Does anyone know what this is?

[hellosailor]

MY first thought was "that looks like the old extinguishers in" my friend's building. But I had no idea that when they got scrapped they ever got repurposed this bizarre way! They used to be hung on the wall. There was a canister of vinegar near the top, and when the entire extinguisher was inverted, this combined with a bicarbonate charge to produce CO2 and pressurize the water in the bulk of the canister to spray out--assuming you knew enough to invert the whole thing so the hose was at the bottom and the water got pushed out.
Or the canister held the bicarbonate, and the "water" had the vinegar in it...I never messed with them to find out.
That's one heck of a kludge job to turn them into oil reservoirs though!

[Cadence]

Originally Posted by hellosailor

MY first thought was "that looks like the old extinguishers in" my friend's building. But I had no idea that when they got scrapped they ever got repurposed this bizarre way! They used to be hung on the wall. There was a canister of vinegar near the top, and when the entire extinguisher was inverted, this combined with a bicarbonate charge to produce CO2 and pressurize the water in the bulk of the canister to spray out--assuming you knew enough to invert the whole thing so the hose was at the bottom and the water got pushed out.
Or the canister held the bicarbonate, and the "water" had the vinegar in it...I never messed with them to find out.
That's one heck of a kludge job to turn them into oil reservoirs though!

Thanks! It has been perplexing me how they got pressurized. I remember it took two men and a boy to get one off the wall and invert it. I guess it is thread drift You probably remember carbon tetrachloride also. Every boat had them.

[hellosailor]

Sure, carbon tet was a "miracle drug". And oddly enough, apparently a key ingredient in the original Lava Lamps. I've only had to use dry powder and CO2 extinguishers though. And that yellow powder really makes you reconsider the option of letting things burn.(G)

[crazyoldboatguy]

Originally Posted by rdowall

Often, inaccessable voids on steel boats are welded shut and filled with oil to prevent rusting. The fire extingusher caps are a clever idea to seal the void between the ballast and the steel plating in the keel area.

For example, Irving and Electra Johnson installed oval/half round steel rub rails on their Yankee III before they embarked on a trip through the European canals. To prevent rust under/inside the rub rails, they installed caps at each end and filled the voids with engine oil.

If my hunch is true, I'd leave them as is.

That's what I like about this forum. I learn something new every day. I am a former shipyard welder (big Great Lakes freighters) and had not heard that. Makes perfect sense.

[eric boglio]

Thanks to everyone for the contributions, pretty confident now of what they were put in for, ie to finish the oil fill over the keel ballast after the keel top was welded shut, which is the only thing that makes sense...

[gjordan]

Even the best yards in Europe sometimes used boiler punchings for ballast in steel boats, and sealed them, then filled with oil through a plug/etc. I didnt buy a beautiful 35 foot steel boat back in the 80s because I was leary of this method. I later found out it was not uncommon. I wish I would have bought that boat. It was better than the one I ended up purchasing. Oh well! ______Grant.

[Rustic Charm]

Looks like an unexploded bomb to me be careful. How old's your boat, is it pre-war.

I have a steel Biorec, which is a French boat. I've got one of the steel ones from 1980 before they went into Aluminium boats which they still are today. I'm lucky enough to have the original hand drawn plans on my boat when I brought it. All in French unfortunately.

Last year I took my Rudder off. A large transom hung thing. I had my boiler maker repair a few things on it and he surprised me by asking me if I wanted to refill the three sections with oil. Well, of course I didn't know it had oil in it. He didn't recommend it but he said it looks like it was designed with oil in it. He also said that my keel probably has a compartment with oil in it too. Now half my keel is clearly a 170 ltr fuel tank and the other seems to be concrete. At least concrete in the top of it which I can see. But on the drawings is a void which I thought on the drawings is full of lead. Earwigs have eaten part of that particular plan. But after speaking to my boiler maker we wonder whether it has a compartment with oil instead. I'm certainly not going to drill a whole into my keel to find out and to date it remains air tight. If it is indeed an oil void.

