Has anyone seen or had a tower crack their gelcoat?

Fishmaster

There is a lot of discussions on this and other boards, as well as questions about towers cracking gelcoat (or at least ways to prevent it from happening).

I have asked around and so far can not find anyone who has seen or experienced damage to gelcoat from a wakeboard tower? (OK, I did hear of a person that had two future Darwin award winners on their tower while jumping waves in the ocean and it created some stress cracks in the gelcoat).

If you have - what kind of boat and tower was it?

Thanks,

K-dub · Ladies Man Joined: 12 Jan 2003 Posts: 14760

I have seen a Moomba with a pro-flight cracked, also a few Malibus...one with a Boss pro-series, and 2 more with the Skylon tuna tower. My old Centurion cracked, it had a Hoochie tower at the time...

Fishmaster · Posted: Mar 16, 2003 6:37 pm Post subject:

Kyle,

WOW, that's more than I've heard in a lot of asking around. Any idea if there was a common thing that caused the cracking?

You mentioned a few Malibu's. Did they have the Titan Tower?

Do you know if the towers you mentioned all had fixed mounts, where a stationary plate is welded to the bottom of the tube and bolted to the boat? The Heim joint that Titan, Skylon, Monster (that's us) and few others use (which is just fancy marketing noise for rod end bearings which have been around longer than any of us) eliminates "torqing" that you would get from a base plate.

Also would love to know if it was the front or rear feet or both?

Thanks so much for the feedback,

Jack V · Outlaw Joined: 19 Feb 2003 Posts: 207

This can happen on any boat. It all depends on how the person installed it. After you drill it, you have to put some soap on your screws when they go through. Otherwise it will crack it around the surface. Same thing when putting a bimini top on.

K-dub · Ladies Man Joined: 12 Jan 2003 Posts: 14760

monster:
the Moomba was cracked at all 4 feet. The front mount was a channeled mount where the tower had a finger that fit inside the channel that had a pin that went through to holt it in place. The rear was a two piece aluminum joint that has held together with a screw. That mount only had two mounting bolts, because it was mounted on the inside of the winshield. So , on the rear...it actually spider cracked the dash gel. That tower swayed alot. It was made of 1 5/8 tubing and had a ton of speakers on it. I'm guessing the gel cracked from stress of the tower moving so much.
The malibus...1 of them had a Boss pro-series. I believe that one cracked because the holes for mounting hardware were drilled slightly off, or crooked. That is the only Boss I have ever seen do that. The other 2 Bu's were both fitted with the Skylon tuna tower. That was a separate foot that mounts to the boat, and then the tower is bolted to the mount. I really have no idea why those two cracked? They both seemed to be mounted correctly, and were solid towers. We sold alot of Bu's that have the titan tower. I have yet to see one come back in for gel work.

I sell 3 brands of tower at my shop, and we service boats that have all kinds. I have seen quite a few boats with gel damage at the tower feet, but I have to say that it is a very small percentage compared to how many towers I sell. I'd also have to say that 90 percent of the damaged gelcoat that I do see that has to do with a tower is caused by installer error.

Mike · Addict Joined: 30 Jan 2003 Posts: 536 City: Orlando

Don't they have a warranty for that?

BIGMAC · Posted: Mar 16, 2003 9:32 pm Post subject:

This may not be true but I heard the Xstars with the square looking towers had a problem with spidering or the such.

Fishmaster · Posted: Mar 16, 2003 10:04 pm Post subject:

Kyle,

Awesome insight & experience, love to pick your brain sometime. We started with great input from people that build Tuna Towers and T-tops for fishing boats but they don't have us adrenaline junkies tying a rope to their products trying to tip their boats over. We talked to most of the major dealers in the Atlanta market and none had seen any problems (that they would mention at least)

I can see a 1-5/8” Tower loaded up with speakers being a problem, it had to have huge side to side motion. The Monster Tower is 2-1/2” and before racks, boards and speakers there was no side-to-side motion at all in rough water or with a strong boarders pull - but with it all pimped out it is now noticeable but not severe.

The earlier towers all were small tubing (under 2”) but everyone is going larger to get stiffer towers. Most are moving to some type of base that prevents the tower from stressing the mount. Since Titan has always used a larger diameter tube with Heim joints I would like to know of anyone has had any gel coat problems with their tower, even loaded up?

