thru-hull removal revisited

[Stan W]

I bought a "spud wrench" from Home Depot. It fit the larger thru-hulls (head discharge and cockpit drains), but they did not appear to have anything that would fit the smaller thru-hulls (head intake, engine intake and galley sink drain). Unfortunately, it is the head intake that I want to remove. Is there a "trick of the trade" for removing the smaller thru-hulls?

Thanks.



smwheatley@capecod.net

[John R.]

I bought a "spud wrench" from Home Depot. It fit the larger thru-hulls (head discharge and cockpit drains), but they did not appear to have anything that would fit the smaller thru-hulls (head intake, engine intake and galley sink drain). Unfortunately, it is the head intake that I want to remove. Is there a "trick of the trade" for removing the smaller thru-hulls?

Thanks.

Spud wrench only fits the one size like you stated. It's a plumbing tool not a marine tool. There is a "stepped" thru-hull tool made that fits the full range of sizes up to 1 1/2 inch. Defender used to sell it several years ago but I haven't seen it in their catalog for quite awhile. You would have to check with all the thru-hull manufacturers to find out who may be making it or where one can be obtained. You might try someone like Jamestown Distributors also.

You could have one made or make it yourself. It is made of flat 3/16" bronze stock. You could use steel also but it will tend to rust on you all the time. The thing is shaped like a triangle with a flat tip instead of a point at the top. The easiest way to picture what it looks like is to draw a 2" inch box. Then draw another 1 1/2" box stacked on top of that and then a 1 1/4", then a 1 1/8", then a 1", then a 7/8", then a 3/4", then a 5/8" and then a 1/2". Do it in whatever sizes you need. It is a good idea to determine the height of each box by checking the location depth of the nibs up inside each size thru-hull because they vary from manufacturer to manufacturer. Some nibs are just barely up in the throat of the thru-hull and others can be as much as an inch up inside. Once you have all the boxes drawn stacked on top of one another you wind up with a jagged edged looking triangle like design. That is now the pattern for your tool. Just cut it out and transfer the pattern onto a piece of flat steel or flat bronze and cut it out.

Now you have one tool that will fit all the various sized thru-hulls you measured for. It's an excellent tool and as an old friend of mine once said "that's the cats ass"! Do yourself a favor and make one if you can't find the commercially made version. This tool will save a lot of frustration and aggravation.

To use it you just slip it up into the thru-hull and rotate it until it contacts the nibs. Then just use a crescent wrench on it and turn.

Groco makes a "plug style" tool that is used for installations but it is made of aluminum and is weak so it can't be used for removal purposes. Dumb eh?

Remember you can always just make simple individually sized removers by cutting a piece of flat stock for the inside diameter of each sized thru-hull but then you are doing a lot more fabricating and have a bunch of tools instead of one.

Of course there is always the hack version of removing and installing thru-hulls where people use a screwdriver and a mallet and bang on the nibs at an angle trying to spin the thru-hull. Usually damaging or destroying the nibs in the process.

[Catherine Monaghan]

Stan,

<a href="http://www.boatus.com/boattech/casey/07.htm">Visit this webpage</a>. It's an article by Don Casey. In it he provides instructions for removing a thru-hull fitting using a piece of 3/8" threaded rod, a couple nuts, washers and a few blocks of wood. There's also a nice picture to help you see what to do.


catherine_monaghan@merck.com
CD32 <a href="http://www.hometown.aol.com/bcomet/real ... ization</a>, #3
Rahway, NJ
Raritan Bay

I bought a "spud wrench" from Home Depot. It fit the larger thru-hulls (head discharge and cockpit drains), but they did not appear to have anything that would fit the smaller thru-hulls (head intake, engine intake and galley sink drain). Unfortunately, it is the head intake that I want to remove. Is there a "trick of the trade" for removing the smaller thru-hulls?

Thanks.

catherine_monaghan@merck.com

[John R.]

This method is a "puller" and requires complete removal of a seacock and disconnection of it's attached plumbing. This approach would be fine for let's say a bilge pump hull outlet thru-hull or similar that doesn't use a seacock. If a person simply wants to replace a thru-hull and leave their seacock and everything else intact then Don Caseys procedure will not work. The only exception would be if someone had an inline flangeless ball valve being used as a seacock that could easily be removed. It seems by looking at his diagram and his description it would be easy to damage the glass surrounding the thru-hull hole if the caulking was firm and had strong adhesion. Slicing the caulk under the flange of a thru-hull can make it easy enough to simply push a thru-hull out of it's hole and not necessitate the rig that Casey illustrates except in the case of situations where people have mistakingly used 5200 as a sealant. Don's method seems rather extraordinary to simply remove a thru-hull except in desperate situations where a proper tool is unavailable and where a thru-hull is being stubborn, then it would be a good technique to employ.

