Cold Spray Aluminimum - experiences? Answer to CUI? 2

[robsalv]

Hello folks.

International paints are promoting a paint product called CSA (Cold spray Aluminium). There are two products in their range: Intertherm 751CSA and Intertherm 898CSA. The 751 seems to be the more mature of the two.

They're saying that CSA bridges the gap between thermally sprayed aluminimum (which I think is becoming the best practice leader for CUI mitigation) and high temperature resistant under insulation coatings.

I was wondering what experiences folks had with the product?


We recently partially coated an insulated vessel that operates right bang in the CUI temperature range with 751CSA. It'll be some time before we can assess how well it performs.

So just incase there are those with more experience, I thought I'd post up to gather some experiences. Is CSA the panacea International make it out to be?? International state that it's cheaper than TSA and has other preferential benefits like insitu application... we brushed and rollered the 751 onto the vessel after a 2 - 2.5 blast... so it certainly goes on the way paints normally do.


Please share your thoughts and / or experiences with CSA... and TSA if you have some experience with it too.

Thanks in advance.

Rob



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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[kenvlach]

Cold spray Aluminium (CSA) isn't paint.
CSA is aluminum particles applied in a supersonic inert gas stream such that cold welding to the substrate occurs.
A one-paragraph intro:

http://www.sandia.gov/materials/sciences/factsheets/SprayCoating.html

Mechanical and Microstructural Effects of Cold Spray Aluminum on Al 7075 Using Kinetic Metallization and Cold Spray Processes, a 25-page paper by Lockheed Martin:

http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA470138

The following explains the process:
COLD SPRAY TECHNOLOGY: INTERNATIONAL STATUS AND USA EFFORTS

http://www.asbindustries.com/articles/Int_Status_Report.pdf

Intertherm[®] 751 CSA is "A two component, high build, high temperature resistant 'cold spray' applied coating, based on inorganic copolymer technology and pigmented with metallic aluminum flake."

http://www.international-pc.com/pc/pds/751CSA_us.pdf

I.e., aluminum paint. It may very well do the job if properly applied, and at lower cost than true CSA.

 

[robsalv]

Kenvlach, thanks for your posts and informative links. Oh and Thanks for pointing out that Intertherm CSA751 is a paint... I kinda figured that one out for myself and intimated that in the OP... lol


InternationalPC market their product as Cold Spray Aluminium, hence my reference to the term. You are correct, it's not true CSA, but let's not get caught up in a sideline trip down the "definitions roadway".

I did find the CSA links informative - but the technique seems fairly specialised and I don't think it has any practical applicablility to the CUI issues I have in mind. As far as I'm aware from EEPC and ExxonMobil resources, true CSA is not even on the radar for CUI issues.



So having said that, I'm interested in direct experiences relating to the suitability, practicality and useability of both TSA and International's Intertherm CSA paints, given that I'm managing a CUI program for a petrochemical plant.

As far as I know, no other paint mob has a similar product that claims to fill the gap between current painting technologies and TSA.



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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[kenvlach]

robsalv, I figured you knew the difference, but others might not. Note Intertherm qualifies the term with apostrophes: 'cold spray' applied coating.

Some other, under insulation paints with similar corrosion and heat resistance:

http://alvinproducts.com/Dampney/

http://www.industrial-nanotech.com/nansulate.htm

Maybe of interest:
A Corrosion Under Insulation Prevention Strategy For Petrochemical Industry Piping
"TSA to Paint costs used for this analysis. 7:1 ratio for Replacement cases & 12:1 ratio for In-situ cases"

http://www.iom3.org/divisions/surface/corrosion/paper2_fitzgerald.pdf

 

[robsalv]

Kenvlach - many thanks for your post. I can see how my subject title does suggest the metalic CSA technique.

Time for a little suggested reading.

Cheers.





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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[ThermalSprayer]

I work for a large thermal spray equipment and materials manufacturer and for the last 5 years I have been working with petrochemical companies (ExxonMobil, Shell, etc.) NACE, and applicators developing low cost TSA coatings.