Thanks again,

Bill

lee · Outlaw Joined: 13 Jan 2003 Posts: 196 City: USA

The spider cracks come from the screws rubbing on the gel coat for a period of time causing it to crack. If you counter sink the hole or make the part of hole the in the gel coat sligthly bigger than the screw it would not do this.

Fishmaster · Posted: Mar 17, 2003 6:14 am Post subject:

Lee,

Good point and there was another thread that went into detail about this. There was a terminology discussion but technically you want to chamfer the hole and you can do it by using a larger diameter bit (see the hole on the right below with a chamfer). Always run the drill in reverse until you are through the gelcoat or it will chip around the hole.

Bill

graphik · Addict Joined: 20 Feb 2003 Posts: 727 City: miller lake

In a universal tower such as the monster tower, with the wide tubing, is there are width limit on the mount area. I've been speaking with you briefly about my tower purchase (It's Brian, the Canadian). The boat is in storage, but I seem to remember there not being a whole lot of room between the windshield (side) and the bumper lip. It's a 1993 Tige SLM COMP. I guess maybe the best thing to do is send you a few pics, and get your opinion. I'll get on this and send it to your e-mail.

thanks
b

Fishmaster · Posted: Mar 17, 2003 9:03 am Post subject:

I found a few pic's of 20' SLM's from 1994 at boattraderonline.com and it looks like you could mount the rear foot on the side or behind the windshield as one had a tower on it. Please send a few pics and I'll be happy to help locate where the feet can go.

Bill

boomerzuma · Criminal Joined: 04 Feb 2003 Posts: 95 City: Wichita

Do you think some of the gel cracks around the tower mounts is from misuse of the tower? I once saw person lounging in a hammick hanging from a tower while the boat was underway pulling a wakeboarder. Also, I can't tell you how many times I've seen people climb on top of a tower. Just a thought.

Fishmaster · Posted: Mar 17, 2003 10:51 am Post subject:

I definitely think abuse will create problems for the boat. A stiff tower (large diameter tubing or trussed design) with joints that don’t stress the boat is good prevention but load that up with equipment and people and everything changes. Climbing on a tower is pretty dangerous when you think about what can happen, especially when the boat is pulling someone.

I saw a boat pulling a boarder with two girls sitting on the tower, no life vests on. Looked like a recipe for disaster. Then again in my teen age years taunting disaster was a big thrill.

If you’re concerned about the tower hurting your boat you’re not likely to let people climb on the tower.

On another note, using board racks for steps to get up on the tower can bend them as well. I've heard from several rack suppliers that this about the only problem they have ever had.

Bill

Nor*Cal · Ladies Man Joined: 12 Jan 2003 Posts: 9479 City: Sac

Sorry but what's a hiem joint?

Also is there a difference if you mount on the side like the swoop towers and some other brands? What are the advantages or disadvantages of a side mounted tower?

3D · Newbie Joined: 17 Mar 2003 Posts: 3

My Skylon cracked my Malibu and I havn't even used it yet. I know, I just heard all of you say I put it on wrong, tightened it too tight, and didn't drill the holes right. I say I bought the wrong tower. There is rod ends in the rear, but the legs can't pivot since the front attatching point is not a rod end. So, if you tighten the knobs, the ones to fold it down, that joint determins the angle of the "feet" that touch the boat. If that angle is not perfect, no amount of moving it around will make it right. The drivers side feet do not fit well, pass side is good. I am machining the conection point trying to improve the fit. Bottom line I wouldn't buy another tower that didn't have some sort of swivel at all four feet. I assumed being a factory tower it would fit better. I obviously caused the cracks trying to make it fit better, it's been off and on a couple times. Live and learn.

Fishmaster · Posted: Mar 17, 2003 6:17 pm Post subject:

A Heim joint is a fancy name for a rod end bearing design created by a guy named Heim. These have been used in automotive, marine and aircraft applications for many years and are not new. The purpose of the joint is to ensure only "axial" or push and pull forces are transferred. The reason this is important is it prevents the gel coat cracking that has been reported with towers that used welded on, fixed mounts. With fixed mounts when the tower flexes (which is normal) it "torques" or twists the mount - bad for the gelcoat.

