To paint an aluminum jon boat, strip any failing paint, clean the hull with KBS Klean, etch bare aluminum with RustBlast, then brush, roll or spray KBS MAXX, a 2K polyurethane that bonds to aluminum without a primer. Give it 7 days to cure before launch.
Updated October 2026 by the KBS Coatings technical team.
- What Do You Need to Paint an Aluminum Jon Boat?
- Do You Have to Remove Old Paint from an Aluminum Boat?
- How Do You Prepare a Previously Painted Aluminum Jon Boat?
- How Do You Prepare Bare Aluminum for Paint?
- How Do You Remove Oxidation and Corrosion Before Painting Aluminum?
- What Grit Sandpaper Should You Use on an Aluminum Boat?
- Do You Need to Prime an Aluminum Boat Before Painting?
- How Do You Apply Paint to an Aluminum Jon Boat?
- How Long Should Jon Boat Paint Cure Before Going in the Water?
- Why Does Paint Peel From an Aluminum Boat?
- Frequently Asked Questions
- Getting Your Jon Boat Paint Supplies Together
| Products | KBS Klean, RustBlast, KBS MAXX |
|---|---|
| Primer | None needed on properly prepared aluminum |
| Mix ratio | 3 parts KBS MAXX Base to 1 part MAXX Activator |
| Pot life | 30 minutes once mixed |
| Application temperature | 45 to 110°F surface temperature, at least 5°F above the dew point |
| Film per coat | 1.5 to 2.0 mils dry film thickness |
| Recoat window | 30 minutes to 3 days, no scuffing |
| Cure before launch | At least 7 days |
| Coverage | About 450 sq ft per gallon at 2 mils, one coat |
What Do You Need to Paint an Aluminum Jon Boat?
To paint an aluminum jon boat with the KBS system you need KBS Klean to clean, RustBlast to etch bare aluminum, and KBS MAXX for the paint, plus sandpaper, mixing supplies, a brush, roller or spray gun, and safety gear. What you actually use depends on the boat's condition and how you plan to apply the paint.
- KBS Klean: cleans and degreases painted and bare aluminum before you sand and again after
- RustBlast: removes leftover oxidation and etches bare aluminum. Skip it only when the old paint is sound everywhere and no bare metal shows
- KBS MAXX with MAXX Activator: the 2K direct-to-metal paint for the hull
- KBS #1 Thinner (optional): KBS MAXX comes pre-thinned, so you only need this if your brush, roller or gun calls for it
- Sandpaper or abrasive pads from 80 to 220 grit, plus scrapers for loose paint
- KBS Paint Mixing Cup for measuring the 3:1 mix, a Hurricane Paint Mixer for the base, and a KBS Paint Spout for clean pours
- A poly bristle paint brush and a high-density foam roller, or the KBS HVLP Spray Gun with the 1.4mm tip if you are spraying
- Clean, lint-free rags, masking tape and plastic sheeting
- Chemical-resistant nitrile gloves, safety glasses and proper respiratory protection
Do You Have to Remove Old Paint from an Aluminum Boat?
No, you do not have to strip all the old paint off an aluminum boat. Paint that is sound and firmly bonded can stay and be scuffed for the new coat. Anything that is peeling, flaking, blistering or loose has to come off, because the new paint is only as strong as the layer it sits on.
Loose coating left on the hull becomes a weak layer under the new paint, and when it lets go it takes the new coat with it. Spots where the old paint has worn through to bare aluminum get the bare-aluminum prep described below, not the scuff the painted areas get.
Strip the whole boat only when the old coating is badly deteriorated, has adhesion problems all over, or is in no shape to paint over. Otherwise, keep the sound paint and save yourself the work.
How Do You Prepare a Previously Painted Aluminum Jon Boat?
To prepare a previously painted aluminum jon boat, wash it with KBS Klean mixed 10 parts hot water to 1 part KBS Klean, remove any loose paint, feather the edges, and scuff the remaining paint with 180 to 220 grit until the gloss is gone. The goal is a clean, evenly dull surface the new paint can grip.
Apply the KBS Klean solution liberally and scrub for 5 to 10 minutes with a sponge, scrub pad or bristle brush to lift dirt, oil, grease and wax. Do not let it dry on the surface. Rinse thoroughly with clean water and let the boat dry. The KBS Klean directions list every dilution ratio.
Next, scrape off any isolated loose paint and sand the edges until they blend smoothly into the firmly bonded paint around them. Scuff the rest of the painted surface to knock off the gloss, then wash off the sanding dust with KBS Klean, rinse and let it dry. Well-adhered old paint is the foundation for KBS MAXX, so anything loose has to go. Pay extra attention to rivets, seams and welds, where dirt and oxidation hide in the recesses.
If sanding breaks through to bare aluminum anywhere, prep those spots with the bare-aluminum steps below before you paint.
How Do You Prepare Bare Aluminum for Paint?
To prepare bare aluminum for paint, wipe it with KBS Klean mixed 25 parts hot water to 1 part KBS Klean, rinse right away, sand it with 120 to 180 grit, clean off the dust, then etch it with RustBlast. Bare aluminum grows a thin oxide layer in air, so it needs this extra step before KBS MAXX goes on.
