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"Roll and Tip" with Sterling L.P. Topcoat

By rolling and tipping the Sterling L.P. Topcoat system, a first time amateur can achieve professional looking results without the high cost of spray equipment or the health risks associated with spraying solvent based paints.
This tutorial will show how to apply the Sterling L.P. Topcoat via the "roll and tip" method.
Use this tutorial in conjunction with the very detailed Sterling Application Guide, which is included with all Sterling purchases through boatbuildercentral.com. This tutorial is not a substitution for the Sterling Application Guide.

Most of the techniques used are applicable to other top coats, but you should follow the recommendations of each manufacturer.

Let's get started:
A super glossy and smooth finish begins with a good fairing job.
Your surface needs to be cleaned before applying any of the Sterling products.
Follow the directions in the Sterling Application Guide with regard to your particular boats substrate.
When wiping down your surface with a solvent prior to the application of any of the Sterling products you should always employ the "two- rag" method. Wipe down the area with one rag that is soaked generously (although the rag should be rung-out to remove any excess) and then come back immediately with a clean, dry rag.
We recommend the Sterling C-8765 Wipe Down Solvent, although you can use denatured alcohol.
The wiping down stage generally takes place prior to the application of the topcoat; however, it can also be used in preparation of the application of the primers.

High Build Primers:

There are 2 primers we used in our evaluation on our test canoe with the Sterling L.P. Topcoat.
The first one is the Low VOC Buff High Build Epoxy Primer and the second one is the Polyurethane Finish Primer.

We will begin our tutorial with the Low VOC Buff High Build Epoxy Primer.

To apply that primer you need Part No. U-4749/Base and Part No. U-4748/Catalyst. The mix ratio is 1:1. (1 part Base to 1 part Catalyst).You may also want a thinner: Sterling U-2965 Brushing Thinner. The thinner is optional, see below.

The Sterling epoxy high build primer is a true "high-build" primer exhibiting excellent film-building characteristics.
The working pot life of this primer is 4-5 hours @ 77°F & 50% Relative Humindity.
When applying the primer with a brush and/or roller (we found the roller to work best with this product) it is recommended to apply 4-6 coats in an eight hour day.
Because the primer has a 4-5 hour working pot life only mix up enough primer that can be used to apply 2-3 coats in the 4-5 hour time frame. If the surface requires more primer then remix when needed.

Coverage:

You can expect to get approximately 160 square feet out of each gallon kit of primer. (1 gallon of U-4749 Buff High Build Epoxy Primer + 1 gallon of U-4748 High Build Epoxy Primer Catalyst = 160 square feet.)

Mix:

The mix ratio is 1:1. (1 part U-4749/Base to 1 part U4748 Catalyst).
Begin by mixing the contents of each component until there is an homogenous mixture.
In the can, the fillers & pigment of the primer will have settled some but not nearly as bad as other brands of primer (you can easily stir-in any sediment in the can by hand). Make sure to scrape the sides of your mixing container ensuring complete consistency.
Now, set the mixed primer aside (put a lid and/or rag on top of the mixing container) for 20 minutes. This time is referred to as the "induction time".

Thin:

After the 20 minutes, re-stir the catalyzed material and reduce for roller/brush application with Sterling U-2965 Brushing Thinner.
You can add up to 25% of your total mixture using the U-2965 or add no thinner whatsoever.
Very thin (meaning 25% reduction) applications will require multiple coats but will leave a surface with less roller stipple.
If you do not thin the primer at all you will apply more material per coat - but it will result in excessive stipple requiring more sanding time.
We found the high build primer to work quite well at a 10% reduction ratio using the U-2965.

Apply:

The high build primer should be applied with a tight foam roller. That roller must be epoxy compatible.
Roll on one coat and then cover the tray and roller with a rag until you are ready to roll the second coat.
The second coat can be applied as soon as the first coat is "tack-free" (our definition of tack-free is when you take your finger and touch the primer, if you leave a finger print on the part but no primer transfers to your finger you're ready to proceed).
The time in-between coats is generally 45 - 60 minutes. The cooler the temperature the more time is needed between coats.
All of our evaluations were conducted in temperatures ranging from 70°F. to 80°F.
Allow the primer cure to over night before sanding.

