Dry ice (cardice) clad cleaning

[teokal]

Dear all,
We are constructing a big tower which is Carbon steel with 410S cladding. Because of the fact that although we took extra care not to contaminate the cladding, the big mass of the tower, the long production time and - last but not least - the fact that we are making the final assembly at the harbour, the cladding has been (not seriously) contaminated. We thought that cardice (dry ice) is a good way to clean. Fast, effective, no remnants, not so much expensive are some of the factors that make it a strong candidaqte as solution. On the other hand (and this is my question) I have some minor doubts about the CO2 (as we all know, Dry ice is 100% CO2): is it possible that blasting with dry ice may affect the carbon equivalent of the plates? May the 410S clad material will be affected somehow? Is there any precaution to take after blasting, to protect the clad material?
Thank you in advance,

Only best result in absolutely necessary time

 

[unclesyd]

Using dry ice blasting will have no metallurgical affect on the clad material. Properly applied it should have no effect on the surface finish. They only problem is that it may not remove the soil.

Make sure you have you use a company well based in the art of dry ice blasting. Dry ice blasting in vessel requires careful attention to safety.

Depending on the contaminates on the metal you may want to look at high pressure water blasting. I would checkout 15,000 psig though you may have to go to pressures over >23,000 psig

 

[EdStainless]

It really depends on the degree of 'dirtiness'.
If there is a lot of crud and gunk on the surface then dry ice will do a good job removing it. And the clean up won't be bad.
If it is just surface dirt and chlorides then washing sounds like a better choice. You could even add rise agents to the water to help dissolve salts.


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Plymouth Tube

 

[fadysabbagh]

Dear Teokal,
CO2 of the dry ice can not affect the CE of the material. If you have concerns due to DIFFUSION (changes of carbon distribution due to movement of carbon), then be noted that diffusion is always accompanied with either high temperature, or very very long time.
Do not worry about the metallurgical structure.
Fady

 

[cap1aa]

Sometimes, it can be contaiminated by the marine condition. I have experience to pack all of the vessel by vinyl to prevent contamination.
In addplease make sure all of the area of the vessel dried after hydrotesting. it would make the problem of contamination by concentrated chlorides from existing water at the localised area.

 

[corrosionman]

As an alternative to Dry ice we once blast cleaned some very dirty furnace tubes with walnut shells - it was surprising how effective they were. OK a bit expensive but it worked so very well. Can you not ask your Blast Media supplier for his comments ??
REgards
CM