How to remove seacock without resorting to C-4

[Cthoops]

We have five unused thruhulls, and the seacocks have come out of four of them with no problem. The fifth one is hanging tough. The other four didn't have backing plates, but this one does. It appears not to have been originally installed when the boat was made (1977 B29.9). It went to the manual overboard pumpout.

Mr. cthoops has already used the Dremel to get rid of the mushroom head on the thru hull. He thought it might be bolted through the hull from the inside, but after sanding down to the gelcoat he can't find any sign of a bolt. He's tried whacking on it with a hammer and it's not budging. Maybe it was installed with 5200?

We've thought about trying wire with dowels on either end to saw along the bottom of the seacock, and will give that a try tomorrow unless there are other, better options. Besides the C-4 of course.

Any suggestions?

[scherzoja]

Hole saw!

I removed several of mine that with a hole saw that had an ID that matched the OD of the mushroom. If you're going to reuse the hole, probably shouldn't go that router, but if you're going to seal the hole off, hole-saw it out.

[zboss]

Here you go...

Removing Stubborn Boat Fittings - BoatUS Magazine

[JPA Cate]

cthoops,

Uhh.... You should have a manual bilge pump, for when the electric one fails. So, won't you need a through hull fitting there? Or are you re-locating it?

Ann

[witzgall]

If you removed the head, have you tried using a pipe the size of the remaining thru-hull stub, and hitting that from underneath?



Chris

[skipgundlach]

Find a place to put a bottle jack; you might have to make some form of brace.

Put a length of whatever in the space between the brace and the jack. Engage jack. Out she comes. Once you break the 5200 bond, it's a piece of cake, so to speak. If it's bronze, some heat will also help.

[jacaranda]

I solved this problem by using a hacksaw blade with 1 sided handle to saw thru in hull element of fitting to remove a section and then collapsing rest ot fitting with a good wallop of a hammer.

[Lokiyawl]

I assume that the thruhull is bronze. In that case simply heat the bronze up and the 5200 will let go. Safest to use a hot air paint stripper gun. Heat it up slowly and evenly. James

[mike d.]

What Lokiyael said!!!! I did all 7 of mine that way! I took out the barrels themselves used a propane torch to get the flange itself very warm. then they spun out like they were put in dry. You just have to put the flame up inside the inside edges of the fitting, that way you don't damage the surrounding gel coat and glass.

[exMaggieDrum]

Originally Posted by Lokiyawl

I assume that the thruhull is bronze. In that case simply heat the bronze up and the 5200 will let go. Safest to use a hot air paint stripper gun. Heat it up slowly and evenly. James

I agree with the above. I removed 13 old ones from my first boat and have removed many, many fittings that have been glued in with 5200. A hot air gun will soften it up. You just don't want to get the surrounding area too hot. You can use a piece of thin stainless cable with a couple of sticks to "saw" between the item and the hull if needed.

I was not going to reuse the thruhulls so I took a reciprocating saw (e.g. Sawsall) and carefully cut from the center of the hole through the bronze (or plastic) thru-hull mushroom in two spots. The pieces would come out much easier that way. Much quicker. Just don't cut into the hull but if you nick it no problem as you just seal it with some resin like you would a new hole.

[estarzinger]

There is actually a 'proper tool' for this job - called a step wrench - THRU HULL INSTALLATION WRENCH FITS 1/2" THRU 3" 741255

Thru hulls have little 'ears' inside them. The step wrench engages those ears and allows you to spin them out with a big breaker bar. That torque will break any bond when even the biggest hammer will not. And you don't risk damaging anything with heat.

[GrahamHO]

Originally Posted by Cthoops

We have five unused thruhulls, and the seacocks have come out of four of them with no problem. The fifth one is hanging tough. The other four didn't have backing plates, but this one does. It appears not to have been originally installed when the boat was made (1977 B29.9). It went to the manual overboard pumpout.

Mr. cthoops has already used the Dremel to get rid of the mushroom head on the thru hull. He thought it might be bolted through the hull from the inside, but after sanding down to the gelcoat he can't find any sign of a bolt. He's tried whacking on it with a hammer and it's not budging. Maybe it was installed with 5200?

We've thought about trying wire with dowels on either end to saw along the bottom of the seacock, and will give that a try tomorrow unless there are other, better options. Besides the C-4 of course.

Any suggestions?

Yes; get a new hacksaw blade and from the inside or outside poke the blade through the hole and saw into the inside of the skin fitting down its length until you just start cutting into the hull material. You might need to make two cuts opposite one another. Then after a gentle tap with a hammer the fitting will easily be removed or spun out maybe with a multi grip on the inside. That skin fitting may have been set in epoxy. That method will also work if there is a skin fitting nut as normal on the inside. The cut shrinks the fitting. You can easily make a wooden handle for the blade with a length of dowel partly cut down the length and a hose clip.

[estarzinger]

BTW, it is quite easy to make your own 'step wrench' to fit a specific thru hull size. You just need to engage the ears inside the fitting. You can do it by cutting slots into an appropriate diameter (which just fits into the thru hull) pipe or even easier by cutting a strong piece of flat plate that just fits into the thru hull. Any of these will allow you to use a big breaker bar to spin off the thru hull. This may not be important in this particular case, but these all also allow you to remove a thru hull without damaging it - if it needs to be rebedded or moved.

[Canuck Sailor]

I made my own jig using a five inch plastic pipe end cap and drilled the centre. It fitted over all of my thru hull fittings from the outside and using a threaded rod with washers on the inside and in some cases the threaded nut off of some thru-hull sizes I pulled the thru hulls out.

[estarzinger]

^^ yea, a puller is another good tool for the job. You just have to be a little careful if the hull is cored. Sometimes they can pull the outer skin away from the core as they are pulling the thru hull. That should not happen in a proper installation, where the inner and outer skin "should be" bonded together at all penetrations . . . But as we all know, sometimes these things have not been installed "properly". The step wrench avoids that potential concern by torquing rather than pulling.