Question

WaterFeature01   QUESTION: This Feature was designed/built by a friend and his contact, who assists a pro WF builder but has little experience on his own. Knowing I couldn't achieve near what they delivered [on a $2,000 budget] going through traditional sources, who am I to bitch about the issues/problems...Hence, I'm on my own to attempt a fix, so any help would be greatly appreciated...

Primary issues are the following:

1) As you can see from pics the epoxy sealant (covering the pre-rusted sheet metal) has bubbled over almost completely. How can I, if at all, strip/re-epoxy (or some other coating) that will resist the same fate.

2) When re-sealing...what advise could you offer that would help maximize the probability of maintaining a full water "sheet". As is, w/ a pondmaster 1800GPH pump the "branching" is worse than the 1200GPH I replaced (and that was far from ideal. (I have since learned my lesson about the turbulence thing...However, looking at the copper pipe/hole configuration...Any suggestions/tips? I'm sure the bubbling doesn't help, but what in the coating process...

Sorry for the long post, but this thing has been a thorn for more than a few years...Thanks, Ed



ANSWER: Eddie:
Unfortunately, I am sorry but I am not an expert on applied epoxy finishes, especially to oxidized surfaces. I would have suggested using a sheet of copper to achieve a mottled metal look without requiring coatings. I will say that I suspect that your clear coating did not properly cure before it was used or that the oxidation was too loose and thick for it to properly bond. Perhaps you should sand the metal and chemically clean it before coating it again. Leave minimal oxidation on the surface. But thats just a guess.

As for ensuring a full sheet of water will fall uniformly over the weir, that requires a sufficient amount of water being pumped and delivered uniformly across the top edge. "Uniformity" in this case requires a perfectly level top edge and a delivery system that will not cause irregular turbulance. Most fountains deliver the water into the bottom of a reservoir that fills and is leveled by gravity. The water fills till it over flows across the top edge. To limit or remove turbulence, some form of baffle is required. The delivery pipe typically hits some sort of plate that diverts the energy back into the bottom of the reservoir rather than allowing it to boil up to the surface. Your reservoir must be sufficiently deep to compensate for any dissipation of the turbulence at the bottom of the tank. You will likely have to experiment with different pump sizes and regulators as well as baffles and reservoirs depths to find what works. Try terminating your incoming water supply into some sort of filter material as the most simple way to create a cheap baffle. You can typically buy sheets of filter material at home and hardware stores as well as pond and fountain suppliers. Just attach a thick piece with a rubber band to the end of your incoming water at the bottom of the reservoir.

Best of Luck
Sean Murphy, LA, ISA, LEED AP
www.seanjmurphy.com
www.amenityarchitects.com
www.seengineering.com



---------- FOLLOW-UP ----------

QUESTION: Hey Sean, thanks for the helpful tips. Having taken steps to prep for the pain-staking task to strip and re-seal my WF, I've decided to follow your advice with regard to helping achieve a clean water sheet. This, i'm sure you'll agree, requires a design mod, that being replacing the WF upper delivery water system from a 1" pipe(w/holes) to a trough system. Hopefully the rules allow for the following link as I'll reference directly regarding the few ?'s/issues that I could sure use some guidance with.



http://www.flickr.com/photos/25624051@N05/sets/72157624964834286/detail/



1st off, do you think I'm close on the dims of the trough in 2nd pic?

Once the pipe is removed where would you seat the trough, on top of the WF adding 5" more height to the overall water wall...or tick it behind the top of the WF so it meshes w/ the top edge, not adding to height.

I guess what I'm really trying to figure out is the best way to seamlessly as possible configure the new trough mod to the existing WF. Confusing? Probably!

What thickness sheet metal would u think appropriate, and should the leading edge (where water rolls off) be rounded off?

Lastly, I realize u r a busy professional, if u could answer one of these somewhat mixed up ?'s I'd be a happy guy. :)



Thanks, Ed

ANSWER: Ed:
Wow, I wish I could be more detailed but a lot of this kind of ONE-OFF stuff requires a bit of trial and error. You are getting into real specific expertise now that I just don't have. I use Hobbs Architectural Fountains or Roman Fountains to design my significant high end fountains when they get this detailed and they would usually do a real life mock up and test it first. I usually go out to their shop and review the operating mock up and we tweak it as needed before final fabrication. I suggest you do the same. Your trough seems about right at 3"x4" but it really depends on the force of the water coming in from the pump, the effect at dampering the water your anti-vortex plate has at the bottom of the trough plus the required amount of water you must deliver over the edge to achieve your desired results.
The metal thickness ought to be about that of a good stainless steel sink you would find at a home store...I'm guessing thats about a 1/32 of an inch? But I really am not positive. If you are having this fabricated a good metal shop ought to be able to advise you on a thickness that will be sturdy enough for your needs. Just be sure to fully explain the usage to them. I would consider building a PVC mock up using a piece of PVC gutter from a home store as a cheap way to test your basic design. You could probably build it for under $30 in parts and glue and use the same pump to ensure you have an idea of the flow you'll get.

Hope this helps...send me pictures when you are all done!!! looks like a cool design.

Best of luck
Sean Murphy
www.seanjmurphy.com


---------- FOLLOW-UP ----------

QUESTION: Hey Sean,


Me again:). Before I leap head first into this thing, I was hoping you could clarify a point from your response. Which I must say from your initial "wow" I didn't expect much, but as I read on was stoked to find some real helpful gems of insight that will help push me forward.

Although I've done my share of research in the last few weeks, some of the terminology??? Could you briefly explain... "anti-vortex plate has at the bottom of the trough"

What is it? Is it fabricated into the sheet metal trough? Is it an add on? Then, where can I buy one or find specifics to provide metal fabricators. I speculate that this dampening element is important and can possibly help "save" an imperfect design to some degree. Remember, "I know nothing" so any tidbits you can provide are gold and (and while admittedly more affordable:) immensly appreciated.

One last thing about your modeling advise...In theory it would be the smart way to proceed or if I was "tight" with the Myth Busters help to take this "low scale" (interesting enough they are a few blocks from me:) . Bad news: I have no modeling experience whatsoever. Good news: I do have a connection to a metal fab shop, so I have a couple of attempts (freebies) to get it right before I've worn out my welcome. But, not being a huge fan of labor intensive "do-overs" the first time sure would be a charm.

By all means pics, of anything less than a disaster, are well on their way...give or take a few.


Thanks,

Ed

Answer
I may have miss used the term as there appears to be use of this term to describe a device in a floor drain that keeps the water from swirling as it drains. However my understanding from past fountain projects, if I am remembering the correct term, was that  Anti-vortex plate is simply a baffle that reduces the effects of water turbulence on the surface of the reservoir from the water being pumped in.

Without an anti-vortex plate there could be (depending on the force of your pump, orifice location, size and depth of your reservoir) irregular surfaces on your reservoir creating an uneven flow of water over the face of the water feature.

These effects can cause splashing, etc in cases where the water coming in is very forceful.

In larger features the plate is typically a metal shield mounted a few inches above the incoming water openings. It makes the turbulence bounce back toward the bottom of the reservoir and keeps the surface flat and even.

Best of luck with your mock up.

Sean J Murphy
www.seanjmurphy.com