The high build primer will fill in small scratches and holes; it's quite handy for this reason. Depending on how fair your surface was to begin with, you may or may not want to apply more high build primer.
We applied 2 applications of the high build primer on our test canoe. The first coat filled in a lot of surface imperfections and was sanded almost back down to the substrate. The second coat evened everything out nicely.

ABOVE: stir up your primer

ABOVE: rolling on the High Build Primer:

ABOVE: rolling on the High Build Primer - notice how unfair the surface is before high build is applied. The high build primer will fill in many inperfections that were missed in fairing:

This tutorial has a video demonstration:

Sand:

Sanding the U-4749/U4748 Buff High Build Epoxy Primer:
You will want to schedule your work so that you are able to sand the high build primer within a couple days of application.
The primer becomes hard to sand with every 24 hours that elapse from the day it was applied.
On our test canoe we waited more than a week to sand the primer and we used twice as many sanding disks as was needed. We found that 80 grit sand-paper sanded the primer quite effectively.

Polyurethane Finish Primer:

To apply that primer you need the base, Polyurethane Finish Primer (Part No. U-1000P/Base) and the Finish Primer Catalyst (Part No. U-1000C/Catalyst) The mix ratio is 2 parts U-1000P to 1 part U-1000C. You may also want a thinner: Sterling U-2965 Brushing Thinner. The thinner is optional, see below..

Coverage:

You can expect to get approximately 150 square feet out of each gallon kit of primer. (1 gallon of U-1000P Polyurethane Finish Primer + a half- gallon of U-1000C Polyurethane Primer Catalyst = 150 square feet.)

Mix:

Begin by mixing the contents of the base portion until the mixture is homogenous.
The fillers & pigmentation of the primer will have settled out some, but not nearly as bad as other brands of primer (you can easily stir-in any sediment in the can by hand).
Mix the two components in a ratio of 2:1. Make sure to scrape the sides of your mixing container ensuring complete consistency.

Now, set the mixed primer aside (put a lid and/or rag on top of the mixing container) for 20 minutes. This product too has an "induction time".

Thin:

After 20 minutes, re-stir the catalyzed material and reduce for roller/ brush application with Sterling U-2965 Brushing Thinner.
You can add up to 25% of your overall mixed amount of the U-2965 or add no thinner whatsoever.
Very thin applications will necessitate the need for multiple coats but will ultimately leave a surface with less roller stipple.
If you do not thin the primer at all, you can apply more material per coat - but it will result in excessive stipple requiring more sanding time.
We found the polyurethane finish primer to work quite well at a 10% reduction ratio using the U-2965.

Apply:

The polyurethane finish primer should be applied with the same tight foam roller which must be polyurethane/epoxy compatible.
Roll on one coat and then cover the tray and roller with a rag until you are ready to roll the second coat.

The second coat can be applied as soon as the first coat is "tack-free" as described in the previous high build primer section.
The time in-between coats is generally 45 - 60 minutes. The cooler the temperature the more time is needed between coats.
Again, all of our evaluations were conducted in temperatures ranging from 70°F. to 80°F.

Allow the primer to cure overnight before sanding.
The working pot of the polyurethane finish primer is 4-5 hours @ 77°F. & 50% R.H.

ABOVE: rolling on the finish primer

Sand:

Sanding Polyurethane Finish Primer:
The finish primer should be sanded to a 320 grit scratch pattern.
There is no need to wet sand.

In an effort to assist you in the sanding of the finish primer we recommend a "guide-coat" be applied to the areas to be sanded.
A "guide-coat" is a mist coat of ordinary (preferably flat black) spray cans found at your local home repair store. Pattern maker dye makes a good guide coat too.
This guide coat will dry in minutes.
The purpose of the "guide-coat" is to give the sander the benefit of visually seeing where one has sanded and not sanded.
Plus, when all the "guide-coat" has been sanded off; the primed surface is now smooth, flat and free of any defects or imperfections. And lastly, the "guide-coat" keeps one from sanding too much primer off the primed surface and may help avoid an extra coat of primer.

