Category Archives: Boat Finish Restoration

The Different Types of Boat Paint

In this article, we will briefly describe some of the different types of boat paint that can be used to repair, restore, protect, and make your boat looks its best.

Topside boat paint is a type of paint you apply above the waterline of a boat. This can include the sides of the hull, deck, as well as interior. Marine topside paints usually consist of one-part polyurethane, two-part polyurethane, and alkyd marine enamel. There are also buffable, two-part acrylic urethanes. Due to the sun’s rays, your boat is vulnerable to UV damage so coating your upper hull and deck with good topside paint can go a long way to protecting your boat.

Blue Water Marine Topside Paints are superior in quality, higher in value and typically, priced better than store brands


Aluminum boat paint can be used for many purposes including to camouflage, decorate, refurbish, or restore aluminum boat surfaces. Paint that is safe for aluminum and can be applied without a primer and can be used below or above the waterline.

Aluma Hawk Paint
Aluma Hawk is a fast drying, high-solids, corrosion-inhibiting coating designed for use on aluminum with no need for a primer.


Fiberglass boat paint usually consists of gelcoat, gelcoat putties, resins, restoration solutions, repair kits, and tools/materials. Gel coats are often used to touch up or repair a boat’s finish. They have a much shorter shelf life and can be a lot more difficult to apply than paint so the manufacturer’s instructions must be carefully followed to ensure a successful result.

Gelcoat can be used to patch existing gel coat, fiberglass repairs, and new construction and projects.


Wood boat paint typically includes traditional types of oil-based finishes, as two-part paints tend to be less flexible. Because wood can flex and swell, especially along seams, expensive finishes will not last any longer than traditional stain or paint. Teak can be used to prevent fading on a boat’s wood finish. If left untreated, it will often fade which leads to the need to clean or treat the wood so it is not susceptible to rot, mildew, and discoloration.

Teak wood cleaner
Just Teak is a simple solution to clean, brighten & protect your teak.


Bottom boat paint is antifouling paint or coating designed to diminish weeds, barnacles, and other aquatic organisms that can attach below the waterline of a boat and cause damage. Bottom paint includes ablative bottom paint, hard boat bottom paint, aluminum safe bottom paint, primers for bottom paint, and boat bottom paint remover.

Biocop bottom paint uses the newest biocide technology which is safe for the environment.

If you need assistance selecting the right boat paint for your next project see Bottom Paint Store’s how-to articles or call our technical support department Monday-Friday from 8:30-5:00 pm EST 888-505-2313.

Testing for Compatibility of Topside Paint with Awlgrip Topcoat

SURFACE PREPARATION
COATINGS COMPATIBILITY & ADHESION
TESTS (ABOVE WATER ONLY)


Test One: Cross Hatch Adhesion (See diagram above)

  1. Select test area(s) on the surface to be painted. Thoroughly clean,
    de-wax and degrease this area.
  2. With a sharp blade, cut 6 lines vertically and 6 lines horizontally to give
    a box of 25 squares. The cuts must be deep enough to reach the
    substrate. On thick fairing systems this test may have to be done to
    several different layers.
  3. Apply 3M #610, #895 or #898 3M Scotch Brand Filament Tape (or
    similar type of packaging tape) over the scribed area, making certain
    that the tape is tightly adhered to the test surface. Do not use
    masking tape.
  4. With an abrupt yank, pull the tape back parallel to the surface. Pulling
    the tape straight up will give no test at all.
  5. Examine the test surface. If any square of old coating in the scribed
    area is removed, the adhesion has failed. All the failed layers must
    be removed.

Test Two: Solvent Resistance

  1. Saturate a cotton ball or small wad of cloth with one of the
    Awlgrip Topcoat or Primer Reducers (T0003 or T0006).
  2. Tape the reducer-saturated ball to the scribed area surface for
    30 minutes.
  3. After 30 minutes remove the cotton ball. If the reducer has dissolved
    or severely softened the old coating, the coating is incompatible and
    must be removed. If the scribed area has remained intact, allow a
    15 minute recovery period and repeat all steps in Test One again.
  4. If any square areas are removed, all the failed layers must be
    removed.

Test Three: Coating Compatibility
If the old coating is still intact after Tests One and Two, perform
Test Three.

  1. Lightly sand a small test area with 220 grit paper. Clean the sanded
    areas thoroughly with Awlgrip Wipe-Down Solvent (NA/AP:
    Awlprep T0008 ; EU: Surface Cleaner T0340) and using clean cloths.
  2. Paint a small patch of the surface with Awlgrip Topcoat. Do not use
    masking tape on the edges of the test application as the paint edges
    created by the tape will ‘print through’ and be visible in the finish.

