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Paint for heater water corrugated stainless steel connections

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jgy2001
jgy2001 Member Posts: 7

Replacing 3 years old 1" FIP x 1" FIP connections for outdoor pool heater water supply. This previous connections has some rusted spots and holes. What kind of paint should we use to prevent future rust and holes? Thank you.

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  • Jamie Hall
    Jamie Hall Member Posts: 23,554
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    It would be lovely if there were a paint which prevented rust spots and holes. I don't know of one, although there are some which will slow the problem down some (some of the Rustoleum products, for instance — not sure how they would work on polished stainless steel, though). A better bet is to keep the stainless clean. VERU clean.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Lyle {pheloa} Carter
    Lyle {pheloa} Carter Member Posts: 59
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    The rust is probably due to the chlorides in the air around pool area, If this was csst gas pipe the manufacturers would recommend wrapping it in silicone tape.

    kcopp
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,361
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    Hi, There is a good chance the old connectors were type 304 stainless. Look at using type 316. They should hold up better. https://pumpsandpipes.net.au/shop/falcon-316l-stainless-steel-flexible-connector-hose/

    Yours, Larry

  • ratio
    ratio Member Posts: 3,676
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    Is that a field-made CSST connection, or a manufactured appliance connector? (The connections on the end will tell you what it is.)

  • jgy2001
    jgy2001 Member Posts: 7
    edited June 5
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    This is corrugated stainless steel connections sold in Home Depot. Already made, not field made. Label show A Reliance Worldwide Corporation Brand. Typical pool hot water from heater is around 80 to 82 degrees F. Yes, pool water likely contain chlorides.

  • Jamie Hall
    Jamie Hall Member Posts: 23,554
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    So? They'll rust. Keep chlorine and chlorides and chlorinated water as far away from them as you can.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • jgy2001
    jgy2001 Member Posts: 7
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    The old 1" FIP x 1" FIP 24" SS Flex

  • ChrisJ
    ChrisJ Member Posts: 15,866
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    They literally carry the pool water Jamie, I don't think you can keep it away from them internally.

    That said, I've had quite a bit of 304ss hardware around my pool from gauges to hose clamps and none of it is rusting.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • WMno57
    WMno57 Member Posts: 1,390
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    For exterior rust on the hoses,

    Wipe them regularly with motor oil. Motor oils usually contain corrosion inhibitors as part of their additive package. I've read that marine motor oils have extra corrosion inhibitors for "The Demanding Marine Environment" Fact or marketing fluff?

    ZDDP (Zinc dithiophosphate) is a good corrosion inhibitor. Lots of ZDDP in STP oil treatment. STP has lots of marketing fluff. STP stands for Scientifically Treated Petroleum.

    Because Science!

    If you are in California, use organic coconut oil.

    Buy 10 identical hoses, 10 different oils, and make a YouTube video. You can throw a pool party with the proceeds. I'll bring the Nitrate Free* Hot Dogs.

    *this product includes naturally occurring nitrates from sea salt and celery powder.

    I DIY.
    EdTheHeaterManLarry WeingartenPC7060
  • hot_rod
    hot_rod Member Posts: 22,382
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    Maybe some PVC or silicone rubber hose would be better. Any online hose shop can build them to your length.

    A hose would have a lot less pressure drop also.

    Or spray a clear lacquer or enamel on the stainless?

    Falcon Stainless has PVC coated stainless connectors, Big Red is their commercial coated gas connector, that may work.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • ChrisJ
    ChrisJ Member Posts: 15,866
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    PVC and even flexible PVC are commonly used on pools.

    Polyethylene used to be but for some reason seems like it died off.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • jgy2001
    jgy2001 Member Posts: 7
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    But this is connections from the water heater to the pool. Typically temperature at least from 82F to 100F. Would this high hot water cause damages to PVC material? We also notice brass fitting here also have extensive corrosion.

  • ChrisJ
    ChrisJ Member Posts: 15,866
    edited June 6
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    Sch 40 PVC is rated for 72.6 PSI @ 140F.

    I think Rod was right.

    Use all PVC including PVC male adapters where necessary. No brass.

    Although like I said in my own pool I've had no issues with 304 at all.

    But I'm very picky with my water.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • hot_rod
    hot_rod Member Posts: 22,382
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    PVC seems to get brittle after years of pool use. Maybe it is related to how well the pool chemistry is balanced?

    I will say the flexible PVC seemed to be softer, less prone to cracking. It is commonly used to connect filters and pumps, I suspect it is rated for pool and hot tub pressures and temperatures.

    I bought some silicone rubber hose to use on pump carts, rated to 180f, crazy expensive, they price it by the inch!

    You see radiator hose on hot rods is sometimes that blue colored silicone hose. It is very flexible also. Probably overkill for pool use. I wonder that standard EPDM heater hose would be adequate. EPDM is used as seals and o rings in many plumbing products

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • ChrisJ
    ChrisJ Member Posts: 15,866
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    I would assume it's from the sunlight.

    PVC doesn't like sunlight and I think the flexible stuff may be even worse. I don't recall hearing any issues with buried PVC for pools.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • KC_Jones
    KC_Jones Member Posts: 5,746
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    Correct, PVC is not supposed to be exposed to the sun/UV rays. It degrades the outside, but in many applications it's more a cosmetic issue than an actual functional issue.

    The company I work for actually paints all ours prior to shipping as the units are just about always installed outdoors, a layer of paint offers enough protection to stop the degradation from the sun.

    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • jgy2001
    jgy2001 Member Posts: 7
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    Wow, that mean we should use PVC for this entire pool water heating system? Too late. We have all stainless steel and / or brass connections. All other cold water connections and filter systems are PVC. May be next pool?

  • hot_rod
    hot_rod Member Posts: 22,382
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    The flexible PVC stuff seems to last the longest.

    My pool pump, filter and heater were in a concrete block building and it became brittle. It would shatter if you tried to cut it. It was 20 years old when we bought the home, however.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    ChrisJ
  • PC7060
    PC7060 Member Posts: 1,204
    edited June 11
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    agree with Larry, tubing made from 316 grade stainless will hold up much better in salt/clorine. Used extensively in for coastal areas.

    Moot point if you go with PVC or another plastic type tubing.

    Larry Weingarten
  • jgy2001
    jgy2001 Member Posts: 7
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    Will PVC plastic pipes in 100F hot water hold up to 30 psi pressure?

  • ChrisJ
    ChrisJ Member Posts: 15,866
    edited June 10
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    As I said a few days ago, Sch 40 PVC is rated for 72.6 PSI @ 140F.

    That's it's actual rating, not where it will fail.

    According to this chart at 100F you're looking at 204 psi. This is all assuming 1.5" which is typical for pool equipment.

    https://pvcfittingsdirect.com/temperature-and-pressure-ratings-of-pvc/

    You can also find similar if not identical info in this pdf : https://www.jmeagle.com/sites/default/files/TB09TempEffectsonPVC.pdf

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • jgy2001
    jgy2001 Member Posts: 7
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    Thank you very much for your response.

    ChrisJPC7060