Those with towers...please help

[brick75]

I'm going to be installing a tower on my boat, but have a concern with which to choose. I've watched the Samson installation video where they talk about how using flat plates for the install against the curved surface of the boat will cause stress that leads to gel coat cracking. Their solution is an obvious one to use machined plates that match the curvature of the boat to eliminate the stress point. I'd love to take advantage of that and get one, but unfortunately I don't have a small fortune to spend with them.

So, what I'm wondering is for those of you that have towers from other brands, do any of them address this problem with anthing other than rubber pads that go against the boat?

Are you experiencing any signs of gel coat cracking, and how much of a curve do you have them mounted on?

I'm currently considering the following brands based on my budget: Big Air, Monster and Aerial

Any advice would be much appreciated!

 

[Bayliner175xt]

Re: Those with towers...please help

Hi we installed a Monster MT1 tower on our Bayliner, we didn't have that much curve to worry about, so we used a very stiff rubber pad.
If you have a big curve you could make a fibreglass resin block on the inside of you hull, then add the rubber pad.
I have heard of people using Marine Ply, shaping it to the inside of their hull and then fibre glassing it into position. Prob need to make it twice the size you need that will help spread the load stress over a larger area.
Remember to drill through jell coat only, with your drill bit in reverse, this will
stop any cracking in the jell coat, once your through the jell coat you can switch your drill to the right direction.

You can search the Net, there are heaps on installing waketowers.

Hope it all works out well for you.

 

[craze1cars]

Re: Those with towers...please help

Machine your own "plate" to the curvature of the boat. Just use wood. Gentle curvature can be followed with plywood, which flexes a bit, as mentioned in the first reply. But even significant curvature can be given a flat under-surface for solid mounting even using standard construction grade wood, which is easy to work down with standard woodworking tools. After you create the right shape, the big important trick with EITHER wood is to thorougly water-proof and then attach the wood block. In boats, this means first encapsulating the block of wood in the fiberglass or epoxy resin that you will be using to glass it in place.

So first you make the blocks of wood in the right shape, and drill all the holes. Then mix up some resin, keep it thin, and just paint the board on all sides, and in the holes, several times before it has a chance to cure. Especially paint the cut ends with extra resin, where the open grain will wick the resin right into that wood like many little straws. After that's done and cured, you'll have an impenetrable-to-water block of resin-encapsulated wood. Now scuff sand the block for bite, also scuff sand the inside of the boat where you will attach it, and then fiberglass or epoxy the block into place with resin and matting. After that cures, install your tower.

I admit it's a bit of a process. But it is not difficult or complex. Just a bit time-consuming. But if you want it done right, you want it done right...

Visit the boat restoration and building section of this forum for more info on fiberglass/epoxy techniques, and the benefits/disadvantages of each product and various methods.

 

[ThreeMileBayWaker]

Re: Those with towers...please help

Mine was a dealer option. So I dropped some bank unfortunately but my dealer at least gave it to me at their cost, but if it causes any problems it won't void my warranty on the gel coat. Their cost was still over $2k

 

[hal2814]

Re: Those with towers...please help

My tower mounts completely flat up front but does have some curve at the rear mount points. Two years in on our flat plate plus rubber pad and no gel coat cracks. But I do occassionally have to tweak the mounting screws to keep them tight (like twice a year). I might try some loctite to see if that helps.

 

[wired1236]

Re: Those with towers...please help

I had the same problem. My tower came with the rubber bushings that go between the feet and boat but I didn't like that I still had a wide gap around the edges due to the curve of the boat. I went down to Taps Plastics, (a store that deals in plastics and will custom make parts), and gave them the rubber bushing and had them make the same thing out of a hard 1/4" black plastic, (that was sun resistant), and then cut the curve of my hull into one side of the new plastic bushing with a table saw & jig. It worked great! You would think is was a custom tower now. The plastic gave just enough to give it a perfect fit without spending a lot of time and wasted plastic. Let me know if you want pics.

