Hi all:
I just bought a Zerowatt CA708 from ebay, its condition is quite good, however the white coating inside the boiler is aged.
Does anyone know how to remove the white coating inside the boiler? It keep coming off in the boiling water, kind of scaring. Sand blasting is an option, but it is difficult to find a right workshop here, I am thinking of paint remover , is it safe to do that?? Sand paper is a stupid idea, I just did that, no help.

Thanks a lot.
Yuwen.

I had to disassemble mine (it's hard to remove the heat element as the space below the machine is very tight) to paint it. But as a powder coat shop painted the machine, it was sand blasted and then painted blue.

But the guy painted the interior too and I have to remove it... Now, even if I took it back to the guy to remove and repaint, as powder coat is very resistent, he'll need to let it at the paint remover before sand blast again...

So I have the same doubt as you, Yuwen, if I could use some remover. I think it should be fine, to remove the paint, then after that some grit paper coarse to fine to polish the aluminum.

Keep in mind that maybe the aluminum will start to "rust". Probably you have something like that (pitting) at the piston sleeve, right?

Beautiful machine, strong spring, simple desing... But some fails on design that give headaches. For instance, the top cap of the piston sleeve scratches the piston rod. The screws of the piston sleeve are some kind of steel and they rust bad if you don't protect them. Mine came with a chromed spring and there were 2 rusted scars - I did the chrome again, but I really don't think it will last.

I thought about making the top cap hole wider and making a teflon sleeve to the piston rod.

As Francesco says, it's a machine to use with care.

Márcio.

Try lacquer thinner to remove powder coating. I have a bicycle that is powder coated and had to clean the paint off the bottom bracket to Loctite bearings in. The rag turned red when I cleaned the metal...

Marcio:
My spring has 2 rust spots at the bottom half also, I reinstall the spring upside down, I think it could survive for a couple of years.
I think I will send it to the professional repair man , he help me to chrome my Peppina boiler before.
Thanks a lot.

Hello Rolleiman,

I have one of these -exactly the same. Just like your the white paint on the boiler is coming away. What did you end up doing with your machine? Did you remove the paint? If you did remove it- did you replace it with anything?

My machine seems very nice- the spring is really strong. I can't wait ti use it but there is no way I can with that paint in the boiler. The walls of the boiler are thin and I am concerned that if you removed the paint and left just naked aluminum it would corrode too quickly...

Jack:
You should remove the heater, sand blasting the boiler and plating it. It is very difficult to remove the heater. I gave up the restoration,Marcio has more experiences for this machine. Good luck.

Bad experience with the machine!

I removed all the paint, as I've striped the machine entirely. But the guy have powder coat all the machine too, including the inside. So now I have to remove the paint inside the boiler (power coat is a little bit hard to remove) and maybe let the aluminum naked.

I think if you toss the water away the aluminum should not have too much problem. I'm thinking about making a sleeve to cover the boiler (it would be sealed against the heat element seal and agains the group too). But on what material, I don't know...

Márcio.

Dang- it sounds like a real pain in the arse...- but it is a really well made machine except for the stupidity of painting the internal boiler walls.... This is the kind of thing that makes me respect the Caravel even more...

Are there any threads that show how to disassemble these machines? Is it really hard?

To remove the heat element was painful too me. Remove and install. That's why I'm waiting a little bit to get it again... I think about removing the internal powder coat that the guy did with some remover, slowly, then later to sand it. Can you tell P-I-T-A?

The original painting (I think it some kind of silicon coat) is easy to remove. If you can sand blast the machine, you can paint it again, if your original paint is not so good. But if you want to remove only the internal coat, some paint remover and sand paper should do...

It seems crappy this interior but I think that's why this machines have such intact boilers. The heat element seems to be nickel (maybe chrome too) plated, but the piston is not. I think galvanic corrosion should appear at the boiler wall, as it appears at the piston sleeve, but on mine there is none pitting/holes.

If this material is aluminum (but what kind of alloy?) maybe it could be anodized? Maybe it could be anodized internally - we could seal the holes, and make it the internal boiler (and anode) the tank for the acid. Then put some cathode inside, acid, and the power supply... Well, I know I have to do some calculations to get the amps right, but that could be a nice solution, and the area of the interior is not so big (although the hole boiler is big and will receive the electrical current). The main problem is to know the alloy as AFAIK some alloys don't work well.

At work I have a lot of co-workers that are chemist (and we have a lab), I'll see if anyone are willing to try.

Or, an easy approach, to toss some zinc rod as sacrifice?

Márcio.