Swimming pool????

Discussion in 'Other metal working projects' started by Jason, Aug 1, 2018.

  1. Jason

    Jason Gold

    How does something like this end up here right? Growing up in Florida, we always had a pool. We had them all from a vinyl liner, to a fiberglass and several gunite pools. My wife has a certain itch and it's going to keep itching until I drop some big bucks. I'm indifferent about it myself, but if the lady is happy, then I get to be happy. I have a certain distaste for scumbag pool builders. They are all great at taking that first lump of cash and leaving you with a dug hole only to disappear for a month as they take your money and go finish the last job. I've been through this racket before and I'm not looking forward to this OR THEM! Anyhow, out here we have soil that is highly expansive and I've seen plenty of gunite pools with nasty cracks and fiberglass pools with bulges in the sides and bottoms. Forget warranties, you own it and any problem after that last check clears. Now, in a month or two, I'll finishing paying off almost 90k on a pilot training loan in just under 10years and getting a "pool loan" REALLY makes my stomach turn. My wife agrees and has been on board driving beaters and dumping cash on this loan and in our home for the last 10years. So I guess I should oblige her and see about scratching that itch.

    Now you know the back story, whats the best way to handle this? A $299 bullshit pool from walmart is not going to cut it so don't bother suggesting that one here. I don't see us moving in the next 7-10 years so might as well get comfy. I'm toying with the idea of a stainless steel pool. Prices on these from what I can tell are basically DOUBLE that of a comparable gunite pool, so in my neck of the woods, that means north of 80k. (Stomach starts rolling over again) Well, doing some fast math, 11ga 304 isn't really that expensive if it will tolerate chlorine at my temps with 316l a little higher. Oddly enough, I do know someone that welds and is probably half crazy to attempt something like this. Now if you think I am about to fall off the face of the net only to be found in a giant hole TIG welding SS in my backyard, you've got the wrong man. I would however consider a 8-12month project constructing 4 large sections MIG welding a stainless shell inside a steel skeleton and then have it craned over the house with final assembly occurring in said big hole in backyard.
    If you've been following Doug in Tulsa building that junk in his front yard, my project seems tiny by comparison. While in europe, I would guess 70% of the pools I saw were all stainless. Stainless steel is relatively new here in the states for pool construction, but the benefits compared to gunite etc make it worth the cost in my opinion. As a previous pool owner, I am all too familiar with the costs, headaches and down right sore back scrubbing walls of a gunite pool. Up to now, I cannot find anyone who has undertaken this on their own and I think a tour of a certain SS pool factory in NC might be in order for some spy shots of how it's done.

    I just want to throw this out to you metal junkies and see what comes back. My friends that know me well all say if there was someone that could pull this off, it's me. Flattery is nice, but still doesn't translate to the large task or deep hole I might stick myself in. Penny for your thoughts as we have tons of welders here that do it more than just a hobby.
    Thanks!
    Jason
     
  2. Jason

    Jason Gold

  3. FredsShed

    FredsShed Lead

    I never thought of a stainless steel pool, that would take a lot of hrs in welding, tig would b the better option for weld I think, I mean if your gonna weld, weld clean, nicer looking welds, and no spatter mess, wow, lots of hrs
     
  4. FredsShed

    FredsShed Lead

  5. Jason

    Jason Gold

    Fred, it's time to up your game man and build some copper or stainless stuff. Cruise that site and see some of the artisan bathroom sinks and tubs.. There is a market for that uber high end stuff if you're good enough. A YT channel running construction would be just the ticket. People like products with a story.

    I agree with TIG welding a SS pool... HOWEVER. I've got my eye on that new HTP propulse 200 mig machine. Zila on yt is a big HTP promo guy. He makes MR tig pushing chinese junk look like a hack. https://www.youtube.com/user/schneetiger77/videos I bet construction time could be cut way down running mig with a decent machine. The welds are going to be smoothed over where ever it would be visible. I have the HTP invertig221, italian made and it has been wonderful so far, but when you have 1000ft to weld, tig would suck big time.
     
