Any suggestions for fixing a rusty rim? Or is this dish even worth saving?

[ancient]

The story on this is that about a year ago I was driving by a house and happened to spot a big 10 foot C-band mesh dish in the backyard that looked (from the road) to be in halfway decent shape, so I stopped and knocked on the door but no one was home. So I left a note in the door basically saying that if they weren't using the dish and wanted to get rid of it to please call me. I stopped a couple more times and left at least one more note but could never catch anyone home, so I forgot about it. To make a long story short, about a week ago I got an unexpected call from a woman who said she was the fiancee of the guy who lived in that house, and she just hated that big ugly dish in his backyard (she really did call it a big ugly dish!), so if I still wanted it I could come and get it. She said he had saved my notes but didn't like to call people on the phone, so that's why she was calling.

So I went to get it and as soon as I got a good close up look at it I wondered if I had made a mistake. We had a real hard time getting it off the pole for some reason, but while we were working on it the woman came out and again made it clear she just wanted it gone, so we wound up disconnecting the dish from the mount first, then removing the mount from the pole. I figured since we were already there and since she wanted it gone so bad, I might as well take it even if it turned out to be junk (could always reuse the panels to repair another dish, if nothing else). I knew we were in trouble when we were strapping it down to the trailer and the rim actually bent a little. And the reason is because one quarter panel (the one that was closest to the bottom of the dish) has a VERY badly rusted rim. When I got it home I gave the entire rim a quick spray with some rust destroyer paint but even after that it looks like this:



I have two concerns about this dish, first is that with that rim so badly damaged is there any hope it will still hold the parabolic shape? It already looks a bit off to me; and with that rim so badly damaged there's not much to pull on if the dish needs to be pulled back into shape, and the panels already look a little "crumpled" in spots, but not horribly bad to me. And the other is, since I had to take the dish off the mount anyway I was going to flip it upside down so that the strongest part is at the bottom, where the snow will collect, but is there any way to repair that badly rusted rim first that does not involve serious metalworking skills? I don't have access to a welder or a machine shop or anything like that; I have basic homeowner tools like a drill and various types of saws but no way to form a new rim that I know of. I just wondered if anyone else might have encountered this and would have any suggestions on how to at least strengthen that rusty rim, if not get it into perfect shape, without spending much money. Or do you think this dish is so far gone that it will never work well enough to be worth trying to save? I was originally thinking of replacing my G16 dish, which is only 7½ feet in diameter, but considering the amount of rust and the possible deformed shape I'm concerned that it won't actually give me any additional signal strength. I don't know how far off from a perfect parabolic shape a C-band dish can be and still be usable.

I also wonder why just that bottom quarter panel is so badly rusted when the rest of the rim was in nowhere near that bad shape, but I guess that's one of those questions that will forever remain a mystery. It's almost as if that one quarter panel was originally pained with a different, inferior paint or something.

 

[FTA4PA]

The story on this is that about a year ago I was driving by a house and happened to spot a big 10 foot C-band mesh dish in the backyard that looked (from the road) to be in halfway decent shape, so I stopped and knocked on the door but no one was home. So I left a note in the door basically saying that if they weren't using the dish and wanted to get rid of it to please call me. I stopped a couple more times and left at least one more note but could never catch anyone home, so I forgot about it. To make a long story short, about a week ago I got an unexpected call from a woman who said she was the fiancee of the guy who lived in that house, and she just hated that big ugly dish in his backyard (she really did call it a big ugly dish!), so if I still wanted it I could come and get it. She said he had saved my notes but didn't like to call people on the phone, so that's why she was calling.

So I went to get it and as soon as I got a good close up look at it I wondered if I had made a mistake. We had a real hard time getting it off the pole for some reason, but while we were working on it the woman came out and again made it clear she just wanted it gone, so we wound up disconnecting the dish from the mount first, then removing the mount from the pole. I figured since we were already there and since she wanted it gone so bad, I might as well take it even if it turned out to be junk (could always reuse the panels to repair another dish, if nothing else). I knew we were in trouble when we were strapping it down to the trailer and the rim actually bent a little. And the reason is because one quarter panel (the one that was closest to the bottom of the dish) has a VERY badly rusted rim. When I got it home I gave the entire rim a quick spray with some rust destroyer paint but even after that it looks like this:

