drilling holes in my hull, are you serious?

ebko84

Cadet
Joined
Mar 14, 2011
Messages
16
man, what a super site, im a 1st time boat owner. i have been reading this site for weeks. I bought a 1984 ebko 18.5 ft cimmaron. apparently rare. it was garaged all its life, its in mint condition. if the hour meter is correct it has 268 hrs. the viynl is original and perfect so the engine etc. all i can think about is how to get more hp out of the aq125/270. im going to do the elec ignition, maybe a better coil. weber carb are out of buget right now. all of this i read about on this site. Like i said super site you guys are beyond super.
so, im looking at smart tabs. however, it bugs me to think of drilling into the hull. then putting in wood screws, what about brass nut zerts or alum. glassing in ss nuts etc. it just seems like those screws would eventually tear out. how thick is the wall of the transom? your wisdom and coments are welcome.
 

Fireman431

Rear Admiral
Joined
Sep 17, 2007
Messages
4,292
Re: drilling holes in my hull, are you serious?

There should be absolutely no problem with drilling into the transom, if done properly.

When mounting tabs (trim tabs or smart tabs), measure 3 times and drill once. All screw holes should be filled with 3M 5200 sealant. This will keep out any unwanted water intrusion. Allow to set for a minimum of 24 hours before using the boat and the sealer is fully cured after 7 days. Use the proper hardware that's supplied with the kit.

I'm not sure how your transom is constructed, but it could be anywhere from 1" to 2 1/2" thick. Depends on the core material. My 37' boat has only a 1" thick transom, but it doesn't support and engine weight and it's 13' wide.

If you are worried about the screws tearing out (many boats with tabs, never had a single screw fail), you can always drill through and thru bolt it with 1/4 x 20 bolts and fender washers on the inside of the hull. Whatever you do, don't forget the sealant.
 

RRitt

Captain
Joined
Mar 30, 2006
Messages
3,319
Re: drilling holes in my hull, are you serious?

i saw a TV show out of Miami where a guy does repairs and custom mods on boats. "This old boat" or something like that. Anyway, he made a big deal out of how to use sealant one day. He said that you do not fully tighten the bolt on the first day. According to him if you want a lasting. waterproof seal then you let the sealant cure for a day before fully tightening the bolt.

True? not true?
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,416
Re: drilling holes in my hull, are you serious?

5200 will work but it's not a permanent solution since it will dry out and crack over time.

To do it right, you drill your holes over sized and fill them with a mixture of epoxy and cab-o-sil. Let dry then drill your screw holes to size. The hole is sealed and you have nothing to worry about.
 

wingless

Petty Officer 2nd Class
Joined
Jul 7, 2009
Messages
195
Re: drilling holes in my hull, are you serious?

My preference is to drill the hole larger than required, then use West System epoxy with filler, wait 'till it hardens, then drill to the correct size and use 5200 to seal around the fastener / fitting.
 

Pez Vela

Chief Petty Officer
Joined
Dec 4, 2004
Messages
504
Re: drilling holes in my hull, are you serious?

all i can think about is how to get more hp out of the aq125/270 ... so, im looking at smart tabs.
Now there's a non sequitur for you ... and why would you want to modify a "rare" boat in mint condition with an unnecessary (probably) after-market add-on, installed by an admitted novice. Sometimes I think you old timers are just making this stuff up.
.
 
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