Faber outside rust

[spectrum]

Wow, that is more than I would have expected. I can see sty you would need to be very careful about moisture & corrosives getting under that skin!

 

[vixtor]

This week-end I took a trip to the stores that should have had the required items for the tank repair.

I discovered that I was only able to find enamel paint and enamel primer, which looked to be a cheap universal paint.

I have found one single "epoxy" item - some Bison Epoxy Universal adhesive. Its package describes it as:
"a strong two-component epoxy adhesive for both interior and exterior use. Especially suitable for the strong and water resistant bonding of a wide variety of objects, such as metal, earthenware, stone and plastic. Gap-filling. Can be painted when cured. For super strong, waterproof bonding of metals, wood, pottery, china, stone, concrete and some plastics (formica, polyester, bakelite) to themselves and to each other. Ideal for large areas and for assembling a number of components. It is temperature resistant from -50C to 80C, sea water resistant, chemical resistant, all purpose, for both interior and exterior use."

I have also found only one type of primer - something based on something called "butanonoxim"(?).

My current plan is to clean the surface with fine sandpaper, degrease with acetone, paint with the primer, allow to dry, then cover the surface with the epoxy adhesive (which fortunately should adhere fine to both the polyurethane coating and to the primer-treated steel, maybe better than just a simple epoxy-paint that I was not able to find).

What do you think? Is this a good plan, or I'm on the wrong track?

My doubts are should I use the primer or the epoxy glue directly?

Btw, I found a page (http://www.crosslinktech.com/surface_preparation.htm) which states that "Epoxy and Polyurethane substrates bond well to each other as long as the surfaces are clean and slightly abraded", so at least one of my worries seems to be solved.

 

[vixtor]

Update: I have opened the primer box. It is a brown paint. I have painted some rusted surface for testing, and I'll see how it looks when dry (and then eventually try to see how the epoxy adheres to that surface - before putting it on my tank.

But somehow, I doubt this is what I need - it looks just too much as a common paint, so probably I'll just use the epoxy.

 

[vixtor]

I have tested the primer on a steel surface. It dries as a thin, rough, brown surface. Also, I have tested the epoxy adhesive (that will replace the epoxy paint). It adhered well to both the primer and the untreated steel surface - almost impossible to take off.

So I have cleaned the spots with fine sandpaper, washed with acetone, painted with primer. I will wait ~48 hours to fully dry, then I'll apply a thin layer of epoxy adhesive, that should stick well to the surrounding surface, sealing it back.

 

[Couv]

Hello Vixtor,

I am in no way a "paint or coatings" specialist, so you might want to defer to Puffer Fish on the type of coating that you use. However, I do have a background in aerospace quality control and one thing I can tell you is that most coating failures are due to improper cleaning/prepping of the substrate. Whatever method you use, please ensure that after you prep the surface do not touch or allow anything to contaminate the area you will paint. After you coat it, if you want to test it, there is a method referred to as a "wet tape test." After the coating is fully cured if you want to do a wet tape test, take a patch of gauze soak it and put it over the area you will test. Then tape a square of plastic over the wet gauze it to keep it wet for 10-24 hours. (or just leave the tank in a water bath for the same amount of time.) After your morning coffee remove the tape and gauze, thoroughly dry the test area and apply a piece of dry masking tape over the paint to be tested. Now cross your fingers and pull the tape off like you are removing a bandage from a hairy part of your leg in one quick motion. Did any flakes come off? If so, it's back to the drawing board and this time do a better job at prepping the surface.

While I'm thinking about it, if you want to check see if you have removed all of the contamination from an area, perform a test known as a "water break free" test. I should have said this from the outset, because you would want to accomplish this test after the prep, but here is how to do the test. Pour or squirt demineralized or distilled water over the test area. If the water beads up, there are still contaminates on the surface that must be removed. The water should run off a clean area in a flat sheet if it is contaminate free.

Sorry for the long winded post….good luck and let us know how it works out.

Couv

 

[widget]

I have tested the primer on a steel surface. It dries as a thin, rough, brown surface. Also, I have tested the epoxy adhesive (that will replace the epoxy paint). It adhered well to both the primer and the untreated steel surface - almost impossible to take off.

So I have cleaned the spots with fine sandpaper, washed with acetone, painted with primer. I will wait ~48 hours to fully dry, then I'll apply a thin layer of epoxy adhesive, that should stick well to the surrounding surface, sealing it back.

Seems fine vixtor, differant countries have differant products readily available so its difficult to say use "this" product as it may not even be available to the man in the street, a legislated product only for industry, or difficult to find.

The best process is probably to do exactly as you have, testing the local products that are easily available and using the ones that work for you locally, following the tested application methods suggested here.

 

[Puffer Fish]

Hello Vixtor,

I am in no way a "paint or coatings" specialist, so you might want to defer to Puffer Fish on the type of coating that you use. However, I do have a background in aerospace quality control and one thing I can tell you is that most coating failures are due to improper cleaning/prepping of the substrate. Whatever method you use, please ensure that after you prep the surface do not touch or allow anything to contaminate the area you will paint. After you coat it, if you want to test it, there is a method referred to as a "wet tape test." After the coating is fully cured if you want to do a wet tape test, take a patch of gauze soak it and put it over the area you will test. Then tape a square of plastic over the wet gauze it to keep it wet for 10-24 hours. (or just leave the tank in a water bath for the same amount of time.) After your morning coffee remove the tape and gauze, thoroughly dry the test area and apply a piece of dry masking tape over the paint to be tested. Now cross your fingers and pull the tape off like you are removing a bandage from a hairy part of your leg in one quick motion. Did any flakes come off? If so, it's back to the drawing board and this time do a better job at prepping the surface.

While I'm thinking about it, if you want to check see if you have removed all of the contamination from an area, perform a test known as a "water break free" test. I should have said this from the outset, because you would want to accomplish this test after the prep, but here is how to do the test. Pour or squirt demineralized or distilled water over the test area. If the water beads up, there are still contaminates on the surface that must be removed. The water should run off a clean area in a flat sheet if it is contaminate free.

Sorry for the long winded post….good luck and let us know how it works out.

Couv

Don't need any comments from me... excellent description.