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  1. #21
    Forum Member Rescue101's Avatar
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    THANK YOU! Aluminum SUCKS! At least this one does,Hehe T.C.


  2. #22
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    I'll lob one over the plate....

    What about poly bodies, such as those Darley uses?

  3. #23
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    Default Stainless

    While I admit that SS does not rust in the conventional sense, some of the alloys do exhibit signs of discoloration or oxidation. This tends to reduce the value of the material to me - it is no longer impervious to the elements.

    Stainless is also a difficult material to work and some alloys tend to be fairly brittle - especially compared to other materials. Difficult to work translates to higher cost.

    Repairs are problematic at best. Probably cut the bad spot out and replace altogether would be the most likely repair method.

    No ss extrusions are available for constructing body assemblies so all bolted or welded assemblies must be made - or a combination of these methods. The resulting weight gain may not be acceptable in terms of effect on cargo/personnel carrying capability. This weight is largely comprised of assembly hardware as well as the need to sandwich panels in bolted compartments. Metal to metal sandwiches are not a good deal in the corrosion world since they tend to accumulate water and water borne chemicals like road salts.

    Stainless is also a heavy material which once again works against us in some cases requiring heavier vehicle components and commensurately more initial expense.

    Higher material cost added to more hardware and more expensive assembly methods again work against this material by upping the cost to the end user.

    With SS, all body lines will necessarily be pretty straight with few curves and almost no compound curves - unless there has been a lot of body putty used. So style may be affected with this material which may be important to some folks.

    Now I understand why most general use trucks are not made out stainless.

  4. #24
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    Default Poly

    Years ago I heard rumors of poly bodies being susceptible to dimensional change problems due to heat. According to the story I heard, the side of the apparatus getting the most sun would expand while the other side stayed pretty much the same. Hot side doors wouldn't open or close properly.

    I have no idea if this is true but can tell you that poly tanks we have been using in our newer apparatus do not seem to have this problem so this was probably just another sour grapes rumor someone planted.

    Door panels, bumper sections, etc on modern cars are often poly, but these are relatively small area components held in place on a larger framework which usually has a reveal area around it to accommodate temperature differential related thermal expansion or contraction. This would seem to imply that the car manufacturers acknowledged a problem and designed around it.

    What happens to poly materials in extremely cold temps? Do they go brittle and crack or shatter? Wish someone from Darley or any other poly builder would join in on this discussion.

    Does poly take paint well? How about poly repairs?

  5. #25
    Forum Member Bones42's Avatar
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    I have no idea if this is true but can tell you that poly tanks we have been using in our newer apparatus do not seem to have this problem so this was probably just another sour grapes rumor someone planted.
    Are your poly tanks normally exposed to much sunlight and/or heat?

    Mine aren't. It's usually full of somewhat cool water.
    "This thread is being closed as it is off-topic and not related to the fire industry." - Isn't that what the Off Duty forum was for?

  6. #26
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    Quote Originally Posted by ponebutton2 View Post
    Years ago I heard rumors of poly bodies being susceptible to dimensional change problems due to heat. According to the story I heard, the side of the apparatus getting the most sun would expand while the other side stayed pretty much the same. Hot side doors wouldn't open or close properly.

    I have no idea if this is true but can tell you that poly tanks we have been using in our newer apparatus do not seem to have this problem so this was probably just another sour grapes rumor someone planted.


    .....
    I believe it was the Rattlesnake Co trucks Darley built that were widely discussed that had big issues with thermal expansion.

    My polytank never sees sunlight.

  7. #27
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    Not just the tank, the whole body. The new Darley trucks have poly bodies on them.

    My guess is that they'd hold up fairly well, because I know that the poly tank on our brush truck as seen some fairly rough terrain.

    That said, the poly tank on our Fouts Brothers tanker (as well as any wetside tanker) is exposed to sunlight and hasn't shown any problems.

  8. #28
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    not sure about the thermal expansion...but it makes scense. As far as repairs, from what I'm told its fairly simple. they cut out the bad and "poly weld" a new piece in...then sand it and paint it and it's done.
    It takes a little intelligence to enjoy humor,satire & wit, but none to be offended by it.

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  9. #29
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    Quote Originally Posted by simpleguy68 View Post
    Not just the tank, the whole body. The new Darley trucks have poly bodies on them.

    My guess is that they'd hold up fairly well, because I know that the poly tank on our brush truck as seen some fairly rough terrain.

    That said, the poly tank on our Fouts Brothers tanker (as well as any wetside tanker) is exposed to sunlight and hasn't shown any problems.
    simpleguy - Our department is researching tankers and builders. Would you mind sharing (here or privately) your impressions of your Fouts Bros rig? How long have you had it, what are the vital stats, Any lessons learned?
    Thanks,
    Andy

  10. #30
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    Cool poly bodys

    only thing i know about poly body on darly unit by us the chief has said the dept lettering has had to be redone 4-5 times as the letters keep coming loose?
    Randy Meyer Chief S.T.F.P.D.

