Posted on 09 January 2009
Written by Tom Neale
What can I do to keep my dodger/Bimini in good shape?
A: Both power- and sailboats often have a windbreak or even a complete enclosure made from fabric such as Sunbrella, with windows of clear plastic. Unfortunately, these must be replaced periodically because of age, no matter how well we care for them. The windows yellow or become cloudy, the fabric tears or begins to leak, threads rot, and zippers break. But there are ways to delay the process.
It helps to use good material and a good craftsman when you get your cover. Cheapness quickly shows with this type of gear. And new boats often come with inexpensive material. Check before you buy. While we can’t recommend any one material over another because we haven’t tried them all, we’ve had good results so far with our latest enclosure using our old stainless frame, Stamoid fabric, Crystal Clear windows, Tenara thread, and RIRI zippers. It was done by Beaver Brand Canvass in Fort Lauderdale, Fla., (954) 763-7423.
Abrasion is a major killer of clear plastic, as is sunlight. Many boaters will keep their windows rolled up or covered to avoid yellowing, but this often contributes to abrasion. Never roll up a window unless it’s clean and salt-free, and keep in mind that some clear window material such as Strataglass cannot be rolled. Often thoroughly hosing down with clean fresh water will suffice, but this will usually not remove a heavy coating of salt. Sometimes dock water itself contains impurities such as minerals, which can, with enough use, impair the windows. Using a water filter such as Wet Spot (www.softwetspot.com) or CleaRinse (www.clearinse.com) can help. We use Plexus spray as a cleaner and protectant after a thorough washing.
There are special products, such as Star brite’s Clear Plastic Window Savers (www.starbrite.com), to keep the window material from “burning” on the hot tubes of the frame, although most canvas makers stitch fabric strips on windows where they come in contact with the tubing to prevent this problem.
Polyester thread will often rot before the material it binds together. A good shop will cover seams and zippers with flaps as much as is practical. Try to keep these in place. Sometimes wind or other activity will move them. Newer threads, such as Tenara (Gore-Tex) and Profilen, have lifetime warranties but are more difficult to sew than traditional polyester. Our Tenara stitching is showing little wear after nearly four years of service. Washing the threads if they become fouled with decay-producing materials, such as bird droppings, also helps. Avoid letting products containing chlorine come in contact with thread.
Zippers are particularly prone to failure, especially inexpensive ones. Aluminum has often been used for slides, and salt water corrodes this alloy quickly. UV radiation destroys plastic zippers exposed to sunlight so, again, make sure your canvas maker has covered them with a flap, and keep that flap in place. Our RIRI zippers seem to be holding up well. They are reported to be eight to 10 times more UV-resistant than others.
No zipper will withstand abuse for long. It’s easy to become impatient and pull too hard when you need to close up quickly. This can break teeth and pull out threads holding the zipper to the surrounding material. Always be gentle with zippers and try to use them as little as possible. Also, there are products, such as Star brite Snap and Zipper Lubricant, that can be used for lubrication and protection. Regular lubrication will help immensely.
Snaps are also a weak point. Pulling them up by the fabric frequently tears it, but there are specially made tools for working snaps, and you should have one on board. They’re in most chandleries. When you try to resnap a section, it’s not uncommon to find that the snap won’t fit back over its counterpart. Temperature changes can cause fabric to shrink, destroying — at least temporarily — a good fit. If you have a problem and can wait, warmer weather or sunshine will help. Also, use the snap tool to pull the snap, rather than the cloth.
Most tops also have webbing or tubes for tensioning the structure. It’s important that these be tight enough so the frame doesn’t wobble and the fabric doesn’t flap, both of which can cause unnecessary abrasion.
Finally, always take down this gear if the weather is going to be too much for it. This is a difficult shot to call, and the old saying “better safe than sorry” isn’t always appropriate, because taking the material down often scratches it or stresses threads or crinkles the plastic, creating future leaks. However, many a Bimini/dodger/windshield has been quickly destroyed by high winds. If you have an enclosure and elect to not take it down, we’ve found that it helps to at least close it up tightly so the wind can’t get inside and blow it out.
Have a question? E-mail it to
or send it to Soundings Editorial, 10 Bokum Road, Essex, CT 06426
This story originally appeared in the January 2009 issue.