Dear Kaile,
I recently bought an exterior chair for my deck, and I honestly don’t know whether to stain and varnish it or to paint it. I stained and varnished one last year, but it blistered terribly — and a knot fell out to boot. Personally, I prefer staining.
Signed, Knot Happy
A:
Dear Knot Happy,
The blistering may well have been the result of improper preparation before starting the project and/or using the wrong type of varnish. We’ll address that later.
Preparation
Always have two work areas — a preparation area and a finishing area. It is important that you not stain the piece in the same area where you have just sanded. You will want to prevent kicking up dust onto the furniture while you are staining and varnishing it.
Look for knots. Most people don’t know how to tell the good from the bad. A black knot means it was dead when harvested. That’s not a good piece of wood. A brown knot is okay, as long as it doesn’t have cracks in it.
The problem with knots is that they loosen and fall out. If your furniture has “bad” knots, you will need to use an epoxy glue to permanently secure it.
Surface preparation
• Check for knots.
• Lightly sand entire piece with palm, detail or hand sander.
• Wipe piece with a linen cloth.
• Wipe with a tack cloth (a cheese cloth with a tacky texture). The tack cloth picks up lint pieces that could show through varnish.
• Apply a coat of wood conditioner. When you have wood that has parts that have been cut across the grain, you will want to be liberal when applying to the “ends.” If you don’t use wood conditioner, you risk having areas that look darker. When staining, you always want as consistent a finish as possible. Let set for an hour or two.
• Rub the piece with emery cloth, which is a fine sand paper, or steel wool. This process will remove burrs caused by wood conditioner.
• Wipe with tack cloth again.
• Move item to the finishing area.
Staining and varnishing
• Apply a coat of stain. Let set overnight. Or you can come back later — one week or one month.
• Prep, then apply varnish using a brush not a roller. Use “spar” varnish made for exteriors. You can’t use interior varnish because it will blister outside. I suspect that you may have used an interior on last year’s chair.
Generally, it is a good idea to freshen up your outdoor furniture with a coat of varnish (no need to stain again) every 3 to 5 years. This may vary depending on whether you bring the furniture in during off-seasons.
Kaile Warren of Windham is CEO/Founder of the national handyman franchise Rent-A-Husband. Kaile is also a national home improvement expert for the CBS Early Show, HGTV and Parade Magazine. When not on the road or working he spends his time teaching his newly adopted white shepherd, Maintenance, how-to ... Send your questions for Kaile to editor@themaineswitch.com.