  11. #31
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    Default lettering

    Probably not using thr correct adhesive to apply the letters. I guess after the first failure I would contact Darley or the sign folks and get a recommendation for the adhesive. Doesn't sound like a poly failure to me.

    Then of course they could also pull out the old router and groove in some letters - look kinda like a state park sign on wheels.

  12. #32
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    Quote Originally Posted by Andy2802 View Post
    simpleguy - Our department is researching tankers and builders. Would you mind sharing (here or privately) your impressions of your Fouts Bros rig? How long have you had it, what are the vital stats, Any lessons learned?
    Thanks,
    Andy
    We've had it two years and it's been virtually perfect. It's a 2006 Kenworth tandem with 3000 gallons and a 500GPM Darley PTO pump. Cummins ISC 330HP with an Allison auto.

    The only thing we'd change is our truck only has a rear dump and we'd go to side dumps, but not the standard Fouts side dump as they're actually above the bottom of the tank and you can't get all of the water out using the side dumps, only the rear dump.

    Our tanker has the electric dump valve that can be actuated in the cab and a rear-view camera, allowing you to back up unaided and dump without leaving the cab.

    We really like the way Fouts does the drop tank. It puts it at a decent height for deployment without having to use electric or hyraulic lifts.

    The truck runs really well, accelerates quickly and stops on a dime. Handling is superb with little water sloshing or body lean.

    Sorry, I know I sound almost like a salesman, but I swear I'm not, just very, very pleased with our purchase.

    The truck can be seen at our website at www.tarkingtonvfd.com

  13. #33
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    Default Poly

    Quote Originally Posted by ponebutton2 View Post
    Years ago I heard rumors of poly bodies being susceptible to dimensional change problems due to heat. According to the story I heard, the side of the apparatus getting the most sun would expand while the other side stayed pretty much the same. Hot side doors wouldn't open or close properly.

    I have no idea if this is true but can tell you that poly tanks we have been using in our newer apparatus do not seem to have this problem so this was probably just another sour grapes rumor someone planted.

    Door panels, bumper sections, etc on modern cars are often poly, but these are relatively small area components held in place on a larger framework which usually has a reveal area around it to accommodate temperature differential related thermal expansion or contraction. This would seem to imply that the car manufacturers acknowledged a problem and designed around it.

    What happens to poly materials in extremely cold temps? Do they go brittle and crack or shatter? Wish someone from Darley or any other poly builder would join in on this discussion.

    Does poly take paint well? How about poly repairs?
    The expansion and contraction is minimal and has never been an issue (that we are aware of) with respect to sunlight exposure. The key is in the "type" of poly being used. A copolymer resin is best. We use Polyprene which is a specially formulated copolymer sheetstock material. The resin used is made up of a combination of ethylene and propylene monomers which results in stronger physical properties in either high or low temperature applications (for example-there are many bodies on trucks in Wisconsin). It's strong enough to do the job, but also flexible enough to resist cracking and fatigue due to constant movement. This type of resin is also used in orthodics and prosthetics

    With respect to paint - It paints beautifully as long as the proper painting instructions are followed with a specially formulated primer.

    Rooftoptrucky is correct on the repairs: "As far as repairs, from what I'm told its fairly simple. they cut out the bad and "poly weld" a new piece in...then sand it and paint it and it's done."

  14. #34
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    Quote Originally Posted by ponebutton2 View Post
    Years ago I heard rumors of poly bodies being susceptible to dimensional change problems due to heat. According to the story I heard, the side of the apparatus getting the most sun would expand while the other side stayed pretty much the same. Hot side doors wouldn't open or close properly.

    I have no idea if this is true but can tell you that poly tanks we have been using in our newer apparatus do not seem to have this problem so this was probably just another sour grapes rumor someone planted.

    Door panels, bumper sections, etc on modern cars are often poly, but these are relatively small area components held in place on a larger framework which usually has a reveal area around it to accommodate temperature differential related thermal expansion or contraction. This would seem to imply that the car manufacturers acknowledged a problem and designed around it.

    What happens to poly materials in extremely cold temps? Do they go brittle and crack or shatter? Wish someone from Darley or any other poly builder would join in on this discussion.

    Does poly take paint well? How about poly repairs?
    Expansion and contraction are minimal and all bodies/tanks are properly designed and engineered to allow for it. Copolymer truck bodies have been in use for over 10 years and there are bodies in very cold and hot climates that have performed flawlessly. The key with respect to extreme temps is that the material used is a copolymer of polyethylene & polypropylene resin which greatly increases the strength & flexibility.

    The material paints easily (but a special primer must be used) and repairs easily just as ROOFTOPTRUCKY described..

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