Seams on and exterior tennis backboard made from MDO

zukeman7 | Posted in Finishing on October 5, 2011 02:31am

Hi I just built a MDO Plywood tennis back board I am looking to conceal the seams. I thought of using a bondo filler my concern would be that it may open up over time with the weather and pounding of my kids hitting tennis balls off it. Do you have any recomandations on a filler that would hold up to the New England Weather and the pounding of tennis balls it needs to be flexible? I am looking to have one 8’X30′ smooth surface showing no seams I am using a epoxy latex paint

Replies

CedarGroves | Oct 07, 2011 07:42pm | #1
A Suggestion From NH

My company used 3/4" PVC sheets (Azek I believe) as a backer for signage on the front of a strip-mall we built in Chelmsford MA in 04'.... despite building in 5/16" gaps and glue/screw combo, the thermal expansion of the PVC in these sheets was so severe that each panel looked like ribbon candy by mid-summer. Our solution was to use MDO instead and it turned out to be a winner - stable, colorfast, and damn near bulletproof. We used Phenoseal brand urethane-based caulk to seal between panels and were very happy with the flexibility and temperature tolerance of that product in our area. It comes in multiple colors, the white latex version can be tinted to match existing trim, and so far we haven't had any callbacks so I would say its a solid product in my experience.

-Ian
GretchenTHE FIRST | Oct 08, 2011 02:13pm | #2
Doesn't vinyl or rubber caulking remain flexible? Is this just for looks, 'cause I don't think it would make too much difference in the ball bounce.

CedarGroves | Oct 09, 2011 02:21am | #3
Yes vinyl and rubber caulking does remain flexible, to an extent. (generally workable to 40 degrees and supposedly flexible to -40). Some are simply better at doing this consistantly over time than others, and from experience I can say Phenoseal makes a good product. I have used the vinyl as wel as the urethane. It does perform the fuction of sealing the panel edges from any moisture that may wick in the ends and cause rot, as well as the asthetic purpose. Combined with a quality paint it provides a good weather barrier, it should not influence bounce at all.

-Ian