Stan,

<a href="http://www.boatus.com/boattech/casey/07.htm">Visit this webpage</a>. It's an article by Don Casey. In it he provides instructions for removing a thru-hull fitting using a piece of 3/8" threaded rod, a couple nuts, washers and a few blocks of wood. There's also a nice picture to help you see what to do.


catherine_monaghan@merck.com
CD32 <a href="http://www.hometown.aol.com/bcomet/real ... ization</a>, #3
Rahway, NJ
Raritan Bay

I bought a "spud wrench" from Home Depot. It fit the larger thru-hulls (head discharge and cockpit drains), but they did not appear to have anything that would fit the smaller thru-hulls (head intake, engine intake and galley sink drain). Unfortunately, it is the head intake that I want to remove. Is there a "trick of the trade" for removing the smaller thru-hulls?

Thanks.

[Carl Jones]

I bought a "spud wrench" from Home Depot. It fit the larger thru-hulls (head discharge and cockpit drains), but they did not appear to have anything that would fit the smaller thru-hulls (head intake, engine intake and galley sink drain). Unfortunately, it is the head intake that I want to remove. Is there a "trick of the trade" for removing the smaller thru-hulls?

Thanks.

I want to support the previous post by John R. regarding the stepped down bronze tool. That is definitely the way to go. I borrowed one to remove all the thru hulls on my CD30 last August. You can put a pipe wrench on it and a cheater if necessary. With this arrangement I was able to remove all my thru hulls with ease. After 18 years in salt water!! We don't haul our boats here in Texas during the winter. The tool was bought at AER Supply here in Seabrook, TX. Find one of these. If you want me to check down here, let me know.
Carl Jones
Spanish Eyes CD30 Cutter



GreatCells@aol.com

[Bill Jarrell]

I bought a "spud wrench" from Home Depot. It fit the larger thru-hulls (head discharge and cockpit drains), but they did not appear to have anything that would fit the smaller thru-hulls (head intake, engine intake and galley sink drain). Unfortunately, it is the head intake that I want to remove. Is there a "trick of the trade" for removing the smaller thru-hulls?

Thanks.

I believe Hamilton Marine has the tool. (www.hamiltonmarine.com)



billjarr@mint.net

[SteveZ]

I rebedded all of my thru-hulls a number of years ago. My method was to take a small, good quality crescent wrench and insert the jaws into the thru-hull. Then I opened the jaws to the inner diameter of the thru-hull, engaging the nibs. A second, larger crescent wrench was closed on the handle of the first to get leverage. Tool abuse? Sure...but it worked like a charm. Just be careful to fully engage the nibs so they aren't damaged.

[Matt Cawthorne]

John,
I had a bad seal on the large plastic through hull unit that houses the datamarine knotmeter. The seal was never properly formed when installed, but the backing plate kept the water out for the first 17 years. I tried everything to pull it out, including hammering it from the inside. Unlike bronze through hull units it had no place to grab to turn it. In the end I went to a system that looked exactly Casey's. It worked great. I turned the wrench slowly and the sealant crept and did no damage whatsoever to the laminate. I believe that the original sealant was 5200. I could not believe how tough it was. Since the unit was plastic a new one was in order.

You are correct that if the seacock does not need to come out this would add work. The thing is that if I were pulling the through hull, the seacock would come out and an new backing plate would go in anyway.

Additionally, if the installer drilled the hole on the smallish side the threads could be grabbing the fiberglass and pulling it out using Casey's technique would be impossible or could do damage to the laminate. This is not likely.

Matt





mcawthor@bellatlantic.net

[John R.]

This is true. Obviously transducer thru-hulls are without engagement nibs because otherwise the transducer won't slip into them. Some have a tab (or tits) under their flange that engage in a notch made in the glass for the tab to lock into when the thru hull is installed and tightened to prevent it from spinning.

Because of that design it can pose difficulty in removing them because you can't rotate them to help break the seal. Casey's method could certainly be of help in a situation like that or in a stubborn situation like the one you were faced with. Any thru-hull that is free from seacock installation could use his method but is certainly not always necessary when a installer uses the correct caulking in the first place. I would think by your description that 17 years ago they probably used an acrylic or silicone based sealant or similar that caused the difficulty. I was in the marine business back then and I don't recall any polyurethanes like 5200 on the market at that time. We did all our below waterline sealing needs with polysulfide such as Lifecaulk which always is fairly easy to disassemble at a later date and holds up extremely well for years.It is still the caulk of choice for below waterline installations.

By the way......someone mentioned in an earlier post that Hamilton Marine may sell a thru-hull removal tool. I was curious to see if it was the one I'm familiar with and it isn't. However it is the same basic idea. It is made by Buck Algonquin. It is constructed from iron. It is not a flat type tool. It is more like the Groco design that is like stacked plugs with two notches in the side of each plug section to lock onto the thru-hull nibs. Sounds like a good strong tool.
The product info is below:

Hamilton Marine (This item not listed in their catalog)
Buck Algonquin thru-hull removal tool
Part # BKA 3BTHW
Price is $25.12

[Stan W]

What did I find Friday night while sifting through the piles of junk that were on the boat when I bought her but a homemade thru-hull tool! Basically just some flat steel stock about a quarter inch thick cut into a spike-like shape. It worked perfectly. Thanks for all the suggestions though.

Spent most of today stripping decrepit varnish from toe/rub rails, bowsprit and "fan-tail" in anticipation of refinishing with Armada. Same thing last Sunday. Still only about half done. Are we having fun yet?



smwheatley@capecod.net