Seized Deckfill Cap

[Drewncrew]

Dear CF Members,
I have a seized aluminium deckfill cap that is giving me grief. I have the type that a winch handle fits in to release but unfortunately is very worn. I have since tried a few methods already such as applying heat to the outer flange and cold spray to the cap, a cold chisel and hammer-which basically destroyed the cap with no progress. Then once the cap was ruined I tried drilling 2 holes and inserted bolts to provide a leverage mechanism along with a long screwdriver. The result was bent 3/8" then 1/4" bolts. I have re drilled and moved up to 1/2" bolts - now they are not bending but the holes are elongating. Next I went back to the chisel and hammer hitting at the base of the bolts but still no joy. Access to the inside to replace the deck fitting is pretty limited and requires removing a black water holding tank and associated plumbing so trying to avoid that can of worms... any advice greatly appreciated

[Lojanica]

Originally Posted by Drewncrew

Dear CF Members,
I have a seized aluminium deckfill cap that is giving me grief. I have the type that a winch handle fits in to release but unfortunately is very worn. I have since tried a few methods already such as applying heat to the outer flange and cold spray to the cap, a cold chisel and hammer-which basically destroyed the cap with no progress. Then once the cap was ruined I tried drilling 2 holes and inserted bolts to provide a leverage mechanism along with a long screwdriver. The result was bent 3/8" then 1/4" bolts. I have re drilled and moved up to 1/2" bolts - now they are not bending but the holes are elongating. Next I went back to the chisel and hammer hitting at the base of the bolts but still no joy. Access to the inside to replace the deck fitting is pretty limited and requires removing a black water holding tank and associated plumbing so trying to avoid that can of worms... any advice greatly appreciated

Drill a small hole next to the threads on the removable cap. Wick vinegar into the hole. The vinegar will dissolve the corrosion. Wack it now and then and keep adding more vinegar. Do the heat again. more vinegar. Wack it a few times. Eventually you'll be able to work it loose. VINEGAR.

[Wotname]

And if vingear doesn't work, use draino!

But be careful, draino is sodium hydroxide, caustic soda, lye, NaOH.
It loves aluminium and will destroy it in short order but you will get your deckfill removed.

[mrohr]

i have the same issue on my 30 y/o Contessa 32. I just take the water hose below decks l
and fill my tank thru the inspection cover to the tank…….end of issue. This simple work around would have saved you many man hours of aggravation and carnage to your deck and fill cap. Please don't take this as criticism………. thru the years ,I have made a lot of work for myself chasing unobtainable perfection in both cosmetics and function. i do not apply this approach to items of safety .
As long as my boat is ready to go on short notice for a daysail or cruise with a few days preparation (food, ice rum, fish gear, dingy, those sort of items) I can have the best of both of these worlds without much compromise. It is interesting how often that term :
compromise, shows up in discussions here.

I have often said that boats are exercises in value clarification …just what does one want to get out of this whole endeavor, and maybe eleven more importantly :What am I willing To give up?

…………………Luv you all……………………mike……………………………………………………………...

[jibstay]

I had the same problem with caps that wouldn't come off.

When I removed the screws that held the fitting in place, there was enough slack in the hose that I was able to pull the deck fitting up high enough through the deck to access the hose clamps and replace the fitting.


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[Steadman Uhlich]

Originally Posted by jibstay

I had the same problem with caps that wouldn't come off.

When I removed the screws that held the fitting in place, there was enough slack in the hose that I was able to pull the deck fitting up high enough through the deck to access the hose clamps and replace the fitting.


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Simple solution! I would try this. You need to replace the fitting anyway.

[cabo_sailor]

One other trick that I've used to free up frozen distributors is place a small piece of dry ice on the frozen part. The thermal contraction broke the corrosion.