The finish primer is white in color and will provide a very even base for the application of the topcoat. If you do sand through to the high build primer and/or the fairing material, it could take additional coats of the topcoat to adequately provide the kind of hide-strength required for even topcoat color coverage.
At that point of the application, one extra coat of finish primer is the most cost effective way in dealing with these dark spots as compared to additional coats of topcoat. On the test canoe, there were several dark spots that had been revealed due to heavy sanding and it took 2 additional coats of topcoat before there was complete topcoat color uniformity.
At 77°F. & 50% R.H. the polyurethane finish primer will be ready to sand in 18 hours.
You can apply the L.P. Topcoat 18 hours after the last application of finish primer.

ABOVE: spraying on a guide coat

ABOVE:Sanding the finish primer

Topcoat:

For the topcoat, you need the topcoat itself and the Sterling Brushing Catalyst (Part No. U-2964). The mixing ratio is 2 parts topcoat for 1 part catalyst.
You also need a thinner: Sterling U-2965 Brushing Thinner.

Coverage:

You can expect to get approximately 300 square feet out of each gallon kit of L.P. Topcoat. (1 gallon of L.P. Topcoat color of choice + half-gallon of U-2964 Brushing Catalyst + half-gallon of U-2965 Brushing Thinner = 300 square feet.)

Prepping the surface for applying the L.P. Topcoat:

After sanding the finish primer with 320 grit sand-paper, you will want to prep the surface for the application of the L.P. Topcoat color coat.
If you have access to clean, dry, compressed air, clean the sanding residue off the surface with a dry rag and the air. If not, wash the sanding residue from the surface with clean water (no soap) and rags.
Dry the surface with additional clean, dry rags.
If neither one of these choices are an option use the Sterling C-8765 Wipe Down Solvent utilizing the two-rag method as described on Page 1.
Extreme dust removal techniques are not completely necessary, however, Sterling's L.P. Topcoat is very glossy and dirt and dust will show.
Next, tack the surface clean with what is called a 'tack-rag'. A tack-rag is basically a 2 foot square piece of cheesecloth that has been impregnated with rosin. There are some tack-rags on the market that are too tacky. It's best to use one that has a moderate tacky-ness to it. When using the tack-rag its sole purpose is to remove any minute dust particles and/or lint. The tack-rag should be wiped across the primed surface just prior to painting with the gentlest of touch. No heavy leaning.

Applying the L.P. Topcoat: Now for the fun stuff! Mark Billingsley from Sterling Marine Coatings offers the following advice for all first-time boat painters: "Thin in the pot and thin on the part will make your boat look like a porcelain sink". All of your prep work will pay off as you begin to apply the Sterling L.P. Topcoat.

Mix:

Begin by mixing 2 parts of your L.P. Topcoat color of choice with 1 part of the Sterling Brushing Catalyst (Part No. U-2964).
Make sure to scrape the sides of your mixing container ensuring complete consistency.
Set the mixed L.P. Topcoat aside (put a lid and/or rag on top of the mixing container) for 30 minutes. "Induction time" again.

Thin:

After 30 minutes, re-stir the catalyzed material and reduce for roller/ brush application with Sterling U-2965 Brushing Thinner.
You can add up to 35% of your total catalyzed mixture with the U-2965.
Billingsley refers to this reduction ratio as "dead-on". However, he does suggest that you may need to add more U-2965 Brushing Thinner to your mixture as the job progresses in increments the size of the cap on the can of the brushing thinner.
For example: mix 4 oz. L.P. Topcoat, 2 oz. U-2954 Brushing Catalyst, 2 oz. U-2965 Brushing Thinner and if need be add 1 cap-full of U-2965.

The working pot of the L.P. Topcoat is 4-5 hours @ 77°F. & 50% R.H.

