If you were building the dream shop

Just making the point that you can do something foolish for years and perhaps get away with it. Greg

Would you include flying in commercial aircraft in your equation?

Harold

Suppose someone said, "I've stored a five-gallon can of gasoline next to my gas water heater for 15 years and never had a problem." Would you be convinced it was a safe practice?

Did you know that a liquid at 120psi compresses very little? The volume at 120psi is very close to the volume at zero psi. That's why hydraulic systems work the way they do. A gas, like air, at 120 psi is compressed into a far smaller volume. When a breach occurs, whatever is inside the pipe will quickly expand to its zero psi volume. A liquid won't move much, but a gas will, propelling anything loose and light, like PVC shards, along with it. That's why PVC isn't rated for compressed gasses.

PVC weakens with time on exposure to UV radiation, also. Some good sources for UV radiation are sunlight and fluorescent lighting. To make it "safe" for compressed air, it would also need to be isolated from shock and impact, and shrouded in something to prevent the shards from going where they could do any damage to people or other things. It's simply cheaper to use metal pipe than to make PVC safe.

I can sympathize with your disdain for OSHA bureaucracy, but it doesn't make sense to extend that disdain to the good science that some of their recommendations are based on.

Jim

Martin,

I've also done an isolated LORAN tour (Kure Island, Hawaii from

1980-1981) as an engineman (we call them MK's - Machinery Technician's). But Kure was a "Gilligan's Island". Thoroughly enjoyed it, but was island happy by the time the year was up and was glad to leave. I was able to do an overnighter on Midway Island after about 8 months on Kure. Wish I could go back, but the LORAN Station has been shut down and leveled (for the most part) and the island is now an animal sanctuary watched over by the State of Hawaii. You have to get special permission to go on the island from the state.

Extinguishers won't freeze stuff when used like they're supposed to. I actually tried to cool a six pack of my favorite beverage one time with a CO2. Nadda. However, if you take a container of the liquid and drop a ball, insect (don't ask me how I know), hot coffee, etc., you get some interesting results. Same thing with halon (back then we didn't know about the ozone damage from it). You can spray someone down with CO2 and it won't hurt them, but will scare the hell out of you if you're not expecting it (again, don't ask me how I know this). The noise and white "smoke" will make an internal mess of your pants, if you know what I mean. If you get a flake of CO2 on you you'll feel it; but it's not really what I'd call painful. It evaporates pretty fast. If I'm ever on fire (God forbid), please feel free to spray me down with CO2 or halon.

Dave Young

Mart> Great! I'd spray myself or you down if we were on fire. with CO2 I'd

This makes sense, and I've told the folks who would use it, to do so and leave the area immediately. But this is the same advice I give for using any fire extinguisher in this house - don't stay around, just get out.

OK, but I suspect that if I take it in for service, they cannot legally remove the halon and re-install it. So I've been simply weighing the extinguisher annually. Here I assume the pressure gage on the unit is worse than useless, as the vapor pressure at room temperature will be constant as long as there is any liquid in the tank.

When it no longer meets the spec, I will replace it with either co2 or dry powder.

Jim

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Only if you want to include driving a automobile on public streets! Greg

The comparison between flying in commercial aircraft and using PVC for airlines is a bit foolish! Many people fly many miles a day because they have too, there is no other choice to do the job in a timely maner. On the other hand there are many options for air lines that are fairly inexpensive, safe and accepted.

I would be willing to bet if there was a way to make a resonable comparison between the safety of commercial flight and PVC air line, commercial flight would be many times safer! (number of feet of air line multiplied by man hours in the shop vs. flying hours per person?) LOL!! Greg

The interesting part is, you invariably see the numbers quoted as "per passenger-mile." If one changes that into, "per hour of exposure" then commercial air travel starts to look a lot worse, approximately the same as, or slightly worse than, private auto driving. But they (the airline industry) never quote it that way.

I posted the question here recently, if anyone here had experienced a catastrophic failure of pvc air lines, ever. Several responded in the affirmative, and that's enough for me. Besides, all my air lines are soldered copper anyway.

Jim

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Sounds to me that PVC is perfectly safe for compressed air usage provided it is encased in a larger iron pipe :-)} Gerry :-)} London, Canada

Keep talking like this and you should consider including a bunkhouse as you will be getting visits from the group. Gerry :-)} London, Canada

The only problem I've had with pvc air lines is when the temps were around 0 or below. I tunked one with a long 2 X 4 entering the unheated shop and it literally exploded a 6 inch chunk out of it. It came apart in small shards about 1 or 2 inches long. The line was already regulated down to 90 lbs, or it could have been worse. I had to pick a few shards out of my face, two good sized ones and a small one. I'm lucky I wore prescription glasses. This happened so fast there was no time to turn my head or duck. I have no idea if this was a temperature thing or not. I know whacking it with the board did'nt help matters. I tore it out and soldered in half inch copper.

