Seeking help with thru-hull leak

[FecklessDolphin]

The thru-hull transducer on my J/27 was installed with adhesive on the outside, but without the plastic nut (approx 1.5" diameter) that holds it on from the inside. While checking the speedo (from the inside) I pushed the entire thru-hull off the hull into the water. I was able to pull it back into place and the adhesive is partially holding so the water is only slowly seeping in. It's freshwater. I tried to find a piece that would thread onto the thru-hull in a local hardware store, but I cannot get their stock threaded PVC parts to thread on. I will look around for the intended part. I am wondering about using some caulk that I can form into a rope and which I can lay around the inside of the thru-hull to stem the leak but which I can later remove when I want to repair it correctly or replace the thru-hull transducer. Any recommendations? It is for a RayMarine speedo.

[Captsteve53]

You could get some underwater mouldable type epoxy (plumbers putty- it's a two pack product), plumbers use it for temp repair or even permanent! , some brands dry in 15-20 minutes other in a few hours, it's normally mixed with wet hands and forms a clay like substance which will sort of form a nut around the threads and at least seal (to stick well it needs to be wet ,

Once to lift the boat out it will be easy enough to remove the epoxy and make preparation for your new fitting, bed with a product like 5200 or similar which is a silicon type adhesive designed for the job, use plenty!

[FecklessDolphin]

I find this product PC Products 4 oz. PC-Plumbing Putty Epoxy-045596 - The Home Depot

They say it cures hard enough for drilling and sanding. Will I then be able to remove it?

[Captsteve53]

Yes it does dry very hard (hard as a rock) but unless the surfaces are well prepared it will come off fairly easily with the prudent use of a hammer and sharp chisel, (this should be considered a TEMPORARY fix only until you can get her out of the water (the sooner the better), It will be impossible to clean around the threads to the degree required to make a permanent adhesive bond, Dont forget these underwater epoxies like attaching to wet surfaces -just work the epoxy onto the threads and hull-being careful not to push the fitting out again, (holding the top of the fitting(vice grips?) while working the epoxy around the lower part to the hull,

Best to get her out of the water actually and replace the fitting as a priority as i wouldn't trust this repair for more than a very short period, Murphy's law applies!!

[DeepFrz]

Do yourself or the next owner a favor and don't use 5200. 4200 or 4000 are much better.

[Mitch K]

Freckless,
There are a number of youtube clips where they replace a thru hull while still in the water. Pretty much they push the old thru hull out, then push a tapered plug into the hole. That slows stops or at least slows the water coming in. They then prepare the replacement thru hull with a fair amount of sealant on the flange, put a plug into the outside of the new thru hull dive in, and push first plug out and insert new thru hull. Install the nut, then remove the second plug. Insert sensor, and it is done. I think they used 4200 or maybe 4000. I would imagine you can get a replacement nut from the manufacturer. A make shift repair until you can get the correct nut, is if there is enough room, a piece of wood drilled out to the size of the thru hull, then split through the middle of the hole, and clamped around the thru hull by running a couple of screws to hold the split pieces of wood tightly to the thru hull, and a couple of wedges under the wood to hold it in place. Not pretty, but should hold until you get the correct nut. Of course, do not forget to clean the thru hull flange and apply a liberal amount of sealant prior to re-inserting. I would not try and stop the leak from the inside. I just replaced a thru hull that had been leaking and a previous owner had did the pack sealant (multiple times, still leaked) around the inside type of repair. I spend a number of hours getting all the old sealant off and back to clean fiberglass before I could install the new thru hull. What a pain. Good luck with the repair.

Mitch

[sailortype]

"Do yourself or the next owner a favor and don't use 5200. 4200 or 4000 are much better."
Agreed. The only reason 5200 should be used on a boat is in permanent structural adhesion situations.

“bed with a product like 5200 or similar which is a silicon type adhesive”

And do not ever use anything that is, might be or will be silicone. It forever contaminates fiberglass surfaces and nothing will ever again adhere to that area.

[stnick]

Trying to stop a leak from the inside is a battle you are going to loose. ! you might slow it but outboard is where you should be looking .
Many years ago i replaced a transducer while in the water . ! 2 person job. one to push thru the diver to take the transducer with 5200 already applied to push the wire thru the hole when plug removed wire goes thru the nut and fast pull till water slows. than tighten the nut. In my case it worked with no leaks. ! unless your real brave and 2nd person is not a team player dont try it !

[um saudade]

I would not attempt to use any kind of putty and rely on it to work. It does not produce miracles and that’s what you are asking it to do. The difficulty in dealing with a transducer is the cable is usually epoxied into the transducer so going in and out requires the entire cable to go with the transducer. You need the end of the cable to drop a regular nut over, if you can find one.

If you can’t find the proper nut try this fix:

Do you have access to any basic tools? I would make a two part clamp out of hardwood (a big two part nut but it will not be threaded, just using compression to hold it on the threads) and use the clamp to substitute for the missing nut. This was you don’t need to pull the cable all the way back to the transducer to fix it. Take a piece of hardwood the size of a two by six (inches here) and cut it so it is about square. Drill a center hole slightly smaller than the size of the transducer threads. Drill two holes perpendicular to the center hole, one on each side, going all the way through the lumber. Use 5/16 or 8mm bolts with large washers on each side. Drill these long holes across the grain, not with the grain and stay away from the center hole by a half inch (12mm) or so.

