Hobie-17 hulls cracking where cat-trax rest

has anyone seen this, i have a newer (06/07?) Hobie 17 - the hulls have been replaced (my dog drove my truck into the first set, while on the trialer - not pretty) - it was the end of the season so it only got used a dozen or so times.......last summer ('08) it was fine all season until the last couple sails, i noticed more water in one hull, then the other, when i took it off the beach both hulls had 2-5" cracks where the cat-trax sit - i repaired both and added some glass inside the hull - again it was fine all season until my last sail - one of the hulls has cracked again, the other is about to......i've been sailing Hobie's (16's, 18's and another 17 and a 33 but that's another story) for over 34 years, this has never happened - the cat-trax the standard axle type....which i've used for over 15 yrs, the boat is not on the trax long (30-50' to the water) - i'm assuming the cat-trax is what is causing the issue - but i can not understand why - or maybe defective hulls? any advise will be appreciated.....

That's a surprise, especially considering that the centerboard well is very close to where the beach wheels sit. The centerboard well should provide a lot of extra support to the area.

Any pictures of the damage?

In any case, I would definitely use hull cradles rather than just the standard round axle. They distribute the hull weight much better and they're easier to use single handed.

sm

I agree with srm, you need hull cradles, the axel with padding only works well for the 16's.

Some cracks from cat tracks, are caused by pushing the bows down to get the boat balanced before you move the boat. This is fixed by lifting the back of the boat insted.

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1992 Hobie Cat 18 #16943
Hobie Fleet 198, Rapid City, SD

thanks for the replies.....i assumed the cradles would help, however i'm disappointed that the Hobie quality that i've known is slipping - 13 years of heavy sailing on my first 17 with no issues at all spoiled me i guess - also, good point on pushing the bows down - i don't have pix, but the damage is about 6 inches forward of the centerboard trunk, there are 2 parallel cracks about 4-6" long and 4" or 5" apart - at least it lasted the season

There were a number of quality issues with the last run of 17s. It was almost as if they had forgotten all the little tricks used to make them.

Mine is an '07 and I've had both hulls leak from the head of the centerboard spring punching through a weak spot in the trunk and found an air bubble between the glass and gelcoat on one bow.

Nothing major, but just little stuff.

I suspect that in an attempt to bring the newer boats down closer to minimum weight, the hulls are not built as stoutly as they were in the mid-80's, especially along the bottoms. From the description of your problem, the hull bottom flexed and cracked where the foam sandwich starts on either side.

May be an issue of quality, it may not.

The reality of the situation is that the Hobie 17 hull is round on the bottom and when you put the round axle of the beach wheels under the hull, you create a severe point load situation since the weight of the hull is distributed over a very small area. If you push down on the boat or someone sits on it with the wheels under it, you up the stress on the hulls that much more. Hull cradles spread out the load over a much larger area and therefore minimize the potential for damage. They're definitely a worthwhile investment.

sm

I'm not disagreeing with you at all - it's just my '87 was built like a tank. I never used cradles with it (many 1,000's of road miles and w/ Cat Trax) and never had a problem. After listening to this, I'm definitely going to be more careful with the new one. I've already been using cradles on the trailer (over 5,000 road miles since 8/07) - I'm going to be extra careful with the beach wheels.

Anyone ever make a set of hull cradles for the beach/road trailer?

Hey Jim,
Is the damage anywhere near where the boat rests on the trailer bunks? Do you use ratchet straps to tie the boat down? One thing to consider, I see that damage several times a year.

Good luck with your repairs.

j

Yes - use the search function.

My 86 has 2 cracks each side of the front hull where the front rollers of the trailer go. Looks sucky but I will just re-enforce the inside once I decide whats more important and what leaks (so far I can make lots of deck ports )
my wing holes need fixing and who knows, now I think I'll check the dagger wells.

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H18, H17 & Various motor boats

thanks for all the good info - i concur with MBounds, my 87 was also a tank, although i don't trailer too much (beginning and end of season) - i sail my Hobie's often, my 87 was sailed 3-5 days/week from may/june to october - using the same cat-trax i'm using now - the only damage on the hulls was from wear & tear (beaching it for all those years will do that) - my current one is an '07, with replacement hulls (my dog drove my truck, ie he took it out of gear, and "drove" it down my driveway, directly in-between the hulls of my brand new, just picked up from the dealer, never sailed, Hobie......it ended up in the woods, with the truck still wedged between the hulls.....very funny now) - thanks again for the info - i'll pickup the cradles - -

as for the cracks MBounds is correct the crack is where the foam sandwich starts on either side (on both hulls) - last yr i cleaned it up, laid a couple layers of glass on the inside over the cracks and a small amount on the outside and faired it.....any suggestions as to a different type of repair this time around?

I developed a crack right where I had a point load on the trailer. I'm not sure but it could have been facilitated by travelling down bumpy roads, over-tightening of straps, climbing onto the boat when on the trailer or a combination of the above.

I have now made molds of the hull at the trailer support points and lined then with high density foam. After the boat is trailered on the rollers, I lift the hulls and place the molds over the rollers to give a perfect load-spreading interface to the hull. The underside of the mold is an aluminium "box" that sits over the roller assembly, locating and holding it in the correct position. The tie-down straps keep the whole assembly in place.
There is still a risk of causing another failure, after all the hulls are incredibly thin. I think that when placing the boat on the trailer I have to make sure it is lined up, the rollers turn freely and that I have sufficient help so that the boat is not stressed as it comes up onto the trailer.

I need to do something along those lines for my beach rollers too...