Having leaks in my canvas bimini top. Need suggestions on how to treat it.
Your top is most likely made of Sunbrella, that being the most common Bimini top material. Sunbrella will last in constant exposure to UV, for between a decade and 2 decades. The threads used in sewing your Bimini will often be ordinary, non UV proof thread. Better Bimini sewers use "Tanera" thread, which, at a higher price, last almost as long as the Sunbrella material. If your leaks are all at the seams, threads are the first suspect. If not at the seams, the Sundrella fabric itself is the culprit.
Remedies: If you are confident that the fabric is still OK, get it restitched. If your leaks are through the fabric, a waterproofing coating, such as Thompsons Water Seal will give you a few years of respite, but replacement is in your future.
When I bought my boat, in 1994, the tonneau cover had been in constant exposure to UV for about 5 years and in summer-long exposure for another 10. Within a year or two I used Thompsons Water seal and extended the life of that bit of canvas another 5 to 10 years. At that age, I replaced it.
As for the Bimini,I am facing this hard choice myself. My Bimini is at least 30 yrs old and the seams are beginning to fail. In addition, I can see through the fabric, away from the seams, in a few places.
I have checked the cost of fabric and of a replacement kit at Sailrite.com. They provide excellent instruction, if you have access to the proper sewing equipment and the skill set to DIY. Their fabric is currently $22.95/ yd. Their kit costs about twice that, but you get the zippers, seam binding tape, webbing and detailed instructions in the package, together with video instructions and a phone help line that is the best I have seen.
If you don't wish to attack the Bimini DIY, replacement is the core business of many shore facilities. Get some estimates and look at their work when you choose a vendor.