Mounting Bimini Top on Classic 15-footer

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Tom in VA
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Joined: Mon Jul 12, 2021 6:04 pm

Mounting Bimini Top on Classic 15-footer

Postby Tom in VA » Fri Nov 26, 2021 12:08 pm

I may buy a Bimini top. I may mount the frame to the railings instead of to the gunwales to avoid putting extra holes in the boat.

Q1: On a 15-footer will a Bimini top be able lay flat when not in use if the frame is mounted to the railings?

Q2: ON a 15-footer will a Bimini top lay flat so a mooring cover can be placed over it?

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Oldslowandugly
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Re: Mounting Bimini Top on Classic 15-footer

Postby Oldslowandugly » Fri Nov 26, 2021 4:43 pm

[To mount the frame of a bimini top on a 15-foot classic hull,] I used the side rails.

The Bimini top frame was stainless steel, and it came from another boat so some bending was necessary.

The top fabric was Sunbrella.

[The Bimini top] folds down and lays flat at the stern [of the classic 15-footer]

[The Bimini top frame] is clamped to the side rails with stainless Bimini mount hardware.

[On my classic 15-footer there are] two stern seats that the backs rest against the folded Bimini top rails.

The Bimini top out of sight when folded down.

fig1.jpg
Fig. 1. Bimini top on 15-footer with frame collapsed and top folded.
fig1.jpg (18.09 KiB) Viewed 5159 times


topMountSideRails.jpg
FIg. 2. Erected BImini Top on 15-footer
topMountSideRails.jpg (19.83 KiB) Viewed 5159 times

jimh
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Re: Mounting Bimini Top on Classic 15-footer

Postby jimh » Sat Nov 27, 2021 7:55 am

I mounted the Bimini top on my classic 1976 SPORT 15 using the gunwales. I show the installation in detail in an illustrated article at

Adding A Bimini Top
https://continuouswave.com/maintenance-logs/bimini/

Due to the slope of the gunwales, a special hinge bracket that incorporates an angled offset is necessary.

The hinge mounting point on the boat must be chosen very carefully in order to permit the Bimini top to fold down toward the stern without interference with other elements of the boat. When folded down the top will just clear the aft end of the side railings.

The advantages to mounting the frame hinge to the gunwales are:
  • the folded top lies closer to the hull;
  • the folded top does not obstruct the side railings; and
  • the folded top needs no retaining straps to keep it in place.

Oldslowandugly
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Location: Queens NY

Re: Mounting Bimini Top on Classic 15-footer

Postby Oldslowandugly » Sat Nov 27, 2021 7:37 pm

My installation is based on Jim's article.

I bought a stainless steel Bimini top from a SeaRay boat for $20 on Craigslist, but the top was too wide and the fabric was shot.

I was able to cut the top tubes, shorten them, and re-attach with stainless sleeves. I then carefully bent them to align with the top of the SPORT 15 side rails. I secured the ends with stainless steel sliding rail clamps.

I bought a new top that was a standard-size Attwood Sunbrella 6-foot model for $50 on eBay.

To get the top to shade each seat and still fold down at the stern was quite an endeavor. The rail clamps made it easy to slide the top fore and aft until I found the right spot.

I also find that the folded down top with three rails on top of the fourth Whaler side rail makes for a very strong and slightly taller safety railing for when my small grandchildren are aboard.

The folded-down top also helps secure the area behind the two stern seats that the kids sit in.

The older I get the more the blazing Sun bothers me. The top was a great addition to the boat.
Last edited by Oldslowandugly on Mon Nov 29, 2021 6:54 pm, edited 1 time in total.

TFrere
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Location: Lafayette, LA

Re: Mounting Bimini Top on Classic 15-footer

Postby TFrere » Sun Nov 28, 2021 8:48 pm

A few years ago I purchased a Bimini top for my 1985 15 Sport. I was reluctant to drill into the gunwale so I searched online and found these fittings.

C5BFB297-9E89-46F3-9FA3-13601BD0012C.jpeg
Fig, 3. Bimini mount on side rail
C5BFB297-9E89-46F3-9FA3-13601BD0012C.jpeg (22.49 KiB) Viewed 5177 times


I replaced the pin that held the ball with a machined screw. So far, it has held up well.
1985 15’ Sport with Yamaha F70

Tom in VA
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Joined: Mon Jul 12, 2021 6:04 pm

Re: Mounting Bimini Top on Classic 15-footer

Postby Tom in VA » Sat Dec 04, 2021 7:56 pm

I’d prefer to rail mount the Bimini top.

Will a rail-mounted Bimini top lay flat and fit under a mooring cover?

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Phil T
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Re: Mounting Bimini Top on Classic 15-footer

Postby Phil T » Sat Dec 04, 2021 8:13 pm

Owner reviews of products purchased from Specialty Marine have been very negative overall 30% favorable, 70 % negative.

Buyer beware.

