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The Big Project | Hobie 18 Hull Repair
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Author:  idahosailor [ Thu Jul 02, 2009 4:20 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

I have been sanding the hulls and smoothing out all the small scratches and nicks. The hulls are looking really nice...except for the two holes in the one hull :) They will be repaired in good time!



Author:  idahosailor [ Thu Jul 02, 2009 4:39 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

My next step is to add reinforcing to the front crossbar. I purchased the anchor plate reinforcing kit from Hobie & have read the thread on adding the fiberglass reinforcement. Below is a photo of the front crossbar inside my boat.


I am wondering if these "globs" of resin should be ground down before adding the strips of fiberglass. It might be that these "globs" are adding a lot of strength to the assembly & I don't want to make it less stable, but I don't think the fiberglass will adhere well to the globs unless they are ground down and smoothed out. Please let me know what you guys think. Thanks!


Author:  hobieboyforever [ Thu Aug 20, 2009 3:12 am ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

idahosailor wrote:
Here are some photos of the cradle production. Thanks to Harry for the initial ideas on making these cradles! They are going to be much better at displacing the weight & protecting the boat than the old roller system.

Cutting the Pipe

Cradles Cut to Size (Circumference cut into 1/3 increments)
I made (6) cradles...(4) for the trailer & (2) for the beach wheels.

Steel Plates cut to size & drilled to match Bolt Holes in Cradles

Welding the Pipe Rotating Axle to the Steel Plate

Steel Pipe Axle welded to Support Plate (Welded each Side)

Countersinking for the Bolt Heads so they are flush with Cradle & will not damage the Hulls

Shake & Bake!

Cradles being formed to Hulls...(Multi-Step process that photos do not show) Keep hulls cool & plastic warm. Warm styrene slowly & gently @ low temp to form to PVC Pipe so it doesn't break or crack. Then warm PVC pipe separate & form to hulls with styrene as insulation between PVC and hulls. (Note: 10" dia. PVC cut into 1/3 increments was pretty close to the right shape, so I didn't have to mold it too much)

All parts ready to be painted!

Cradles Glued up with Polystyrene & Nylon Carpet & Strapped to Hulls for Drying/Curing

Another Photo of the Cradle Assemblies Curing to the form of the Hulls.
:mrgreen: Hi Tad, you have done a Fantastic job of those hull supports, Be proud they look great.

Author:  pionex [ Tue Jul 06, 2010 12:41 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

I know this topic is quite old, but maybe someone is paying attention. I was just wondering if the styrofoam should be left on for usage or if this is just for shaping the PVC. My guess is you don't leave it on and just glue the carpet to the PVC? About what temp was used to form the PVC / Foam?

Author:  idahosailor [ Tue Jul 06, 2010 1:50 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

The polystyrene stays on the cradles for padding and the carpet is glued to it on the trailer cradles. (One thing I found out was that contact cement will dissolve the polystyrene, so you have to use a different kind of adhesive). For our beach wheels I just glued the carpet directly to the cradles since the boat isn't on them for any length of time. Can't remember the temperature I set the oven to. I think Harry had some recommendations. The polystyrene gets soft at a pretty low temperature and the PVC required a higher temperature. There is a drawing of the entire assembly earlier on in this thread. Hope that helps! --Tad

Author:  Harry Murphey [ Wed Jul 14, 2010 5:56 am ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair


You have done a wonderful job .... you took my information and basic concept .... and improved upon it to a new high !!!!

Good Job Dude


Author:  Harry Murphey [ Thu Jul 15, 2010 11:33 am ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

Just curious ..... have all the repairs been done .... new graphics applied ..... has she gotten wet yet from lake water (not rain water!!!!)

Let's see some pic's of her in the water sailing!!!!

Author:  idahosailor [ Tue Aug 10, 2010 12:21 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

She is finally done!! Maiden voyage was this weekend. My wife and I trailered up to the Lake that I grew up on for the first time on the water since the re-build / restoration. It took me over a year to complete the restoration but it was worth it! Everything worked well and we had good wind for a couple days of nice sailing. Always amazed at how fast & nimble these cats are. Thanks to everyone on the forum for their advice and expertise and especially thanks to Jeremy at Surf City Catamarans for all his help and advice. http://www.surfcitycatamarans.com

Here are some photos from the maiden voyage!
http://picasaweb.google.com/tadajones/2 ... directlink

Author:  srm [ Tue Aug 10, 2010 4:03 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

Your downhaul/mast rotator is not rigged correctly at all.