  6. You'll have to passivate the stainless somehow after final welding to prevent the chlorine from the acids and salts from causing a "Tea stain" from surface iron so a stainless expert would be handy. You will also have the same issues with it popping out of the ground if the water table is high and you accidentally empty the pool.

    Fibreglass pool liners usually are ok if installed over a gravel/sand bed and backfilled carefully, the big issue is ensuring the drain is connected properly and pumps out to the street/sewer or whatever to prevent the liner popping out from retained water. I like the idea of steel reinforced sprayed concrete pools myself, but it takes a skilled crew a week to lay the steel and spray the concrete.

    Any hipster breweries that have gone bust lately and have electropolished food grade vats going for scrap?.
     
  7. Jason

    Jason Gold

    Like this?????? https://cougartron.com/

    No water table issues here. Just expansive soil. That could be solved with hollow cavities on the sides of the pool. These are self supporting shells. In fact, It could even be pulled out of the ground and taken on the road if need be. Commercial SS setups usually have "hallways" down the sides of them for maintenance. Digging is not an option for those guys.
     
  8. That's the eco friendly version that uses citric acid and electricity I think. The old version was to swab down with 20% nitric acid in water until the acid no longer causes a tea brown stain on the metal, I've only ever done it once or twice for that 316 stainless box that the temple bronzes were mounted on and it took about three swabs from memory. There are all sorts of precautions like using fresh grinding wheels and flap disk to avoid cross contamination. I remember using a wire wheel to polish some 316 earth straps for these 30 foot Moonraker HF whip antennas and being pleased with the shiny finish only to find them a dark chocolate brown on the ends where the Denso protective tape ended, a week later down at the slipway.

    Nitric is a powerful oxidising acid so it will remove the surface iron and passivate the remaining nickel and chrome with an oxide layer. Use in an extremely well ventilated outdoors location and park the cars upwind.
     
    Last edited: Aug 1, 2018
  9. MIG is the way to go. No reason you couldn't use backing plates so you can weld hot. You might consider a salt water pool instead of chlorine. Don't underestimate the force expansive soils can exert on a rigid structure. I'm assuming there are no basements in your area, like here.

    However, unless you just want the highest end pool in your part of Texas, have you considered an aboveground pool. for a few thousand dollars the can be made pretty nice, including an elevated concrete slab. They can be half buried with a select fill earthen berm around to where you don't really know it is an aboveground pool. Not much different than a liner pool. Why have you rejected a liner pool?
     
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  10. DavidF

    DavidF Administrator Staff Member Banner Member

    Last edited: Aug 1, 2018
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  11. DavidF

    DavidF Administrator Staff Member Banner Member

  12. Al2O3

    Al2O3 Administrator Staff Member Banner Member

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  13. Jason

    Jason Gold

    We looked at moving. Remember the idea was to NOT rack up another big loan. I sleep better this way. Paying cash for a year long project is better than signing up for 20years of being strapped to a larger home loan or some other house that needs and needs. Mine doesn't need anything. Once upon a time the lure of a 500k house was a goal; NOT ANY MORE! The yearly taxes are just pissing money down a hole. We are only 2 people and choose to live smart and not large. We don't want to owe anyone anything!

    The only above ground I might go, would be something like this. I need next to zero maintenance. We had a liner pool a long long time
    ago. It was a pain in the ass. Never looked good, sagged and leaked. We ripped it out and went gunite. This pool below is probably
    150grand. But given just material cost, I bet it wouldn't top 40k!
    Remember the old adage, Time, quality, price.... PICK TWO. Time I've got! I can do quality, now to sort out price.

    cdnassets.hw.net.jpg

    Private_Pool_D_Schondorf.jpg
     
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  14. DavidF

    DavidF Administrator Staff Member Banner Member

    But did you see the shop you get with the one house??
    Wife gets pool, you get bigger shop, everyone is happy :D.
     
