Can't open deckfill.

[mainemandean]

Okay, here's what I don't get about the idea of using heat.

Heat expands metal.

We have two parts here: the cap and the "doughnut." If you heat the whole thing, two things happen. 1) The cap expands outward, increasing in diameter. 2) The doughnut becomes fatter, expanding outward along its outer circumference; but also expanding inward along its inside circumference; that is, into the hole.

So the cap, and the doughnut's inner surface, are expanding towards each other, closing the gap. This seems like the last thing one would want in this case.

I think the next thing I'll try is to use penetrant, and then set a bag of ice on the entire fitting for a while. The cap and the doughnut should then contract away from each other. Which is what we want. Then I'll attack with force once again.

[mainemandean]

Originally Posted by AlanT

Have you tried liquid wrench?

Spray, then leave for an hour, then spray again then apply shock (tap downwards with a hammer) then try to remove.

I've used Kroil. But the next go-round will be with liquid wrench. And I'll hammer with a hard rubber mallet; last time I used a hammer, and I was afraid of damaging the top of the cap too much. (Did scar it up some already.) Thanks, man.

[GreenWave]

I had this happen to both of my deck fills when I first went to Pumpout after buying the boat. PO stated they hadn’t been opened in three years. Noth8ng I tried budged them. So I took my cabinet in my head partially apart and removed the hose from underneath, then removed the entire deck fill and replaced with new. I still need to do the other one on starboard but it is more difficult as the access to the hose is behind the ac/dc panel. It is going to require some gymnastic maneuvers unless I totally disassemble the panel and wiring. But at least we have one working tank.

[mainemandean]

Originally Posted by GreenWave

I had this happen to both of my deck fills when I first went to Pumpout after buying the boat. PO stated they hadn’t been opened in three years. Noth8ng I tried budged them. So I took my cabinet in my head partially apart and removed the hose from underneath, then removed the entire deck fill and replaced with new. I still need to do the other one on starboard but it is more difficult as the access to the hose is behind the ac/dc panel. It is going to require some gymnastic maneuvers unless I totally disassemble the panel and wiring. But at least we have one working tank.

Yikes. Good luck!

[chris mac]

Originally Posted by Allied39

Sounds to me like you are about to install a new deckplate pump out fitting.
I would drill two holes and send a couple of 5/16 bolts into it and then use the longest bar possible to apply as much torque as possible to find the weakspot.....well unless the weakspot is your cockpit sole....stop before you tear that up.
And when you install the new one.....add a little lube.
A wise man once said " lubrication is the key to happiness"......and yes...obviously he was refering to mechanical situations......

This is the approach I used. Drill and thread 2 holes. I put in 2 bolts and used an 18" pry bar to rotate. If it doesnt come undone with that much leverage, it isnt coming apart!

If you seal the bolts, you could continue using the cap until you source a new one.

[sanibel sailor]

Originally Posted by mainemandean

Okay, here's what I don't get about the idea of using heat.

Heat expands metal.

We have two parts here: the cap and the "doughnut." If you heat the whole thing, two things happen. 1) The cap expands outward, increasing in diameter. 2) The doughnut becomes fatter, expanding outward along its outer circumference; but also expanding inward along its inside circumference; that is, into the hole.

So the cap, and the doughnut's inner surface, are expanding towards each other, closing the gap. This seems like the last thing one would want in this case.

I think the next thing I'll try is to use penetrant, and then set a bag of ice on the entire fitting for a while. The cap and the doughnut should then contract away from each other. Which is what we want. Then I'll attack with force once again.

The inside diameter of the donut expands. As the metal gets bigger, the inner circumference enlarges. Think if the donut was near solid with just a tiny hole. The hole would not get occluded. Similarly, a solid disc would not crush itself at the very center. If it did, a big disc really hot would behave like a black hole and increase density, etc.


If the cap and fitting are in contact (they are), differential heating will be hard due to rapid heat transfer. Keep trying heat. Even though cap and donut will expand at the same rate, heat makes metal cooperative. Get it hot, not just warm. Like "am I going to burn the gelcoat?" hot.

[mainemandean]

Originally Posted by sanibel sailor

Get it hot, not just warm. Like "am I going to burn the gelcoat?" hot.

It's that "burn there gelcoat" thing that frightens me!

Thanks!

[mainemandean]

Originally Posted by sanibel sailor

The inside diameter of the donut expands. As the metal gets bigger, the inner circumference enlarges. Think if the donut was near solid with just a tiny hole. The hole would not get occluded. Similarly, a solid disc would not crush itself at the very center. If it did, a big disc really hot would behave like a black hole and increase density, etc.

Thanks. A friend messaged me, and told me exactly what you're saying. Hey, I got HS and college diplomas without a minute of physics. Journalism major. The "fairness doctrine" does not seem to apply here.

[VChild]

Drill 2 quarter inch holes in the cap (nice and plumb). Borrow a boat neighbor’s Groco adjustable spanner wrench if you don’t have one. This gives a very solid grip and good leverage. If more leverage is needed, extend it with a pipe. Eventually replace the deck fill (or possibly just the cap) with the type that already has the 2 holes in it designed for the spanner wrench.

[sanibel sailor]

If your cap is stuck, you are not breaking my spanner. Sorry.

[VChild]

Originally Posted by sanibel sailor

If your cap is stuck, you are not breaking my spanner. Sorry.

Not likely. I've used a 3 foot extension pipe on one before. They are solid bronze with stainless steel tips and nearly indestructible. Besides they are only $23 on Amazon.

[JPA Cate]

By now, you've tried Kroil (which at one time was our go-to), and Liquid Wrench (okay for rust). Try "weasel piss", a home made mixture of equal parts ATF and acetone. We have had truly remarkable results with it for some years now, and it is the new go-to. It even works pretty well for fragile things. Let it set over night, if possible, but you can give it a go after about 2 hrs., and just may be amazed.

[Obviously, it is a toxic substance, so don't leave it where little kids might see it. We keep ours in a mustard jar (about 4 ozs). with a metal lid.]

It is far easier than all the other options...

Ann

[Celestialsailor]

Sheesh!...Cut the hose and replace both the deck fill and hose. $50 and 1 hour.