See a Heim joint at http://www.monstertower.com/images/balljoint.jpg

I'm really suprised with the troubles you are having with the Skylon, the are a respectable tower company. I assume you have contacted them but if not certainly do. If should fit right otherwise they need to do something for you.

Bill

Mike · Addict Joined: 30 Jan 2003 Posts: 536 City: Orlando

Do you think that jumping off your tower will hurt it and possibly make it crack?

Fishmaster · Posted: Mar 17, 2003 7:09 pm Post subject:

Mike,

If you have a sweet ride with a phat tower, and dont want gelcoat cracking, dont let people climb on your tower. A person on a wakeboard with a side pull is no match for a people jumping off a tower from a "might crack the gelcoat" standpoint. If your tower has fixed mounting plates and is under 1-3/4" diameter then the problem get's even worse.

"Thats my opinion but I could be wrong"

Bill

Brad Embleton · Addict Joined: 13 Jan 2003 Posts: 511 City: Niagara Falls

Damn you guys are making me nervous

I just had my tower intsalled I had a guy make mine, (he has made 3 others). It has fixed mounts and is 1 3/4 " in dia he also made me 2 racks for the side. I had planned on putting 2 speakers and a light bar on it do you see me have any problems. It is on my I/O.

I wont be allowing to climb up it.

Like I said teh guy has made 3 other towers and is a mechincail engineer.

Fishmaster · Posted: Mar 18, 2003 1:14 pm Post subject:

I'd say if there are not problems with the other ones he built that you should'nt have a problem.

Realize there are many thousands of towers out there and only a very, very small percent have ever caused a problem. I think in nearly all of those cases there was some wild wake jumping and tower climbing in the picture. All of them have wakeboarding yanking them with all they got and many have speakers, racks, lights and bimini's.

Most of of would trade family members over our boats so it's healthy discussion to educate each other and protect a prized possession, certainly not to make anyone nervous.

Bill

jim Bogden · Outlaw Joined: 12 Jan 2003 Posts: 178 City: Sandy, UT

It really pisses me off when people start doing pullups on my tower, I tell them the jungle gym is at the playground.

monster, I may be looking for some extra racks for my tower, I have a 2001 Tige so I have racks on top but would like some on the sides too, since we sometimes have more than four boards, please email me if you have something that will work!

RioThePimp · Posted: Mar 19, 2003 4:12 pm Post subject:

The mounting system is the key to protect your boat from spider cracks. We may be more $ but our mounting system is the best on the market, remeber you get what you pay for solid mount to a boat is crazy, all boats flex and twist in the water that is a fact so why mount solid, the mounting system !!!! I spent 26,000.00 dollars in R&D before I got what I wanted this is the only way to go, mail me with any questions I can give all the correct advice.

Rio

RioThePimp · Posted: Mar 19, 2003 4:21 pm Post subject:

Couple more pics out there for you new tower companies out there who are trying to come up, but carefull this one is patented. Keep up the good work.

Fishmaster · Posted: Mar 19, 2003 4:27 pm Post subject:

We studied the designs of most of the major tower vendors and Boss, Titan, Roswell and Skylon all do a great job on well designed bases on the model of towers we saw. There are a few niche / local tower builders out there doing some very innovated base designs as well.

There is some really great insight into tower design at http://www.inboardtalk.com/tower/tower.html where Matt does Finite Element Analysis (which is engineering software to put a part through all it's stresses and gain lots of valuable insight) on the tower he made himself. If you want a technical view on it Matt did a great job.

"We may cost a little less, but sometimes you get more than what you pay for!"

Bill

Nor*Cal · Ladies Man Joined: 12 Jan 2003 Posts: 9479 City: Sac

MonsterTower- Will matt do that work for anyone who submits a design?

K-dub · Ladies Man Joined: 12 Jan 2003 Posts: 14760

Rio.....you have been busy on the internet today, bro! Laughing

Fishmaster · Posted: Mar 19, 2003 8:59 pm Post subject:

NorCal,

I really dont know but check with Matt if your working on a design. He's done a awesome job making his own tower and did a ton of work on the project. It's truly amazing on what you can learn from FEA when your working throug all the design details.

