Painting for Hot Surface 90 Degree Celcius

For what you do need to paint? 90degree celcius.

Apply Inorganing Zinc 3mils (After mechanical surface cleaning) is enough.

Yes, you are right Guest,

But just I'd like to add that you can use a primer of Inorganic Zinc Ethel Silicate to withstand higher temperature, taking into consideration to apply it at vessel after full removal of old paint and rest of corrosion (may be by grit blast) to avoid incompatibility between old and new primers which lead to scaling of the 2^nd primer at least, and the surface preparation is recommended to be as per code SSPC-SP10 (Sa 2 1/2) to attain the white metal.

Note. The primer must be applied at ambient temperature and no way to apply while the vessel in operation with higher temperature 90 ^oC.

See the following picture for surface preparation to Sa 2 1/2 extracted from code SSPC (Steel Structures Painting Council) - Pictorial Surface Preparation Standards for Painting Steel Surfaces.

This a great & very expensive manner to achieve something simple. Try converting the rust to a calcium based product with "OSPHO" or similar product & then paint with A zinc rich paint to solve the rust problem. Sand blasting is not necessary with this method & it will take the heat as long as it is not an exhaust manifold.

TSA (Thermal Spray Aluminium) coating is usually regarded as the best "preventative" coating for CUI. Exxon Mobil have looked at alternatives and despite the cost impact, TSA is what the specify under insulation. It can be applied on hot surfaces up to about 400C, and with proper QA, they do not open the insulation for 20+ years to check for corrosion.

There are a number of types of heat-resisting paint. 90degC is not particularly onerous. Try Google.

Suggest the use of DTD 5555 Epoxy paint system.

Ref: http://www.indestructible.co.uk/cat2/DTD5555S.html

Strongly recommend removal of the existing coat either chemically or by grit blasting before recoating the surface, for ensuring failure free life.

Correct, chemical conversion is a lot cheaper than blasting.

Thiumy

I wanted to paint the outer housing chamber of a electrical heater unit. When asked to give a temperature resistant paint, the technicians applied a black coloured temperature resistant paint, which worked. You may enquire in the market and I am sure you will get. The auto Mobile engine cover, hot line coating paints also should be workable. Better enquire your automobile line friends / contacts.

They sell a special paint for barbeque grills.

I'm curious, you are wanting to paint a vessel surface while it is at 90^oC and that is to warm for the application specifications of the coating you were planning to use?

Yes UV

We want to paint when the vessel in operation around 90 degree celcius.

It seems difficult that's why I asked for similar case feedback experience

Thanks to all

Seconding the information supplied by Kiwi Bill. The petrochem industry is adopting TSA more and more with companies like Exxon and Shell using the process increasingly on new and existing plant. Spraying is often done on live equipment too. Google CUI and TSA for loads more information.

You need to clean the scale off of the vessel first & brush the powdered iron oxide clean, but not perfectly. Then you will spray or brush a product named "OSPHO" that you will leave for 24 hours & the iron oxide will be converted to a calcium based product(it will be black).There are other products that are either blue or green liquid,they are acids that do the converting of the rust. Then after 24 hours you will paint the vessel with a zinc oxide rich paint,either spray or brush,either paintable or non paintable, whichever you desire. That should fix the problem better than Rustoleum@ or anything else would.You should be pleased as I have been repairing rusty panels in this manner. It is far better than other solutions have ever been.