Ghetto hot water tank repair?

rattlenbang · July 05, 2013, 07:42 PM

I discovered that my hot water tank has a leak and has had one for what looks like a very long time. Lots of corrosion on the tin. I pulled the tank and cleaned it up, and found the hole. I plugged it with epoxy putty for now, but looking for a longer fix. My choices are a new tank (amazingly available after 40 years) for $300.00, or a weld repair which would add a whole new bottom to the tank for $100.00. While the last one appeals to me, I'm the type that loathes having someone else fix my stuff, but I don't have a tig welder. I'm wondering about a rubber patch covered with sheet metal and held in place with several self-tapping stainless screws around the hole. Any opinions on whether this would work? I'm not sure what kind of pressure is in these kind of water systems, but it seems to me that metal over rubber held tightly in place should work.

DaveVA78Chieftain · July 05, 2013, 09:12 PM

tig welded patch works

Aluminum MIG welding with gas works (flux core aluminum wire not available)

Aluminum Bronze weld will work on a pinhole but the flux boils resulting in pinhole leaks for a split tank (winter freeze)

Epoxy patch will work for a season or so if you can get it to hold under heated water pressure. It will fool you by holding cold water pressure but fail when heated up.

Best option is a replacement tank or a new unit. Determine tank P/N (http://www.marksrv.com/store52/agora.cgi?cart_id=6447674.13485&product=Atwood%20water%20heater%20parts&user4=replacement tanks) then look around a bit. Should be able to find one around $200

maxximuss · July 06, 2013, 03:00 AM

Kwik steel might help you with this till you replace it. It's a 2 part epoxy that works wonders.

rattlenbang · July 06, 2013, 01:06 PM

The stuff I used was similar. Funny no one has offered a comment about my suggested patch method.

Froggy1936 · July 06, 2013, 07:46 PM

David i have a roll of MIG aluminum flux core That i purchased at Home Depot It is a fairly new item . I have not used it yet But it does now exist ! P.S. the usual pressure in a R.V syestem is under 50 LB PSI usually( mine is set at 45 PSI ) But when hooked up to a city supply can go as high as 80 PSI

As far as your patch idea goes I think not !! Frank

moonlitcoyote · July 06, 2013, 08:14 PM

Well my husband says it should work if you can caulk it. That is the type of repair that he would do. Then if it doesnt work you can always buy a new one after you at least try it.

DaveVA78Chieftain · July 06, 2013, 10:38 PM

QuoteAs far as your patch idea goes I think not !!

Not exactly sure what you mean. I have seen both weld a split direct (no cover patch) and a rectangle patch used. They both used tig welding though.

Thanks, I will keep a look out for aluminum flux core mig wire.

For reference, I have tried the epoxy and aluminum brazing methods with only temporary results. Epoxy failed after a year. Couldn't keep Brazing from having pin hole leaks.

Dave

rattlenbang · July 07, 2013, 01:11 AM

So much for the epoxy; it didn't hold under cold water pressure.

I am curious about a screwed-on patch, but the way these things work usually you spend hours fighting with something and end up taking it in anyway. Every now and then you get lucky or stumble on something great, but not often. I once tried to fix a cracked plastic auto radiator tank using everything at my disposal, but no dice. Some things can't be fixed.

ClydesdaleKevin · July 07, 2013, 06:38 AM

Try an RV junkyard. You might be able to get a whole newer hot water heater for less than the cost of just a tank.

Kev

M & J · July 07, 2013, 04:10 PM

Affirmative on what Kevin said. I replaced our water heater with a 2009 Atwood for $300 from a salvage yard. I helped pull it and they bench tested it before I paid for it. Only 100 more than just a tank and better than half the cost of a new one.

pvoth1111 · July 07, 2013, 04:19 PM

What is your safety worth?? Mine is worth way more than a couple hundred bucks. fix it correctly

DonD · July 07, 2013, 06:09 PM

Recently put in a new Atwood, paid $262.41

rattlenbang · July 08, 2013, 12:59 AM

Not sure what safety issue is pertinent here, but While in the campground I decided to give this a go as a temp repair. It worked (so far).

[smg id=5321]

pvoth1111 · July 08, 2013, 07:04 AM

When you heat water it creates pressure and it can fail terribly and if the tank is in bad shape I wouldn't trust the relief valve either....BOOM!!! A hot water heater can level a house I 'm sure if it "failed" it would have any trouble ripping through your coach and you in it...its your call just don't park next to me.

pvoth1111 · July 08, 2013, 07:20 AM

I just looked on ebay and you can get a heater for less than a hundred bucks that can automatically switch between 110 and LP....others are a couple hundred or less....why not just fix it right by replacing it with a new one that may out last the coach?

maxximuss · July 08, 2013, 09:41 AM

I have to agree with Pvoth. I didn't think of the potential hazard that could be overlooked.

rattlenbang · July 08, 2013, 12:08 PM

Holy smokes I think that's a real reach. These aren't pressure vessels. They are limited by the pressure ratings of the water system itself as it is open to both cold and hot water lines. Over pressure could theoretically happen if the propane system kicked in and stayed on and set the water to boiling, but I can guarantee that that patch would blow off long before the pressure release valve went. How does one go from patching a leak in a tank to making a bomb?
This was an experiment based on curiosity no more, obviously I will have to replace the tank or heater. But an exploding tank that would rip through the coach is not realistic.

pvoth1111 · July 08, 2013, 02:16 PM

I would rather be wrong than you be wrong....I hope I'm wrong.

Stripe · July 08, 2013, 03:25 PM

When I was in the Navy we used patches similar to the one you used RnB, on pressurized piping, they seemed to hold pretty darn well until we got to a shipyard which usually took a few months to get to. My only modification I would do to that would be a metal strap around the tank over the patch. Gives it a bit more security and if the patch were to "pop" the banding would mitigate any projectile hazards.. Also, dun forget to rewrap it in insulation and an outer hard cover..

moonlitcoyote · July 09, 2013, 07:16 PM

Nice patch job, I dont see any problems since its not the propane that leaking. If anything your patch wont hold and you'll lose water. No big deal. You can come park next to me.

Oz · July 09, 2013, 08:37 PM

It looks very secure and although the water gets hot and is under some pressure, it's not like a pressure cooker. With the rubber seal, if there were any issue at all, I think the water would leak out from the spaces between the rivets.

The only issue I can think of is, with that hole patched, if there's a really thin, rusted spot somewhere else, that's where you might get a new leak. So, you can see that replacement tanks and even replacement water heaters can be purchased at very reasonable prices.

I also assume you have an on-demand pump so, when you're not using the water, the pressure is maintainded by the closed system. The only time pressure is added is when you open a faucet or water outlet in order to maintain the flow.

rattlenbang · July 10, 2013, 01:43 AM

It's been a couple of days, and so far it works fine. I'm happy. Meanwhile I just found a replacement tank for $150 bucks at a wrecker that he swears is in pristine condition. So it was a fun experiment. But I also installed a shutoff valve for both the propane and cold water line to the tank, because I hate it when appliances don't have shutoffs and you have to shut down and drain systems if you ever need to work on them. Swapping the tank will take like 15 minutes now.