With the proper parameters, training, and equipment, TSA coatings can be applied at the thickness required for CUI at less than $1 per SqFt / $10 Sq Meter now (the cost of gasses and wire) and at 180 SqFt / 17 Sq Meters per hour , so they are pretty cheap! I have trained over 200 applicators on how to do this.

By the way, ExxonMobil has found a TSA coating applied to a vessel operating in CUI conditions that was coating in 1958. The 50 year old coating still looks fine! The vessel was reinsulated with no maintenance work done to the coating. It is pretty evident that there is no longer lasting, less expensive coating than "true" TSA.

 

[robsalv]

Bloody interesting post there Thermalsprayer. Are you at liberty to say more about the ExxonMobil experience? If yes, let's work out a way to share the info offline.

Until recently, my plant was part of the EM circuit. I still have some contacts and could probably speak with someone who could give me direct info about that experience.

I hadn't heard about this example in normal network comms.

Thx

Rob

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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[gr2vessels]

Rob,
Very recently the Australian Institute of Engineers has held a seminar in Melbourne for static equipment, piping engineers and associated painting, etc... The "International" rep presented the CSA as a novelty in this country and just as you said, it failed to mention that the process is a paint application and has nothing in common with the thermal spray of aluminium, particularly in CUI applications. It somehow appears to be a trumped up application, perhaps trying to pull some coals under their cooking bowl, from under the hot TSA. ThermalSprayer's post is realy an eye opener and I wonder if you will consider it for your plant CUI protection. I have use it (TSA) excusively for the protection of duplex and superduplex vessels on FPSO, as an additional investment protection (the Australian applicators have never heard of ThermalSprayer's rates...they always quote their phone number...!), but the rates above tend to open wide the door for TSA.
I shall dig a bit deeper in it.
Cheers, gr2vessels

 

[ThermalSprayer]

Hi All!,

As a designer, manufacturer, promoter, and training "guru" for the past 22 years in just about all types of thermal spray, I am amazed at the price some applicators charge for a simple TSA coating. So is ExxonMobil! That's why they push me to train more and more applicators, so they can bid against each other and charge some realistic prices. I have seen prices from ~$3.50 USD per square foot (fully automated system coating miles of riser pipe) to over $50 (welds in pipe racks)! The costs depend on a lot of factors, similar to paint systems.

Warm Regards,

ThermalSprayer

 

[robsalv]

At those rates, CSA doesn't stand much of a chance IF it's feasible to do insitu and can get past the JSA and permitting issues of a live petrochem plant. For turnkey type /prefabbed type work though, cost effective TSA would be a slam dunk.

I shall dig a bit deeper in it.

Please do.

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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[ThermalSprayer]

We do live, operating equipmet at ExxonMobil and Shell all the time. That's the great part aobut TSA. We did a Shell reactor that was cycling between ambient and >350F with no problems. Flame spray is easy to permit (little to no sparks, smoke, or dust). Arc spray is not allowed in most facilities. I train applicators to arc spray offsite.

 

[moseley]

I am the current ExxonMobil coatings specialist, and the Intertherm 751 has been my choice in applications where TSA wasn't advantages. The results so far are outstanding. The follow up inspections has found this coating to work along the same lines as TSA without the use of Thermal equipment in operating areas. I am quite pleased with the results it has provided me.

 

[robsalv]

G'day from an ex ExxonMobil "relative" from Australia Moseley (we were sold off a couple of years back)

Thanks for entering into the discussion.

The folks at Esso claim that 751 interferes with UT measurement, so they've stopped using 751.

What's your take on 751's suitability for UT?

Cheers

Rob



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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[robsalv]

Just following up in this thread.

Does anyone have any further experiences with International's CSA751?? I understand that Santos is South Australia is in the process of using it extensively... still too early for experiences. We have three insulated equipment items partially coated in 751. Again too early to tell if there are any concerns. It painted on very simply and the quality of the coating looked excellent in all cases.

Last I spoke with the Inspection guys down at Shell (down the road from us), they were trying to find a TSA (thermal spray aluminium) applicator rather than going with an under insulation painting system. I'll see if I can catch up with them to find out whether they've had any luck.


We're also hooked into the EEPC (european ethylene producers conference) and they have a CUI user group which is red hot on TSA... so it would seem that CSA751 isn't gaining broad acceptance ?

