Wet Sanding & Buffing
Bristol Finish Traditional Amber Urethane is designed to deliver a beautiful finish to your wood using standard application techniques; however, there are also post-application procedures that may be used to eliminate minute defects from dust, as well as the blending of repairs. Wet sanding out small defects, then buffing out the sanding scratches back to a high gloss is a standard finish procedure for the most demanding applications.
Perform the standard application of Bristol Finish, applying two extra coats (up to eight). Allow to cure fully, usually one or two weeks, depending on factors such as temperature, humidity, air flow, and coating thickness. As a general rule, more time is required in cold weather, and less is needed in hot summer weather. More time may be allowed with no problem.
Wet Sanding
Start sanding with whatever grit is appropriate for the defect size, generally no coarser than 400 grit, and no finer than 600 grit wet-or-dry paper. Sand until completely smooth.
Remove any dust, and sand again with a grit increment of 200 higher than the previous, either 600 grit or 800 grit; on the final pass 1000 or 1200 grit should be used.
Wash the surface with clean water and towels to remove all of the dust and wet sanding sludge.
Buffing
We recommend the use of 3M buffing, polishing, and waxing compounds simply because we know that they are top quality, we have experience with them, and we know they work. Their full product line can be viewed at www.3m.com. There are, of course, many other manufacturers of this type of product.
Buff the sanded surface using either 3M Perfect-It Foam Polishing Pad or 3M Superbuff 2 Plus 2 Pad 
on a slow speed (1500 to 2500 RPM) machine.
Start with 3M Imperial Microfinishing Compound and buff overlapping areas (2′ x 2′ or smaller) until gloss is achieved. Follow the manufacturer’s directions for use.
If further finishing is desired, use 3M Finesse-It Finishing Material. Again, follow the manufacturer’s directions for use.
These steps will produce a high gloss, totally defect-free surface. If desired, you may also use final finishing products such as UV resistant glazing and wax products.
Read MoreDIY Guidelines Part 3 – Application…Getting Results
This is where the project really starts to move, and the results begin to quickly show. It’s just the thing to lift your spirits after the dirty parts of the prep work.
Taping and Masking
This is a very important part of the job, but it’s really no big deal. There are a few things you need to know that make a big difference in both the effort required and the results you will get.
First, decide now how to break the project into workable sections. Don’t assume that you will tape up the whole boat in an hour. It takes a little longer to do the job right, and we sometimes plan this for the last day before beginning the application. It makes for a very easy and usually short day.
Second, don’t use cheap white masking tape. At the very least, get the green or blue tape, which can be left on for a couple of days, and used for several coats. If you want the ultimate, get 3M #1071 blue vinyl tape. It can stay on for long enough in the Caribbean sun to get the entire job finished, and be easily removed in a single piece. It costs more, but it saves a lot of time. One tape-up job as opposed to several sure makes sense to us. Available at better marine and hardware stores.
Take your time and get the taping done right. Back the tape away from any joint by 1/32″ to 1/16″, to make sure that no small slivers of wood are left bare. Burnish the tape down with a paint stirring stick so that nothing creeps underneath.
Now the Good Part
Finally you’re ready to go! Give all of the surfaces a really good wipe-down with acetone as you go, and don’t get too far ahead of yourself. Mix the Bristol Finish like the directions tell you (you did read the directions in the kit, right?) and you’re ready to start.
Proper Painting Technique
People make this out to be much more than it should be. Here’s the info you need, and you can ignore all the nonsense you will hear. It’s just so simple…the “experts” want you to think that varnishing is something difficult.
First, always use the widest brush that will fit on the piece. Keep a small one handy for corners and tight spots. For example, varnishing a 2′ x 2′ hatch cover with a 2″ brush will guarantee brush marks.
Second, lay the coating on with one brush stroke. Gently, using light pressure. You’re not whitewashing a fence, so there’s no need to madly flail back and forth with heavy pressure on the brush. Resist the temptation to give it one final stroke. Without all of the needless over-brushing, the finish will flow out like glass, with no bumps or lumps or brush marks.