Alternate vendors with positive reviews include:

Mills Canvas
Carver
Westland
Great Lakes Boat Top
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

Tom in VA
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Joined: Mon Jul 12, 2021 6:04 pm

Re: Mounting Bimini Top on Classic 15-footer

Postby Tom in VA » Sun Dec 05, 2021 9:07 am

TFrere:

What brand bimini did you purchase?

What was the source for those [rail mounted Bimini frame hinge fittings]?

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Phil T
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Re: Mounting Bimini Top on Classic 15-footer

Postby Phil T » Sun Dec 05, 2021 12:14 pm

railmountfitting.jpg
Fig. 4. A typical rail-mount Bimini top frame hinge fitting made by TaylorMade.
railmountfitting.jpg (15.27 KiB) Viewed 4972 times


The TaylorMade rail-mount frame hinge fitting can be bought from Wholesale Marine for about $63 a pair:
https://www.wholesalemarine.com/bimini-canopy-top-rail-mount-hinge.html
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

Oldslowandugly
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Location: Queens NY

Re: Mounting Bimini Top on Classic 15-footer

Postby Oldslowandugly » Sun Dec 05, 2021 7:09 pm

Just the fact that [the hinge for the frame of a Bimini top] will be rail mounted negates the idea that [the Bimini to[ will lay down [outboard of] the rails. The Bimini top MUST lay atop the rails.

The Bimini top will then act as a barrier to access the stern.

I don't mind [the added five inches of height due to stacked railings when the Bimini top is folded down]; the added railing height makes the sides more secure for the children--but it may irritate you.

I use some pool noodles to cushion the [original boat railing] from the Bimini top rails [to suppress] rattling.

But please measure, measure, measure to get it right the first time.

TFrere
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Location: Lafayette, LA

Re: Mounting Bimini Top on Classic 15-footer

Postby TFrere » Mon Dec 06, 2021 1:52 pm

I purchased from vortexdirect.com. It was important to me to have a stainless steel frame. The top is nice but may not be the same quality as a Mills' Flying Top.

I don’t remember where I got the fittings; I suggest a search for "ball mount bimini hardware."
1985 15’ Sport with Yamaha F70

Tom in VA
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Joined: Mon Jul 12, 2021 6:04 pm

Re: Mounting Bimini Top on Classic 15-footer

Postby Tom in VA » Mon Dec 06, 2021 5:35 pm

Greatly appreciate you sharing this info with me. Am I correct that your Bimini rests flat when it is not being used? From the photo you shared, that’s what I’m picturing and what I am after.

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Oldslowandugly
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Re: Mounting Bimini Top on Classic 15-footer

Postby Oldslowandugly » Mon Dec 06, 2021 6:01 pm

[The frame railings for the Bimini top on my boat that are mounted to a hinge on the original boat railings] lay flat on the side rails.

railsFlat.jpg
Fig.5. Added rails for Bimini top lay flat atop the original hull rails. For an additional view refer to Figure 1, above.
railsFlat.jpg (6.08 KiB) Viewed 4965 times


[Regarding the choice of fore-and-aft location for the hinge] the Bimini top wrapped in the boot [when folded down] lays [aft of] the [custom made and added] stern seats [on this particular boat]. Also, the engine when tilted up does not hit the top. The top is as out-of-the-way as it can be.

TFrere
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Joined: Wed Sep 05, 2018 11:16 pm
Location: Lafayette, LA

Re: Mounting Bimini Top on Classic 15-footer

Postby TFrere » Mon Dec 06, 2021 6:13 pm

My bimini lies flat on the gunwales of the boat with the ball and socket fittings.
Last edited by TFrere on Mon Dec 06, 2021 6:15 pm, edited 1 time in total.
1985 15’ Sport with Yamaha F70

jimh
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Re: Mounting Bimini Top on Classic 15-footer

Postby jimh » Tue Dec 07, 2021 10:42 am

If there is a strong preference to locate the hinge fitting for the frame rails of a Bimini top on the the side rails of a classic 15-foot Boston Whaler boat, there is really no impediment for accomplishing that.

The rail-mounted hinge fittings seen above in Figure 4 will result in the frame railings piling atop of boat's side railings when the top is in the stowed down position, as has already been explained and illustrated several times.

The unusual ball-and-socket hinge fitting seen in Figure 3 which is mounted to a vertical stanchion post for the boat's side railings will result in the frame railings resting outboard of the boat's side railings. However, the choice of fore-and-aft location will then be limited to the location of the vertical stanchion posts for the boat's side railing. Whether or not there is a vertical stanchion post in the boat's side railings that will produce the desired location for the folded-down top will depend entirely on the height of the top and its longest railing.

A further consideration is whether the height of the top should be chosen for the best fit when the top is deployed as sun shade, or whether the height of the top should be chosen to make it fit best when using the pre-determined attachment point of a vertical stanchion post for the existing side railing.

In my experience, if a boat has a Bimini top, the top is generally almost always deployed when the boat is in use. To alter the dimension of the top to enhance its fit (due to use of a fixed mounting point) when stowed seems inappropriate.