The work he did on our tower is at http://www.inboardtalk.com/tower/concept/monster.html and Matt even did some really cool animations. One of the guys we've been working with that I met through my Church is an older guy that retired from being a Marine design engineer for Hummingbird (boat products) and he really ate up the stuff that Matt did.

Matt's been part of our "ad hock" team for about 6 months and has made huge contributions technically in everything we've done. He's also a really cool guy and a lot of fun to work with. Now I wish he did'nt have a tower so I could give him one.

Bill

Fishmaster · Posted: Mar 20, 2003 6:09 am Post subject:

Rio,

Just got our call from the Correct Craft laywer - WOW. We were certainly expecting it and the license fee is in our cost model but we thought it would be after our coming out party. Funny thing is we tied off on the tuna tower of fishing boats 20 years ago (wow that makes me sound old) to get sick air on kneeboards, sure wish we had some pictures.

Bill

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Climbing on and jumping on your tower should not harm it or cause spiders cracks if it is installed right, if you have a bad installation my guess is that you will get them no matter what, just the vibration and bouncing from driving your boat would be enough. Also, ideally you don't want any of the force from the tower being transferred to the boat through the screws, this applies the force to a very small area. You want the screws to clamp the mounts on the fiberglass over a larger area, it would be best if the screws don't even touch the fiberglass. My guess is that this contact is what is causing your spider cracks. As in each crack starts at a screw hole and travels from there.

Also, looking quickly at monstertower's webpage, those towers look great! Of course they turned out well, you had a Georgia Tech grad working with you! (I also graduated from Georgia Tech).

Nick
________
Kitchen Measures

Fishmaster · Posted: Mar 20, 2003 7:32 am Post subject:

Nick,

I'll pass your Yellow Jacket comments along, a few other guys that contributed to the project are Tech grads also.

Your right on that the tower should be able to handle pull ups and a person on it from a strenght point. The downward force on the rear legs from a wakeboarder will get towards 300lbs, yet a person doing a pull up would be well less than that.

The first reason people should not climb on them is it's dangerous. I have this nightmare of someone without a vest falling off, getting knocked out on the way down and spending a few hours at the bottom of the lake. If you jumped off to the side you would exert a pretty serious side load, probably way beyond what a boarder can do and that is where the likelyhood of damage comes in.

Thanks for the nice comment on our "new baby",

Bill

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

Also, I was thinking about designing and building my own tower. Where are you guys getting those pivots that the tower uses when it folds? Finding the hardware for mounting it, etc... is the part that I hate.

Thanks,
Nick
________
Knight rider advice

Fishmaster · Posted: Mar 20, 2003 8:01 am Post subject:

Nick,

Good luck on building your own tower as that's how we got started. Feel free to email me and I'll help if I can if you go for it. As far as the bases, a lot of the tower companies buy their bases from eTec (http://www.etecmarine.com/) but not sure if eTec sells to end users, so if not Morse industries is a distributor for them. We ended up creating and manufacturing our own to help keep costs (and stresses) down.

For the rod end bearings (Heim Joints) check out http://nationalrodends.com. You can buy these through Grainger, McMaster-Carr and other industrial suppliers.

Be sure to post your pics when your done.

Bill

OttoNP · Addict Joined: 13 Jan 2003 Posts: 848 City: MI

What about the pivots on the upper part of the tower that are used in allowing the tower to fold? Do you create and manufacture them as well?

Nick
________
Zx14 Vs Hayabusa

C-Stone · Posted: Mar 20, 2003 1:03 pm Post subject:

All towers have the posibility of causing stress cracks, theres not to many ways around it, the decks on boats are not thick enough to withstand many of reasons why fractures are caused. Most of the time it is cosmetic and not structural, although in some cases it is structural and depending on the seriousness of the damage it could be dangerous. This damage can be repaired easily and not challenge the dexterity of the boat. Ive seen fractures caused by not countersinking holes, from the backing plates themselves, bad fits, tweaking the tower to fit, overtightening, shaking the tower hard, etc... If this is happening to your boat, dont worry about the damage itself, just repair it before it spreads and starts to look really bad.