adding u clamps to hull - stern

[PatinMD]

ok, I've got a 09 GTI and I want to strap a cooler to the back and maybe two cans of fuel. Not a novel idea, I know. And even if I go with a 500$ rack, I still have the tie down problem.
But there are few tie down points. I don't like the metal hooks, even the wide ones, that grip onto the underside of the hull seam and hold on by the tension of the tie down. I've seen that most skis have uclamps on the hull, stern side. I also see on part diagrams that the 09 GTX had two of the clamps.
Has anyone added uclamps to their ski? Any pointers?
In looking at what it would take, there's foam blocking the upper part of the stern so I'd be limited to what can be reached, which is a couple of inches above the bilge drains.
Thoughts??

thanks

pat

 

[LouDoo]

Just drill two holes, use the original nuts and stainless steel fender washers. I used tow hooks from 90's SeaDoo's.

 

[PatinMD]

Thanks LouDoo. I see there's a selection of used clamps on ebay at a better $ than OEM. Any thoughts on working around the floatation foam in the stern? Or the placement of the bolts in the stern a couple of inches (2?) above the bilge drains?
In a blue sky scenario, I'd figure a way to position the uclamps in the same location as the manufacturer did on the GTX. They're well above the water line and well placed to be functional. The foam makes that difficult if not nearly impossible. But many peole here on the forum have solved problems in ways that wouldn't have occurred to me.

 

[LouDoo]

Depending how thick the foam is, drill a hole from the outside of the hull with a bit long enough to penetrate the foam. From inside the hull use a hole saw just a little larger than the fender washer, install the "U" bolt then glue the foam back inside the hull. Actually you probably don't even need to replace the foam in the hull.

Lou

 

[PatinMD]

I just measured and the flotation foam in the area where the clamps would be best installed (same location as the GTX) is about 12 inches thick. But I can't think of a better idea than you supplied, that is a very long drill bit from outside (the diameter of the u bolt leg), then a larger diameter one (socket size or flat washer size) from the inside to the stern. Then an operation like a surgeon to put washers and nut on the u clamp thru that long hole, once the clamp is thru the stern.

I've stared at the ski for a while, but I can't figure how to get the foam out no matter what parts I remove from the engine compartment.

 

[LouDoo]

12" WOW, I had no idea. Take another look and see if there is a way to remove the foam, or maybe cut out a section, the when you're done glue it back in place. [MENTION=43374]Coastiejoe[/MENTION] Kevin have you got any ideas?

Lou

 

[Coastiejoe]

[MENTION=76096]PatinMD[/MENTION] [MENTION=31048]LouDoo[/MENTION]

Sorry for the late reply,,, I saw but lost the notification...

Ok,, the foam that is in the hull is VERY specific in regards to sinking vs swamping. Sinking is a BAD thing in regards to the safety of the passengers. They are designed to swamp so that the passenges have something to hang onto and wait out the rescue.

So,,, removing the flotation in itself is a safety issue more than anything else.

Here is what I would do.

If possible, slice the foam out in a chunk or larger manageable chunks. This will allow for it to be replaced and easily glued to itself.

If that is not easily possible, the break out what you need to in order to do the job. Use all Stainless Steel hardware and seal the CRAP out of the inner hull with BLACK RTV. I suggest black as it is good for anything including oil and gas and will not break down due to salt water. If the hull is not as think as you feel it should be, cut two squares of MARINE GRADE plywood and using the Black RTV glue it to the hull where you will be doing the work. This can be done easily if you drill the hull first, drill the wood with matching holes, Coat the ENTIRE piece of wood with the RTV, hold it it in place and nut and bolt it until it dries. Or,, completely assemble it with the U-Clamps.

For the flotation, buy the expanding foam and fill the area you removed the foam from. The stuff floats very well. If you are worried about the foam surrounding things such as hoses or lines. Put a black garbage bag up aginst them and the foam will normally go only as far to push on the bag a little bit them move to an easier path.

Does the above sound reasonable/feasible?

 

[Spimothy Leary]

as much as i'm totally behind your idea of adding the u clamps, simply for the fact that you'll have a solid base to attach your rack, or dam near anything else, but I'd like to add a question to the mix if I may.

Have you already purchased or designed the rack you intend to use ? the answer to that changes the questions below.

there are some nice custom rack designs that i've seen around over the years, from the most basic to extremely elaborate and the vast majority simply tension clamp onto the hull seam and the tow hook, (3 attachment points)

At least from my small window of observation, nobody has experienced a failure "oh crap my rack fell off" at that fault points w/o admitting that their rack had a poor design or wasn't attached tight enough, ie: was doomed to fail.

Personally I don't like the off the shelf versions I've seen, although i'll admit I haven't gone looking into them that deep because I never had the need so forgive me

I'd design the attachment points around the rack design and what fits best with the least amount of effort, giving full security as well as maximum cosmetic factor

so, if option a) is a u clamp, her are some thoughts

a) U clamps , seems like a lot of work to attach a rack thats only slightly more stable than the hook design, and you might snag a toe on the protrusion, at least a few times...

