Sealants for leaky waste tank

[gimmeagig]

Hi,
I just had to replace my blower and now I have another problem. My wast tank is leaking.
It's an older (1999) CDS machine.I have had a couple of leaks already I was able to drill out the hole,put a bolt and washers through it and that worked. This time the hole is at the front edge where the waste water drain valve is. I drilled out the hole again and was able to thread a bolt into it with a washer again but it's so close to the bottom that I can't even get a nut against it on the other side. So I siliconed the washer to the tank from the outside and then epoxied the washer in place so it won't come off even if the threading of the bolt or the silicone fails.
But and when I look into the bottom the whole first 10" is is pretty deteriorated. Could be only a matter of weeks before i have another leak. So I did some research and I found two coatings that are self leveling and might work.
One is a Sherwin William product called Armor Seal 650 SL/RC
The other is sold by my local marine supply store and it is called Glove It.
I know eventually I'll have to take out the tank and have it repaired. A local shop can fabricate some kind of tub that fits around the bottom of the existing tank for about 500.- plus whatever LPM in spokane would charge to take the tank out and then reassemble it.
In the meantime I really would like to get my tank sealed so that I can at least make it through the winter.
Have you guys used these coatings? Do they work? Could they work even permanently?
If it do this should I coat the whole bottom of the tank instead of just the front part?
Hydramaster is not selling replacement tanks anymore. Is there another option?
That blower cost me almost 4000.- so I'm really looking for a solution that I can swing at this point.

 

[Chris A]

No replacement tanks? Wouldn't a current c.d.s. have the same tank?

 

[bob vawter]

yes Roxy....go find a local fab shop that works in aluminum (I'm assuming)...
have them brake a flat piece of 6061 alloy...11 ga.... so that it goes on the bottom AND about two inches up the side of the tank and tig it up...if you can afford it ...do the whole bottom..wrapped 2"up...it'll last ya another 10 years
easy peesy!

when you put a steel bolt and washer on aluminum ...
you jus speed up the electrolysis that rots the aluminum out

ps
a waterjet co is what you need

 

[shadygrady]

Use aluminium washers/backer plates. I have used these, mine are cupped and hold a little dab of silicone nicely on each side. I didn't use them on a deteriorated tank, just to seal some holes where the tanks used to bolt together.

 

[Vivers]

Sounds like it's time to ante up and get a new waste tank

 

[gimmeagig]

QUOTE=Vivers;4311311]Sounds like it's time to ante up and get a new waste tank[/QUOTE]
Like I said earlier, Hydramaster told me they don't have that tank anymore.
I know it sounds strange because their new machines look like the old one but maybe the hookup for the blower is different. i don't know.
I just bought a can of Gluvit.
http://www.marinetex.com/gluvit.html
I'm going to just coat the part of the tank that's under the filter basket. That's the worst area. I patched one hole but the bottom looks like it will start leaking soon.
I need to get back on the road ASAP because my second payment for my blower is due.

 

[gimmeagig]

I applied the second coat and it is setting up really well. 72 hrs of drying time but the product is self leveling so I it really reaches into all the weak spots.
I really hope it works.
BTW I took to truck to another welder to get a second quote. He wanted 800 to replace the bottom compared to the under 500 quote I got from the first shop.
So 400.- for LPM ( my local shop) to take the tank out and put it back in plus around 500.- that's not too horrible considering how much work is involved.
The second guy who probably is a good welder because he has been in business for 43 years said I should really have stainless tank in there, and that he could build one for me. But his shop looked awful, more like a junkyard, crap everywhere no place to walk, no sign outside the building. I wouldn't trust him with my truck. But I might ask the first guy for a stainless quote.Has anybody here replaced a waste tank with a custom stainless one?

 

[bob vawter]

if you're gonna build a stainless one..
find a co with a large brake and make it all outta one piece.withe the strengthening breaks in the side like these...

 

[TConway]

Back when I had drywall biz one of my spray rigs had a metal mix tank, and over the years the tank would rust and little pieces would pop off they would be about the size of a pencil eraser just not that thick, anyway I went to a LineX spray in bed liner. He said go sand blast it and bring it back.
He lined it with about a 3/32" coating lasted very well and when I sold out it was still good.
Rigs are like plaster/cement mixers except the material was not full of sand/rocks. More like pancake batter.
Point being it held up VERY well chemical res pretty tough stuff. It was fairly reasonable. Check and see if you have some one like that in your area and ask.
He did garbage truck,dumpsters, all kinds of stuff. He even patched holes in truck beds then lined over.

 

[dgardner]

Do you have a sacrificial anode? Might slow down the rate of corrosion......

Like this (or similar):
http://www.boatzincs.com/n-1.html

 

[gimmeagig]

I do have a anode in my tank. Like the one on the link you sent. I don't know much about how Anodes work and I thought it was necessary to connect them to the tank. I drilled a hole into the inside baffle and then ran a copper wire to the anode which sits in the bottom of my tank.
Later on I read that I could just drop it into the tank because that alone connects it. Duh....
But looking at the condition of the anode that is in my tank, it really looks pretty deteriorated so it must be doing something to slow down the corrosion process.
If one anode is good to have, are two in different parts of the tank better?

 

[dgardner]

You're correct. A solid connection to the tank is required for the anode to do its job. The best way is bolting the anode directly to a part of the tank. Dropping the anode in is questionable, too much chance it would end up insulated from the tank by a layer of scum or oxidation. It would still break down, but would do nothing to protect the tank.

 

[gimmeagig]

Maybe a stupid question. I assume I would need to install that anode in a place where it is submerged, right? Can I use a stainless bolt to attach the anode to one of the panels or should I use a different material?

 

[dgardner]

Yes, submerged. Stainless bolt is fine. Make sure the aluminum and the anode's surfaces are clean and held tightly together, ensuring good electrical contact.

 

[gimmeagig]

Cool, the anode will be my next project. BTW the Gluvit epoxy worked, I will probably coat the whole bottom of the tank.If I add the anode I think I have done as much as I can to make that tank last. I really want to whole rig to last me another few years. I kind of get attached to things and I can't get myself to let go easily. I've gotten fond of my truck, I'll just replace or fix stuff as it breaks.

 

[GeneMiller]

Not an expert in it but I believe magnesium works better to protect aluminum because of higher voltage difference.

Gene