Thinning Gelcoat and Using PVA

Gelcoat does not fully cure without first supplementing it with a surfacing agent or wax additive sanding aid. Gelcoat may be thinned for use in a Portable Preval Sprayer with styrene monomer. You can spray it with a polyvinyl alcohol (PVA) before gelcoat reaches its gel stage (5-10 min.), or adding 1oz per quart of a wax additive sanding aid.

PVA or Partall Film #10 is a release agent that helps with removing parts from a mold or can be used as a surfacing agent when using gelcoat without a wax additive (sanding aid).

PVA is soluble in water making it easy to wash off. Applying can be achieved by spray or wiping the green liquid on with a sponge. It will foam slightly but dry to a clear, glossy shine. It can take 15-30 minutes depending on temperature.

For spraying gelcoat our FGCI brand does not recommend thinning.

If thinning is needed for gun/nozzle used then Patch Booster is an additive that will thin out gelcoat and not affect colors, such as acetone or styrene. This is added at 20-25% and the gelcoat will require catalyst at 2% so purchase an extra tube and omit wax (sanding aid).

Another thinning alternative is the Duratec High Gloss Additive. This is used with gelcoat for many reasons. Mixed at a 50/50 ratio this will produce a high gloss finish and will serve as a thinner for your gelcoat, that is why this is commonly used when spraying gelcoat. In addition, you’ll omit any additional sanding aid. After waiting a full 24 hours you can buff when cured, for a hi-gloss use 600 or higher grit paper and buff with Aqua Buff 2000 compound. Purchase an extra hardener as your gelcoat will need to be catalyzed at 2%.

Tips for Using Brushable Gelcoat

Brushable Gelcoat, often referred to as gelcoat paint, is a specially formulated product that is made to be applied like paint and eliminate the need for spray equipment. It has excellent leveling, Water/Osmosis resistance, UV light Stability, great Gloss Retention, and fantastic long-term durability and is available in a variety of colors. Here are some tips for successful brushable gelcoat application.

Applying Gelcoat by Brush or Roller – (Use a Brushable Gelcoat) When applying gelcoat by brush or roller, we recommend the Ultra Plus Brushable Gelcoat. (other Gelcoats are best applied by Spray) The Ultra Plus Brushable Gelcoat is designed for self-leveling and is a much easier application. It allows for a much smoother finish and less time finishing the gelcoat. It is easy to use for the “do it your selfers’! Choose a good pure (natural) resin-resistant bristle brush with tapered ends. Avoid brushes that are either too stiff or too soft. For most work, a 3″ or 4″ wide brush will suffice. If there is a trim color, you should have a narrow trim brush on hand. Our Brushable Gelcoat comes with MEKP hardener with every purchase, but you may need more which you can purchase as an option depending on the application, temperature, and other environmental factors. Gelcoat needs to be applied evenly. We suggest a thickness of 18-20 mils to properly cure. The thickness of the matchbook cover is approximately 18 mils. If you’re not sure how thick it is, pick up a mil gauge. This is a simple, easy way to see the thickness of your gelcoat.

  1. Don’t add Patch Booster or Sanding Aid (wax). You don’t need to add sanding aid (wax) to Brushable gelcoat to have it dry tack free. The self-leveling technology added doesn’t require any additional products or additives.
  2. Proper gelcoat application requires you apply your coats about 15-20 mils thick. We offer mil gauge for purchase.
  3. Allow the gelcoat to cure overnight and then lightly sand it and buff it for an outstanding shine!
  4. Use Acetone for your cleanup. Just like other Polyester-based products, Acetone is the best cleanup material!
  5. The most important step: Adding the proper amount of Catalyst. We recommend 1.5%-2% Catalyst ratio. After adding the catalyst, you will want to mix for two minutes, preferably with a mechanical agitator (drill mixer). For your reference, here is the catalyst chart so you know exactly how much catalyst you need.

Tips
1 mL = 1 ccIf using wood mixing stick, place stick in resin before adding catalyst so wood doesn’t absorb catalystOnly catalyze slightly more than needed. Resin that cures still in the mixing pot is unusable.

