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-   -   Pan under water heater is corroding? (http://www.diychatroom.com/f7/pan-under-water-heater-corroding-145733/)

neight 06-02-2012 02:39 PM

Pan under water heater is corroding?
 
Hello,
The pan under our water heater seems to be corroding. There is a build up of metals or something (see pic 1 below). The heater is less than a year old. Seems an odd spot to corrode, there's no water or anything there, just the controls directly above the spot (pic 2). There also seems to be the starting of another reaction under one of the footings (pic 3). Any ideas? Thanks!

-Nate-
http://farm9.staticflickr.com/8166/7...94170093_b.jpg

http://farm9.staticflickr.com/8142/7...2edfafd0_b.jpg

http://farm8.staticflickr.com/7098/7...2bf2e25e_b.jpg

gregzoll 06-02-2012 03:15 PM

Brush that garbage away and take another picture and post it.

wctekkk 06-02-2012 03:18 PM

what the orange piece going into the pan?Is the elect ground on the gas line

Homerepairguy 06-02-2012 03:44 PM

Not sure what's causing the corroding but thought of an idea for a possible fix. This is a long post but I've tried to give you a lot of info in case you've never used fiberglass resin before.

Clean up the corroded areas. Mix up some fiberglass resin and pour it into the pan so it completely covers the bottom. Use a disposable brush to coat the sides. If the corrosion is bad, you could patch those spots with some fiberglass cloth first and then pour the resin into the pan.

There are different types of fiberglass resin like epoxy, polyester, etc. Epoxy resin has greater bonding and strength but polyester resin will work fine for your situation. I've only worked with polyester resin so that's what I'll discuss below.

There are two types of polyester resin. Laminating and finishing. Laminating does not cure fully so it allows additional layers/coats to be applied. It will remain tacky "forever". Finishing resin contains wax which floats to the surface and then allows all of the underlying resin to cure fully. If additional coats are to be applied over finishing resin, it has to be sanded to remove the wax coating.

You can just use finishing resin. If you apply some fiberglass cloth, mix up a small batch of resin and patch the spots. Let the resin cure completely and then sand the surface. Then mix up enough resin to completely cover the bottom of the pan and coat the sides of the pan.

The amount of hardener you mix with the resin will determine the cure time. Cure time depends on the resin/hardener used, and ambient temperature. Follow the directions for the resin and hardener you buy. Once the resin starts to harden, it goes very quickly so you will have to work fast when mixing and applying. If you've never worked with fiberglass before, suggest mixing about 1/4 cup of resin adding about 3 drops of hardener and mixing that up. See how fast it cures. Adjust your actual mix accordingly. I've always used empty milk cartons to mix resin. If you use a plastic container, test it first to be sure it won't melt.

Note that the resin will get hot as it cures. The thicker the resin, the hotter it gets. I've read that really thick resin, like casting objects, can get hot enough to start a fire. I've never seen it get that hot but just be aware of that characteristic.

HRG

joecaption 06-02-2012 03:51 PM

Just replace it with a plastic one.
I can not think of one reason that orange thing should have been run through the pan instead of over the lip.

neight 06-02-2012 04:07 PM

Thanks for the replies. I guess i should have mentioned I put an orange colored pencil into the corroded hole in the pan. I figured it would show up best in a photo. Plastic replacement and fiberglass patches are good ideas. I was concerned more with a possible reaction between something coming up through the basement floor and the pan, or if something was leaking from the tank that was creating a reaction. I did mention no sign of water, but something has to be causing it. Thanks again!

-Nate-

wctekkk 06-02-2012 04:07 PM

i think you should find the source of the problem if you say there is 0 leak on or near w/h, to me my first thought is some kind of electrolysis.

neight 06-02-2012 04:15 PM

I hadn't cleared anything, because I wanted to post exactly as I found it.
http://farm9.staticflickr.com/8022/7...8a05b00d_b.jpg

Homerepairguy 06-02-2012 04:33 PM

Quote:

Originally Posted by neight (Post 934616)
Thanks for the replies. I guess i should have mentioned I put an orange colored pencil into the corroded hole in the pan. I figured it would show up best in a photo. Plastic replacement and fiberglass patches are good ideas. I was concerned more with a possible reaction between something coming up through the basement floor and the pan, or if something was leaking from the tank that was creating a reaction. I did mention no sign of water, but something has to be causing it. Thanks again!
-Nate-

If you have the skills to cut the water pipes above the heater to be able to lift it and install a plastic pan, then that would be best and negate any electrolysis causing corrosion.

If you don't have the skills, then fiber-glassing the existing pan extensively will probably last the life of the heater. In this case, use laminating resin and cover as much of the pan as you can with fiberglass cloth. Use about 3 layers of cloth around the sides for strength. Then using finishing resin, pour about a 1/4" thick bottom layer and coat the sides to cure everything. Since there aren't any structural requirements under the heater where you can't apply fiberglass cloth, the 1/4" thick resin will work fine.

HRG

neight 06-02-2012 04:51 PM

I think i need to understand why electrolysis would be occurring. A quick search showed me nothing that applies to this situation.

Homerepairguy 06-02-2012 05:56 PM

Quote:

Originally Posted by neight (Post 934623)
I hadn't cleared anything, because I wanted to post exactly as I found it.
http://farm9.staticflickr.com/8142/7...2edfafd0_b.jpg

I just had a thought. Is there a capacitor in the electronics above the corroded part? If yes, it's probably leaking and the acid corroded the pan.

HRG

joecaption 06-02-2012 06:25 PM

Plastic pan and never have to deal with it agin.
Stray electricity, reacting with the surface it's sitting on, two differant metals it's in contact with causing the problum, you can patch, and play with it forever or just deal with it one time, your choice.

neight 06-02-2012 06:31 PM

Quote:

Originally Posted by Homerepairguy (Post 934666)
I just had a thought. Is there a capacitor in the electronics above the corroded part? If yes, it's probably leaking and the acid corroded the pan.

HRG

Good question! What am I looking for? Diagnostically.

Homerepairguy 06-02-2012 07:00 PM

Quote:

Originally Posted by neight (Post 934689)
Good question! What am I looking for? Diagnostically.

Electrolytic capacitors are the kind that leak so that's what you would be looking for. They would look something one of these:

http://image.made-in-china.com/4f0j0...-Capacitor.jpg

They can be in all silver metal cans, or be encased in plastic like the ones shown above. They are usually black or blue in color if encased in plastic.

Be sure to turn all power off to your water heater before you take the electronics above the corrosion apart. There will be lethal voltages/current involved. Also, it's possible for capacitors to hold a charge even after all power is removed, depending on how the circuit is designed. So you will need to be aware of that too and not touch exposed terminals of the capacitor. If you're not familiar with electronic/electrical work, it may be advisable to have someone who is take the electronics apart. If you do try it yourself, advise wearing rubber soled shoes or slippers and wear rubber gloves. I always wear rubber slippers when working on electrical stuff around the house, though I don't wear rubber gloves since I've worked on electronics & electrical stuff for my job for over 40 years.

HRG

neight 06-02-2012 07:46 PM

there is no exposed compacitor nor is there any evidence of leakage from the housing. there is conduit directly above the spot which shows no corrosion. still baffled.


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