Option b) maybe a hidden cleat option in the stern, still structurally sound, no snags, minimal cost difference, same amount of effort but cosmetically an improvement.

Option c) sticking with the metal hook design for a proven or custom rack (no hull mods, but maybe you spend more on a rack than you expected to)

Option d) maybe adding hidden cleats back up near the rear under back of the seat, and attach it from 5 points, 2 on the stern hull seam, and 3 on the bow side of the rack on the tow hook, and two hidden cleats which will also double up for convenience when the rack is not in use. hidden cleats under the back of the seat seem like a 20 minute job, and adds a little security to option c.

that's my 2 peso's

 

[PatinMD]

Keeping the flotation is pretty important I realize so I was never thinking about total removal, but like you said, maybe drilling thru it or removing it in hunks to access the stern. Then replacing it. I hadn't thought about using the spray foam to glue it or replace a hunk. That would be a good back up in case the foam didn't fit back in place.
I was hoping that the hull would be thick enough as so many other models have the clamps installed. And the plywood idea would work if I found it wasn't thick enough. Although sitting here, i'm not sure what is thick enough. I've looked at the clamp used for pulling skiers and I'm surprised at it's strength. I wouldn't have thought that was strong enough. Then again, I'm overthinking this. It's just holding a platform for a cooler and some gas cans.
Sure, it's reasonable and feasible.
Thanks for the input.

 

[PatinMD]

You bring up some very good points.
I've pretty much designed the rack. Basically it's two four by fours to raise the platform up higher than the upturned sides of the ski. Then a platform of either plywood or decking that will measure about 15x42. That's enough for the cooler and two 5 gal gas jugs.
I had looked at a lot of commercial made racks. Most seemed too big for the ski. It's a 09 GTI and the back platform is only about 9 or 12 inches deep. I inquired from two rack manufacturers concerning their racks on that ski and both said their product wouldn't work on that ski.
In looking around I saw only one or two that had the under hull hook to mount the rack. It was then I realized that most skis have the u clamps on the stern making the tie down much more secure, or so I thought.
But perhaps I need to review the plan. A pipe rack would be nicer to look at, would sit higher making the items easier to hold down. It would also make hooking the turnbuckle to the ski rope hook simpler. And it would lend itself to the metal clamp that fits under the stern edge lip of the hull top seam.
Thanks for the thoughts. The wheels are turning.

 

[Spimothy Leary]

Have you browsed some of the homemade pvc racks ? i've seen a couple on greenhulk with detailed plans and photographs, could be customized to fit your particular hull.

keywords DIY PWC rack or homemade pwc rack

 

[PatinMD]

I've looked at everything I can find. Unfortunately, I could have built a rack with the time I've spent looking at racks. I started with the idea of a rack to hold cooler, gas and rods. Then saw the prices and thought of making one, then downsized again to putting the rodholders on the cooler and mounting the cooler on the back of the ski, which is what I have now. But usage of the ski has made us want to travel farther than a tank of fuel so I'm back to looking at how to mount extra fuel.
I'm pretty risk oriented in my considerations which is why I've been looking for something more secure than the metal hooks under the back stern seam and PVC for the rack. 10 gallons of fuel (2x5's) and a loaded cooler is about - 100 pounds give or take. I'm not sure I want to have all that (fuel, tackle, etc) bouncing on the Chesapeake Bay waves betting on the breaking strength of 2 inch PVC to keep it attached.
Maybe I should build one and try to break it.

 

[Spimothy Leary]

I've looked at everything I can find. Unfortunately, I could have built a rack with the time I've spent looking at racks.

that cracks me up, i'm guilty of doing stuff like that myself.

build a cube out of 2" and go after it like a dog on a bone.... that stuff's pretty tough, even the thin stuff, I believe there are two different thicknesses.... although i've never really worked with it except for sprinkler repair.

 

[PatinMD]

Thanks for everyone's help. Ski stuff gets pushed back for the next week but then I'll be at it again. I'll post on whatever ends up being done.

 

[Sportster-2001-951C-Stock]

I can't tell you how many water-logged hulls with rotten stringers I've witnessed all because that wonderful flotation foam was waterlogged adding over 1,000 lbs or more of weight to a hull.

 

[PatinMD]

Well, I've decided to add the ubolts, just above the drains. I found and purchased the parts then had issues with another ski and have spent all my available time working on the other ski. I still hope to get the ubolts added before putting the skis up for the cold season. Hope. where would I be without it.

 

[Premix]

http://www.walmart.com/ip/Attwood-6-Gallon-Fuel-Tank/16350987

Or three of these:
http://www.bwproducts.com/racks/racks/triple.html
http://www.scribnerplastics.com/utility-jugs.html