Confused about hull structure

[uptimejeff]

Hello

I'm a new owner with a 2010 Sport 185

I installed Smart Tabs (SX) last weekend.
The directions claimed NO THROUGH HULL DRILLING
But, when I drilled (with a bit depth set to the length of the included machine screws and properly countersunk) I clearly go through one layer.

I could push the bit in and out deeper than what I drilled, so I clearly have drilled through to a gap (or inside the hull)

Is there another layer?

What am I misunderstanding?

FYI- the smart tab install went smooth due to advice here on the forums.

Thanks

 

[SCORPIO]

How long are the screws? You may have drilled into a void between the inner and outer skins. Have you looked in the bilge area where you are drilling to see if you can see the drill bit sticking into the boat?

 

[Hampton]

I can't imagine a void in that area. The transom is not as thick as you might think out near the edges. My guess is that you are in the bilge.

 

[uptimejeff]

I just took a look....

The top bracket screws are visible (just barely) in the bilge.

The bottom bracket (hinge plate) screws aren't visible from my initial inspection. I do need to step into the bilge with a flashlight and examine it better..
It looks like the bottom has a horizontal void space (perhaps for the engine mounting) and I may have drilled into this void.

So... Uhh...
Did I make a big mistake?

 

[jason78]

So... Uhh...
Did I make a big mistake?

I can't tell you for certain if you made a mistake but I would recommend you at least back those screws out and apply 3M 5200 before you re-insert them. 5200 is the sealer to use for below water line penetrations in the hull.

 

[Hampton]

I can't tell you for certain if you made a mistake but I would recommend you at least back those screws out and apply 3M 5200 before you re-insert them. 5200 is the sealer to use for below water line penetrations in the hull.

3M 5200 will make them permanent. I think 3M 4200 is perfect for this application and will let you back them out when you need to.

 

[Redhook98]

Go with the 5200. It takes a long time to dry. In case you made a mistake, you can still adjust things.

Every boat I have had has the bolts going all the way through the hull. Just make sure you seal all the holes properly (recommend 5200, but 4200 will work as well).

 

[uptimejeff]

Thanks for the replies.....

I was worried that I should NOT go through the hull at all... sounds like it's OK to go through the hull with proper sealing....

Gotta admit- the idea of punching through the hill is very unnerving, but I hope the improved handling with smart tabs will offset that

Thinking of a nightmare scenario.. I back into something that knocks a trim tab plate off and the screw holes open up...
Any suggestions to deal with a situation like that (or am I thinking about this too much?) ?
I imagine that I would go overboard with a ripped piece of cloth and stuff it in the holes...???

Cheers
Jeff

 

[Redhook98]

Not sure if you could even back into something that would rip them off without first hitting your outdrive and/or swim platform. Never heard of one ever ripping off either. I think the danger there is near non-existent.
Once you bed the tab with 5200 and screw it in place, it will take a very LARGE accident to open any kind of hole. I would not lose any sleep over that.

Beside, you are usng SS screws anyway, right? They will shear off before ripping out of properly bedded fiberglass.

 

[Hampton]

I have knocked a tab loose from the strut on a fender jammed against a floating dock. Two screws broke and had to be fixed. That wouldn't bother me, even if all of the screw holes opened up. They're pretty small and won't sink your boat. If your bilge pump didn't work, then you'd have to get it to a trailer or haul out that day, or, run around on plane to drain it back out of those holes, but, that's an extreme circumstance. These are not things to be concerned about.

 

[Prater]

I would also use 4200 from 3M, the 5200 is designed to be permanent. The 4200 will allow you to remove easier if you have to make repairs.