Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  T-Top Bolts Leak

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   T-Top Bolts Leak
dwfrank7 posted 04-23-2010 07:46 AM ET (US)   Profile for dwfrank7   Send Email to dwfrank7  
I recently bought a nice 2004 [Boston Whaler 170 MONTAUK that had been fitted] with a[n] aftermarket T-Top. [I have] a problem with [the T-Top] anchor bolts coming lose and allowing water to leak into [the] hull. [I] noticed the screws coming loose, so [I] took off [the T-Top]--sure enough the sealant had [broken] loose. [I] sucked about two cups of water out of each side of [the console] with my shop vacuum. [I need your] knowledge on this situation. [H]ow [will I] know when the hull is dry[?] [Is there a] better way of sealing? [T]han[ks].
Jeff posted 04-23-2010 09:06 AM ET (US)     Profile for Jeff  Send Email to Jeff     
You will never get all the water out and completely dry the hull. I would re-seal it with a polysulfide chalk or 3M4200 that cures in wet conditions. Since the 170 Montauk is not designed to have a T-Top you will likely continue to encounter these problems from time to time. Especially since every time you remove and re-install the anchoring bolts you are creating hole with less and less holding capacity. Eventually you may have to over drill all the holes and fill them with resin.

Does your T-Top connect to just the floor, or does it also get braced to the console? If it is not bracing to the console I would look into having it altered.

Buckda posted 04-23-2010 10:37 AM ET (US)     Profile for Buckda  Send Email to Buckda     
If you aren't willing to just remove and sell the top (my recommendation, because it will continue to be a headache and may further damage your hull), I would go a step further than Jeff's recommendation:

1.) remove the T-TOP.
2.) overdrill the mounting holes. Use a BIG bit - I'd drill a "column" that was about 1 or 1.5 inches wide by 3 or 4 inches deep.
3.) use an allen-wrench or other tool to scrape out an even wider cavity under the deck of your boat in the foam.
4.) allow the area to dry throughly
5.) apply some kind of sealant (polysulfide caulk works) around the entire cavity
6.) fill the cavity with an epoxy plug - Marine Tex would work fine for this application. Allow to cure.
7.) re-drill your mounting holes, ensuring the screw will NOT penetrate through the plug into the foam underneath
8.) reinstall the top, and, as Jeff suggests, consider modifications to add additional cross bracing to the console.

All it takes is one bad day on the water for a poorly installed T-TOP or arch or whatever to pound it's way free on a small boat.

contender posted 04-23-2010 04:29 PM ET (US)     Profile for contender  Send Email to contender     
Buckda has a good answer, but instead of Marine Tex I would use a 2 part epoxy resin (Superbond 1:1 Epoxy Adhesive) I would also use like a large syringe to squirt the epoxy in the hole/cavity this will force any air pockets out. I would also try to screw some kind of block wood/aluminum/or even out of fiberglass to the floor and attach your t-top to the support you just made, I would seal the screws with 3m's 5200 to protect from any water entry. Jeff also made some good points, having the t-top attach to the console,(this would be the best) I also agree with him that the 17 is really not design for the t-top...good luck
dwfrank7 posted 04-23-2010 06:13 PM ET (US)     Profile for dwfrank7  Send Email to dwfrank7     
[Y]es[,] [the T-Top] does brace to the console, with fittings that allow it to move slightly. [I] was pondering about removing [the T-Top] altogether, but sure love the rocket launchers on top. [D]o you think the moisture will cause any major damage or long term damage to the core [of the hull]? [T]hanks] guys[.] [I] appreciate the information.
number9 posted 04-24-2010 01:30 AM ET (US)     Profile for number9  Send Email to number9     
Sounds as if the the t-top wasn't properly mounted and sealed. Whether or not you decide to keep or re-install the t-top removing the water between the hull and inner liner may be a priority. If you do a search here on CW most of the linked topic will be dealing with older Whalers. Since yours is relatively new the water may be more easily removed/drained. You will also find many good suggestion for hardware to the deck that should provide secure mounting and prevent future leaks.
jimh posted 04-24-2010 01:56 AM ET (US)     Profile for jimh  Send Email to jimh     
The T-Top probably became loose because it put too much force on the mounting fasteners. The 170 MONTAUK was not really designed for a T-Top. When Boston Whaler adds a T-Top to a boat, they include substantial reinforcements in the hull at the points of attachment, and they use fasteners that can handle the load. The point of attachment of the T-Top to your hull is probably not properly reinforced, and as a result the fasteners have loosened and created larger holes. The holes are a conduit for water to get into the hull.
dwfrank7 posted 04-24-2010 02:37 AM ET (US)     Profile for dwfrank7  Send Email to dwfrank7     
[T]he bolts were toggled-in. [L]ooks like [the installer of the T-Top] drilled holes and put some kind of toggle bolt below the deck with some kind of plastic guide.

