Blistering powder coat on cast iron radiator

[pjamiwatts]

We have new cast iron radiators that were powder coated and the sections joined by the manufacturer. The powder coating is now blistering on the top of the radiator at the virtually all the joins. The manufacturer says this is because the plumber may have twisted the radiators during installation. I don't think he did. Has anyone come across this problem before? I am concerned that the blisters are cause by seepage, will burst, exposing the iron below and lead to corrosion.

 

[Keefy]

Never heard of a cast iron radiator twisting, you sure that's what they implied? Sounds to me like they haven't cleaned the joins up properly before applying the paint. Post a few pics if you can.

 

[pjamiwatts]

Hi Keefy - thanks for the quick reply. The manufacturer blames the plumber saying that they cannot have carried the radiators vertically and therefore damaged the joins during installation. I don't believe that. Here are some pics.

 

[Keefy]

I still think the welder hasn't done his job properly to be honest.

Just out of interest how long are the rads?

 

[Reg Man]

I still think the welder hasn't done his job properly to be honest.

Just out of interest how long are the rads?

Keefy, I do not think theses sectional rads are welded together. Used to be tie rod sections.

There does not appear to be any cracking to the powder coat, so I would suspect this to be a manufacturing issue. It looks like bubbling from very small seepage.

 

[Keefy]

Keefy, I do not think theses sectional rads are welded together. Used to be screwed sections.

There does not appear to be any cracking to the powder coat, so I would suspect this to be a manufacturing issue. It looks like bubbling from very small seepage.

I thought there would likely be some kind of weld to 'seal' round those joins? Whatever the cause, they're having a laugh blaming the plumber for carrying them wrong. Maybe Ray will have a better idea of where the customer stands with this.

 

[pjamiwatts]

Keefy, I do not think theses sectional rads are welded together. Used to be tie rod sections.

There does not appear to be any cracking to the powder coat, so I would suspect this to be a manufacturing issue. It looks like bubbling from very small seepage.

The radiators are 14 and 15 sections in length. The manufacturer assembled the sections before powder coating. The blisters are initially quite soft, so it could be seepage. I can depress them with a fingernail.