining Gluvit will stay.
FIVE: Expose Clean Aluminum
Photo 5 shows the bottom once it had been gone over a second time with the grinding wheel to provide a base for the Gluvit to adhere to.
Photo 6 – Cleaning with Acetone removes oils and contaminants. After a while it gets really groovy too, but the hangover is a killer.
SEVEN: Prep for Gluvit
Because I did this project in December, temperatures were very cold. Cold temperatures slow the chemical reaction of the epoxy, dramatically lengthening cure time. To counteract this, I used a propane heater beneath the hull to warm the aluminum and achieve a faster cure rate. Preheat the hull realizing that flooring has to become warm before the heat will get to the bottom itself. Leave the heat on during and after the application process. This step is only necessary in cold environments.
Photo 7 shows my makeshift hull heater, along with the newspaper protected sides prior to coating the bottom.
EIGHT: Apply the Bottom Coating
A brush is handy for addressing the chine and any detail areas. Apply the whole gallon (or however much actually comes in the gallon container) to the boat.
Photo 8 shows the Gluvit and hardener additive. Gluvit and Coat-It are competitive products and as far as I know both are good. I haven’t seen a side-by-side comparison to really judge them against each other.
NINE: Baby-sit the Job
If you happen to be running a heater under the boat like I did, do not leave the heater unattended. One small gas leak and the flames get quite large (don’t ask me how I know this, but thank God I was there).
TEN: Allow to Fully Harden
Don’t rush to get your boat back on the trailer. If the coating is not fully cured, you may glue your boat to the trailer. Be patient and take your time. When it is ready, flip the boat back over and reload. You’re set for another few years, depending on the amount of use.
While you’re waiting for the bottom to dry, the boat being upside down offers an easy opportunity to hit it with a coat of wax.
Photo 9 – Fully cured Gluvit will be clear with maybe a little color in the deeper areas. It should have a mirror-like finish and be seemingly hard as glass.
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