ISO 12944 paint systems applied to machinery

[geesaman.d]

I'm seeing this more and more. ISO 12944 paint systems are built around structures of welded construction where seams, exposed threads, machined surfaces, lubrication fittings, etc simply do not exist.

I know I can provide paint systems that meet ISO 12944 corrosion resistance ratings within the context of the paint testing samples and method. But applying that paint system to machinery violates basically every other ISO 12944 best practice and surely compromises the real-world performance.

Is there any other standard or practice I might look that is a better fit for painting machinery installed in corrosive environments? Or anything useful I can say to my prospective customers who demand machinery protected according to ISO 12944?

 

[TugboatEng]

Have you considered making changes to the machines so that they can be coated properly? Consider sandblasting after assembly, covering or plugging exposed threads, use corrosion resistant lubricating fittings, avoid using lock washers etc...

 

[geesaman.d]

It's supposed to be our standard gear-reduced 1.1kW machine, quantity of one. So it's not worth designing a whole new product, building a prototype, and going through all of the ATEX evaluations. It seems that literally any other paint system standard could be applied better to a small gearbox than the one written specifically for massive steel superstructures. So while I could eliminate the lock washers tailor the standard product design a bit more, I fully expect to spend the next 1-2 years rejecting our submittals or see the order rejected at final inspection, because application of the wrong standard to involves countless subjective decisions. I just got done with a massively unprofitable job for this customer and they were consistently inflexible and unwilling to think.

 

[3DDave]

What kind of lock washers? Split lockwashers are generally as effective as flatwashers in securing joints.

 

[TugboatEng]

3DDave, all types of lock washers have gaps that prevent the head of the bolt from sealing again the surface. This causes corrosion.

Are you able to disassemble the machine and apply coatings such as flame sprayed aluminum that will protect areas where paint coatings are not ideal?

Can you enclose the machine and treat the enclosure to the appropriate ISO standard?

There are some novel coatings based on thixotropic gelled calcium sulfonate that may be more forgiving on geometries that a problematic for paint. They're non-drying so they can self-heal some.

 

[SJones]

Are you saying that you don't believe that epoxy polyurethane systems, detailed in ISO 12944-6, as being suitable for machinery? I've never noted any issues on big compressor and pump packages. If you are not happy with ISO 12944, try NORSOK M-501, or IOGP S-715. The latter is free to download, but requires the possession of a superseded version of the former to work.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[geesaman.d]

It's the supporting requirements for radii, eliminating tiny gaps, steps, electrically isolating dissimilar metals, etc, etc. From a coating performance perspective, the value of these things is understandable. I could fairly readily apply those measures to certain components we provide (and design from scratch per order), but the gearbox is a standard design of ours and repackaging it in some other kind of housing or enclosure becomes a huge mess.

But I can't take any kind of existing machinery, install it the most severe atmospheric corrosion environments, apply 12944 CX High durability paint requirements, and expect that is the complete solution to the corrosion problem. I can't take a need for a forklift that must operate on an ocean dock for 15 years and solve it by sending a PO to Toyota for a single forklift with an adder for 12944 CX High paint.

I don't have any opinion on the various paint systems - I only need to watch the paint system that gets thicker or otherwise affects its cooling behavior.

 

[SJones]

Then stick with NORSOK/IOGP

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[TugboatEng]

It may be possible to use your same patterns and have a casting done in bronze.

 

[EdStainless]

There is nothing to keep you from tripling the price to cover this.
Often these demanding customers are money losers because sales can't bear to say no.
Just quote this as a separate line item and put the real cost on it.
I have been there.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[geesaman.d]

There is nothing to keep you from tripling the price to cover this.
Often these demanding customers are money losers because sales can't bear to say no.
Just quote this as a separate line item and put the real cost on it.
I have been there.

A pleasant surprise - my companies Techstreet subscription includes M-501:2022. NORSOK M-501 has a useful paragraph, "It is further highlighted that a coating friendly design is a prerequisite for achieving a durable corrosion protection with limited maintenance and repairs. As a minimum the design of structures, equipment, and items ... shall comply with the recommendation of ISO 12944-3. To meet this requirement is outside of the scope of a coating applicator since due considerations need to be taken at a much earlier design phase."

This is the deeper problem I'm facing - I need to redesign the whole machine to quote to this; the scope and cost is wholly unknown. If I'm pushed to provide an adder, I might need to provide a price to perform an engineering study to do the detailed work with the deliverable of an accurate price and lead time that meets the requirements and clarifications where we had to make difficult decisions. If they need it they'll have to be on board with that plan.