Continue with the other coats when the last one is dry enough (as described in the kit directions). If you get lucky with the weather, you’re done in a day or two at the most. We have applied six coats in one day so many times, but three today and three tomorrow isn’t bad either. Let it dry, pull up the tape and admire the beautiful finish that you’ve created!
Also (after you get some dinner and rest) get ready to continue admiring the beauty for years to come. This is where Bristol Finish really delivers the payoff – a stunning appearance and very low maintenance.
You will wonder why everyone tried to tell you how difficult a varnish type job is.
Read MoreDIY Guidelines Part 2 – Weatherproofing the Project
The success of any finishing project is very dependent on the condition of the surface that is going to be coated, as well as the preparation of the surface. If a varnish type finish is expected to hold up well in an exterior situation, the pieces must in effect be weatherproofed so that exposure to continual moisture doesn’t have a chance to lift the coating.
Joint Integrity
All of the joints in the structure must be properly glued and holding together. If there is excessive movement in any joint areas, proper repairs should be made before the finishing project, otherwise the coating may crack and allow moisture entry. If any joints need repair, clean them out thoroughly with a saw blade or sharp knife, and then flush away the debris with acetone. Re-glue the pieces with epoxy or a polyurethane adhesive like 3M 5200.
Exposed end grain areas must be fully sealed with either epoxy or the coating material, or both. Saturate these areas repeatedly until no more material is absorbed.
Mounted and Bedded
Any wood that is mounted to other structures such as deck areas should be properly bedded in compound that will keep moisture out of the back side of the piece. This is an area that can be unrecognized as a future problem, but is actually very easy to deal with. If you don’t know if there is bedding compound present, you should assume that there isn’t. It’s surprising how many manufacturers overlook this very important step. If there seems to be compound in place, but it has breaks or gaps, these must be caulked. Make a close inspection to see if a knife blade or piece of paper can go between the wound and the mounting surface. If so, there will be a problem with moisture intrusion.
When a small piece is easily removable, clean the mounting side thoroughly and bed it back in place with Dolphinite, polysulfide, or a non-adhesive bedding compound. Don’t use silicone caulks or household caulks for any reason. If the piece cannot be removed, clean out the joint and caulk with 3M 5200. Scrape clean with a knife or razor blade, and flush away the debris with acetone. Next, caulk the entire edge with 3M 5200, forcing the material into the joint as far as possible with a fingertip. Finally, wipe up all excess or visible material with the recommended solvent and plenty of rags and allow to cure.
Screw holes should be sealed with a removable compound. Don’t use any type of silicone caulk, as it offers no adhesion to wood, and is not paintable. Use polysulfide type materials.
There is one final step in the sealing process that comes later, but we’ll cover it here. After the other preparation steps are completed, the masking-off process must be done. When applying tape, back the tape away from any joint by 1/32″ to 1/16″, to make sure that no small slivers of wood are left bare. Then the coating is applied over the entire piece and the caulking, and it forms a seal properly onto the mounting surface.
The Project Moves Along
Now you’ve really made some progress. It’s time to start with the coating application. The next article, DIY Guidelines Part 3 covers some basic and easy painting technique information.
These steps may sound like a lot of work and bother, but trust us – the old staying is completely true – proper and thorough preparation accounts for at least 90% of your success. These prep steps will pay off for many years to come, and make that beautiful finish stay that way for a long time!
Read MoreDIY Guidelines Part 1 – Preparing the Surface
The appearance of a finished surface depends more on smoothness than any other factor. Smoothness also plays a very important role in the durability or longevity of the coating, as a rough surface will have small, sharp edges and thin spots in the coating that is applied to it. These spots will show a premature “burn-through” or wearing due to insufficient coating thickness, so it’s necessary to get the surface sanded smooth before any finish is applied.
Any wood that is to have a finish applied to it must be sanded smooth. This is a process that seems to be greatly misunderstood. We hear people saying “I can’t sand my wood, too much will be lost.” This is a common misconception. Yes, you will lose some wood thickness, but it is absolutely necessary. No, you won’t lose too much. Maybe you will need to re-glue a few thin plugs, but that’s easy. We do it all the time.
