Home made bimini top

[mandolinut]

I am getting ready to make a rectangular bimini top for my Compac 16.
I am looking for some measurements and suggestions  from those of you that have done a similar project.
Much thanks in advance.

[mandolinut]

This is a follow up to my post on making a bimini . Some time ago, I read about the author of Trailerable Sailing making one with no metal frame. Probably pvc.
Looking for the best way to support the cross bars fore and aft. I tried attaching a cross piece of pvc  to the shrouds, but it wants to slide down.

[Bob23]

Mandolin:
   Great idea with the pvc. Gives me some ideas for a low budget bimini for my 23 using either a tarp or some old boat cover material I have lying around. Keep us posted on your project, Thanks
Bob23

[bobhutson]

Hey Mandolinut,
Couple of thoughts...If you look at the pic Wolverine used to illustrate his thread "installing a round cover", a couple of posts down, you'll see the home made bimini on my boat...I don't have the dimensions but if that design interests you I will be happy to get them and post them to you in a couple of weeks when I get back to Galveston.

The option you described probably provides more shade and may be the one Bob Burgess designed and used in his book "Handbook of Trailer Sailing". It is described in detail beginning on page 173. If you don't have a copy of the book I'll be glad to post the details on that as well if you need them. Mr Burgess started with bamboo cross bars, then used PVC and ended up with 1" dia thin wall aluminum tubing. I believe you can keep the ties from sliding down the stays by installing pieces of small diameter CPVC cut to the appropriate length on the side stays. 

Either of these designs can be used while sailing. Let me know if you need additional info,
Bob H

[skip1930]

Could use these fiberglass folding tent poles that just about bend 180 without shattering. But you'll need to anchor them on deck some where, or hang them off the life lines. Clamp them to the life line stanchions? Or...??

skip.

[mandolinut]

To Bob, The Burgess system is the one I remember. I could not recall the author's name or the book's name.  I liked the idea that it had a great deal of coverage and that it stowed away easilly and very compac.
Your idea about cpvc around the lower shrouds is a good one to keep the foreward crossbar from slipping down. I am invisioning the rear crossbar being supported by two legs, and having two lines coming off on either side of the crossbar  tied off on the two cleats aft. This I believe will stabilize the entire canopy and make it taut. May need to add a few "T's" in the middle of the crossbars to run another piece of pvc fore and aft to prevent sag. This is where I was in hopes that somebody that has made a similar set up could suggest what works and what does not work.
I really like the look of your bimini. Very professional. I have a brother-in-law that is an electrician and could bend the pipe for me. Would have to find a source for the deck hardware.
I will look for the Burgess book at our lacal library now that I know the book and author. Much thanks.

[mikew]

I built one using the book mentioned and it worked great. I paid about $75 for materials about 10 years ago, which consist of white marine vinyl material ( Weblon), 4 - 3/4" alum. tubes and 8 nylon bimini top fittings.
The top is cut to the inside width of the cockpit and the length is about 2 ' shorter then the length of the open cockpit. A cuff is sewn into the front and rear of the top for the tubes. The front tube slides into the front cuff and is tied off at the ends to the side shrouds. The angle of the stays prevent it from falling. The other tube fits into the rear cuff and is held by shorter ( vertical )  alum. tubes on an angle to mid outside coaming, where it mounts. The nylon fittings secure the  tubes and let them fold for storage. Two lines come off the rear tube ends and tie on an angle to the rear cleats to tension the top. (Holes are drilled in the tube ends for the ties) Plastic tips fit over the pipe ends.  
This top can be used while sailing, allows one to stand at the helm, and allows the boom to swing with clearance for the main sheet. The best part is that it rolls up for storage on the bunks below and sets up in a few minutes.

Finished top 70" x 56" ( allow extra length for the cuffs) A canvas shop should sell the vinyl material and sew cuffs.
Front/rear tubes: 62" each   Side tubes 32" each Aluminum tubing from Hardware dept.  3/4" OD
Bimini fittings; 4 External eye ends, 2 Jaw slides and 2 Bimini mounts, Nylon 3/4" ( West marine)
It helps to step mast and set up boom with mainsail hoisted and adjust top to just clear your head while sitting , before drilling mounting holes in outside coaming.
 
Picture: http://s1061.photobucket.com/albums/t479/ke2ee/

Mike

[skip1930]

I really like this sun shade on this CP-19 MK1 with it's smooth curve. I think those fiberglass folding tent poles would do just fine. The ends may be in a deck socket or better yet clamped onto the life lines.

It's on the cover of Robert F. Burgess's book Handbook of Trailer Sailing. Be sure to pick up a copy for yourself. $11.95 ISBN 0-396-08303-X The Putnam Publishing Group.

[Salty19]

Looks like a bunch of us want to make DIY Bimini's.  Have been thinking long and hard about this as well, read several ideas and still haven't settled 100% on the design but am close.
I like the Bob Burgess design but I want maximum headroom near the beam like Mikeg's and others.  It would be for a CP19 as shown in the picture of Bob B's boat.

Here is Mikeg's bimini for reference.