Use a very soft, non-abrasive pad with the KBS Klean solution. Wipe the surface without letting it soak, and rinse immediately so the solution never dries on the aluminum. Then sand to give the coating some tooth, without polishing the metal smooth. Remove all sanding residue.
How Do You Remove Oxidation and Corrosion Before Painting Aluminum?
Remove oxidation and corrosion from aluminum by sanding down to clean, sound metal, cleaning off the residue with KBS Klean, then keeping RustBlast wet on the surface for 10 to 20 minutes before rinsing. RustBlast etches the aluminum and leaves a light zinc phosphate coating that helps KBS MAXX bond.
Oxidation on a jon boat looks dull, chalky, white or gray. Heavier corrosion shows up as white powdery deposits, rough patches or pitting. Light oxidation sands off; heavier corrosion takes coarser grit or more aggressive abrasion to reach stable metal. Work pitted areas carefully, because corrosion can stay inside the pits after the surrounding metal looks clean.
After sanding and a KBS Klean wash and rinse, apply RustBlast full strength. Despite the name, it works on aluminum too. Keep the surface wet for 10 to 20 minutes, reapplying and agitating as needed, and never let it dry. Rinse thoroughly with water, which also neutralizes the acid, and let the aluminum dry completely.
Once dry, RustBlast leaves a slight white powder. That is zinc phosphate, and it stays on: it helps the paint adhere. Coat the boat within 7 days of the RustBlast treatment. The RustBlast directions cover the full procedure.
What Grit Sandpaper Should You Use on an Aluminum Boat?
Use 80 to 120 grit to remove failing paint and heavy oxidation, 120 to 180 grit to prepare bare aluminum and feather paint edges, and 180 to 220 grit to scuff sound existing paint. Coarse grits cut through bad coating fast; finer grits leave a surface profile without gouging the metal.
- 80 to 120 grit: failing paint, heavier oxidation and corrosion
- 120 to 180 grit: bare aluminum, and feathering edges between bare metal and sound paint
- 180 to 220 grit: scuffing firmly adhered paint to remove the gloss
Do not sand bare aluminum glassy smooth. You want tooth for the paint, not a polish. These ranges are a general guide; with KBS MAXX, follow the prep steps above.
Do You Need to Prime an Aluminum Boat Before Painting?
No. KBS MAXX is a direct-to-metal (DTM) paint, so it needs no separate primer or self-etching primer on aluminum that has been cleaned with KBS Klean, sanded and treated with RustBlast. It bonds straight to the prepared aluminum, so you skip the separate primer coat.
How Do You Apply Paint to an Aluminum Jon Boat?
Mix 3 parts KBS MAXX Base to 1 part MAXX Activator, then brush, roll or spray it at 1.5 to 2.0 mils dry film thickness per coat while the surface is between 45 and 110°F and at least 5°F above the dew point. Add coats within 30 minutes to 3 days with no scuffing between them.
KBS MAXX is a two-component (2K) polyurethane. The Activator sets off a chemical cure that forms a hard, crosslinked film that stands up to water, abrasion, impact and UV. On its technical data sheet, KBS MAXX rates Excellent for water immersion and passes 160 inch-pounds of direct and indirect impact.
Mix it. Stir the KBS MAXX Base until it is smooth and uniform; a Hurricane Paint Mixer on a variable-speed drill makes this easy. In a KBS Paint Mixing Cup, measure 3 parts KBS MAXX Base to 1 part MAXX Activator and mix thoroughly. The mixed paint doubles in viscosity in about 30 minutes, so mix only what you can apply in that time. You do not have to mix the whole kit at once. Never pour mixed material back into the can. For a walkthrough, see how to mix and apply 2K paint.
Thin only if needed. KBS MAXX is pre-thinned and ready to brush, roll or spray. If your equipment calls for reduction, add 5 to 10% KBS #1 Thinner or xylene. Never reduce KBS MAXX with lacquer thinner; it is not compatible and is for cleanup only.
Apply it. Roll the flat hull panels with a high-density foam or low-profile roller and use a poly bristle brush on the ribs, seams and rivet lines. Brush an area and move on; going over it again and again forces out the solvent and leaves brush marks. To spray, use a 1.0 to 1.5mm tip. The KBS HVLP Spray Gun with the 1.4mm tip is the one we recommend.
Build the film in coats. Lay down 1.5 to 2.0 mils dry film thickness per coat and recoat within the 30-minute to 3-day window. Two coats of KBS MAXX build 3 to 4 mils, the film that reached 1,000 hours of salt spray (ASTM B117) in testing. Do not try to get there in one heavy coat; too much film at once slows drying and curing. The KBS MAXX directions have the full spray settings.
Stuck or unsure? Search the KBS Support Desk for instant answers
How Long Should Jon Boat Paint Cure Before Going in the Water?