Be sure to have a good strategy when applying your gelcoat. Once you mix and catalyze, you have about 15 minutes to apply the gelcoat before it starts getting hard or starts to “gel.” The actual working time depends on the amount of catalyst and how hot the working conditions are. Anything below 60 degrees, and your gelcoat will not cure, but as you get warmer and warmer, your working time will decrease rapidly. At 70 degrees, you get 15 minutes, but at 90 degrees, you only get 5 minutes. If you need more time to work, be sure to sit the can in some cold ice water to cool it down to 60 degrees to allow you a little more working time.

Here are some helpful tips on how to work with brushable gelcoat, especially during the warmer months.

  1. Cooling the gelcoat, by refrigerating the product to around 70 degrees, will give you up to 15 minutes of working time.
  2. Humidity can be another factor, so, make sure the mold and surrounding area is dry before applying your brushable gelcoat.
  3. Make small batches of gelcoat at a time and catalyze at 1 ½ % to avoid the material from getting hotter. When spraying the gelcoat, make sure you catalyze at 2 %. If you choose to use Duratec, please note, the product must be cool as well.
  4. If you seek to roll on the gelcoat, the product should be applied evenly at 14 mil thick.
  5. Do not apply gelcoat in direct sunlight.

What to Use on the Deck of My Boat?

Over the lifetime of any boat there will come a time when the deck needs to be renewed. You have a choice of non-skid additives, or paints that already contain a nonskid compound.  A non skid boat deck helps protect the surface as well as the occupants.

When looking for a non-skid surface you have many options. If your boat floor is currently gelcoat, you can re-gelcoat the surface with or without a non-skid additive. More information about gelcoat application can be found here. Gelcoat is more durable than paint and once a gelcoat surface is painted gelcoat will not adhere.

If paint is desired, non-skid can be added to our marine paints by Duralux and Awlgrip. Often an exact match can be found to your hull paint color. Find more topside paint options available and detailed instructions on adding non skid found in our how to section.

Customers painting the floor of a jon boat, frequently use the Aluma Hawk aluminum paint with a non skid additive. This paint serves as a paint and primer in one for your aluminum surface.

Interdeck boat deck paint is a non-skid deck paint by Interlux and offers an excellent slip resistant finish. It contains a fine aggregate and will apply easily on substrates. Its low sheen finish prevents dazzling that can be reflected by sunlight off decks. Interdeck is also easy to apply and available in numerous colors. The tough polyurethane resin protects decks against everyday wear and tear.

Depending on your paint choices, follow the manufacturers application instructions whether applying to aluminum, fiberglass, or wood to ensure best adhesion and slip resistance.

For cleaning the teak on your boat deck, JustTeak™ is a marine-grade teak cleaning system is designed to rejuvenate your teak quickly and easily. JustTeak™ will clean, brighten, and once sealed protect your teak decking. We have an application instructions video How to clean and protect the teak on your boat.

How To Mark Your Waterline for Bottom Paint

The waterline can also refer to anyline on a ship’s hull that is parallel to the water’s surface when the ship is afloat in a normal position. There are many reasons a waterline needs to be marked, it is a new vessel, the old paint has been blasted off for a new finish, or you’ve loaded it up with more stuff the original marking is off. Marking the waterline is often met with dread and getting the correct line for your bottom paint will provide stunning results. Getting it wrong, especially when paired with a boot stripe, will stand out like a sore thumb.

If your boat is new, the waterline should be marked on the designer’s drawing, if that is available. If not, you can take the measurements from a similar boat. If the boat has been in the water, even a few days, there may be some slight staining along the waterline (or just float the boat) that can be marked with a grease marker (best if it is full with fuel). Others have advised to throw sawdust in the water around the boat. Haul the boat and see where the sawdust has stuck to the wet hull.

Fine-line masking tape is ideal for this because it has some stretch and conforms very well to hull shape, especially if the hull has a lot of reverse turns. Don’t press the tape too firmly yet – you may need to peel it back for small adjustments. Once you’re happy with the whole line, press the tape firmly against the hull. Since the boat is already level, all you have to do for the second side is to set the level at the correct height and mark the stern with a piece of tape or transpose the wax crayon mark.

When the boat is aligned athwartships, set up the laser tripod, the exact spot is not critical providing the laser beam can see the whole side of the boat (if you can see it, so can the laser beam). Turn on the laser and adjust the height of the beam until it touches the marks you made at the bow and the stern. If it touches the mark on the bow but the stern is too high, lower the jack-stands at the stern or raise those at the bow—vice versa if the stern is low. Double-check the spirit level in the cockpit to make sure you’re not tilting the boat.

How to Paint a Boot Stripe

What is a Boot Stripe?

