Painting equipment

[EricR]

I have a few projects in the works that I would like to paint when finished.  The first being a prentice loader and a timberjack skidder.
I plan on using these projects to play around with painting with a gun.  How the finish looks is not as important to me as the durability and longevity of the finish.  Every thing will be sandblasted to clean metal.  I went to a finish master paint shop the other day and explained what I was doing.  He sold me a epoxy primer and for the finish told me to use a hardener that they sell added to rustoleum and spray away.  I told him I was willing to spend the money for something better  and didn't  want to listen to him but he kept insisting there was no need.  Does anyone have any thoughts on this?  I find it very hard to believe the expensive paint isn't that much better.  I wasn't thinking I would use imron but something in between the 2

[moodnacreek]

Things I painted 35 years ago and still own prove that name brand epoxy primer is worth the money.  Singel stage 2 part top coats are also best but like the e. primer expensive. If you top coat with regular air dry enamel like rustoleum try to get 3 coats on as it will wash away over time and leave the primer showing.

[doc henderson]

You can go with some of the ag/industrial enamels and primer.  they take 24 hours to dry, you can add hardener for more gloss an durability.  i also like for little projects the Rust oleum prof. enamel.  it comes out faster in larger cans and i always have some gloss black to touch up the log splitter and conveyor, or the log bunks on the gooseneck.

[Resonator]

Some of the best paint I've used on machinery was John Deere yellow (from the dealer) that I used when I painted my backhoe. It was expensive ($75 a gallon then), but I put it on with a roller and was pleased with the results. Five years later and even the paint dripped and smeared on my trailer is holding up well. ;D

[barbender]

I have to paint my dump trailer due to MN salt, and I think it will be a bit of a laboratory for different paint and rust sealing products😂 Sandblasting some of the panels is kind of out of the question, there wouldn't be much left🤦‍♂️ Sandblasting is too expensive anyways, I'd just as soon buy a new trailer than put $3000-$4000 into a sandblast and paint job.

[scsmith42]

My only complaint with Rustoleum products are that when used outdoors they fade pretty quickly as compared with most mid and high quality automotive paints.

Their "hard hat" industrial spray paint is my go to product for spray painting stuff around the shop though.

I don't know if adding a hardener will improve the resistance to paint fading.

[peakbagger]

I used to be the "paint guy" for a corrosive industrial operation. Here my comments

Surface prep is everything in corrosive situations (like road salt and all the other deicing agents used on the road). Ideally every bit of visible rust needs to be gone by sandblasting. There are standards for surface prep and the absolute minimum is SP-1 solvent wash and then SP3 - power tool cleaning to get every bit of scale and loose rust off. Dont skip the solvent wash as grease can survive power tool cleaning. Also do not use shop air which is usually loaded with oil mist and moisture. Either use an oil free air source with an air dryer or invest in some good coalescing filters with an upstream air dryer.  

Iron oxide (rust)is still buried in the surface of the metal and if a corrosive liquid gets at it, it will spread rapidly and ruin whatever expensive paint you put on it unless that paint is a 100% barrier to moisture. Ideally a SP5 near white metal blast is the way to go immediately followed by a zinc rich primer. Few folks will do that, so various "rust converter" primers are used. Some systems use an acid rust wash, it converts the surface rust from iron oxide to ferric oxide. Ferric oxide does not rust but once water gets to it turns back into iron oxide and will start rusting again. Usually, those washes are washed off and then a moisture cured polyurethane primer (POR is one brand) or a zinc rich primer is applied, if the surface is clean with good rough texture they will bond quite well.

The problem is that primer is not a top coat, many of the primers like POR or epoxy based priers are not UV resistant. They need to be topcoated with a UV resistant layer. Epoxy is a great choice for indoor operations but when exposed to sun it eventually starts breaking down (chalking). The preferred top coat for outdoors is a two part catalyzed polyurethane. For folks who have been around for a while the well known Imron paint system is catalyzed polyurethane. The US military also used it for the Chemical Agent Resistant Coating (CARC) as it was durable enough to be steam cleaned without breaking down. The problem with catalyzed poly is the components are incredibly toxic and must be applied with supplied air equipment for the painters and controlled ventilation. Many vets had their lungs and kidneys ruined by CARC and the truck and auto painters did the same with Imron.