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[Greenhand]

Originally Posted by mrohr

i have the same issue on my 30 y/o Contessa 32. I just take the water hose below decks l
and fill my tank thru the inspection cover to the tank…….end of issue. This simple work around would have saved you many man hours of aggravation and carnage to your deck and fill cap. Please don't take this as criticism………. thru the years ,I have made a lot of work for myself chasing unobtainable perfection in both cosmetics and function. i do not apply this approach to items of safety .
As long as my boat is ready to go on short notice for a daysail or cruise with a few days preparation (food, ice rum, fish gear, dingy, those sort of items) I can have the best of both of these worlds without much compromise. It is interesting how often that term :
compromise, shows up in discussions here.

I have often said that boats are exercises in value clarification …just what does one want to get out of this whole endeavor, and maybe eleven more importantly :What am I willing To give up?

…………………Luv you all……………………mike……………………………………………………………...

This is actually the solution that a previous owner of our boat came up with, as well.

In your case, it sounds like you have already done so much to the cap that you should just keep drilling and dremeling until you get very close to the threads, you should only need to get one small wedge out, then there won't be any pressure, just the corrosion.

[Cheechako]

Sounds to me like you have to get at the underside to replace it anyway at this point. Just get 'er done!
Arent you glad they saved those 2 ounces and happy with how much faster your boat is with the aluminum fill unit? :>)

[belizesailor]

Originally Posted by jibstay

I had the same problem with caps that wouldn't come off.

When I removed the screws that held the fitting in place, there was enough slack in the hose that I was able to pull the deck fitting up high enough through the deck to access the hose clamps and replace the fitting.


Sent from my iPhone using Cruisers Sailing Forum

Ditto. If the cap is so corroded that you can't get it to open then I think it is best to just replace the whole fitting (that's what I'v done). The old corroded surface is likely to jamb on you again, even if you do manage to free it. If you do want to free it then its much easier to that ashore in a vice...so removing it is a good idea anyway...and that way you don't damage your deck trying to free it.

For future reference, a little lubrication of the threads after each use can prolong the life. For fuel fills I just wipe a little diesel on the threads. For holding tank maybe just use a little lithium grease or similar.

This problem happens eventually with stainless too. My deck pump out caps, which have not been opened in over a decade are firmly galvanically welded shut. Still look bright and shiny on the outside though!

There are plastic fill caps available which don't corrode, but do discolor over time. I've got one in an original metal deck plate that is about 12 years old now...no problems. Replaced a metal cap that was starting to jamb.

[JPA Cate]

Hey, Drew,

Hope you can pull it up, or you've got a big yucky job in your future! Where's the fun in that?

Hope you get it sorted, soon.

Ann

[MarkSF]

I guess I don't understand why you can't undo the hose clip under the deck fitting, and remove the entire thing from above.

[hpeer]

Caution....McGuyver story.

I had this same issue with a 30 year old plastic cap. I'm in St. John's, NL and a couple of us threw in to get the fuel truck to come to the wharf. F'ing fitting won't come off, guy ain't gonna wait forever.

Wham bang boom I gotta hole to fit the fill in. But I lost some plastic down the hole.

Three days later I notice the engine will come to to revs, but then go down again after an irregular period. Go to idle, then she will rev up but go back down again after some time.

A couple of days latter I figured it was some of the plastic partially blocking the pickup. So I threaded some rigging wire down the pickup tube ahead of the filter and into the tank. Problem solved. The wire sticking out the pick up kept the plastic out and allowed fuel to pass.

[belizesailor]

Originally Posted by hpeer

Caution....McGuyver story.
....
A couple of days latter I figured it was some of the plastic partially blocking the pickup. So I threaded some rigging wire down the pickup tube ahead of the filter and into the tank. Problem solved. The wire sticking out the pick up kept the plastic out and allowed fuel to pass.

Pretty clever. How long ago was that...and is the wire still in there? ;-)

[hpeer]

It got me from Newfoundland to Delaware.

Here I had to cut the fuel tank out due some rust underneath. I was able to confirm the wire into the tank and the plastic bits in the tank.

I also confirmed that cutting out a steel tank from underneath your cockpit sole sucks! Trust me.