replace thru hull fitting

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99Parker2520

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Need to replace the forward bilge thru hull fitting. Should I use bronze or stainless and I trailer the boat, it is not left in the water. Also what type of sealant should be used?

Thanks
 
SS by Gem or Marine Part Depot.

I'd also recommend LifeCaulk by BoatLife - very similar product, but a MUCH better value than any 3M product in that the tubes don't turn hard and unuseable before your next use ...
 
1. Remove plastic fitting and clean the opening of any residual sealant.
2. Replace the old fitting with the new one using sealant on both sides.
3. Screw on the backing nut finger tight, then wipe up any extra sealant making a fillet on the outside.
4. Come back 24 hours later and tighten the part gently.
5. Replace the bilge hose, and you are done! 8)
 
4. Come back 24 hours later and tighten the part gently.

That is where I have a problem...The sealant is also a adhesive or glue of sorts. Trying to of turning the nut after 24hrs is going to break the glue seal.

I've never tightened a thruhull X-ducer nut after a install. I've tried and it wouldn't budge. I just snug it up while the sealant is wet.
 
I had the same experience with the thru hull transducer that I just installed (Airmar B164). I had every intention of not over tightening, but given that their instructions called for sealant everywhere including all the way up the inside of the spacer, there was no way that I was going to be able to move that nut once things tacked. So I did my best to apply the appropriate amount of sealant, and then tightened knowing that I was trying not to squeeze all of the sealant out.

So far so good, no leaks.
 
Ludicrous40":1ap0pj2a said:
............ there was no way that I was going to be able to move that nut once things tacked. So I did my best to apply the appropriate amount of sealant, and then tightened knowing that I was trying not to squeeze all of the sealant out.

So far so good, no leaks.

True that........if you get sealant on the threads you're not likely going to be able to come back later and get any more turns on it.

FWIW the Airmar transducer has a groove on the flange where it mates against the hull which prevents starving the joint of sealant. I generally put a solid bead of 4200 on each side of the flange/hull, snug it and be done with it. YMMV
 
warthog5":1mrvl4mt said:
4. Come back 24 hours later and tighten the part gently.

That is where I have a problem...The sealant is also a adhesive or glue of sorts. Trying to of turning the nut after 24hrs is going to break the glue seal.

I've never tightened a thruhull X-ducer nut after a install. I've tried and it wouldn't budge. I just snug it up while the sealant is wet.
True, where this works best is when the part itself or a large SS fender washer is between the goop and the nut, so you can torque the fastener and nut a tad without disturbing the bedding.

The opposite problem, which I believe to be more prevalent, is that most people tend to torque the snot of it a new install so much that they squeeze out ALL of the goop ... resulting in a dry joint.
 
Decided to replace both forward and aft bilge thru hull fittings...came out fairly easy but had to cut the aft 90 degree, sealed very well but both had the inside (nut) only hand tight. All cleaned up and new installs tomorrow. Thanks for all the advice guys, really a no brainer other than deciding on what fitting... ss/plastic/bronze and the sealant. I ended up with the 316 SS and lifecaulk.
 
These are the 90deg fitting I have aft. This set's you up so the hoses have the proper loop.

Get them at the same link i posted above.

100_4132.jpg


100_4135.jpg


100_4555.jpg
 
If you don't have the 90 degree fittings like Bobby has, you can still make a proper weather loop as shown in the photo below.
 

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