Imron and Imron like coatings are still out there but best to avoid them. They have mostly been replaced with moisture cured polyurethanes. The moisture comes from moisture in the air. That also creates an application problem, when spraying, the mist in the air can be breathed in by poorly trained or poorly equipped workers where it can get in the lungs and immediate catalyze in the lungs and once it sets up there is nothing that breaks it down. That is the other issue with poly systems, once it cures there really are no solvents that will break it down so clean up is difficult unless it is done immediately. The only way you get it off the skin once cured is to let it wear off or scrape the skin off. The mist from spraying carries so if its not done in a booth or separate building, the entire interior of the building will be covered with what feels like fine sandpaper. It can be brush applied which is lot easier, and it does tend to self flatten but its not going to be automotive like finish.

Someone with the skills can lay down a nice flat coat with a spray gun and if there are sags and runs, they can be sanded down and blended in once the paint cures. If either the old style two part Imron or new moisture cured systems are applied correctly, its effectively "forever" paint for most applications but usually someone scrapes through the surface coating at some point exposing the underlying metal and it not dealt with quickly and properly, the rust will start under the coating and it will start flaking off from the underlying surface. When rust goes active it expands so it break the bond between the coating and the underlying surface allowing water mixed with corrosives to seep farther in under the paint.

Ultimately to get a good long term coating you need to choose a system and follow the applications instructions, take shortcuts and its either going to fail early or people could have long term health issues.

I use the POR rust converter around the house with the POR primer. It sets up into a very tough primer, but as I mentioned it is not UV resistant. Ideally the top coat of UV resistant poly is applied within 24 hours for chemical bond, otherwise it has to cure and then be sanded or lightly brush blasted for give a good mechanical bond.    

[EricR]

Thanks peakbagger. I live on the coast so marine paint is easy to find.
https://www.pettitpaint.com/products/topside-paint-finishes/single-part-polyurethane/ez-poxy-easypoxy/

Would something like this do the trick?  Would you add a hardener to it?  Thanks

[barbender]

So Peakbagger, in a case like my dump trailer, getting it totally clean and free of rust before coating it isn't a possibility. What is the best thing I can do, with what I have? Even if I go over it with flap wheels etc, I'll never get all the pitting- I will be painting over rust. 

[moodnacreek]

POR has some disadvantages . It stays on well on rough surfaces only. Stable rust or sand blasted areas are where it adheres but not painted or 'new ' metal. Sanding it to gain adhesion is almost impossible so you have to buy their special primer to make color stick. Priming it before it drys is suggested. The process scares me. On the other hand it can be used with fiber glass cloth on rusted through areas. Works good on gas tanks also.

[Tom K]

So Peakbagger, in a case like my dump trailer, getting it totally clean and free of rust before coating it isn't a possibility. What is the best thing I can do, with what I have? 

Honestly, buy a new trailer. We deal with the same thing in our area, nothing you do will be more then a bandaid to make it look nice for a little while. Dump trailers seem to be the worse, by the time you get around to cleaning them up it's already too late. With what you would have cost wise into the DuPont make over you would be better off to trade and let someone else deal with it.
A friend of mine has a very similar background as Peakbagger and has very similar advice. He use to do quite a bit of sand blasting, get it clean (white steel or almost) then epoxy primer within 24 hours so it doesn't flash rust. He would usually top with a poly or epoxy topcoat. It is far from cheap to do it right.

[doc henderson]

If it is from abrasion from the firewood, consider some inside rub rails or a plastic liner to protect the powder coat or what ever they use.  If gloss black, just get some rattle cans to touch up the bare spots.  

