Inman

How to fix a deck sealing gone wrong

Q: Our 160-square-foot, 15-year-old redwood deck and stairs never had any coating or sealing applied to it. Two months ago, we hired a handyman to put a clear waterproof sealer on it.

He applied two coats of (a brand of) clear sealer. But the instructions clearly state, "Apply one coat only." Many parts of the deck are still tacky. We called the company, which said it is as dry as it is going to get and it will remain tacky. They suggested the only thing that might work now is paint remover.

Our handyman returned and used paint thinner, which did not work. We still cannot walk on the deck without sticking. Falling debris is making a mess, too. We are concerned that using paint remover will be hazardous and won’t cure the problem.

The makers of (the product) say it should accept oil-based deck paint just fine. We wonder if painting is the solution. But our concern is that this will be a short-term fix and the paint will eventually peel, which would mean refinishing every few years.

A: The handyman messed up. He should have read and followed the manufacturer’s instructions.

Painting the deck will only exacerbate the problem. It will create a maintenance nightmare of repeated sanding and repainting, with each result being less acceptable.

The handyman should have avoided overapplying the product, allowed only enough for wood penetration, and immediately wiped off all excess material.

Kevin made a similar mistake a couple of decades ago. Back then, Kevin used a "witches’ brew" of equal parts masonry sealer and paint thinner to seal redwood decks. The instruction he received from the manufacturer was to "flood it on." He did, and left the job before it dried. The homeowner called and complained of a gooey mess.

When he returned, he found that the liquid pooled, dried and did not harden. The surface was not only tacky, but left a shoe print when stepped on. Kevin was able to fix it. You should get the handyman to come back and do the same — at no cost.

Both Kevin’s concoction and the sealant you referred to are products made of solids suspended in solvent. Paint thinner is used to clean wet tools and uncured splatters, but it will do nothing to remove dried material.

Kevin tried paint thinner but took matters a step further and tried lacquer thinner. It worked. He applied it with a scrubby to loosen the film, followed by a rinse with paint thinner to remove the residue. This should take care of the stickiness, but if a little residual material remains, a light sanding with 100-grit aluminum oxide sandpaper should clean it up.

Caution: Lacquer thinner is very flammable and its fumes are toxic. We presume the deck is outside so ventilation is not a problem. But open flames and smoking are definitely not allowed. Wear rubber gloves, eye protection, pants (no shorts), a long-sleeve shirt and, most important, a respirator when doing this job.

The next thing is to go slowly. The goal is to remove the finish from the overloaded sections and blend those areas into the parts of the deck that have soaked up more of the sealer.

Finally, be gentle with the sandpaper. The idea is just to give the deck a little "tooth" and not sand it so heavily that you’ll end up recoating.