View attachment 119508 View attachment 119509 View attachment 119510

I have two concerns about this dish, first is that with that rim so badly damaged is there any hope it will still hold the parabolic shape? It already looks a bit off to me; and with that rim so badly damaged there's not much to pull on if the dish needs to be pulled back into shape, and the panels already look a little "crumpled" in spots, but not horribly bad to me. And the other is, since I had to take the dish off the mount anyway I was going to flip it upside down so that the strongest part is at the bottom, where the snow will collect, but is there any way to repair that badly rusted rim first that does not involve serious metalworking skills? I don't have access to a welder or a machine shop or anything like that; I have basic homeowner tools like a drill and various types of saws but no way to form a new rim that I know of. I just wondered if anyone else might have encountered this and would have any suggestions on how to at least strengthen that rusty rim, if not get it into perfect shape, without spending much money. Or do you think this dish is so far gone that it will never work well enough to be worth trying to save? I was originally thinking of replacing my G16 dish, which is only 7½ feet in diameter, but considering the amount of rust and the possible deformed shape I'm concerned that it won't actually give me any additional signal strength. I don't know how far off from a perfect parabolic shape a C-band dish can be and still be usable.

I also wonder why just that bottom quarter panel is so badly rusted when the rest of the rim was in nowhere near that bad shape, but I guess that's one of those questions that will forever remain a mystery. It's almost as if that one quarter panel was originally pained with a different, inferior paint or something.

Too bad that bottom is in the condition it's in - it looks like a decent dish other than that. The bottom likely rusted out because water will get in there when it rains or snows (and melts) and if there were no drain holes drilled then it just sets there rusting things away. If you are in the east and get acid rain or near the coast (salt water) it speeds up the process. Short of finding a similiar dish and cannibalizing it, perhaps you could take one of the good panels to a metal fabrication shop and they could duplicate the bend with a correctly sized piece of tubing that you could use to repair it.

 

[armadillo_115]

Maybe you could make mark the shape of a good rim section on some plywood and make a jig to bend a piece of steel PIPE. Use pipe sized to fit into the square channel and make it long enough to extend into both sides.Then all you would need is a drill and some bolts to attach it all together.Thatt would be a cheap way to get it up and test it.

I just realized that it is a buttonhook.Lack of feed arms makes it even more likely to have warped. Getting that 'hook centered/stable might be a chore.

There are too many 10fter's around here for me to spend much time or money reviving that dish...but your area may be different.

If nothing else, save the polar mount and mesh. You might could even sell that mesh to fellow member here. Best of luck!

Just my 2 coppers.

 

[Hockeynut]

I would scrap it out for scrap metal pricing..Saving the scaler ring,feedhorn and lnb`s...Sure a Sunday trip just driving around will have better results?..Oh also the actuator is another item to hang on to even if it is seized up...Just my 4 coppers..LOL..

 

[migold]

I am using a 10 foot mesh button-hook, with success, even though it is dented in one area of the outer ring. Your situation is worse than mine, but if you can implement the suggestion by Armadillo, you may end up with a usable dish. You can usually find metal conduit at hardware suppliers that is not too difficult to bend, and is designed for outdoor exposure.

 

[ancient]

Thanks. I understand what you are saying about conduit, I just don't know how I'd bend it accurately or how I'd attach it to the ribs. I've always done much better with wood than metal but unfortunately even treated wood warps, otherwise I'd maybe try to make something out of treated plywood. It's one of those ideas that sounds good in theory, but not if you're the one that has to actually try to make it work.

In my area there are a lot of dishes around but they all seem to fall into one of several categories:

Big old heavy white fiberglass - we tried saving a 7½' fiberglass one a while back and with three people could barely lift the doggone thing (though we were successful, I had a sore back for a couple weeks after), plus around here they tend to turn not-so-lovely shades of green and black due to leaf mold, and for some reason the fiberglass seems to react with all the screws and bolts and they turn extra rusty. Only way I'd want a fiberglass is if somehow I found one that could be disassembled into sections so we didn't have to try to lift the whole thing at once, and I'd probably only attempt that if it were a 12 footer.

Beautiful mesh dishes on tall poles - unfortunately the primary installer in this area also owned a tree service and had a bucket truck, so most of their installs were on really tall poles (around 15 to 20 feet off the ground, you can't even touch the bottom rim of the dish). There's probably a reason they're still around after all these years; nobody can figure out how to safely get them down without damaging the dish or injuring themselves or destroying property. You could probably push them over with a bulldozer or a huge truck, but I have neither, and the dish would almost certainly be damaged when it hit the ground, not to mention that it would tear up the lawn, which to most people is far more valuable than the dish.