[peakbagger]

Thanks peakbagger. I live on the coast so marine paint is easy to find.
https://www.pettitpaint.com/products/topside-paint-finishes/single-part-polyurethane/ez-poxy-easypoxy/

Would something like this do the trick?  Would you add a hardener to it?  Thanks

That special additive is one of the major components of what made Imron so great but so toxic. If you are willing to wear a respirator it does toughen up a system. As and aside years ago we sprayed a MG Midget with Corvette yellow Imron. Definitely a half ass spray job way before we knew about safety. Soon after, the owner left the road and ran it into the brush. It dented several panels but the dents popped out and with a bit of rubbing compound it didnt need a respray. I think I spotted it a few years ago and its still got that darn corvette yellow paint job.

BTW, if you are near Hamiltons Marine they are usually worth the trip. I tried some of the two part Epifanes they carry, its durable but pigment dispersion when brush applied wasnt as good as I hoped. It self leveled well but the pigment didnt move around. 

[peakbagger]

I agree with observation about POR but my experience is it applies to any good primer system, blasting gives a good surface texture and that is what paint grabs onto put it on smooth metal and it could flake. The POR "primer" is really rust converter with zinc. It preps the rusty surface which usually has plenty of texture. POR does cure quite hard in a few days and its rugged stuff but if exposed to abrasion its only a few mils thick of plastic so it can scrape.

One big warning with POR is do not buy in bulk as once a can is opened it cure when resealed and getting it open is darn close to impossible. Amazon sells 6 packs fo small cans I keep around for small jobs. Other tricks is to carefully pour it to old glass jars avoiding getting any on the threads. Storing the can upside down also helps and putting it in the freezer also prevents a cure. BTW POR and most other polys need 70 degrees to cure. 

If you go with top coat for UV make sure you apply it within 36 hours or you have to rough it up and depend on a mechanical bond versus a chemical bond. where the primer crosslinks with the top coat. If you leave POR primer in the sun it will chalk out in about summer.  

[Frickman]

Back in the day I used a lot of John Deere industrial/commercial yellow, John Deere industrial gloss black and International Harvester old agriculture red paint. I even painted work trucks with those paints. I can't remember what I used for primer. It may have been a good quality primer in a rattle can.

I didn't do much of the actual painting myself. Instead, I would invite young guys studying auto body at my local high school's vo-tech to do the spraying for me. I paid them well and they got to start a portfolio of their work. I would do most of the prep work myself and hire a kid to plug his gun into my compressor and spray away. One kid was a fourth generation body man who grew up in a body shop. He was really impressed with the quality of paints I used, especially the John Deere gloss black.

None of this painting was done on equipment destined for a museum. It was all on equipment I intended to use, so a few runs and other irregularities here and there were acceptable. With proper use though the John Deere and International Harvester brand paints worked very well and gave us few defects. And they ended up being a lot more durable than automotive paint.

[Frickman]

I am going to get up on my soap box for a bit here. If you don't want to read through my ramblings please don't. I just want to talk about the benefits of painting forestry equipment.

I liked painting my equipment and owning good looking equipment. Why? Let me list the reasons.

(1) I like to look at it. Enough said.

(2) It always seems like good looking equipment is easier to maintain and repair. I can see oil leaks easier, and it's a lot easier mentally for me to wrench on a good looking tractor than an old decrepit rust bucket. Just through the act of cleaning up and painting an old tractor I fix a lot of small problems that may later develop into big problems. 

(3) I think this is the most important benefit. When I rolled on to a job with a good looking tractor it made me look more professional. By design much of my equipment was thirty to forty years old. When I showed up with a thirty year old skidder that looked brand new the landowner knew I would take as great care of their property as I do of my skidder. I couldn't call myself a professional timber harvester if I didn't run professional looking equipment.

OK, get down off your soap box Frickman.

[EricR]

Frickman. All those points makes sense to me.  I'm just trying to make things look a little better drips and whatnot are fine with me. I'm probably going to try the cheap harbor freight paint guns.  Don't need a pro job just hoping it will look good for a while.