The Boot Stripe is a narrow stripe that runs the length of the boat and is usually positioned a few inches above the waterline. The stripe provides an aesthetic touch and creates an optical illusion that makes the boat appear to be longer. It also gives the boat a nice “finished” appearance that many boaters take pride in. Boot stripes also define the separation between anti-fouling paint (below) and the topside paint (above). Vinyl boot stripe tape is available in different widths, colors, and designs, but unless the boat has a flat, slab side this will make the boat appear to sag or squat in the water. Painting the boot stripe on the hull allows the width to change with the geometry of the boat and give the finished stripe a uniform look. Repainting an existing Boot Stripe will be easier than starting from scratch since you won’t have to mark and score the stripe.

Find and mark the Boot Stripe. The boot stripes of many fiberglass hulls are cast into the hull from the mold by the manufacturer. They can only be removed if you sand down to the fiberglass.

If there is no stripe on your hull you will need to mark the waterline on your boat and transcribe it up to the desired height of your stripe. This can be done by applying successive layers of masking tape along the waterline curve. There are other numerous methods worth investigating online. Also, consult a professional and ask them questions about your specific boat.

Mask off the stripe with tape and get within 1/32nd in. to the edges of the old stripe. This will allow you to sand to the very edge of the old stripe, and avoid damaging the surrounding gel coat.

bootstripeinstallDe-wax the stripe area using a de-waxing solution and a rag.

Sand only the stripe area with 220 grit sandpaper. Once sanding is complete, remove the masking tape and wipe the area with acetone. This will remove any remaining adhesive and sanding remnants. Sacrificing the first mask will contribute to a sharper finish. It is possible that the first application of tape can transfer sanding residue to the paint and result in a poor finish. Mask twice and you will only have to paint once! Be sure to take your time with the second masking. Remember: If the stripe doesn’t look good in tape, it will look even worse once painted. Now you’re ready to paint!

What type of paint should I use?

There are many different varieties of topside paint suitable for painting a boot stripe, but we have narrowed it down to just a few options for you.

Good: Duralux Marine Enamel – Easy to use, economically viable, with a nice color selection. When applying this marine enamel to fiberglass, no primer is needed. Simply wipe the surface with acetone before and after sanding, then apply your paint. For aluminum, prime with one coat of Duralux Zinc Chromate and apply 2 coats of paint. This high gloss enamel will create a bright and colorful boot stripe on any vessel.

interlux-brightside-polyurethane-28238-500x539Better: Interlux Brightside or Blue Water Mega Gloss– These are a one part Polyurethane with a crisp, high gloss appearance. More durable than regular enamels, but just as easy to apply! If you are applying Brightside or Mega Gloss to fiberglass, make sure the surface is clean and in good condition.  Application of Mega Gloss Water: blast surface to remove all loose paint, dirt, oils and grease. Abrade with 240 grit dry sandpaper or equivalent. Solvent wipe down to remove all sanding residue. Prime with Mega Gloss Primer for best results.  For Brightside, remove wax and other contaminants using Fiberglass Solvent Wash 202 and then sand with 220-320 grit paper. Apply Pre-Kote. Brightside offers excellent flow and gloss retention especially for painting a boot stripe.

pettit-easypoxy-off-white-3108-quart-31128-500x539OR Pettit Easypoxy – Another single-stage Polyurethane that provides a nice sheen of gloss and durability for painting a boot stripe. However, the color selection is more limited than Interlux Brightside and Blue Water Mega Gloss.  Easypoxy is only available in white. Both products produce a high quality finish and are easy to use.

 

Removing Stains from Gelcoat

A gelcoat surface is a very smooth, mirror-like finish when it is new. As gelcoat ages, it becomes porous which means the more easily it stains, the worse it looks and the harder it is to clean. Most all gelcoat can be restored, providing it is not completely worn through. Exhaust stains, like diesel, can develop on the surface of the Gel Coat. These stains can set in on the wax surface of the gel coat but the right cleaner can remove them. If the stain goes deeper, a bit of elbow grease will be needed.

Clean and inspect the surface with a wash with a mild cleaner like 3M’s boat soap or some alternative stronger cleaners if needed. After cleaning, dry and inspect surface for needs to be addressed: scratches, dings, cracking and crazing and to fix these flaws before rubbing out the gelcoat and restoring its shine. See the fiberglass/gelcoat repair section for options and the West System Video for “how to” instruction.

Apply a fiberglass stain remover, like 3M Fiberglass Restorer and Wax , Mothers Marine Black Streak Remover, or 3M Marine Cleaner and Wax to the stained gelcoat area with a clean rag. The black/gray stains are the result of soot being deposited on your hull. It can happen when wet exhaust systems mix the exhaust gases with seawater and discharge those gases or dry exhaust systems discharging the soot directly into the atmosphere and it lands on your boat.

