Frank, Peter and Heidi Dunkl produce Chilmark Spring Water, the Island’s own bottled water. But this winter, the siblings’ attention went beyond water.

They’ve been working on one of the Island’s most revered 19th century buildings, the old bandstand at Ocean Park in Oak Bluffs. From their plant at the Martha’s Vineyard Airport Business Park, they’ve worked on five new oak replacement posts.

The new posts are critical pieces for the troubled 19th-century building.

The bandstand has stood as a sentinel at the seven-acre Ocean Park for at least 133 years. Altered little over time, it has experienced every hurricane, every blizzard that has raged over the last century.

Despite its fatigue, every summer the building contributes to the town’s appeal, its character and personality, especially when loaded with musicians playing a John Philip Sousa march.

A rising number of people in Oak Bluffs have urged restoration work.

Though the Dunkls’ work began this winter, the results won’t be seen for a few more weeks. The five new large oak posts, which measure 117 inches in length, were fashioned in the Dunkl’s unassuming headquarters, a white steel building at the airport business park.

This week Frank Dunkl spent some time sanding the last of them with the help of his brother.

The five new posts will join seven others in keeping the roof over the musicians this summer. The new posts will replace posts that are crumbling, rotten almost to the core.

Frank Dunkl also brings a musician’s perspective to the situation, for he is president of the Vineyard Haven Band. He and his brother each play the French horn.

Two years ago, he took his worries about the bandstand to Oak Bluffs town leaders. The building didn’t seem safe for concerts. The rails were weak, so musicians couldn’t lean against them. And some of the original posts that were standing were only doing just that.

“The Vineyard Haven Band does 11 performances a year, eight of them there at the bandstand. One of those is with the fireworks. We got concerned,” Frank Dunkl said.

“Those posts are made of soft wood, probably poplar, perhaps linden wood, maybe even white pine,” he said. “You can be certain those posts are the original. They were never replaced, because to replace them you’d have to take the whole thing down.”

The Dunkls are no strangers to caring for old Vineyard structures. Years ago they were hired to do renovation work on the Flying Horses, built in 1876 and brought to the Vineyard in 1884, the same year the bandstand was built.

Speaking of the bandstand, Frank Dunkl said, “We’ve been trying to work with the Parks Department for a number of years to see if we could get something done. It wasn’t happening.

“In desperation, we said if we don’t do something to repair it, it won’t get done,” Mr. Dunkl said.

“Two years ago we had a talk with Rene Balter of the Oak Bluffs Association,” he said. “We proposed we would try and repair, not restore, areas where there was structural need, at a cost which would be miniscule compared to them getting an off-Island contractor to do a bigger job.”

A collaboration arose between the Oak Bluffs highway department’s Richard Combra Jr., who is also with the parks department, the Friends of Oak Bluffs and the Oak Bluffs Association.

A total of $15,000 was pooled together for the immediate work needed.

The Dunkls acquired some pretty special wood for the project.

“We were told by Ross Gannon and Nat Benjamin that the best place to get quality wood for turning was at the Cataumet Sawmill. They have the wood suitable for marine use,” Mr. Dunkl said. “So we approached the sawmill last spring and they told us they had a few pieces left over from a lot of wood that was purchased by the Navy and was left over when they restored the USS Constitution.”

The wood had sat at Otis Air Force Base for some 20 years, then sold to the mill. “These were the last five pieces from that lot,” Mr. Dunkl said.

They were eight inches square at the time; Mr. Dunkl said they were dressed down to 6.5 inches square by their business park neighbor Gary Reynolds at Reynolds Woodworking. To save money, the two companies did a labor swap. “He did a beautiful job,” Mr. Dunkl said.

The next step was to spin each of the five in a lathe to perfectly match the existing 12 posts in the bandstand. Using scrap pieces of wood and machinery parts, some spot welding and assembly, the Dunkls then made a pattern lathe, the device would hold and spin the posts. The Dunkl brothers then got carpenter chisels.

The turning was done in February.

“We completed the work in two weeks. That is the time when things were slow with Chilmark Spring Water,” Mr. Dunkl said.

Their plan for the installation of the posts will be tricky, but Mr. Dunkl said they have checked with the town’s building inspector Jerry Wiener and others.

Each new post is going to replace only a portion of the existing post, the most visual part of the original. The tops are solid — it is the bottom of the post that needs to be replaced.

Without having to take the roof down, each new and a portion of the old post will be joined together using a mortise and tenon joint. The foot of each new post will be connected beneath the bandstand floor with another post. Hidden from view, the bottom of the new posts will be joined using steel plates and bolts.

Mr. Dunkl said they believe the work will certainly be better than what is there and as close to, if not as good as, the original when it was built.

By the way, don’t call the bandstand a gazebo. Nothing raises the ire of the Oaks Bluffs residents more than calling the Ocean Park structure by its incorrect name.

A gazebo and a bandstand are two different kinds of structures. A gazebo sits on the ground and is accessible to everyone. The bandstand is elevated and accessible using stairs and is for musical performances.

Priscilla Sylvia is the treasurer of the Friends of Oak Bluffs, an organization about 30 years old and committed to keeping the town beautiful. Since last fall her organization has put $6,929 towards the Dunkl project.

“Six years ago we replaced the interior base of the bandstand and put in a stairway at a cost of $16,339.57,” Mrs. Sylvia said. All the money that the Friends uses comes from local contributions.

“The bandstand is on the town seal,” Mrs. Sylvia said. “It is the centerpiece of our town and it is in dire shape, from the platform up. There are rotting timbers. The Friends of Oak Bluffs have a goal to have permanent lights on it like we do during Christmas.”

Oak Bluffs voters will have an opportunity at their annual town meeting, Tuesday, April 8, to approve a $200,000 effort to make additional significant improvements to the bandstand. The money would come through the Conservation Preservation Act funding, a match of state and local funds.

Mr. Combra said he and others went to the community preservation committee last November for help. The committee is recommending $200,000 be spent on the building.

“The bandstand is in terrible shape,” he said. “This is for the entire bandstand, rebuilding the floor, rebuilding the ceiling and roof of the structure, adding new sound and security and a handicap lift,” Mr. Combra said.

If approved, work would begin next fall.

When the wastewater project was done in Ocean Park, the bandstand was lifted off its foundation and a new concrete foundation was put in place. But there wasn’t any work done to the structure itself. Water seeps through holes in the wood apron that surrounds the bandstand. From inside the bandstand, upstairs and downstairs, the troubles are most evident.

For the last six years, Mr. Combra has been superintendent of the highway department and chairman of the parks department. While the bandstand has been on the priority list, he said, “It has always been a challenge looking for money.

“When you think of the town, you think of the bandstand,” he said. “The town really needs to get it to A-1 shape.”