Dishes owned by people who think that their dishes are solid aluminum (usually they aren't) and that aluminum is worth more per ounce than gold. In one case I found one that was on a high pole next to an attached garage and the lady still wanted $100 for it. That dish will probably stay there until the pole rusts away and it falls on her garage. Even if she had given it to me free I have no idea how I could have ever got it down in one piece. Oh, did I mention I am deathly afraid of heights?

(Yes, I've heard of "gin poles", but I have never seen one used and don't really understand the concept, and have no idea where you'd get one anyway. Plus that would still require being on a very tall ladder leaned against a small round pole. Not going to happen).

And, dishes on the roofs of closed businesses. Usually the only contact is a real estate agent and they will not reveal the owner, for fear you might try to go around their back and try to buy the place direct from the owner, depriving them of their commission. I've tried sliding notes under the door, etc. of such businesses but have never had any response. Someday they will probably tear those places down and scrap the dishes but unless I happen to drive by just as they are starting that process (not likely because none of those places are near anyplace I regularly visit) chances are whoever does the demolition will just see the dish as another piece of scrap metal.

The worst part about this area is half of it is forest so even if a house had a dish it would be nearly impossible to see it from the road. And I think all the mesh ones that were easily visible and close to the ground were claimed by the scrappers long ago. So the only ones left are the heavy fiberglass ones, the really hard to get ones, and the ones where people either don't want to part with them or think they are sitting on a scrap metal gold mine. Oh, and the ones that are damaged even worse than this one I just got, yet the owner still thinks they have gold. The sad part is, someone in my family recently took half a utility trailer load of scrap metal (including a bent 6' aluminum step ladder) to the recyclers recently and couldn't even get $20 for the load. So I have no idea where these people with the beat up dishes get the idea that their dish is worth so much.

 

[FTA4PA]

If you can find a way to bend it properly you can get what you need here:

Aluminum: http://www.metalsdepot.com/products/alum2.phtml?page=tube&LimAcc= &aident=
Steel: http://www.metalsdepot.com/products/hrsteel2.phtml?page=sqtube&LimAcc= &aident=

 

[armadillo_115]

Ancient, it's like making a hoop house without having to buy a hoop bender.Smaller scale of course.
Below is a photo I found online...Except I would make TWO rings on the jig so that your conduit drops down into a 'trough' for better accuracy as you bend it around.
Insert the bent pipe into both ends of the channel rim and add a couple bolts at each end.The ribs and mesh can be attached with screws or even pop rivets.

Anyway, just a cheap way to do it without metal working tools/skills.Hoop greenhouses are built in a similar fashion all the time .(1.5, 2 inch or larger pipe depending on the size of the green house needed)
Several videos on Youtube showing how the pros do it if you're interested.

Channel iron would probably be stronger and look better..but I don't believe you could bend it in such a manner.

 

[migold]

Since it's a 10 foot dish, getting it repaired seems possible. Even if your new side isn't perfect, it will be close enough to get you some good performance. I encourage you to try, if you can put in the effort!

 

[ancient]

I really wasn't going to use this dish, since it looked to be in such bad shape, but as it happened I decided to mount it on a pole and try it. I straightened it as much as I could, trying to get it back into something resembling the original shape, and came pretty close. A couple cans of Rust-Oleum Rust Reformer at least stopped the development of more rust on the worst spots while I decided what to do with it. As I sort of alluded to in my first post, I'm not particularly mechanically inclined, particularly when it comes to working with metal, but it worked well enough (probably at least as good as my 7.5 foot dish, and I know I can do some more tweaking to get it better) to try to do something to repair it.

The inspiration came when I was watching a syndicated home repair program that's transmitted weekly on one of the feeds channels. The guy in that show had to repair a support column with some rotted wood, not enough to replace the entire column, but after the rotted wood was removed there was still kind of a large hole. Now I thought he was going to use some kind of wood filler to repair it, but he used something completely unexpected: Bondo, a substance that is normally used to repair dents in auto bodies. He said that when it cures it's tougher than the original wood, and it sticks to just about anything. It comes in two parts, a white goopy substance and then a tube of some kind of curing agent. You mix the two together (there are several videos on YouTube that show you how to do it, just search for Bondo). It is not like epoxy where you mix equal parts, instead you knead the tube of curing agent and then use just a small amount compared to the amount of Bondo. You then mix them together completely. I do suggest watching at least three or four of the videos since they show you how to do it, and more important, what not to do (don't use too much curing agent, and don't mix it on cardboard or any kind of paper-based surface).

