Author Topic: building a hard bimini  (Read 724 times)

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  • Sr. Member
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building a hard bimini
« Reply #1 on: April 16, 2018, 02:16:43 PM »
By the time we delivered Atlantis from Miami to Annapolis 2 years ago, all that was left of the original canvas were the frames.  We did not want a bimini that covered the whole cockpit, just from the binnacle to the helm seat - a distance of 4 feet.  After getting a quote of $7,000 for a fiberglass bimini a friend convinced me 'we' could build one.

Day 1

assembled the bits - MAS epoxy, 2x6s, sheet of plywood, foam core, glass cloth, glass mat and 2 4x8 sheets of FRP panel from Home Depot to use as skins.  (Jamestown Distributors said the FRP would bond to epoxy)

Took a 2x6 to the boat and clamped it to the existing frame and marked the curve. Realized that a 2x6 was not wide enough.
Cut the 2x6, screwed 'extensions' on the end so they were 2x12, clamped it to the rail. Cut the rest of the curve. Verified that the 2 bows had the same curve and repeated the process.

Them came the evil FRP. It has a bubble finish on one side that needed to be sanded. This stuff is hard as a rock and creates a fine white powder that goes everywhere. You MUST wear a mask! It also consumes sandpaper. I got frustrated with 80 grit, so tried 60. 80 was marginally better. Did the sanding on the garage floor. Spent more time on my knees than a cheap hooker at a national convention.

Set aside the FRP and screwed the sheet of plywood to the 2x6s to get the shape.

Day 2 - part 1. Trimmed the excess off to get the size to its proper size 48 by 76.
Cut G10 into squares for the attachment points as recommended by Jamestown distributors.
Cut holes in the foam core sheets for the G10 to fit in. Measured distance from the edges.

DAy 3 Did the first layer of glass cloth and foam last night. MAS medium hardener is not fast in 50 degree temps! I was short on foam core, so ran a piece of PVC about 5 inches wide to make up for it. Unlike West epoxy, MAS sticks to PVC. Hoping to get another layer or two done tonight.

Day 4 Drilled pilot holes through the G10 and FRP so I know where the U Bolts go.
Added epoxy, another layer of 6 oz cloth, more epoxy and the top sheet of FRP last night. Clamped it, let it cure. It is now hard as a rock!
Next steps are to drill holes for a couple of U Bolts, test fit and decide on the radius for the corners. Then, cut the corners, fill the edges, sand and paint.

Day 5
It FITS!! Did. A test fitting yesterday. Today rounded the corners uses a lid from a 10 quart pan to give me the right radius. Then filled the edges with 3M filler, sanded and repeated. One good sanding away from a coat of primer. ... sp=sharing

Hoping to finish it this week.


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