 

[brick75]

Re: Those with towers...please help

That's an interesting idea wired1236. Not sure how you would have cut the curve with a table saw though. I was thinking that the curved end of a bench belt sander or drum sander would work nicely for that.

I think we have a Tap plastics here in Portland, I might try that out. Out of curiosity, how much did they charge you for those?

Thanks

 

[wired1236]

Re: Those with towers...please help

First make a wood jig to hold the piece so you don't cut your fingers off then just raise your saw up from the table just enough to graze the plastic. It will give you a nice accurate radius when you pass over the blade. You could go the belt sander way but I think the saw would give you a lot better curve and be a lot less work.

I'm in Portland so yes, we do have them here. I went to the Tigard one. I think they charged me $10.00, maybe less.

 

[brick75]

Re: Those with towers...please help

Well, finally got the tower delivered on Friday. Luckily it looks like I'm going to be able to mount it on an almost completely flat part of the boat, and avoid the whole curved surface issue.

I'll still be reinforcing with a larger backing plates and putting epoxy or liquid nails on it just to be sure any gap is filled. But doesn't look like I'll need to machine any mounting hardware for the exterior. I'll post up some pics once it's installed.

 

[oldjeep]

Re: Those with towers...please help

On my tower it uses 2 flat bars rather than a single plate on the back. While mine is mounted on a very flat part of the boat, the dual 1/4" thick bars are less likely to flatten out the hull if they were on a slight curve.

 

[brick75]

Re: Those with towers...please help

On my tower it uses 2 flat bars rather than a single plate on the back. While mine is mounted on a very flat part of the boat, the dual 1/4" thick bars are less likely to flatten out the hull if they were on a slight curve.

That seems like it would make sense. But I've heard people say that the two bar approach doesn't provide enough distribution of the load which can sometimes lead to gel coat cracking. I believe that might be the type that the other guy who posted a thread about his gel coat cracking has.

 

[oldjeep]

Re: Those with towers...please help

That seems like it would make sense. But I've heard people say that the two bar approach doesn't provide enough distribution of the load which can sometimes lead to gel coat cracking. I believe that might be the type that the other guy who posted a thread about his gel coat cracking has.

The guy on that thread mounted his tower to a radiused section of the hull. His issue isn't load distribution it is that he tried to mount a flat mount to a very un-flat hull.

 

[brick75]

Re: Those with towers...please help

Yea, I know that was the main issue. But if he had used larger backing plates and filled any gaps with epoxy, there would be less chance for any flex in the fiberglass, therefore less chance of cracking.

In any case, I think we can all agree that it's best to reinforce the backing, as well as use mounting hardware that has the same curvature of the outside of the boat (assuming you have a curve). I'm just relieved that I'll be able to mount in a flat location!

 

[wired1236]

Re: Those with towers...please help

Yep, the backing is definitely the most important part especially if you have thin fiberglass as the instructions say. I think the guy on the other thread said his was around 1/4". Mine was pretty thick, (>3/8" in the front and over 2" deep in the back since I mounted them on the top rail). I didn't install any but the two bars that came with it, but will very soon after seeing the others having problems. The inserts are working flawlessly after 5 trips out. I posted a pic on the other thread. Good luck!

 

[daymienrules]

Re: Those with towers...please help

I cut plywood backing plates and resin puttied them onto the hull. Then fiberglassed the exposed plywood to the inner hull. My plates ended up being about 4" x 8-10". i made them as big as i could given the space i was working in. If I were doing it again; I would have found some thick plastic plates like they use in the Samson video, instead of using plywood. Just liquid nails them to the inner hull, avoid all of the fiberglass work. I used 3/4" plywood, which was about 1/8" to thick to get the nuts started easliy, should have used 1/2". You can drill all of the holes in reverse, it's not really any slower. Also, predrilling the plywood backing plates didn't work for me, I ended up drilling the boat, glassing wood in place, then drilling the wood, then filling the holes in the wood with 5200.