Since Bondo was originally intended for use on metal, it dawned on me that it would be perfect to repair the rusty rim - after all I was going for strength, not appearance. The hardest part of the repair was keeping the Bondo from running down off the metal, since I probably applied a little too much and it is a bit runnier than you would think. Ideally you apply it in ¼" layers but if you are impatient and try to apply it a bit thicker on a vertical surface or someplace with no support underneath, it will tend to sag or drop off after a bit. The solution is go in your kitchen and grab a box of waxed paper, and use pieces of wax paper to hold the Bondo and roughly form it the way you want (the waxed paper will release cleanly after the Bondo is cured enough to be firm). Even then you will probably still need to go over it a few times to fill in the gaps. Here is the result after a coat of black spray paint was applied, it's not pretty but I was going for strength and rust repair, not looks:



An auto body worker would have the tools to sand it down nice and smooth, and make it look like the original rim. I don't have such tools, so I used a surform-type device (a round one that attaches to a power drill) to take down the worst of the high spots, and then just painted it. I applaud you guys that have the patience to make stuff look like the original, but I don't, and the goal here was to keep the rest of the rim from totally rusting away.

One thing I did not do, that you are supposed to do, is sand the original surface down to bare metal. I did not do that for a couple reasons, one is that I had painted it with the Rust Reformer, which converts the rust to a black substance that I really didn't want to remove. But the other is that it would have been nearly impossible to get all the paint off anyway, given the original condition of the frame (how would you get sandpaper into all the cracks and crevices?). I figure that in this particular application it wouldn't matter as much, and so far that seems to be the case. If I were patching a somewhat flat surface like a car body then I would think it much more important to get the paint completely off, but here I was basically replacing part of the tube with Bondo, and it seems to have worked. The stuff seems really tough when cured, I would guess at least as tough as an aluminum tube, if not a steel one.

After getting the dish up onto the pole it became apparent why it rusted so badly. Most C-band dishes cover the ends of the support tubes in the center of the dish. This one didn't, instead they were left wide open so water could run inside during any kind of wind-driven rain or snow event. And, there were no "weep holes" anywhere around the rim of the dish. So I did two things to try and stop this from happening again. First, I drilled a small "weep hole" at the lowest point on the dish rim, so that collected water could drain out - and as soon as I drilled the hole, some water did come out!



The other thing is that on the back side of the dish, I plugged the ends of all of the downward-pointing tubes with Bondo.



I also tried to work some Bondo into the gap in the outer rim on the downward-facing side, just above the repaired section, so that water could not run down and collect just above the Bondo'ed section. What I was trying to do was make sure that any additional collected water has a path to escape, either through the weep hole or out of the gap in the outer rim. This may not be perfect (and I guess I'll know if any additional rust develops) but the real point is that this dish was poorly designed, or maybe poorly assembled, I am not sure which. If by chance you have such a dish, you may also want to drill a "weep hole" at the lowest point. Of course, if you plan on using a positioner arm to move the dish then the lowest point will vary depending on which satellite you have it pointed at, so in that case you may want to drill more than one. I'd also plug any downward-pointing open ends on the support ribs, if not with Bondo then with silicone caulk.

I'm not claiming this is the best way, or even the correct way, to repair such a dish but if you are like me and have almost no metalworking skills whatsoever, it's probably the easiest way. But before applying Bondo I would remove as much surface rust as possible, and then use some kind of rust converter product to change the remaining rust to something that is not rust. This may not last forever, but I'm pretty sure it will extend the life of the dish by at least a few years, and I can always use another C-band dish.

EDIT: Forgot to mention that I had removed the dish from the support ring, both so I could remove the rust and repaint the ring and mount, and because when we got the dish the mount was rusted so badly that we could not get it off the pole until we'd detached the dish (it's kind of a weird mount anyway, not like anything I've seen before, and also rather poorly made in my opinion). Anyway when I put the dish back on the ring I somehow managed to get it at a 90 degree angle from its original position, so that the rusty part of the ring was on the side rather than the bottom. This actually helped when applying the Bondo, because it was much easier to apply from the side than from the bottom up.

 

[JFOK]

ancient,

Your dish repair won't win any awards for beauty, but performance is the most important factor here.
Kudos for your efforts.

John