Cheers

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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[ThermalSprayer]

Hi Rob,

So far, I have not seen anyone accept a painted on coating as a good alternative to TSA. I am not saying that paint doesn't work, it just that these guys (ExxonMobil and Shell) know that TSA works and they have over 50 years of testing to prove it. It can be applied safely and cheaply with the right training and equipment.

I am in Singapore right now, helping ExxonMobil get their TSA/CUI program in action. They plan on spraying on live, operation equipment, as they are doing in the UK and USA. Shell in Singapore has already started doing offline equipment here with TSA and they too will start doing online equipment. They are also spraying live, operation equipment in the UK and USA. If I can help you in any way please let me know.

 

[robsalv]

That sounds very interesting ThermalSprayer.

I read in the other thread (now closed) that you prefer to train abrasive blasters/painters how to do TSA since it's more akin to painting than applying an engineering wear coating.

I have a fair idea what the risks of painting and blasting are, but TSA is a bit murky - what sort of safety issues are there? Does the molten spray bounce back? Can it be readily used in congested plant areas or is it best in unconfined spaces? How susceptible is the TSA to atmospheric conditions?


I note that Australian petrochem companies are agreeing that TSA is world's best practice for CUI prevention and mitigation, but I don't see many dedicated TSA mobs (in the low cost vain you talk about) popping up - so there's still a reluctance to use it from what I can gather.

Anyway, I hope the Singapore project is proceeding well.

Cheers

Rob




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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[ThermalSprayer]

Hi Rob!,

I’ll try and answer your questions as best as I can, without appearing to be the thermal spray zealot that I am! <smile!>

1). I have a fair idea what the risks of painting and blasting are, but TSA is a bit murky - what sort of safety issues are there?

1a). The answer to this really depends a lot on which plant you are in, what process you are using, and what the safety people think they know about thermal spray. In an operating plant, we only use the flame spray process, and never arc spray. This reduces many of the safety risks, so I will only discuss risk reduction in respect to flame spray. Here are the key items that we usually discuss;

Fire – The flame spray process has a small, open flame (about 25-75mm long) which can ignite flammable materials. Everyone is aware of this and it is seldom a concern. When blasting, you are also creating sparks, and these sprays are directly on the substrate!

Noise – This process generates high noise levels (~120dB), so double hearing protection is required.

Explosion – Fine aluminum dust accumulation in confined spaces may create an explosive concentration; however the combustion spray process dust is minimal and mostly larger granules. Plant safety people that were extremely concerned about dust explosions have completely changed their minds once they saw the flame spray process in action. I also point out to them that the dust from blasting is much greater than the dust from flame spray.

Inhalation - metal dust, fumes, and CO are generated. A good respirator is forced air helmet (like the ones that are used when blasting) is required.

Radiation – A small amount of UV is generated by the flame, similar to propane torches used for soldering copper pipes. Usually applicators wear tinted safety glasses.

High pressure and flammable gasses – As in gas welding, care must be taken when using bottled gasses. Plant people are accustomed to dealing with flammable gasses.

2). Does the molten spray bounce back?

2a). No, it does not. When aluminum is sprayed with a combustion gun it barely reaches its melting point. The aluminum wire just gets soft enough to be atomized by compressed air and then directed to the substrate. The particles are actually quite cool once atomized. During spray demonstrations with aluminum we often coat the backs of paper business cars with aluminum, and even show that you can coat the unprotected palm of your hand if you feel daring! On large, flat surfaces the deposit efficiency is greater than 90%, with very little bouncing off. That does bounce of is mostly AlO2. Also note that there is no messy overspray stuck to everything. (I am trying to send some spraying movies to the file sharing server here!)

3). Can it be readily used in congested plant areas or is it best in unconfined spaces?

3a). If you can somehow blast it, you can apply TSA. They do spray in many confined spaces and tigh areas, like closure welds in pipe racks. It is not always easy, but it is done.

4.) How susceptible is the TSA to atmospheric conditions?