  15. Jason

    Jason Gold

    The shop is decent, but I can't handle those low ceilings and homes on an alley. They always look trashy back there and you NEVER get to see the front of your house. They don't build them like that anymore thank god. Must be a texas thing. Putting a pool that sits next to the driveway and alley with everyone's stinky trash cans is stupid. Zero privacy. Thanks for trying, but I'm planted, If it's on the market here, we've seen it. I'd have no choice but to go new construction. We have been here for 10years and the value of our house has increased by 65%, amd we are sitting pretty as far as equity goes. I'm not concerned about spending some money short term, but refuse to get buried in any larger long term loans. ;)
     
  16. Peedee

    Peedee Silver

    I mig welded a LOT of 316 and second the brown stain issue. The other thing to consider is how you are going to cut/prepare all that sheet. If it were me I would probably look up a fab company and design the pool around sheets they can prepare, joggle the edges for laps, a corner for returns on the base and keep as much of it to a standard sheet size as possible. Delivered as a kit your parts drawings and then weld it up on site. (let there expensive machine shop do the hard prep)
     
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  17. Jason

    Jason Gold

    Excellent point peedee. I know working stainless can be a royal pain in the ass.
     
  18. Jason

    Jason Gold

    Small progress this week, been super busy.. I'm learning I should have paid attention in calculus class! DOH. I'm starting to collect suppliers and builders capable of assisting this project. I'm getting numbers now for 11ga 316L in the neighborhood of $15 a square foot. Yeah the stuff isn't cheap and I only would need around 700sq ft of it.:eek: So my initial estimate for SS was only a grand off. Good so far! I'm pretty confident I can get that number lower by working a bulk buy, outta state and calling in some favors for shipping. No way can I fit 5X12 sheets into the airplane. I found a local pool builder that's onboard with this. I think the money I'll pay him will be worth it for his help doing pool guy stuff, like digging the hole, setting the pool and small stuff like getting an electrical contractor, permits etc. He says this will be a first for this small town and is excited at the prospect of something this cool. When I told him I didn't want gunite, vinyl or fiberglass, he said so you don't really want a pool. Some what disconcerting is he never even heard of a stainless pool. I didn't dare tell him they build copper pools these days or he would have fainted.

    Does anyone have any websites handy for enginerding? I'm looking particularly for specs like load limits for different sizes of metal. Fortunately this thing won't be any deeper than 5 feet so that will give me some slop if my calculations are off. At the same time, I don't want to rely on backfill to keep from exploding out a wall or overbuild the bejesus out of it and piss away a bunch of money and time building stuff it doesn't need. My dad was REALLY good at figuring out this kind of stuff, but I lost him in 2012 due to cancer. I sure could use the old salts help on this one. I suck at drawing, but would like to post some sketches some time on how I envision this thing is constructed and I'm sure some of you smarter than me guys would have some great input. For now, envision a square metal box. The rails will be cut in simple L shaped sections to minimize welding and bending. These will be welded on the top edge of the box. That bending and cutting will be farmed out. Now this entire SS box will rest inside a mild steel ladder box spanning length and width. The two will not be joined together to prevent contact from two dissimilar metals and will be separated with silicone strips. The tricky part I see right now is the braces that must run around the walls and up to the L rail. These must keep the walls from bowing out. Not so bad so far right? Now on one end of this box, a raised section will allow just an 8" water depth extending about 6 feet into the pool for a tanning ledge. From there, stairs will lead down to the bottom. As much as I would like complete overflow for the entire thing, I haven't sourced someone yet for the complicated channel to pull that off and I want no part of building that nightmare. So that part kinda sucks, but I'm okay with a pair of conventional skimmers running the show and simplified construction. Even with skimmers, an infinity edge is still possible if I get creative. By creative, I'm thinking only setting this thing a few feet in the ground any ways. When your back yard is flat as a board, adding some elevation changes would create lots of visual impact. I'm in a fenced yard with nothing much to look out, so a front facing infinity edge might be a cool addition. (insert pool guy professional here) No thoughts yet on decking.... wife wants to see me use travertine with raised platforms and a wall where a certain large pair of gas lanterns will find their home separating a waterfall that pisses into the water. (getting the vibe yet?) :p

