Finishing Custom Staircase

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Tips, tricks, and rituals. February 26, 2005

We are part way through construction of an open, stain grade staircase. Balustrade is all custom stain grade parts. Newels are big simple box sections. I am seeking advice for spray finishing using polyurethane through a conventional spray gun. Should I assemble balustrade then disassemble and pre-finish? Or assemble balustrade in place and then spray in place? There are pros and cons to both.

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(Finish Forum)
I was involved in staining a big entranceway curved staircase once. This is what we did (I wasn't in charge of this). One day, two people sanding 180 to ensure even stain color. One day, two people staining (one wiping on followed by one wiping off). One day, two people sanding off the second half when the 2nd gallon of stain we were using didn't match in color. One day, two people re-staining. One day, one person masking and hanging poly. One day, one person spraying lacquer seal coat. One day, one person sanding. One day, one person spraying lacquer topcoat. Two days, two people buffing overspray (it's impossible to avoid overspray) and paste waxing.

I have restored quite a few large staircases and my experience has been that disassembling the parts and shop/ground floor finishing is always faster and higher quality. We used awls to mark a dot code on any necessary parts to make re-assembly simpler. We also used a $30 air ratchet and a foot switch to make a simple rig to spin the balusters while staining and topcoating. Because an air ratchet is a gear motor, it has good torque and won't stall at very low speeds.

If you are finishing onsite and you are not the only crew on the job, be prepared for a real pain when all of a sudden everyone needs to do something on the second floor. Consider a scaffold or ladder and have two people spray the case. They play tag on the balusters. This helps you get a wet coat on everything to reduce your overspray and insures that you get good coverage on the underside of any baluster ogees. Be prepared to use a lot of masking paper.

We're currently building a custom Douglas fir staircase using a gel stain and topcoat system. Everything is finished in the shop then transferred to site. The gel stain makes touch-ups relatively easy. Just be careful with the material onsite. The system is very successful for us.

I agree with disassembling. You'll get a nice and even coat of finish when sprayed individually. However, if you decide to spray onsite, adding retarder or using a slower thinner to your finish will help absorb a lot of overspray.

Always a lot less man hours pre-finishing stairs. Another method I've tried is bringing finish up to final coat and when installed, sand any nicks, dents and apply final topcoat (still a lot of work but less mess from spraying and staining). If balusters are painted or another stain color, I'll finish banisters, treads and risers first and then paint balusters (since they're painted, you don't have to tape off from the clearcoats). You get the picture.

P.S. Spray from bottom to top of stairs - wait for coat to flash off and final coat working your way back down. If you start spraying at top, all dry overspray lands on dry wood, so it helps to get a wet coat down even if it's not a perfect cover coat first lap.

If you can, pre-finish, then install and touch up. This will be a lot easier. If you're going to finish onsite, try brushing and/or padding on a water born (oil-modified), like Target's Oxford, or Last n Last Ultra Gold. It'll save you the hassle of spraying and will provide a good finish, especially one you can easily wax and rub to give the handrail a nice polished feel.

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Comment from contributor J:
I know your problem. I have spray finished many staircases, including handrails. Install stairs completely on site. Cover up treads and stair string nearest wall, spray spindles outside and in, then handrail up the outside, then inside newels also. Rub down between coats until finished. Once dry, cover up handrail spindles, newels and spray treads. Drying time is 20 minutes between coats, normally.