These liquid one-step products that combine a polish or compound with a wax remove oxidation, and protect the gelcoat in one step.

Wait 10-15 minutes. If the stain is simply laying on the surface of the Gel Coat, the stain will begin to loosen; rinse and inspect the results.

If the stain is lifting, repeat. If not, then something stronger like a more abrasive compound with a polisher may be needed; in that case a wax will be needed to restore the shine. Each time compound products are used, some of the gelcoat is removed. Use caution to use the least aggressive product that will get the job done. Frequently all that may be needed is to apply a protective coating of wax, such as 3M Ultra Performance WaxScotchgard Marine Wax, or Mothers Marine Synthetic Wax to help keep that shine.

For more gelcoat restoration tips see our how to Maintain and Restore Gelcoat link and Aqua Buff information.

Awlgrip Paint, the Best Topside Boat Paint

Awlgip Marine PaintsAwlgrip Topcoat, also referred to as awlgrip paint,  is a polyester based high gloss polyurethane topcoat giving long lasting gloss and color retention. It is considered the among the best Topside Paints in the marine industry. AwlGrip Topcoat  may be applied by brush/roller or spray. For application above the waterline only. See Awlgrip Application Guidelines

Awlcraft 2000 is an Awlgrip paint that is a 3 component, premium polyurethane finish that must be applied by spray only, and delivers a high gloss finish in a wide range of colors with enhanced color and gloss retention.  Awlcraft 2000 comes in a number of unique color options.  You will need to choose the appropriate Converter and a Reducer. 

awlgrip 545 primerThe most common practice for the do it yourselfer is priming the boat with Awlgrip 545 epoxy primer. This is a 2 part primer, so you will need the base (either white or grey) and the converter. Awlgrip also recommends a reducer. The links to the converter and reducer can be found on the base primer product page.

Mixing and Reduction:
This is a two part system. You must order the base primer in either gray or white along with the D3001 Converter in the appropriate size. The mix ratio is 1:1 so if you purchase 1 quart of primer you also need 1 quart of converter for a total of 2 quarts. Additionally you need to purchase the appropriate reducer (spray or brush) for spraying reduce up to 25% with T0006 and for brushing reduce up to 10% with T0031.

Theoretical Coverage: 497 Sq feet/gallon at one mil dry (25 microns) 165-248 Sq. Feet at recommended dry film thickness. Calculated based on a theoretical transfer efficiency of 100%.

Then you will choose your base color of Awlgrip Topside paint, the converter and reducer. The reducer and converter change depending if you are spraying or brush/rolling.

Mixing and Reduction

Spray: Mix by volume one part AWLGRIP Topcoat Base Component (Color) with one part AWL-CAT #2 G3010 spray converter to a a smooth homogenous mixture. Reduce up to 25% with the spray reducer(s) appropriate for conditions. Overall mixture is 1:1:1/2 volume. Example: 8oz Base, 8oz G3010, 4oz Reducer. 25% reduction is a standard mix. Clear coats. metallic colors, and painting in high temperature conditions may require additional reduction. 40% reduction is the maximum recommendation.

Brush/Roller: Mix by volume two parts AWLGRIP Topcoat Base Component with one part AWL-CAT #3/H3002 Brushing Converter until one smooth, homogenous mixture is obtained. Reduce 25% to 33% with T0031. Overall mix is 2:1:3/4-1 by volume. Example: 8 oz. color base component, 4 oz. H3002, 3-4 oz. T0031. 

Theoretical Coverage:
Brush/Roller Application: 700-725 Sq. Feet at 1 mil (25 Microns) dry: 285 Sq. Feet at recommended dry film thickness.
Recommended Wet Film Thickness: 4.5-6 mils (112.5-150 Microns), Total of 2 Coats.
Recommended Dry Film Thickness: 2-3 mils (50-75 Microns), Total of 2 Coats.

Spray Application: 530 Sq. Feet at 1 mil (25 microns) dry film thickness; 210 SQ. Feet at recommended dry film thickness.
Recommended Wet Film Thickness: 6-9 mils (150-225 Microns), Total of 2-3 Coats.
Recommended Dry Film Thickness: 2-3 mils (50-75 Microns), Total of 2-3 Coats.

You can view the links provided above to see more information about the products, mix ratios, surface prep and auxiliary products.

Awlgrip Color Chart