Saturday, November 10, 2012

AF3 Cockpit Tent

Fitted tent for camping
We used a polytarp for a recent trip to the Core Sound of North Carolina's outer banks and it served its purpose well.  

Polytarp cockpit tent for AF3 Cream Cheese
It kept the rain out during a 35-45 mph storm one night and sheltered us from the wind when it was in the 50's Fahrenheit.  But the tent takes a lot of time to setup, is noisy, ugly and bulky.  Running the lines under the hull is awkward.

Having achieved some sewing success with my third reef project, I decided to embark on another sewing project; a custom fitted camping tent.

I spent a few spare evenings reading through my copy of "The Complete Canvasworker's Guide" by Jim Grant.  Then I made a few line drawings of various designs including various configurations of hoops and frames.  I finally settled on a simple A-frame design slung over the sprit boom and bimini similar to what we had used in North Carolina:

Cockpit tent design - side view
Cockpit tent design - top view
Use gravity  
This project required many 10' to 12' flat felled seams.  At first I tried put the sewing machine and fabric on the floor but I quickly found out that my Janome Magnolia 7300 sewing machine doesn't have the power to pull all of that fabric.  I solved this problem by following the advice of of Emiliano Marino's "The Sailmaker's Apprentice" and constructing a gravity feed system.

Sewing long seams using a gravity feed system
Sailrite's 3/8" basting tape
I made the first seams using pins.  The results were crude and tended to have puckers.  Later in the project I ordered a roll of 3/8" Seamstick basting tape.  What a difference it made.  My seams were more uniform and took far less time.

Walking foot
Also halfway through the project, I ordered a walking foot attachment for my sewing machine.  It also makes for more uniform seams.

No boom needed
I sewed 1" polyester webbing along the centerline and terminated each end with 2" webbing and a 2" bronze ring.

Ridge reinforcement
This allows me to stretch the tent taught between the bow and stern and eliminates the need to use the sprit boom as a ridge pole.  I clip the mainsheet to the stern ring and pull it taught.

I used stainless rings and webbing to attach the cover to the boat.  I found sailrite's how-to videos to be very helpful in figuring out the mechanics of assembly.
Corner Attachments
Ready for assembly
Attachments and Setup
I sewed in sleeves for fiberglass tent hoops but after experimenting with the fully assembled tent, I decided that the hoops added almost nothing and complicated the setup.  The sides of the tent clip to lashing hooks fastened underneath the gun'nle.

Side attachments
The bow uses a single pole with a line tied to the forward mooring cleat.

Bow detail
The stern is open to the air, .  The corners are tied to the stern mooring cleats.

Stern detail

Next steps
I am very pleased with the results.  The tent only takes about 6 minutes to setup.  I will probably sew in a few windows and I may fabricate a panel to cover the stern.