thru-hull replacement question

[mattttt25]

i want to replace all of my below-water level thru-hulls. currently have plastic and want to upgrade to bronze. i found the fittings at boat/us, and looked at the sealants out there. i think i found the right one- 3m sealant, says it's for below water and seals to metal and fiberglass. my only question is procedure- do i just remove old parts, clean area, apply sealant on both sides, and screw on? am i missing something? has anyone done this type of work that can offer some advise? also, the sealant stated that it takes 2-3 weeks to completely cure. is this possible? thanks-

 

[flashback]

Re: thru-hull replacement question

I don't know what type of 3m sealant you are using, but I have installed many thru-hull fittings using a product called "life caulk" made by boat life. when you tighten the nut just be aware that it needs to be tight but not so tight that you damage the fiberglass around the hole..in many cases you may need a backing plate on the inside of the hull to take up space if there are not enough threads on the fitting to be able to pull it up tight. this can be made of fiberglass, marine ply etc. but if the hull has a lot of curvature such as on a sailboat, then the backing block will need to be shaped to fit the curve........

 

[Reel Appeal]

Re: thru-hull replacement question

mattt,<br /> Make sure you use a thiokol or polysulfide based caulk below the waterline.3M brand or otherwise....

 

[mattttt25]

Re: thru-hull replacement question

i saw the product life caulk you talked about, right next to the 3m products. ok, got the sealant. make tight, but not too tight. anything else i need to know?

 

[magster65]

Re: thru-hull replacement question

Don't forget to goop up the screws too.

 

[Mikedg]

Re: thru-hull replacement question

Now that your thu-hulls are bronze, they will have to be wired into your bonding system to prevent corrosion.

 

[mattttt25]

Re: thru-hull replacement question

mike - that's a whole new problem i never thought/knew of!!! i thought the bronze are the best choice for thru-hulls? i've been on numerous large boats (45+) and never saw wiring to all the thru-hulls, and can't imagine they would. i hope you're wrong, but if you are, i have to rethink this.<br /><br />anyone else?

 

[mattttt25]

Re: thru-hull replacement question

^

 

[mattttt25]

Re: thru-hull replacement question

^ help, help

 

[rickdb1boat]

Re: thru-hull replacement question

mattttt25 <br />Here's a couple of articles that may interest you.<br /><br /> web page <br /> <br /><br />maritimeconsultantsinc

 

[flashback]

Re: thru-hull replacement question

on rare occasions where there are severe stray currents you may need to ground the thru-hull fittings, but in that case you might as well sink your neighbor's boat and save a whole lot of folks the problem........