Jim Kovar Vulcan, Mi

Just curious! I don't defend the use of PVC for air lines. :-)

Harold

Dave -

We were on Kwajalein atoll and island. The Loran station was up-atoll.

The best story I heard regarding the hero stuff out of coastal rollers and the war times was during the early 60's - the Coast Guard had sent the typical flotilla checking on various Loran stations and other sites here and there. The Sea Air Rescue based at the airport was Navy. The Island was Navy until (ugh) the Army took over and that is another story for my annuals.

The drama : Soviet sub was in the Lagoon - 70 miles on a diagonal - boomerang shaped. Normally they were out at sea - they were spying on us - doing the odd missile shot - rather being shot at by the local shooters in Ca. Sometimes subs - they were rare shots.

If out at sea, the sub would be 'flowered' with baking flower - sticky mess and the photo team and sub nasty. Such is life. Then they picked the lagoon.

The cutters were coming into service the Loran station - oil for the generators, food, life and that stuff - when they spotted the sub. Wish I were there - I bet there was sweat on more than one brow!

The Coasties decided to give chase and call home (Washington naturally) Washington was slow to respond (or think) - the sub went into a shallow area in the northwest - really un-charted area - might have been looking for an outlet.

The cutters laid a sub net and bit fingernails waiting on Washington.

After a bit, the sub commander - likely under threat himself solved the incident.

He fired two tubes at the net, it blasted like all heck (phew) and without orders, the Coast Guard had to part way. They really had a foreign power within a Trust Territory in trusted to them - but had no war powers in that sense.

The Russians went back to the deep ocean and the Coast Guard went on their way.

It was one of those phew no one got shot and things went back to normal.

Kinda reminds me of the movie - "The Russians are coming" only differently.

We were the mid pacific refueling and missile target range - so we saw Deep Ocean trackers and typically cargo ships to us. It was a restricted port, but we had drop-ins.

Had a New Zealand carrier come to visit - picking up some planes after a typhoon....

Mart> Martin,

Balderdash! I The one I have in the office was just hydrotested and refilled 4/17/2003, and they didn't ask any questions at all... I even bought a new Halon for the Corvair a few years back, it was about $50 but they sold it to me. They are discouraging Halon use, and taxing it, but it isn't illegal yet...

If you don't believe me, call a local shop and ask them "hypothetically" if they can service it for you. The only thing that would stop them is if the previous owner engraved their name on it.

And Halon 1211 units have nitrogen for delivery pressurization over the liquid Halon contents that has a low vapor pressure, so the tare weight and cylinder pressure are both important.

You never mentioned a brand or model number... The only thing I could see stopping them servicing it is if it is one of the Plastic-head "Disposable" units the size of an aerosol can and sold as a "kitchen extinguisher" that was made to be one time use only. In that case, if it's 1201 inside they can capture the Halon in their big tank and recycle it, and give you a credit for the contents. Unless you get the fire really early, and inside a confined space like an oven, one pound or less of Halon won't go very far.

The important part is to find an extinguisher service facility in your area that is set up to work with Halon, they will usually also have their own hydrotest cell so they can do it all there.

A lot of small shops and mobile services don't have the gear, they farm it out and mark up the prices to cover the shipping.

If you are in Los Angeles, call Pioneer Fire Protection in Van Nuys, they do it all in-house and will take good care of your service needs.

818/785-8571 I take quite a few odd units found at garage sales for them to refill, including CO2-cartridge style, Purple-K, Army WWII Surplus 2.5# CO2 - but that doesn't get me an exemption from any of the safety rules. I've had to scrap a few units for dumb stuff like the serial number on the belly band was illegible.

-->--

I think they would then just include the time from showing up at the airport, till you get your luggage at the other end, and still come out OK.

jk

That inch (between the inside floor and the outside) stops rain blowing under the garage door. Depends on how exposed it is, it would be easy enough to make a shallow ramp. Geoff

Concrete... I'm happy with the way our new place worked out. Previously had a concrete driveway apron with exposed-aggregate finish that was pretty but not helpful for rolling any kind of steel or other small wheel.

For the new place we got a "light broom" finish, that is a tradeoff because it will eventually wear smooth enough to possibly be a hazard, but it sure is easier on the wheels.

Same here, the shop slab is flat and extends 6" past the door, then transitions in-line to the apron. There is no step or joint, just poured against the edge of the slab, it has held up OK for 4 years.

The overhead door is a 9' wide x 8' high that is under a 24" overhang and is on the lee side of the building anyway. No water entry to date.

