Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Fastening T top to deck

Posted by chirp on 06/19/07 - 10:31 AM
#1

I have a custom al. T-top on my 17 Montauk, but a huge wave the other day seems to be the reason it (along with the center console attached to it) ripped off of the deck. The screws pulled right out. Any ideas on how to reattach? I'm thinking I'll just fiberglass the area, forcing glass into the holes, and reattach with some two part epoxy... Since you can't get a backing plate under the deck of a whaler, there doesn't seem to be much more I can do?

Posted by DelawareDan on 06/19/07 - 11:01 AM
#2

A good method (there are others): For a permanent mount, grind the area under the t-top pads to give it a clean, rough surface to bond to. Drill your holes a little bigger, and re-attach the t-top using thickened epoxy resin (colloidal silica is a good filler). First tape off the deck around each pad so you know where to grind, and to keep the epoxy that squeezes out off the deck. You can drill and fill the holes with epoxy first, and then bond it to the deck as well, after predrilling the hardened epoxy in the holes. If you do it all at once, be sure to wax the threads of the screws so that they're removable. This "permanent" bond isn't really permanent. If you heat the pads to over 150 degrees, and hit it sideways with a 2X4 or something, it should come off. I wouldn't install the console that way, though... just fill the holes, redrill, and install that separately.

my opinion B)

The stresses on a T-top in heavy weather can be enormous. Most boats allow through-bolting with backing plates.

Edited by DelawareDan on 06/19/07 - 11:03 AM

Posted by Buckda on 06/19/07 - 1:06 PM
#3

Chirp –

If you want to make the T-TOP permanent, you are going to have to be resolved to either go boating in calm waters, or do a pretty hefty mod to your deck.

Dan has some good suggestions. I’d position the top, and use tape to mark off the “footprint” before you go to work to modify the hull.

You’ll need to completely de-rig and remove the console and the T-Top from the boat.

Remember too, that because you’re mounting hardware that was never intended to be mounted to this boat, that any modification you make may be subject to failure – we’re just trying to help you get a pretty solid setup.

Here is what I’d do:

Use a plunger attachment to a router and router out approximately ½ inch of material under the “footprint” of the top’s base plates. Insert ¼ inch thick aluminum plates that extend the length of the console…don’t just put pads in, put two parallel “strips” of aluminum on either side. Use fiberglass matting and epoxy to cover these aluminum strips.

Next, buy and cut some teak that will be approximately ½ inch thick by about ¼ inch wider than the base plates of your T-TOP. Coat the teak in WEST System epoxy resin, with special 207 hardener (3 coats). Varnish (6 coats).

OVERDRILL original screw holes for the console to ½ inch and fill using thickened epoxy. Re-DRILL and TAP those epoxy plugs.

Install the console.

Position the T-TOP so that it is on the new teak (or you can cheap out on me and use STARBOARD with rounded edges) strips and positioned over where the aluminum plates are. DRILL and TAP those holes and install the top.

The teak should cover up the massacred portion of the nonskid “repair” and the aluminum should be embedded well enough to endure the common stresses on a T-TOP.

Pray for calm seas and SLOW DOWN in chop.

Enjoy.

Dave

Posted by chirp on 06/25/07 - 1:38 PM
#4

Thanks to both of you. I already did the re-install however (not patient!). I boar a 1.5" hole, wedged 1" by 2" long aluminum backing plates under each hole, poured the same epoxy with filler Dan recommended, filled the holes and the 1.5" hole with it. I did that in stages to allow it to fully cure. Backing plates are now fully encased in epoxy. THen buttered the flanges down to the deck, drilled, tapped, and put 1/4-28 bolts through. Should be pretty rugged now!

I have the only aluminum t-top I've ever seen on a montauk, and I can't believe I haven't seen more. Along with my aluminum through deck mounted sampson post, people mistake me for sea tow.

That's not me in the picture.

Posted by chirp on 06/25/07 - 1:38 PM
#5

Thanks to both of you. I already did the re-install however (not patient!). I boar a 1.5" hole, wedged 1" by 2" long aluminum backing plates under each hole, poured the same epoxy with filler Dan recommended, filled the holes and the 1.5" hole with it. I did that in stages to allow it to fully cure. Backing plates are now fully encased in epoxy. THen buttered the flanges down to the deck, drilled, tapped, and put 1/4-28 bolts through. Should be pretty rugged now!

I have the only aluminum t-top I've ever seen on a montauk, and I can't believe I haven't seen more. Along with my aluminum through deck mounted sampson post, people mistake me for sea tow.