Equipment
Sandpaper is sandpaper. There are some brands that last longer than others, but don’t get hung up on this. All good boat and hardware stores carry decent brands. What you need are three different grits- 80 grit, 150 grit, and 220 grit. Get plenty of each.
Power sanders are necessary. We like to use Porter Cable random orbit machines for the heavy sanding. Both Porter Cable and Roybi make good machines for smaller areas and finer grit sanding. These brands costs a little more than cheap gear, but they last much longer, and they do a far better job than cheap junk, and the operator doesn’t get as tired. Worth every penny.
The Process – Bare Wood
This is a brief article, and if our description doesn’t make enough sense, then go to your library and check out a stack of books. There are lots of good ones that take a lot of time to go into the basics, but relax – the important part is all right here.
Step One: Sand the wood completely smooth
Start with 80 grit paper. Use the machines for everything you can, and hand sand the tight spots. Sand and feel the results with your bare hand as you go, and keep using the 80 grit until the wood is completely smooth with absolutely no high spots. Get rid of the dust with a small broom or an old paintbrush.
Step Two: Stains in the wood
If your wood has black stains from weathering, now is the time to get busy with the teak cleaner. Use any good two-step teak cleaner to remove excess oil, stains, or discoloration from weathering. For other wood types, use a mild one-step wood cleaner if required. Follow the manufacturer’s instructions carefully and fully rinse to remove all residue. Allow the wood to dry completely for a minimum of 24 hours.
Step Three: Resume the sanding program
After sanding with 80 grit, and whether or not teak cleaner is used, what you have now is smooth wood with small gouges in it from the 80 grit sanding. These must be smoothed out or they will show through the finish, and this is what the 150 grit is for. Simply repeat the sanding process using the finer grit, sanding and feeling with your hand as you go. You will notice a big difference, and the start of a silky smoothness.
Step Four: The finish pass
You probably guessed this one – sand everything again with the 220 grit. This is to reduce the gouges left by the 150 grit.
All sound like a lot of hard work? It’s really not. Matter of fact, it’s less work to get this done right, compared to dealing with premature coating failure. Proper sanding is not as hard as you think, and the results are very rewarding, not to mention absolutely necessary!
Previously Varnished Surfaces
One of the nice features of Bristol Finish is that it can be applied over existing finishes, saving you a lot of labor if what you have to start with is in decent condition. Of course, if what is there is badly deteriorated, it’s got to go. If it’s missing patches, it should go. You don’t want the project looking spotty in color.
Coating Removal
There are generally only two different coating removal situations that most boat owners face. The first is if your boat has been slathered with teak oil for years. If this is the case, go and get plenty of teak cleaner and get to work. No coating will stick to teak oil. If this has been done for many years, it may take a couple of passes with the cleaner, but it’s fast and easy.
If there’s old, thick, failing varnish on the boat, it’s got to be removed. The best way we’ve found to do this is with a heat gun and scrapers. This is the cleanest way we’ve found, and you avoid the toxins of paint remover.
In either case, after removing the old coating, this is where you start with the sanding program that’s described above.
Existing Coatings in Good Condition
Areas that have existing finish on them generally need only a fine sanding with 220 grit paper, to remove any oxidation on the surface, and also any minor roughness.
Sand by hand using even pressure, and making sure the sandpaper is changed frequently enough. Use a red ScotchBrite pad on any corners and sharp edges, to make sure that the coating is not removed all the way to the wood. Wipe away the dust frequently to make sure that all areas are evenly sanded and uniformly dull.
The Project Moves Along
After the sanding is done, get all of the dust and such off of the boat with brushes or brooms. Now you’re ready to have a look at any potential problem areas that need to be addressed. These are described in the next article, DIY Guidelines Part 2.
These steps may sound like a lot of work and bother, but trust us – the old saying is completely true – proper and thorough preparation accounts for at least 90% of your success. These prep steps will pay off for many years to come, and make that beautiful finish stay that way for a long time!
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