4a.) I assume you mean can it be done in bad weather? As long as rain is not falling on the freshly blasted steel, you can coat it. However, and a demonstration, 3 years ago I coated a long section of freshly blasted pipe during a torrential rain. The pipe was already blooming with rust, but the customer (a natural gas distribution company) wanted to see me spray. So, driving away sheets of water with the TSA, I sprayed on the wet and rusting pipe. I saw that same pipe a few months ago and it still looks perfect after three years of atmospheric exposure! No,I don’t recommend that you apply coatings to wet, rusty pipes, but I did want to illustrate to you that the coating process is very insensitive to atmospheric conditions. We have also been coating live, operating equipment in the plants. Some are quite hot during spraying, approaching 500C at times.

The only place these thermal spray “mobs” are turning up seems to be where I am training them! I went on this trip to help the petrochemical company in Singapore pick a few contractors that we can add to the TSA Mob. It went well and we have at least two companies that look promising. I’ll have to come to Australia and help you get some people into the TSA Mob!

Warm Regards,

Jim Weber

 

[robsalv]

Thanks Jim, that was exactly the sort of information I was after.

Ourselves and a couple of other Petrochem companies in our neck of Australia, have tried to get a local painting contractor (largest in the area) interested in TSA, but have had varying degrees of dis-interest. Perhaps they fear what they don't understand? The way you describe it, the technique is really just an extension of what they are already doing...



On a more technical point, does the TSA provide a galvanic or barrier protection to the substrate?? Aluminimum is anodic to carbon steel, but if the aluminimum has a stable and encompassing oxidised layer, it's not really sacrificing itself to the more noble substrate in the classic galvanic sense. What's your view?



I note that my TSA websearches have pulled up a Woodside Petroleum coating specification which has a TSA protection coating spec - a clearcoat over the top of the TSA. I seem to recall that Exxon Mobil (when we were tied in to them) were thinking of something similar. Is this an overkill in your estimation?


Thanks in advance.

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"Life! No one get's out of it alive."
"The trick is to grow up without growing old..."

 

[ThermalSprayer]

Hi Rob,

The painters here were disinterested as well, however when ExxonMobil told them “You are going to learn how to apply TSA (from me!) or you are going to be looking for a new job!”, they listen and learned how to TSA! LOL!

Once I had them trained they loved it and wanted to TSA everything and stop doing the three coat paint systems they were applying. One coat of instantaneously drying TSA is a lot easier.

TSA is more of a barrier coating if there is not a lot of uncoated iron that is connected by an electrolyte (water). It only acts as an anode when the current and voltage potential is high enough to get through the oxide layer. This layer is very thin, only a few molecules, and it doesn’t need much EMF to get it to conduct. So it is a rather unique coating situation.

Most of the time, TSA just sits there, turns gray, and protects the steel beneath it (as in the CUI scenario). Pure, un-oxidized aluminum is firmly attached to the steel (>2,000psi bond most of the time) and is always ready to sacrifice itself if needed, but this will only happen if there is some mechanical damage done to the coating and the steel is exposed (a deep cut through the TSA and into the steel). This is very hard to do, as the coatings are very tough and not much happens under the insulation. If you do get through the TSA, the aluminum anode tends to passivate the steel in the cut and slow or stop the corrosion cell.

For CUI, nobody uses any sealers for CUI applications, especially not ExxonMobil or Shell. If sprayed properly, the TSA coating will not rust bloom at >200 microns, and most specs call for an average of 300 microns and no less than 250 microns. By the way, rustbloom is strictly cosmetic. It happens once, the steel passivates, and the pores in the TSA close up with oxide, and it just sits there and has some rust dots.

It does look ugly though and people complain that this “wonder coating is rusting already” when they see it! I only recommend sealers when a coating needs good cosmetics and it won’t be covered with insulation.

The coating porosity, if unsealed, collects all kinds of dirt, acid rain, bird droppings, etc, if not sealed. I like aluminum pigmented silicone as a sealer.

Warm Regards,
Jim Weber

 

[gmichie]

I am desperate for some help!!!

We hydroform a 6163 Aluminum rail and buff and bright dip anodize it. We are trying to provide a perfect surface but are running into porosity, flow lines, scratches, tool marks, etc etc.

Can the substrate be repaired by coating the surface with a cold spray aluminum and then sending it back through a bright dip anodizing process?

Does anyone know who I could send some parts to to try it?