The French ship yard still exists and I have emailed them numerous times when I first brought the boat, but they responded with a rather impatient 'yes we built your boat', it's number such and such for client such and such and that's all we have recorded. They clearly were not interested in their 1980's vessel.

But food for thought with your unexploded bomb.

[Cadence]

Originally Posted by gjordan

Even the best yards in Europe sometimes used boiler punchings for ballast in steel boats, and sealed them, then filled with oil through a plug/etc. I didnt buy a beautiful 35 foot steel boat back in the 80s because I was leary of this method. I later found out it was not uncommon. I wish I would have bought that boat. It was better than the one I ended up purchasing. Oh well! ______Grant.

That makes sense. I'm not sure I hadn't read from Roberts' info. back when that punchings could be used for economical reasons. I did build a fiberglass hull from his plans and was pleased with it. For what it may or may not be worth to the OP?

[Fine Tolerance]

I am involved in the steel boatbuilding industry and I can state that it is common practice to fill the empty portion above the ballast of an integral steel keel with oil when the space is not being utilized with tankage. When this method of extra corrosion protection is utilized nowadays vegetable oil is generally used whereas boats from the '70's and '80's were more likely to use mineral oils (either new or used). Mostly it is just a 3/4" plug tapped into a sealing plate welded near cove level and although I have personally seen innumerable examples of oil sealed into a keel void I have never seen old fire extinguisher tops used as the filling point. As the vast majority of Roberts boats are owner built it is possible the original builder was a fire extinguisher repair man and just had them and a welder on hand at the time and not a 3/4" tap.

[Cadence]

Originally Posted by Fine Tolerance

I am involved in the steel boatbuilding industry and I can state that it is common practice to fill the empty portion above the ballast of an integral steel keel with oil when the space is not being utilized with tankage. When this method of extra corrosion protection is utilized nowadays vegetable oil is generally used whereas boats from the '70's and '80's were more likely to use mineral oils (either new or used). Mostly it is just a 3/4" plug tapped into a sealing plate welded near cove level and although I have personally seen innumerable examples of oil sealed into a keel void I have never seen old fire extinguisher tops used as the filling point. As the vast majority of Roberts boats are owner built it is possible the original builder was a fire extinguisher repair man and just had them and a welder on hand at the time and not a 3/4" tap.

You can learn something every day, thanks. Again, if memory serves me, Bruce Roberts Goodsen was an Aussie.

[patprice]

Eric they must work well as otherwise you would have got blown away last night in Hobart lol. Big winds from a passing low sent my brother's yacht ashore in North West Bay.
Pat

[Nicholson58]

Originally Posted by rdowall

Often, inaccessable voids on steel boats are welded shut and filled with oil to prevent rusting. The fire extingusher caps are a clever idea to seal the void between the ballast and the steel plating in the keel area.

For example, Irving and Electra Johnson installed oval/half round steel rub rails on their Yankee III before they embarked on a trip through the European canals. To prevent rust under/inside the rub rails, they installed caps at each end and filled the voids with engine oil.

If my hunch is true, I'd leave them as is.

Our yard mate has a 68 ft steel home-built. The keel is filled with junk steel & re-bar. The remaining air volume is oil filled to prevent rust. Fill & vent holes on top, drains outside on the bottom.

[FamilyVan]

Originally Posted by Nicholson58

Our yard mate has a 68 ft steel home-built. The keel is filled with junk steel & re-bar. The remaining air volume is oil filled to prevent rust. Fill & vent holes on top, drains outside on the bottom.

I knew there was a reason I have a boat built by a yard.

Sent from my SGH-I547C using Cruisers Sailing Forum mobile app

[Dave Isom]

Hi, I would say that you are right and it's likely to be a means of sealing off the keel after it's been filled with oil. This would be done to prevent rusting in inaccessible areas like deep in the keel.
Re the hole, welding might be a little risky with the possibility of fire developing.
You could drill and tap the hole, put a bolt in there and seal it with metal epoxy or lock tight.
Good luck.