Streaks (stop/start marks) can occur if a finish is not applied evenly, or when too much or too little finish is applied. Try to be as uniform with the application as possible. Check recommended coverage rates to give you an idea of the thickness required for the finish and try to stick to it. Also use a recommended applicator. Importantly, make sure the finish does not have chance to dry prematurely due to site conditions as force drying of finish will create difficulty in application, causing it to streak. Difficulties can also be experienced by not fully or correctly mixing finish formulas before use.
Peeling or bubbling problems can occur when the floor is not adequately abraded before applications of finish, or a contaminant substance has not been removed from the surface prior to application, or is present on the applicator. If the problem is severe it will require sanding and refinishing, but if it is only minor damage in the top coat the surface may only need abrading with a screen disc and recoating. Similarly, to help prevent rejection of the finish, it's essential to use an ethanol based barrier seal prior to coating sanded floors that have previously been waxed over a number of years. Tannic acid in some species may prevent the finish from adhering successfully. If this happens the only option is to replace the board.
Prior to commencement of work, use correct instruments to check if there is any moisture present beneath the floor before you begin. Resolving such an issue can only be accomplished by correcting any moisture problem, letting the timber dry out and then refinishing the floor.
To prevent the finish from yellowing, always use a good quality finish with UV stable properties. Sunlight may lighten areas, but a good quality finish will not do so until the floor is ready for a refinish.
Abrade between coats - it may take longer, but the appearance will improve and the grain will not lift. Vacuum after each abrasion to ensure the best possible surface.
Make sure the heating or air conditioning is switched off whilst you are finishing to ensure it doesn’t start to dry out areas whilst finish is still being applied. Always ventilate the room, allowing for correct curing/drying of the finish.