Basically all I want is one that can be used while under sail, easy to install/remove/stow, not huge so it's less in the way, doesn't interfere with sheets, cheap but not poor quality. The permanently mounted, heavy traditional type doesn't appeal to me as often we won't want to deal with it in the way. I'll make a stow bag for it as well.

I'm still considering pro's and cons of meshed weave vs. sunbrella or vinyl.  Meshed fabric lets air through to reduce windage, wear at seams and movement in stronger winds as air will pass through. The mesh lets you see the sail trim and is cheaper than sunbrella.   Not that you need much fabric.  Meshed is not water resistant at all, does let some light through (95% is good enough for me).   Shade grades are around 60-95% shade depending on which fabric you choose.    Vinyl is out for me, too hot underneath vinyl and tough to sew, may as well match the rest of the sunbrella if I can.

Thinking about see-through yet still good shade mesh with Sunbrella trim for extra stiffening and to make it look and feel a little better along seams, 1/8" shock cord for the aft tie offs and 3/4" round alum poles but with internal pole bungies to collapse like tent poles, quick detach pins for angled "leg" poles.

Also toying with making a full cockpit enclosure for at anchor.  Maybe roll down no-see-um netting, roll down storm flaps with windows in all directions. Full support for maximum tent area and little chance of water getting in.  I made a full sized at anchor awning (fom mast to backstay-just for shade, would still get drenched in rain)  and some other canvas work so so have built up some sewing skills to get this a shot.
Definitely planning on camping out more on this year and next.

[mikew]

Salty19, Thanks for posting the picture of my top and boat , I just left the link to photobucket. I understand you are thinking of different fabrics- good idea, I choose the white marine vinyl because of its construction. The product " WEBLON" is made of a sandwich with white on top to reflect the light,
a middle mesh layer for strength and a light blue or denim like grey fabric underneath to break up the reflected light from the water and stay cooler. I built the same top years earlier when I had another CP-16  in Florida and sailed on Tampa bay. The thing saved me from heat stroke during sailing  the summer months!  The vinyl is water proof too which is great during rain storms, also I found a heavy duty sewing machine could sew up the cuffs. I didn't notice much windage up to 20 kts, probably because the top is mostly of horizontal construction. Saying all this , if the same top was made for the cp-19 maybe a lighter material would be necessary because of the size.
Bob Burgess had a good design but it couldn't hurt to experiment.

Mike  

[capt_nemo]

Hey Guys,

Glad I checked out this thread.

As an intrepid DIY'er, been thinking about a Bimini for my Sun Cat. Thanks for all the neat ideas and especially the photos - definitely worth a thousand words.

I find the CP-16 forum quite active and informative. Keep up the good work!

capt _nemo

[skip1930]

The trouble with a lot of these bimini' s are they provide direct overhead shade when anchored or sailing but not much shade from the sides when a low sun sneaks in under the top.

I like the thought of a Velcro drop down curtain. Much like the drop board cut in half with the upper half in place, blocking the low sun when I may be puts-ing about in the cabin, with companionway hatch slid shut, and with the lower drop board piece stowed away and not in place allowing for cabin ventilation.

skip.

[mandolinut]

Thanks for the photos and measurements and some of the other ideas. I decided to go with a modified Burgess. I will post some pictures of the final project when complete. I added some cpvc 1/2" pieces to the shroud lines today. Somebody suggested this for preventing the foreward crossbar from slipping down. I capped the cpvc and drilled a hole in the caps . I attached two brass toggles to the 3/4" pvc crossbar so attaching the foreward bar and taking it down will only take seconds. The length of the cpvc height was dictated by the boom height. I wanted the forward bar to be as high as possible without chaffing on the boom.
Another advantage I noted was that when tacking with the genoa, the cpvc should act as a roller and decrease sail wear and tear, so probably a good idea even if you do not intend to add a bimini top.
I plan on making a mock up using an old sheet tomorrow and make sure the size works.
Thanks again for the pictures and ideas.

[Pacman]

Another advantage I noted was that when tacking with the genoa, the cpvc should act as a roller and decrease sail wear and tear, so probably a good idea even if you do not intend to add a bimini top.

You are absolutely right about the value of rollers on the shrouds.

Although I have not had any real problems with jib sheets or sails on my C-16 dragging on the shrouds, my Catalina 22, which had forward lower shrouds that sometimes got in the way.

The North Sails Tuning Guide for the Catalina 22 recommended shroud rollers.  They were a big help and they cut down on wear on stiching on the genoa.

My only improvement was that, like you, I used end caps and stainless washers to povide a "jewel" type bearing surface on the top edge of the turnbuckle body.  I simply unscrewed the turnbuckle and inserted the stud through the bottom end cap.

However, because the C-16 uses loops to fasten the turnbuckles to the shrouds, you will have to cut a slot in the top end cap to admit the shroud and then use a plastic disc with a similar slot inside the end cap to keep the end cap centered.

When you assemble the top cap and disc, make sure the slots do not line up so the cap will remain centered on the shroud.

I used a small hole saw to cut my discs from a HDPE bucket lid.

Keep us posted.

[Cevin c Taylor]

I'm following this thread, too.  I love DIY projects, and I hope at some point to make one of these tops.