first time painting - should I grind off the thin surface rust or just apply rust converter?

[wwwfarmer]

I agree with the phosphoric acid treatment but you need to make sure it is completely dry before priming. It will have a chalky look when dry. If you are painting with a compressor/gun, also make sure your spray air is dry during priming. Use a filter/drier before the hose and blow-out the hose before using it. Drain the filter/drier after each use.

This is cheap insurance when you think about the cost of good paint and all your hard work. Ditto on the excellent welding job. Can't wait to see the finished product.

Thanks for very interesting comment about dry air. We currently have 95F weather and around 30% relative humidity. I attached an air prepping unit to the compressor (the one that has 2 cylinders, one for oil removal and one for water + pressure regulator) and not a single drop of water was collected while spraying.

 

[Tinhack]

You are fortunate to have such dry air. I'm frequently compressing 85-95 degree air with 75-85% humidity. Besides having an air dryer/cooler after my compressor, I have a filter/dryer before each hose outlet. In addition, I use a small "ball" filter at the spray gun. There's a lot of times spray painting is just impossible due to humidity. The evaporation of the thinner will sometimes cause dew to form on top of the paint. This fogs the paint or gives it a dull white overcast.

 

[Egon]

I wonder how it is all my stuff isnt rusting thru? What makes it rust?

Intergranular Corrosion: What It Is and How To Stop It

Intergranular corrosion (IGC) or intergranular attack (IGA) is a preferential or localized corrosion that proceeds along a metal’s grain (crystal) boundaries.

www.corrosionpedia.com

 

[Sberry]

What planet are you on? Is he painting an implement6 or a space satellite? The guy is doing his first simple paint job,,, this is obviously something that should be explained more clearly I guess. Too simple for some people.

 

[Egon]

What planet are you on? Is he painting an implement6 or a space satellite? The guy is doing his first simple paint job,,, this is obviously something that should be explained more clearly I guess. Too simple for some people.

Just some facts on real life common occurrences! Perhaps go back and review vehicle painting procedures.

 

[fried1765]

What planet are you on? Is he painting an implement6 or a space satellite? The guy is doing his first simple paint job,,, this is obviously something that should be explained more clearly I guess. Too simple for some people.

A "simple paint job" that fails in just 2 or 3 years is much too "simple" for me.

 

[Sberry]

For the guy doing this job. Get some maroon Scothbrite,,, the painters best friend, scuff it off and spray some shat on it. Put the color on it. A lot of equipment doesnt even get primer, gets color sprayed on it.

 

[Sberry]

This would be different IF it did. This is just speculation. Leads me to wonder if some of you actually ever did it?

 

[Sberry]

I know you guys answer good posts etc and I read them but on occasion this type of thing takes a spin. I be glad to look at pics of your paint shops.
Here is what I know as fact. The stuff I thought was so important,, wasn't always so and I didnt always listen to the practical stuff from elder timers and there are a lot of those not very good so I focus here on what I didnt know, where I changed my mind, where I have hindsite now and own paint jobs decades old.
When I babble here its usually from some book learning but mostly long history from hundreds of paint jobs, cant really recall a "fail'.
Have seen them rust thru, mostly on cars but it ain't for anything in this thread, it's simply painting foil thin steel and rust coming thru. ,, just like it did from it's original factory paint where it was in "procedure" .

 

[Sberry]

The fails come from simple things in this kind of work, didnt scrapa a gob off, on cars its people running their hands on them af6ter eating chips, its from not scuffing after blast where paint sticks thru. Rusts thru where a hole was repaired with bondo.
I would tend to think it wouldnt need to be pointed out that link has nothing to do with painting a simple implement. Would be different if he came asking about some exotic stainless alloy in a unique industry.

 

[Sberry]

Yes, hi humidity makes it blush. Its been a while since I read it but believe 60% was kind of a threshold for some paint. Some list it on the can.

 

[fried1765]

For the guy doing this job. Get some maroon Scothbrite,,, the painters best friend, scuff it off and spray some shat on it. Put the color on it. A lot of equipment doesnt even get primer, gets color sprayed on it.

"A lot of equipment doesnt even get primer, gets color sprayed on it".

Yup....absolutely correct!
King Kutter, EA, Land Pride, and most implement makers do exactly that.
CRAPPY (sometimes thick) PAINT JOBS ..... with NO PRIMER!

 

[Sberry]

Just some facts on real life common occurrences!

Where? No facts posted, no common occurrences, just a post of a link totally irrelevant. Nothing to do with anything you ever did, nothing common about it, not even anyone elses example.

 

[Sberry]

The lack of primer doesnt seem to be a big deal. I dont do it at every repaint to equipment. We dont usually repaint just for paint, mostly when it's been major serviced, reman, major repair and lots of this stuff, a brush hog is worn out if it's used well before the paint has a lot to do with anything other than appearances.

 

[Sberry]

Just needs to look good while its sold. No one wants to pay for fussy work on hot roofing kettle
Sanding is what makes good paint. Old paint not a problem if its bonded and will sand smooth and blend.
I see as much or more paint needs service not cause they didnt use a bunch of stuff but simply not clean enough or missed scuff or sand.

 

[Sberry]

On equipment repaint gets soap, industrial purple, hot pressure wash way before it hits the booth and cant even remember using a thinner wash and unless that done rather correct smears it around.
This was 25 years old 25 years ago when I wash, scuff and shoot a heavy blast of white on it
Sits outside, how much better should it be done?

 

[Sberry]

Hard to believe its north of 40 years. When I start had to spray gun and mix everything and now I got no problem using a spray can or sponge brush.
Paint outlast the car in this case, any extra would have been a waste of effort. Be different if it was a hobby or high value restoration but was worth 1500 book at best.

 

[Sberry]

Almost seems like it's a law a guy has to use that stuff at every chance. My thought is it's ok but no need to make the guy out to be a loser if he doesn't. He can clean it and get some color on and get to use it. 5 minutes after its painted wont be able to tell.

 

[Egon]

Where? No facts posted, no common occurrences, just a post of a link totally irrelevant. Nothing to do with anything you ever did, nothing common about it, not even anyone elses example.

The process of rust is pretty well defined. Lots of time has been spent to formulate steel that has rust resistance and coverings that delay rust. These process are disseminated throughout industries where steel is used.

In days long gone there were always cars with primer coat on and waiting for it to properly cure so the finish coats could be applied. Paints and application methods have changed a lot since then.

You have absolutely no knowledge of what my involvement with rust or corrosion has been!

The link posted was definitely rust/corrosion related with grain boundaries as a definite in the corrosion process. Rust in these grain boundaries requires a microscope to see. On a rusty piece of iron that has been polished to a shinny bright finish will have rust in the boundaries.

 

[Sberry]

Feel free to post post something relevant.