Thru hull 3M 4200

Apr 25, 2015
282
Oday 26 Oscoda, MI
Just a question on thru-hulls. I have to replace my head thru-hull due to getting rid of the head and installing a porta-potti and they have gate valves on there anyway with one blown out on the side.

When I replace them do I just put 4200 on the flange lip of the thru-hull before sticking it back through the hull? Is this good enough or does one put more 4200 on the inside around the threads and it does have a wood base/support on the inside.
 
Jan 27, 2008
3,092
ODay 35 Beaufort, NC
Why do you need a through hull fitting with a porta potti? If the through hull is not connected to anything what are you going to use to cap it off? Put the sealant all over the flange where it contacts the hull but also all over the external threads where it goes through the hull. Are you putting on a seacock or a ball valve?
 
Apr 25, 2015
282
Oday 26 Oscoda, MI
Why do you need a through hull fitting with a porta potti? If the through hull is not connected to anything what are you going to use to cap it off? Put the sealant all over the flange where it contacts the hull but also all over the external threads where it goes through the hull. Are you putting on a seacock or a ball valve?
I don't want to take the time right now to glass over the holes and/or want to leave the holdes in case I or possibly the next owner if years wants to go back to an orginal head system. I was just planning on capping the thru-hull which I hear others have done. I ould put on a ball valve though and then a plug in that.
 
Jan 14, 2014
225
Newport Newport 28 Fair Haven, NY
I put it on both sides of mine, for the extra peace of mind. It might be overkill, but I figured hey, why not. Though if it's getting through the outer layer, then you're also getting water seeping into the hull anyway, regardless of if you have another layer inside. So in that regard, maybe it's best NOT to have another layer inside, so you can see it seeping if that's the case... I hadn't thought of that until just now.