In four places around the center hole drill 5/16 holes parallel with the center hole. Now if you have the tools you can drill these undersize and thread these holes but it is not absolutely needed.

Split the wooden nut in two halves with a small kerf saw. Use two long bolts with fender washers to compress the nut halves onto the threads. The nut should fit tightly but not slip on the threads. Now this is where it gets a little complicated. The other four holes that are parallel to the big hole will be used for bolts that will go through the lumber and push against the hull. If they are threaded, then that’s all you need. Screw in the bolts, put some kind of a plate on the hull surface where they meet and gently apply some torque. This will pull the transducer tight to the outside and the way you described the leak, should get it down to a minimum or even stop the leaking entirely. If you did not thread the lumber you can put a nut against the bottom of the wooden nut to push against as you tighten. If you are really anal, thread the lumber and use the nuts too.

All this is written no knowing what kind or room you have to work in. but if you cut it to fit, you can get into a pretty minimal space.

This is not a permanent fix but properly done should give you many miles and some time to do a haul out and do it properly.

[SeaAlaska]

Look at Petit Splash Zone Epoxy.

Its a two part epoxy that works like a putty. Just Google it and you will see various suppliers and can read all about it.

Good luck.

[jibstay]

I've replaced a thru-hull in the water. It is a 2 person job. I used 5200 underwater and it sealed nicely. A couple of months later I hauled out and replaced all of my thru-hulls and had no trouble removing the 5200. I'm wondering if butyl tape might work. It would be easy to roll into a rope to put around the threads/mushroom head while underwater. Because of the wire, a wooden peg might not work to temporarily seal the hole after pushing the transducer out. I would just have the person inside the boat use their hand. Once the transducer is pushed back up into the hull with the sealant around the threads, you will want to jury rig something to help hold it in place until you get the proper nut.

Airmar makes a lot of the transducers, they can probably provide the nut. You will need to put the nut over the end of the wire, which might be difficult if it's a long, inaccessible wire run. I'm thinking that cutting and splicing the wire is a bad idea, but, I don't have any actual knowledge to back that up.

Best of luck.

[Outlaw7]

If it is a Raymarine speedo it was made by airmar. Try Gemeco on South Carolina. 803 693 0777 they are wholesaler but will get you the correct part number and help you find a dealer to sell it to you. For a temporary seal get a toilet wax ring and mold it around the current thru hull.

[Captsteve53]

In order of clarity regarding my earlier statement using 5200 or a similar silicon based product, I was not insinuating 5200 is a silicon based product as it is not, its a polyurethane base, The similar silicon based products referred to are the numerous ones available thru local chandeliers which have been used also for years for many reasons, for one- such as when you are not in the US and cruising around the world where 5200 is VERY scarce to say the least (even today), That said products like 4200 or 4000 are even harder to find thru the world smaller countries,Cruisers usually dont have the luxury of a Defender or West marine store in there back yard.

The main difference between the 4000 range and the 5200 is that yes they can be removed more easily (mainly due to the fact they are approximately 50% lower in strength ) and dry very quickly which may or not be a good thing- I recently surveyed a yacht(IIMS) with 6 thru hulls all leaking after a re fit where 4200 was used,- mainly due to the hull shape the action of the quick drying didn't let the 4200 slump into the small voids under the heads and nuts of the thru hulls, these were all removed and re bedded with 5200 and solved the issue!(probably more of an operators/installation issue but a fact!)

It's an over statement to say that 5200 cannot be removed (difficult yes but not impossible) there are several spray can products that will dissolve 5200 and assist with removal, 3M the maker of 5200 state the main/primary use of 5200 is for deck to hull joints but there second SUGGESTED USE(in a long list) is thru hull fittings-which boat builders have used for the past 50 years.

As for silicon type products used will degrade your vessel for ever more, again is incorrect, if normal care is taken with the use when bedding or installing items there wont be silicon spread all over the vessel, Again various products will remove silicon (acetone for one), a lot of car polish/wax contains silicon based products but is removed when the car is to be re painted,

[UNCIVILIZED]

Another tip or two is that you can form a nut out of underwater epoxy, remove it, even if in 2 halves, & then meassure the size of the unit exactly, along with the size & pitch of the threads. Or with the proper tools, you can take these measurements directly off of the unit. Either to know what to ask/look for in a replacement, or to have one custom machined.

[HopCar]

Get the right nut or buy a whole new transducer if you can't get the nut. If that thing falls out, there is a good chance your boat will sink.

When you re-install it, use 5200 to bed the mushroom. Despite the crying of little girls (just kidding) on this forum, you will be able to get it off. If it's metal it's easy, just warm the metal with a propane torch. It'll pop right off. If the ducer is plastic, you'll probably destroy it. But if you need to remove it, it's shot anyway.

The last thing you want is a leak and 5200 doesn't allow leaks. It will also setup underwater.

Remember, real men use 5200.