You've got the rotator line rigged through the tack fitting on the sail. There should be a separate line used to pull the tack down (the downhaul). It's important to get these systems set up properly as they have a significant effect on performance, especially when you sail in higher winds.


Author:  Sailinagin [ Tue Aug 10, 2010 6:40 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

Boat looks great. Been watching a recommending your thread to others to reference. SRM is right, may be worth taking detail pics of other rigging on the boat to confirm its right. Congrats, all the work looks like it was worth it.

Not sure the jib sheet is correct. It should be long line tied to each jib traveler and running throug both cleats and the blocks connected to the jib foot.

Author:  Harry Murphey [ Wed Aug 11, 2010 5:01 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

Great Job!!!!

The boat looks awesome .....

Next .... little improvements ....

1) Continous Trapeze Bungy System ... see my post ... big help for trapping off of wings!!!
2) Double up the stopper blocks on the trap system .... they're the little black things that set the trap hieght .... less likely to move ... or break/bend
3) Upgrade tiller/rudder crossbar connection ... install "Miricle20" connectors .... $$$ ... but well worth it!!!!!!
4) Yah .... that rotator-downhaul combo ... not good ....

For the rotator ... I tie a small "bullet" block to the rotator ... then I tie a 3' line to the boom by passing it through the holes under the junior jamcleat and tieing a stopper knot ... the other end go to the bullet block .... around/through bullet block and back to the junior jamcleat ..... voila .... a 2X mast rotator system ....

For the downhaul .... I recommend a system that is adjustable from both sides w/ exit blocks w/ camcleats mounted on each side of the mast ... that system is diagramed in several catalogs w/ pics. Note: Since you have "Wings" you need to mount the exit blocks as high as you can on the mast ... just below the gooseneck ... but maintain easy angles so the downhaul line doesn't bind up .... if they are too low you can not work the downhaul when you are sitting on the wings or trapped off the wings ....

5) Pigtails for the jibsheets/jib connection .... take 28" length of 1/8" spectra/vectra/dynema .... find mid point and tie to jib at that point (clove hitches work) .... now you tie the jibsheet blocks w/ the pigtails ..... this helps w/ tacking the jib.

6) For safety change those "dogbones" out ... as they like to chip teeth as they swing around wildly .... either use "easyHooks" (you can make your own) ... or change over to the "ball&socket" trap system. We just make loops of wire from our old shrouds ...

There's a few easy and cheap ideas .... a mildly $$ one (trap bungy system) ... slightly more $$$'s (tiller/crossbar connector) ... and a expensive $$$$ one (downhaul, as the exit blocks are pricy)

Take care of that sail .... that was a very nice color pattern .... and they all seemed to "race well" .... ie: they were fast ....

Again .... REALLY REALLY nice job .....

Author:  ffstone [ Thu Aug 19, 2010 8:59 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

That quite scary just how similar the cracks on our hulls look compared to yours.

When we started this project, our intention was only to repair the bottom rudder joint (it's midnight and forgotten the damn name lol). When we had the boat dismantled and upside down we noticed a giant dark patch, and a massive wavy section nearing the rear of both hulls. Chisel and hammering later, good 5mm to 1" thick epoxy's peeling off to reveling the cracks.

Rather then redo it from the outside we decided to go from the inside, we've cut 2 new port holes in the rears of both hulls and did all our work from there. We're almost done, just needs good fine sanding and then gel coat and it's finished.

http://picasaweb.google.com/iarp.comptech/Hobie18?authkey=Gv1sRgCO_62ZDEqp7O8wE&feat=directlink Should be public so anyone can see the images.

Author:  Sailinagin [ Fri Aug 20, 2010 6:32 am ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

ffstone - great pictures! I think this thread will be valuable for years to come. Can you put info on your captions that list the products you used at the various steps? Also, is it done? Would like to see the finished project!

Oh and thanks for restoring those hulls I think one pair of saved hulls is worth the effort -

Nice job.

Author:  ingasguns [ Wed May 18, 2011 10:16 pm ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

what did you use for the adhesive? (the cradles) i am going to use this process of yours as i plan to store the boat on the trailer with the stick up....

Author:  idahosailor [ Fri Dec 02, 2011 10:00 am ]
Post subject:  Re: The Big Project | Hobie 18 Hull Repair

Thanks for the comments on the rigging. That will be really helpful. We modified the downhaul after those first few photos were taken, but I am still not sure if it is correct. This next summer I will try to remember to take some photos of the rigging & see if we can implement some more of the suggestions. Thanks for the compliments on the boat!! Hope you all had a great sailing season!


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