ABOVE: Rolling on the Topcoat

Roll and Tip application:

Now for the roll and tip method of applying the L.P. Topcoat:
Always be sure and strain the catalyzed and reduced L.P. Topcoat before pouring it into the roller tray and/or working out of a paint pot.

The purpose of the roller in the 'roll-n-tip' method is to get paint from the tray to the part being painted in an even amount.
The purpose of the brush is to 'tip-off' the excess air bubbles and stretch out the topcoat on the surface being painted.
The foam roller is not always a must when applying this material. Billingsley said that most times the roller is used on large surface areas; otherwise the brush by itself works fine.

Roll out the paint:
You should only roll out as much L.P. Topcoat as the foam roller will hold, generally about 3-4 square feet.
Use the roller to move the paint onto the surface until you are satisfied that the surface is sufficiently covered in color.

Now for the tipping part!

Using a fine tipped brush (we recommend the Corona Europa badger hair brush because of its super-soft tips) brush out the L.P. Topcoat.
On our test canoe Billingsley kept referring to "stretching" the topcoat out.
A 3-4 square foot area covered in L.P. Topcoat should be stretched out into a 3½ - 4½ square foot area.
You should always brush in one direction only and always brush from your wet edge back into your previous wet edge.
Never brush from you wet edge forward. Always work back into the wet edge.
You will immediately see how the brush knocks down the air bubbles and allows the paint to "flow out".

As you work your way around the surface being painted you will begin to see the paints truly remarkable self-leveling characteristic that has made the Sterling L.P. Topcoat the product of choice for brushing L.P.'s around the world.

If you begin to feel the L.P. Topcoat act as if it's 'dragging' or 'pulling' it's time to add some more U-2965 Brushing Thinner to loosen the mixture up.
Billingsley also noted that most first-time L.P. users tend to over-brush the material.
He said they look back into the area they just completed five minutes earlier and see a brush stroke or two and they try and brush it out.
His advice is it to just let it go and let the paint do its thing! Strange as it may sound we saw it first hand. Believe him!

ABOVE: tipping the paint

ABOVE: more tipping

ABOVE: brush towards the older paint

Now, roll on more paint (another 3-4 square feet).
Roll the new paint up to the edge of the tipped section.
When tipping the new section, the direction of your brush strokes should be the same - always back towards the previously tipped section.
In the example of our dinghy: we began on the starboard side (upside down) of the transom and worked our way towards the bow.
As we stated before, the idea here is to carry the fresh paint onto the previously tipped paint and overlap that area by as much as 2-3 inches. You can carry new paint over older paint but not the other way around.

ABOVE: work your way around the boat

ABOVE: 5 minutes after painting

ABOVE: This is the final gloss after only one coat!!!

L.P. Topcoat coverage rates are approximately 300 square feet per catalyzed gallon of whites and/or colors.
There is no need to sand between coats of L.P. Topcoat provided subsequent coats are applied within 24 hours of one another
There has to be a minimum of 12 hours cure time between L.P. Topcoat coats at 77°F. & 50% R.H. Cooler temperatures will prolong the re-coat time. It is not advised to use any of the Sterling products when temperatures are below 55°F.
If more than 24 hours have elapsed between coats of L.P. Topcoat then a 'light' sanding is required before the next coat is applied. All existing gloss does not have to be removed in order to apply the next coat. Re-clean. Re-tack. Re-paint.
When sanding the primers and topcoats a dust mask should be used at all times.
When applying the primers and topcoats a charcoal-filtered respirator should be worn.
Try to avoid applying the L.P. Topcoat in the direct sunlight.

Rolling and tipping Sterling Marine Coatings products is not just for the do-it-yourselfers.
Sterling has been brushed on motor-yachts, custom fish-boats and custom sail-boats world-wide for over 25 years. A first rate roll-n-tip crew is capable of delivering a paint job on a boat that is unequal to a conventional spray job.

Good luck and happy painting!

If you did not find the answer to your question, please use our message board and we will respond within a few hours.
Or explore the HowTo files at our technical support web site bateau2.com

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"Roll and Tip" with Sterling L.P. Topcoat