The problem with this 170 Montauk and its T-top is the way it was anchored. There is plywood underneath the T-top. Under the plywood is a drywall hanger that has fine threads so it can be screw headed in or bolted.The problem I believe is they were screw headed. What should have happened was to put a bolt threaded to the hanger that catches the underside of the plywood then a [nylon stop] nut on the base of T-Top with [3M4200] in place at threads and under base to floor. Does this sound like it may work or be worth a try? The holes for T-top posts three holes each are already there.

jimh posted 04-24-2010 02:48 PM ET (US)     Profile for jimh  Send Email to jimh     
I am afraid your description has confused me. From your narrative it sounds as though you have access to the underside of the deck of the Boston Whaler 170 MONTAUK. This is confusing because typically the deck of a Boston Whaler 170 MONTAUK is part of the Unibond hull structure, and there is no access to the underside of the deck.

If someone just drilled a hole and forced a folding bolt into it, doubt there is enough strength to hold the T-Top.

I don't think there is much I can offer for a long-term solution to the problem of fastening the base of the T-Top to the deck in places were there is no reinforcement of the deck structure or embedded materials which can receive a machine screw fastener. When you analyze the load or bending moment on the legs of the T-Top created by the wind pressure bearing against the surface of the T-Top, I suspect the bending moment will be quite high. To resist this force you need some strong fasteners and a suitable structure in the hull. On boats built with more conventional construction it is not very hard to add some back plates below the deck and spread the load over a wider area, but with a Boston Whaler Unibond hull has to be done before the hull is molded.

cworthy posted 07-07-2010 12:51 PM ET (US)     Profile for cworthy    
I have a similar issue with the T-top on my Dauntless 180. The three screws holes in the deck are stripped for one of the legs. It is secured to the console and is very stable even with these stripped screw holes.

I would like to repair using Buckda's instructions above but am hesitant to remove the screws that are currently secured to the deck. Will I lose the strong connection that I currently have and need to repair every hole?

Also, what is currently holding the screws, the fiberglass deck or the deck and foam? The holes are two inches deep.

Thanks for any help.

Gary L posted 07-12-2010 08:42 AM ET (US)     Profile for Gary L  Send Email to Gary L     
Nice to find this discussion.

I just bought a C E Smith T Top for my Classic Montauk and want to install it right the first time.

My CC is out now and I am repairing the old and worn out holes in the floor. The console was mounted to the floor with 30 inch strips of teak between the floor and the console wings and it raised the console a full inch or more off the floor.

My thought is to use a composite material such as UHMW plastic and extend it beyond the wings and far enough to accommodate the T top mounts. Before attaching the material to the floor I will mount T nuts from below to accept both the CC and the T top. This should give the floor the added strength it needs as well as being fairly rot proof. 1 inch thick UHMW is about as tough as nails, works easily and if fastened to the floor in numerous places should provide the right height and rigidity I would think.

Extending the floor plate out past the wings is not an issue for my boat because I have the raised fishing platform that essentially covers the entire area around my CC and provides me with a floor above the floor to walk past the side of the console. The Platform will have to be altered some to allow the T top brackets to go through it in the front.

Any other ideas will be appreciated.


andygere posted 07-12-2010 09:03 PM ET (US)     Profile for andygere  Send Email to andygere     
Big plugs of epoxy alone don't have much strength, and are prone to cracking over time. If following Buckda's advice (which is generally sound) be sure to used some chopped glass fiber or "kitty hair" in your resin so it has some strength. In general, machine screws tapped into the wood/glass/resin matrix develop a lot of holding strength provided the hole drilled is the proper size. If there is sufficient thickness of solid floor material, consider repairing the existing holes, then drilling and tapping for machine screws. These will generally have more resistance to pull out failures than more common self tapping sheet metal or wood screws that are often used.
cworthy posted 07-12-2010 09:25 PM ET (US)     Profile for cworthy    
Andy - can you define what you mean by "sufficient thickness of solid floor material"?


