I'm using a Commodore Plus brush from Serwin-Williams for tipping. Just tried it today during application of Interlux Perfection Plus, 2-part urethane on cockpit teak bright work. I like it a lot. Very soft bristles (white china bristle locked in epoxy resin per the literature). In fact I first tried a "Fool It" brush from an on-line supplier and it shed bristles. The "Fool It" is supposed to be an upgraded chip brush, but I wasn't impressed. I even wrapped the bristle bundle in masking tape toward the top, and it still lost a few. Cheap chip brushes were worse the last time I did this.
Regarding application of the Perfection Plus...I used a 5 1/2-6" cheap roller from Home Depot. It came with a very dense white foam roller, which worked great on bright work and did not eventually disintegrate like the extra dense (expensive) Wooster foam brushes that I used last time around. (Forget about using cheap foam brushes as they melt within minutes. Additional white foam rollers are sold in packages of two at the big box stores and Ace hardware. Since the Perfection Plus instructions specify several coats, and it takes a day in cooler temperature zone before applying subsequent coats it will take a number of extra rollers.
Last time I did this job I made the mistake of rolling on an extra thick layer on the cockpit door cap rail and sure enough micro bubbles popped up. So I switched to thin layers in other sections with about 20% thinner and the problem pretty much subsided. Once I had the first layer on all surfaces I went back and poked the bubbles with an exacto knife. If they're not deflated, they will generate a tiny white dot that remains after sanding off the bubble. Those white dots are deep in the finish and the only way to eliminate them is to sand off the entire application. F'n nightmare.
Anyway, I'm currently having to time each layer with the weather forecast...wildly variable on Lake Michigan this time of year. A three day, rain free window will net three (maybe four) coats without sanding between coats...depends on temperature. (You don't want to have to sand this stuff as it's like stainless steel once cured).
One more thing about Perfection Plus...it is susceptible to turning opaque if it encounters high humidity during the cure cycle. (Maybe any finish does). I cover it with plastic if it's tack free cured and nightfall is imminent. Overnight dew gets you a guaranteed sanding job....been there too.
It's spectacular stuff once it's finished. In Southern California or Arizona, it's a no brainer for outside application. No problem elsewhere if inside. Turns into a two week job outside in early Spring in the mid-west....
My cockpit cap rail is about 11" wide (including curved edges) and about 22 feet long overall. It will take two one-quart kits @ $100 each for 3-4 coats.