8' out from the door, before the apron slab was poured I set two pieces of 4" sched 40 electrical conduit in footings and plumbed them carefully. Plated welded to the bottom, the open end is about 12" above the slab. After the slab was poured, they served as sockets for a lift frame built with 3-1/2" sched 40 pipe and a wide-flange beam. The 3-1/2" pipe eventually got welded to the 4".

There's a good photo here:

The scaffold in the photo had just been used to erect the frame, a rush job so we could get that lathe out of the back of my truck.

My evil twin brother apparently.

Having done a bit of research ... after the fact ... for air I have a few hundred feet of 3/4" sched 40 PVC underground, bedded in sand. Transitions to hard copper or galvanized steel before turning up towards the surface. Black pipe or copper above ground & in walls.

I chose a 2nd story instead of a high ceiling. For indoors, I use a pallet jack, a set of machine moving carriages or as last resort a cheap engine hoist.

Bob

Martin,

I can't come even close to that story. Closest I can come was when we were being refueled. A 180' buoy tender out of Honolulu would tow a Navy fuel barge to the island and hook up on at an off-shore connection. I was on the beach with a radio talking to the cutter. They were close enough that I could hear them making pipes on their 1MC (loudspeaker). I heard them pipe swim call and before the pipe was finished the crew was diving in. When one holds swim call on a cutter, you always have a look out with an M16 for a shark watch. Well, it just so happened that where the off-shore connection was was also where sharks liked to linger looking for Hawaiian monk seals. When I heard swim call, I called them immediately and told them that the area they were in was known for the shark activity. All you could see was asses and elbows trying to climb that cargo net. I literally rolled on the beach laughing....one of the funniest things I ever saw.

Same island, different subject. We had a LOT of spiny tailed lobsters at the atoll. So many in fact, there were scientists from Honolulu there studying trying to figure out why. They actually hired some of the crew to go out daily to count the lobsters they had caught in the lobster traps, kind of a census kind of thing. We would go out into the lagoon snorkeling and catch all the lobster one could want. We had hundreds of lobster tails in our freezer. We'd have a party on the beach occasionally and cook lobster and crab and lots of beer (Side note was that wood was a scarce commodity and we'd normally use pallets that came in on logistic flights. One day we had a large mahogany log wash in. Thing had to have been 15 foot long and 2 feet in diameter. It stayed wet a long time. We thought we'd gone to heaven as there was more wood than we could use for a long time. We found out that wet mahogany gives a horrible taste to lobster. So much wood, but none to burn.). Anyway, we had planned to have another cook out on the beach and we were going to cook some hot dogs also. Turns out the cook didn't want to part with his hot dogs and we could only eat the crab and lobsters we had caught. The crew was pissed. LOBSTER AGAIN!!!! We wanted hot dogs. Sounds silly now, but at the time it didn't.

Last story. I went to Midway with a DC3 and a non-rate. We got there early and went to the Acey-Ducey Club (E-5/E-6 club). We got there about 1100 and started drinking. There wasn't any air conditioning so we sat down in front of a pedestal type fan. We were drinking slowly and were by no way drunk. At normal quitting time (1600?) the Navy started showing up with their Navy girl friends (the island was being shut down, and there wasn't any dependents there anymore). They sat down (about 6 guys and 3 girls) and started drinking. One got up and went to the fan and turned it toward them. The DC3 got up and turned it back toward us. Another got up and turned it toward them. I got up and turned it toward me. Navy got up and turned it toward them and the non-rate got up to turn it back and the Navy guy punched him. Course there was a brawl. They beat the crap out of us and the NAVY Shore Patrol came and told us we had a choice of either going back to our quarters or to the brig. When we got back to Kure the next morning, we looked like hell. But we did get a few good punches in, but we were way outnumbered..... These days it would be considered an alcohol related incident. Two such incidents and you're normally kicked out.

I've never been to Kwajalein, but I was stationed on Guam on a 180' buoy tender. Our AOR was being changed to include Kwajalein, but I left before it happened and the cutter has since been decommissioned. No idea if we took over responsibility.

Dave Young

Mart> Dave -

This reminds me of when I was working nights, with a great co-worker. The place was about 100 degrees during the day, and they had big floor-mounted circulator fans to try to keep the guys from passing out from the heat. Things would calm down and we would run the fans at night, to bring in outside air and blow it over us while running the machines.

I would sneak up behind Don and quietly switch off his fan, and he wouldn't notice it for a bit. Then I would look over and say, "sure is hot tonight, eh?"

He got his revenge though, he would pull a load of parts out of our annealing furnace, and park the fork truck so the fans were blowing the air through them, right over me. Now

*that's* hot!

Jim

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