I have a friend that swears by the cat paint.  Just scuffs lightly and paints it on with a brush and roller.  Comes out pretty good

[doc henderson]

HF guns may be made in the same factory as the high end ones.  I use and like there airless for applying wax emulsion.

[EricR]

Just thinking out loud.  Someone should come up with some primer system where you could prime parts as you prep them and when you are ready to topcoat mist it with something that softens the surface so it will stick or doesn't fully cure until it is top coated ( their are some fiberglass resins that work this way).It's a lot to try to prep/blast, prime and topcoat in the same day.  It's humid/ damp and I live very close to salt water. If you don't prime the day you blast it's rusty the next day

[scsmith42]

I agree with observation about POR but my experience is it applies to any good primer system, blasting gives a good surface texture and that is what paint grabs onto put it on smooth metal and it could flake. The POR "primer" is really rust converter with zinc. It preps the rusty surface which usually has plenty of texture. POR does cure quite hard in a few days and its rugged stuff but if exposed to abrasion its only a few mils thick of plastic so it can scrape.

One big warning with POR is do not buy in bulk as once a can is opened it cure when resealed and getting it open is darn close to impossible. Amazon sells 6 packs fo small cans I keep around for small jobs. Other tricks is to carefully pour it to old glass jars avoiding getting any on the threads. Storing the can upside down also helps and putting it in the freezer also prevents a cure. BTW POR and most other polys need 70 degrees to cure.

If you go with top coat for UV make sure you apply it within 36 hours or you have to rough it up and depend on a mechanical bond versus a chemical bond. where the primer crosslinks with the top coat. If you leave POR primer in the sun it will chalk out in about summer.  

Have you ever tried displacing the oxygen in the storage container with argon?  There is a commercial product called "Bloxygen" that is basically argon in a can.  You simply spray it for a few seconds into your partially consumed can of paint and if forms a barrier on the surface to keep oxygen away.
It works great with most woodworking finishes that would otherwise develop a skim coat or harden in the container after opening.

[Tom K]

I'm probably going to try the cheap harbor freight paint guns.  Don't need a pro job just hoping it will look good for a while.

I have a friend that swears by the cat paint.  Just scuffs lightly and paints it on with a brush and roller.  Comes out pretty good

I know the type of gun can be somewhat personal preference, but I would much rather have a pressure pot then a cup gun. Haven't a pressure pot you are not limited to the direction you can hold the gun like you are a cup gun. I've got a couple cheap 2qt pot guns I use a lot. For the size of your project it would even be worth looking into a 2 1/2 gallon pot & gun. The cheap ones would work fine for you and really aren't that expensive. Just make sure you have the right tip size and cap for the thicker paint you'll be spraying, or be prepared to thin it down. 
I have also heard people say good things about Deere and Cat paints, the key with them is to always use a hardner. 
What your doing cleaning up and repainting is much simpler then trying to fix rust and stop corrosion. As long as you don't have deep rust and corrosion you should be able to decrease and clean up the surface rust and you should have pretty good luck making it look good for awhile. 

[peakbagger]

Years ago we had a demo at the mill of a flame applied coating system. There was something like a pressure pot with hose and gun that had a propane line run to it. With the gas turned off it sprayed a fine plastic powder. When the gas was on there was peizo trigger that fired off a flame that melted the plastic and sprayed a stream of molten plastic onto a properly blasted surface. They were selling it for plow trucks and sanders. It laid down a thick coating that looked like it was well bonded. I thought it was an interesting idea but I never saw it used anywhere other than our demo. The claim was once it was applied it could be reapplied and it would fuse to the layer underneath. 

[Walnut Beast]

HF guns may be made in the same factory as the high end ones.  I use and like there airless for applying wax emulsion.

Sata spray guns made in the same factory. I don't think so 😂

[Walnut Beast]

Cyanide is what makes Imron so nasty!

Polyurethane paints give off cyanide gas when being sprayed. The paint is safe when in liquid or cured form; the gas is only released when sprayed. If you are ...

[Walnut Beast]

That paint right there was and still is King for

  durability. From Aerospace, jets, big rigs and everything in between!