KBS MAXX needs at least 7 days to fully cure before an aluminum jon boat goes in the water. It is dry to the touch in 30 minutes and hard in 3 to 4 hours, but the 2K polyurethane takes the full week to develop its hardness, adhesion and resistance to water and abrasion.
Cure depends on time, temperature and film build. Cooler weather or heavier coats can stretch it past 7 days, so give it extra time when in doubt. The published dry times were measured at 77°F and about 70% relative humidity.
Why Does Paint Peel From an Aluminum Boat?
Paint peels from an aluminum boat when something keeps it from bonding to the metal: contamination, leftover oxidation, a surface too smooth to grip, old paint failing underneath, or paint applied or cured outside its specs. Sometimes it fails within weeks; sometimes water, abrasion and weather expose the weak bond later.
- Contamination: oil, grease, wax or dirt sits between the aluminum and the paint. KBS Klean removes it.
- Oxidation or corrosion left behind: the paint bonds to unstable oxide instead of solid aluminum. Sanding and RustBlast take care of it.
- Too little surface profile: glossy paint or polished aluminum gives the new coat nothing to grip.
- Painting over failing paint: the new coat sticks to the old paint, and both peel when the old paint lets go.
- Application outside the specs: wrong temperature, too close to the dew point, an off mix ratio or too much film at once all interfere with the cure.
- Launching too soon: putting the boat in the water before the 7-day cure exposes paint that has not reached full strength.
Frequently Asked Questions About Painting an Aluminum Jon Boat
What Is the Best Marine Paint for an Aluminum Boat?
Look for a two-component (2K) polyurethane that bonds directly to aluminum and holds up in water and sun. KBS MAXX is a 2K direct-to-metal polyurethane that needs no primer on properly prepared aluminum, rates Excellent for water immersion on its data sheet, and is permanently UV stable, so the color and gloss hold up outdoors.
Is Painting Aluminum a Good Idea?
Yes, painting aluminum is a good idea when the surface is prepared correctly. Paint seals the boat from the weather and gives it a uniform color, but it lasts only when it bonds to clean, sanded and etched aluminum. Skipping the cleaning and etching steps is the most common reason painted aluminum peels.
What Is the Best Thing to Clean Aluminum With Before Painting?
Clean aluminum with a water-based cleaner and degreaser such as KBS Klean, mixed 25 parts hot water to 1 part KBS Klean for bare aluminum. Wipe it on with a very soft pad, do not let it soak or dry, and rinse right away. Avoid solvent-based cleaners, which can leave an invisible residue that interferes with paint adhesion.
Can You Paint Over Already Painted Aluminum?
Yes, you can paint over already painted aluminum as long as the old paint is well adhered, because it becomes the foundation for the new coat. Remove all loose and flaking paint, scuff the rest with 180 to 220 grit, clean it with KBS Klean at 10 parts hot water to 1 part, then apply KBS MAXX. Prep any bare spots with RustBlast first.
Should You Paint the Bottom of an Aluminum Jon Boat?
Yes, you can paint the bottom of an aluminum jon boat with the same prep as the rest of the hull. Most jon boats come out of the water after every trip, but KBS MAXX has decades of use on boats left in the water for a full season, and it rates Excellent for water immersion on its technical data sheet. KBS MAXX is not an antifouling paint. Let it cure the full 7 days before the boat goes in the water.
Can You Paint a New Aluminum Jon Boat?
Yes, but new aluminum still needs full prep. It can look clean while carrying oxide, mill oils or other contaminants that stop paint from bonding. Clean it with KBS Klean, sand it, and treat it with RustBlast, following the bare-aluminum steps above, before applying KBS MAXX.
Can You Brush or Roll Paint on an Aluminum Jon Boat?
Yes. KBS MAXX can be brushed, rolled or sprayed. Roll the large flat panels with a high-density foam or low-profile roller and brush the ribs, seams, corners and rivet lines with a poly bristle brush. Brush each area once and move on; overworking it leaves brush marks.
How Do You Paint the Inside of an Aluminum Jon Boat?
Paint the inside of an aluminum jon boat the same way as the outside: clean with KBS Klean, sand, etch bare aluminum with RustBlast, then apply KBS MAXX. The floor and ribs take the most wear from gear and boots, so give them full coats and use a brush to reach around ribs and seams.
How Much Paint Do You Need to Paint an Aluminum Jon Boat?
KBS MAXX covers about 450 square feet per gallon at 2 mils dry film thickness for one coat. Measure the surfaces you plan to paint, multiply by the number of coats, and divide by 450. For example, 200 square feet at two coats is 400 square feet, just under a gallon, before you add extra for application loss.
Still have questions? Search the KBS Support Desk for instant answers
Getting Your Jon Boat Paint Supplies Together
Most of a jon boat paint job is prep, so order the prep products with the paint: KBS Klean for every wash, RustBlast for any bare aluminum, and enough KBS MAXX for two coats at about 450 square feet per gallon per coat. Then plan a week between the last coat and launch day.
Related guides: What marine paint needs to hold up, How to mix and apply 2K paint, How to repair boat trailer frame rust, or browse all KBS application guides.
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