Part 5: Repairs and Maintenance
For best results Bristol Finish Traditional Amber needs to be maintained or it will gradually deteriorate like other finishes. Fortunately the advantage of the Bristol Finish is that it does not need attention as often as other finishes. Maintenance is determined more by exposure conditions and wear factors than any fixed schedule. How much sun exposure there is, and how many coats were put down.
Here are some general guidelines:
- In equatorial climates, (Caribbean) top coat once per year.
- In southern latitudes (Florida, Georgia, the Carolinas) top coat once every 1 to 2 years.
- In mid-Atlantic areas (Chesapeake Bay) a top coat should be applied once every 2 to 3 years.
- In New England, a top coat is needed only once every 3 to 4 years, if the boat is not covered during winter storage.
- Customers have reported extreme high wear areas like commercial flooring requiring a top coat about once per year.
- Residential flooring or cabin floors aboard boats should only need to be top coated once every 3 to 5 years.
This modest maintenance schedule will renew the coating thickness and UV resistance and keep the finish looking new.
This is a minimum. More is not going to hurt.
Waxing the finish with a UV stable wax can also help extend the life of your finish but is not a substitute for re-coating.
Do not wait until the finish begins to break down, it will be too late and you will have to start over from scratch.
Here is a maintenance log that can be printed to help keep track of your finish work.
Damage to your finish can occur for several reasons:
- From a ding, a hit, or a scrape against the finished surface. This can crack, crease, or crush the finish (if severe enough and not repaired these may lead to moisture intrusion).
- As the result of contamination of the wood surface before application
- From moisture intrusion.
If you notice an area of Bristol Finish that appears to be discoloring, this usually indicates that the coating is beginning to lose adhesion with the surface. It is likely lifting from the wood surface. The appearance is often a white or yellowish area, and the coating feels smooth on the surface.
Assess and diagnose the damage and follow the appropriate repair instructions shown below.
Ding/Hit/Scrape damage and Contamination are repaired the same way:
If the problem stems from contamination, only an isolated area is usually affected. Also, the discoloration is not noticed in an area near a joint or a bedded edge, rather out in the middle of a piece of wood. Contamination can often be present even after sanding, as the penetration depth could be greater than the amount of old wood removed during sanding.
Ding/Hit/Scrape damage may show no discoloration but simply cosmetic disruption.
Sand the area back to about 1″ beyond the discoloration or damage. Saturate the area repeatedly with acetone and wipe firmly until clean. You are now ready for coating repair as described below.
Repairing damage from moisture intrusion can be more involved depending on the degree of intrusion. If the discoloration is noticed in the area of a joint, the joint probably needs repair. This is usually a sign that the glue bond has failed. The coating has broken and allowed moisture to penetrate the end grain. Be aware moisture can often migrate quite a distance beneath the finish.
This problem should be corrected, as the constant permeation of moisture will lead to rot and adhesion failure regardless of the type of coating used.
Sand the area back to about 1″ beyond the discoloration, and let the wood dry thoroughly for a few days (cover if necessary). A heat gun or hairdryer may save some time. If the joint is open or the glue has cracked, it should be cleaned out with a knife or thin saw blade, and flushed thoroughly with acetone. Fill the joint with epoxy or a suitable waterproof glue. Tape the sides if necessary to hold the glue. When cured, sand smooth with the surrounding area. Saturate the area liberally with acetone or lacquer thinner, and wipe firmly with a clean rag. You are now ready for coating repair as described below.
Sometimes this discoloration will show up on a bedded piece of wood, indicating water intrusion from the back. The probable cause is insufficient use of, or failure of the bedding compound. See DYI Fundamentals and Recommendations Part 2: Weatherproofing the Project for instructions on re-bedding. Sand back all discolored areas as described above, and allow the wood to dry. You are now ready to proceed with coating repair.
Build up fresh Bristol Finish in the bare area, allowing a very small overlap (1/8″ or so). You should apply the equivalent of 6 coats or more. When cured, sand the lumpy edge flat with the surrounding surface. At this point, you may follow one of two different methods for blending :
1. Progressively wet sand the scratched area with 600, then 800 and finally 1000 grit paper. Buff the sanding scratches out with buffing or polishing compound.
– or –
2. Scuff sand the area with 220 grit back to both a nearby starting and stopping point and re-coat. Apply 1 or 2 thin topcoats with no sanding in between, at least 3 or 4 hours apart.