Gary L posted 07-13-2010 09:07 AM ET (US)     Profile for Gary L  Send Email to Gary L     
I have never cut open a whaler floor but I suspect you would find 3/4 inch plywood as a substrate under the no slip around your console. If the existing holes are worn out and water has gotten in then I doubt you can depend on any repair to have the durability from below.

I would work from above the no slip and install plates mounted to brand new holes after filling and patching all the old holes. Stainless T nuts mounted in the underside seem to work well and provide a solid threaded anchor but the new plates have to be well fastened to solid wood in fresh holes or you will get to do it again and again.

Your console could be raised 3/4 to an inch without too much issue and that added thickness might provide the necessary strength a T Top needs.


andygere posted 07-13-2010 11:24 AM ET (US)     Profile for andygere  Send Email to andygere     
For the loads from a T-top I'd want at least 3/4" to 1" of material to cut threads into. Do a test piece with some voidless plywood and a few layers of glass and test the pull out strength yourself. The key is to be sure the screws are in tight, but not overtightened so the threads get stripped.
cworthy posted 07-13-2010 03:44 PM ET (US)     Profile for cworthy    
I have been reading other threads to try to learn more about the foam in the hull and the impact of water entering. However, I am still not sure what I might be looking at in my case. I have a T-top leg with three screw holes that are stripped, however, I have kept the screws in the holes even though they are not secured. I understand that some water will get into these holes, but enough to cause significant damage? Will it completey dry out each winter when the boat shrink wrapped for five months?

Also, the BW website states: "The Unsinkable Legend is built around one thing - foam. Our closed cell foam does not absorb water and is the foundation of the solid ride of each Boston Whaler." Then why the numerous posts about water filled foam?

Gary L posted 07-16-2010 07:02 PM ET (US)     Profile for Gary L  Send Email to Gary L     
I have read all the horror stories like I suspect you have cworthy. My '74 Montauk 17 was rescued from a back yard where it sat under trees and uncovered for 3-4 years. Beside being filled half way up the gunwales with leaves, sticks and trash the drain hole was plugged and the drain tube was completely gone. I actually found trees sprouting in the wire tunnel.
The CC was held on with just 4 screws and all the others were gone for years.

If there ever was a hull that should be water logged this was it.

I drilled a few holes as described in other threads and tilted the hull so the transom was on the ground. I had my wife hold a measuring cup under 2 of the holes I drilled and we got a grand total of 2 cups of water out initially and it dripped fairly steady for 2 days. I seriously doubt there is all that much water left in my hull and I also doubt I could ever get the foam completely dry unless I cut the deck out and left it under cover for a year or more. I am sure there is pockets of water left inside but so goes the life of a neglected Whaler. I won't kick her out of my stable for being wet and she was a gift that I have come to love even with all the twigs and leaves.

I do not advocate this or even recommend it but plugging the holes from old transducers and the ones I drilled was a challenge. Not many glues we use will work on wet foam or wet wood as in the transom and then accept gelcoat over it. Gorilla glue requires moisture to cure and the more the better. Terribly mess stuff to work with but I drilled all the old holes to 3/8" and had a number of 3/8 inch fiberglass rod plugs ready to go. I injected the glue till it oozed out and stuffed a rod in and taped it in place. A little sanding and clean up and a fresh patch of gel coat over the fiberglass rods and I should be good to go.

I do believe that any water that gets inside will seek the lowest point in the bottom and when I plugged the holes where the CC was attached I found nothing but completely dry foam under the subfloor. I am very confident that even my severely neglected Whaler will live up to the unsinkable legend.

Preparing to mount the new T Top on a secure base is proving to be another challenge given all the info we have at our finger tips. I agree the floor is not strong enough given the fact that most of the center consoles have pulled loose over the years. Here is my solution of adding a solid Teak 5/4" thick X 6" wide and 36" long plate under the CC and attaching it to the floor in numerous places. The CC and the feet of the T Top will be bolted to this plate with T nuts inserted from the bottom. The original beveled Teak plate is still there to match the bevel of the winged console. This raises my CC a full inch and a quarter.

I also have the fishing platform that had to be re worked to accept the T Top legs. It is all in my garage right now awaiting the stainless screws and bolts I need to finish the install.


Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.