Pipe Paint

It is difficult to make a statement on this.

You have to check up the paint technical data. As per my experience 125μ in a single coat looks to be a bit too high. However there are highbulid Epoxies that are upto the job, and this portion you have to see.

The second portion is not clear- is it the repair coating (ober the peeled/ scratched) portion you are trying? This is a tricky business. You have to contact expert on this area, there are certain strict guidelineds for this. We know about our paints, but the paint you are using will have its own.

And if it is new coating and the paint TDS allows this, you have to ensure the surface preparation, environmental condition (dust, humidity, temperature, dew point,...) for a good paint. Also check up whether the paint recommends special surface preparation/primer.

wow :) getting murkier every minute ..thank u fr the update

tc

This is an epoxy lining, right? Then doesn't someone need to get inside the pipe in order to brush it on? If the pipe is that large, why not use a roller rather than a brush? Am I missing something here?

Sorry--more questions than answers....

We qualify painters; in part, by testing their ability to apply the correct thickness required by the coating specifications. A good painter can apply the specified thickness within a few mils (thousands of an inch). 125 microns is about 5 mils and is on the lower side of the ranges I've seen for epoxy.

Why not have a professional painter apply the coating to a test piece, and check the thickness either wet or dry. Make a dozen or so tests to determine the range and std. deviation. This resulting information should tell you what your "chances" are "that it will be 125microns." There is a tolerance I assume, you are not going to get exactly 125uM over the entire surface.

the pipe manufacturer company officials present at site, and they r talkin this way...thats why im frustated coz i really want to issue a letter to them and inject seriousness regarding quality of works

If you have the responsibility and not the authority, then you are in a tough spot. In quality assurance/control this is a common occurrence. Only you can choose which battles are worth fighting by weighing the consequences of inaction against the benefits gained and at what risk to your position. Is this attribute that critical to the overall quality that you must fall on your sword over.

Collect the data during production. When and if the the coating fails you'll have a basis for your argument. It may take time to gain the respect of management who often shortsightedly focus on production, but when you have data you can usually bring them around.

You could use one of these to check the thickness. They're cheap and easy to use/understand.

Cheers!

The first step should always be to keep the customer on side and in the discussions. If they want a second coat by brush, then do some parts with them and MEASURE the outcome.

If the measured result is thicker than specified, but they still want it (They perceive this to be "improved" quality.) then you have a means to discuss with them the additional cost of the work.

While you might prefer not to have to apply a second coating at your site, the alternative of the customer choosing to go somewhere else altogether is real. I presume that alternative is less desirable than having to apply a second coating.

From my limited experience I thought it was very difficult to get a complete coating with a single layer (this is especially so for spraying) and that a minimum of two layers were required and three was advised for spraying.

I have done a lot of pipe work over the years where we coated large diameter DI and Steel that was exposed to the environment at creek crossings. I have gotten to the point of always spec'ing three coats, 1 a primer to ensure proper bond of the second coat to the pipe, the primer is designed to overcome the residue oils on the pipe from fabrication, etc. The second was my protective two part epoxy and the muscle of the paint scheme. The third was a protective, abrasion resistant coating to protect the epoxy from dust, wind blown sand etc., from rain/hail and UV.

What is the original protection that is being touched up? Is it suitable as it stands or do you need surface preperation in the way of wirebrushing to get rid of adjcent paint at the damage site to ensure that you are not painting over coats that are no longer bonded but have not spalded off. If the existing location is damaged, has water and dust worked under the existing paint at the edges of your repair, if so you are putting good paint onto bad paint and not protecting the pipe nor bonded to it.

I always spec'ed that each coat be a different color, rust for the primer, gray for the epoxy and white for the overcoat, this makes it easy to inspect as you will see the darker coats showing thru the progressively lighter colored coats that follow.

ANY paint should be applied by a qualified applications crew, these folks are experienced with the products, warranty the application and know what the thicknesses should look and act like going on, do not try to apply this with your maintenance crews, they are experienced in slapping house paint on or in painting the sheetrock walls in thier homes. Get qualified painters to apply the product. Spend time worrying about proper preperation, you are throwing money away to apply paint of any kind to a surface that has not been prepaired to receive the specific coating in accordance with the coating manufactures guidelines.

Good luck

thank you for the support guys.. my life wud hv been so grt if i had colleagues like u... the full day was roller coaster ride, i stopped works for not conforming to thickness...had heated discussion with Site manager... i hv meeting aftr lunch with project manager.. but i believe what i did ws correct.

Hi Prasoon,

First, surface preparation following what's the status of the pipe to paint. What is the conditions, temperature, etc..., of the painted pipe and how long in time? You make or you buy the 2-pack epoxy coating?

Let us know by answering to these questions, GIl.