Flaking paint on pipe

[Robopug]

Hi
I have a Jotul F105 and after a few weeks the stainless steel flue pipe which had been sprayed black started to peel/flake off. It was sanded down, cleaned and repainted but it flaked off in patches again. It was sanded, cleaned and sprayed again but it has started to flake off a third time. Any idea what is causing this? Could it be the seal at the base of the pipe? Thanks

 

[Squirrel]

Stainless is very hard to paint in any circumstance, on a flue pipe I would think it's impossible. I think your only alternative is to have a baked enamel finish applied at a specialist facility, it will be expensive.

 

[Robopug]

Stainless is very hard to paint in any circumstance, on a flue pipe I would think it's impossible. I think your only alternative is to have a baked enamel finish applied at a specialist facility, it will be expensive.

Thanks, the firm I used is very well thought of and they seem to think SS is normal when sprayed with black high temp paint!

 

[Lake Girl]

I had to buy a special primer to repaint outdoor cast aluminum patio furniture ... perhaps there is something similar for stainless steel that will promote the bond.

 

[Robopug]

Thanks, the temperature may be an issue. I am waiting for the company to come back again and look at it. It is just a bit strange that it keeps peeling.

 

[Lake Girl]

This is the paint I have for the pellet stove ... http://www.vhtpaint.com/high-heat/vht-flameproof-coating/ Duplicolor is another brand of automotive high-temp paint.
I went on some car/motorcycle forums and found that etching/scuffing the stainless is best before painting when they do stainless exhaust pipes. You can get self-etching primer (mentioned above) but not sure if it is high temp. Ceramic powder coat holds up the best but is very $$. Other powder coats don't seem to hold up well...

 

[Robopug]

Thanks for the link, I will take a look.
Cheers

 

[begreen]

Did the flue pipe get exceptionally hot at some point? That can cause paint to flake off.

 

[Lake Girl]

Did they scuff the stainless before painting?

 

[Chimney Smoke]

It's probably not the temperature but the smooth stainless steel surface that is preventing the paint from sticking well. I imagine a lot of prep work would have been needed to successfully paint a mirror finish stainless pipe. Sanding down the paint and repainting doesn't address the initial surface bond needed between the paint and metal.

 

[Robopug]

They did sand/scuff the pipe each time they have repainted it and I haven't let the stove overheat, I only use a log at a time because I am conscious of the problem. Bit of a mystery!
The fitters have said that they may need to pout a joint in the pipe to let it expand but I can't see how this would help. The metal will expand regardless. The pipe is only around 1 1/2 foot anyway so not very long!

 

[Chimney Smoke]

Can you post a picture? It's hard for me to visualize only needing to paint 1.5 feet of chimney.

 

[Robopug]

Can you post a picture? It's hard for me to visualize only needing to paint 1.5 feet of chimney.

Hi
Here you go. The stove is in an old chimney opening.

 

[webby3650]

We paint SS all the time. Nearly every install has some SS than needs painted and we rarely ever see it fail. We wipe it down with white vinegar and then paint it with Srove Bright.

 

[rustynut]

robo, if you cant get that paint to stick to the ss how about wrapping a piece of standard black pipe around that ss in the area that you see ?
rn

 

[sportbikerider78]

Paint is all about the prep. Can you remove it and paint somewhere else?
I would think you would want to strip all the paint to get a nice finish. I'd have it sandblasted to get it uniform.....but i'm really picky like that.

 

[Robopug]

Unfortunately it isn't me doing it, its the installation company. I will try and get them to put in a new pipe if possible.

 

[Chimney Smoke]

Can't you just install a piece of black stove pipe? Why did that need to be unpainted stainless steel?

 

[Robopug]

Can't you just install a piece of black stove pipe? Why did that need to be unpainted stainless steel?

It is how the company we used do it!

 

[webby3650]

Can't you just install a piece of black stove pipe? Why did that need to be unpainted stainless steel?

Often times it's a piece of SS that protrudes from the masonry thimble. Or even more often, it's the snout that comes off of the Tee.

Surely they can get it, it sure doesn't look like a big deal. Sure can't see wanting it replaced over that.

 

[Lake Girl]

We paint SS all the time. Nearly every install has some SS than needs painted and we rarely ever see it fail. We wipe it down with white vinegar and then paint it with Srove Bright.

Mild etching with the vinegar ... amazing what a fairly innocuous liquid can do!