    Anyways.. enough of that for now. I think the place to start should be with a machine capable of welding this stuff, QUICKLY. That means MIG! I've never welded stainless so some sample material is in order and I need to learn to do it well. 2 years ago, I didn't TIG either so how hard can it be right? :D Doing the passivization thing is another important thing to master. The machine I'm looking at of course is another HTP (stel) machine. The propulse 200 is getting a little cheaper now that they came out with the pp300. Which one of you is skilled at welding SS? Any thoughts on pulse? How about gas choice? I'm hearing argon/helium/co2 is the way to go because stainless puddles move slow...? Any truth to any of this? I think zila on YT might be the guy for this question. Trimix is super expensive and maybe pulse might let me get away with 98argon/2Co2....?

    thanks gang! Could one of you nerds please tell a dumb guy if the water pressure/force on a 5 foot wall changes due to the area of that wall? Example wall 5ftx12ft versus 5ftx20 ???? I know it doesn't matter if there is 10 feet of water behind that or 5 miles of water, but depth is depth. If water has a spec gravity weight of 62.4 lbs per cubic foot, my guess is at 5ft depth, I'm holding back 3744lbs of force at the bottom. Am I all wet here and drowning before I start?:oops: FWIW, I'm thinking 12x20x5, ~9000gallons (1200cu ft of water weighing around 75k) This thing will be heated with a 400k btu gas heater and I want to be able to heat it FAST.
     
  19. You'd have to think of the water pressure in terms of a 1" square column 5' deep: 0.036127 pounds per cubic inch of water. So you'll have a water pressure at the bottom of the pool of 60 inches x 0.036127 pounds per cubic inch = 2.167 PSI . Makes sense when I stop to think about it, if it was much denser you'd get the air squeezed out of your lungs at the bottom of the pool.

    The weight of water is another thing entirely, metric would be so much easier to do the calculations: 1 cubic metre of water weighs 1 metric tonne. 3.6 metres x 6 metres x 1.5 metres = 32 tonnes of water at a maximum of 2.2 PSI.

    A circular/cylindrical pool would allow the sheets to be under tension and above ground would just need joining and no other reinforcing to contain the volume of water, it's only when you make it cubical shaped that the problems start. I would imagine many closely spaced vertical posts of about 2" x 1" box section with an outrigger brace halfway down would work. At 2.2 PSI x 8640 square inches per sheet, you'll have roughly 19000 pounds force per sheet. The actual weight is going to be half that as the pressure only increases with depth to 2.2 PSI.
     
    Last edited: Aug 18, 2018
  20. My gut feel is 11 ga is way too heavy. 16 ga should serve you fine. Maybe 11 ga strips at the bottom corners rolled to a 6" radius. You are going to be relying on tension across the bottom to hold the side wall loads. And you really need to plan on using compacted backfill to hold the load or you'll have an aboveground aquarium at 4X the price.

    Assuming the floor is supported underneath by the backfill (look into lean concrete, you can get it to flow under your pool), then you can calculate the tension on the bottom by looking at a 1 ft strip of pool, 5 ft down, 12 ft or 20 ft across, then 5 ft back up. Without using calculus, the pressure varies from 0 psi at the top to 2.2 psi at the bottom so it will average 1.1 psi. 1.1 psi over a ft wide strip is 792 pounds. So 800 pounds on the wall, and 800 pounds on the other wall. If the wall is only held at the top and bottom you have 400 pounds only on the bottom so will have a total of 800 pounds trying to pull the bottom, 400 each way. If you chose 20 ga at 0.0375" thick the one ft strip would have a cross sectional area of 0.45 sq in. 800 lbs will put 1,778 psi on 20 ga. Conservatively you could plan to load 316 SS to 10,000 psi conservatively (nominal 30,000 psi yield). In my opinion you'll save a lot of money by overexcavating and installing clean sand or a non-expanding select backfill to cushion to pool from the clay rather than trying to build a bullet proof box.

    But if you start looking at supporting all the weight of the water on a steel substructure you are looking at holding up 75,000 lbs, or an average loaded semi.
     

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