What colour to paint mill and rust treatment?

[smartecosse]

So as I'm looking forward to when I get the mill building finished I thought I better start thinking about what colour I'm going to paint it as the rusty metal style doesn't really appeal to me

Being Scottish I thought I might go with a traditional finish .

 

Do I need to remove all of the rust and scale right back to bare metal before I paint it or can I just take off all the loose stuff with a wire brush.

Also....for the ends of the hollow section.....I guess it's best to weld a plate over the end to stop water ingress but do I need to out any sort of treatment in first or not bother?

Thanks

[bandmiller2]

What kind of a mill do you have mate. If its circular and cast iron get a wire cup wheel and angle grinder, prime and paint with rust oleum. If its steel, wire wheel it and coat with a rust killing treatment then rust oleum. Frank C.

[Southside logger]

Look into "Por 15" for painting rusty metal. I don't know what they make the stuff out of but from a wear standpoint it makes Rust-Oleum look like kids finger paint, it is absolutely amazing. 

[Crusarius]

I have plenty of tubes that have open ends. was contemplating thinning paint to a water like thickness then filling the tube sloshing it around them dumping it into the next tube. This will only work on the small ones I will not try to do that on the 24' main rails. As for the ones that I have capped, I did not full weld them I will probably just get a close color matching caulk to seal the gaps. It does not need to be airtight but keeping water out would be nice.

As for color. If you plan on trailering it in the dark please don't make it black unless you plan reflective stripes or lots of lights. I cannot tell you how many times I have almost been taken out by black trailer. Either me not seeing them or them not seeing the trailer and thinking I am clear.

I ended up using a an oil base primer and am putting Behr Alkyd paint over that. So far seems to be working nicely. Only have 1 coat of color on it hoping to get second coat done today.

[moodnacreek]

Look into "Por 15" for painting rusty metal. I don't know what they make the stuff out of but from a wear standpoint it makes Rust-Oleum look like kids finger paint, it is absolutely amazing.

Only on a rough surface or it will peel right off. Also tricky to recoat and goes dull in the sun. It can last a long time on stable rust or sand blasted surface. I keep it on the shelf and have used it a long time. You can use it with fiberglass cloth to patch rust holes.

[Hilltop366]

If you can't or don't want to remove all the rust and leave a ruffed up surface then a bit of sanding with course paper to remove any loose rust. either way to prep I will then clean with some low flash solvent and rags then two coats of rust primer and two coats of paint seems to work best for me.

Any colour will do but I will agree with the higher visibility colour, check the mis-tinted or dented can bargain bin for deals.

[SawyerTed]

Rust-mort is a rust converter that I've had excellent success using on various items including some farm equipment.  A light wirebrushing to remove loose rust is all that's necessary. Rust-mort doesn't do anything to bare metal.  Three or four light coats of Rust-mort applied with a brush will convert the rust into black hard surface overnight.  Think thin watery coats not a paint like consistency. 

You can apply the primer/paint system of your choice once you wipe the surfaces with solvent. 

[Southside logger]

goes dull in the sun

There is a UV top coat that you can apply and it will not dull.  

[Skipper11A]

Rust-mort is a rust converter that I've had excellent success using on various items including some farm equipment.  A light wirebrushing to remove loose rust is all that's necessary. Rust-mort doesn't do anything to bare metal.  Three or four light coats of Rust-mort applied with a brush will convert the rust into black hard surface overnight.  Think thin watery coats not a paint like consistency.

You can apply the primer/paint system of your choice once you wipe the surfaces with solvent.

I have used several rust converters and the best value I have found is at The Rust Store - Solutions for All Rust Problems, $50 USD for one gallon.  Rust converters are not the final answer to rust, but they knock it back alot.  What I like best about rust converters is that they are also an acrylic primer that really takes alkyd paints well, so you won't have to buy a separate primer. 

As to your color selection, It would be a huge mistake to use too light a color (like white or a light tan) because these colors will begin showing rust bleeding through them within a couple of months if kept outside.  I suggest either red or orange, they are both high visibility colors that will hide the rust that bleeds through your paint and keep your sawmill looking great for years to come.   Oh and I would use rustoleum, two coats.

[moodnacreek]

I was not aware of the uv protection for por 15.  People are discovering por and slapping it on everything. Sometimes you have to go back to oil paint. I am down to my last gallon of the real rust primer, 769 damp proof, fish oil rustoleum.

[btulloh]

For a rust converter I've been using Ospho, which is mainly phosphoric acid.  Been getting good results and it's about $20 a gallon.  Widely available. That approach doesn't work to well if your going for a concourse-ready paint job, but for machinery it's fine.  If I get the loose rust off, treat with Ospho, and then use a two part epoxy primer, I get some pretty tough and durable results.  Top coat with a good machinery enamel that needs hardener added.  Never been worried about fading or chalking.  

I've heard of the Por15 but never used it. I did use their product for cleaning and coating the inside of a gas tank and it worked well.  

Lately for small jobs I've experimented with some of the rattle-can primers that contain a rust converter.  Seems like everybody's got one these days.  I used Rustoleum's version and it worked pretty well, but I'll have to get back to you in ten years on that.

I've never been happy putting a top coat on machinery unless it used a hardener.  Paint without hardener just doesn't get real hard.

There's lot's of ways to skin that particular cat.

Like mentioned above, wash, dry, clean with metal prep solvent, don't touch it with your bare fingers.  More problems come from improper prep than anything else.

I like the tartan paint you have.  Not the correct one for my clan though.  I want to see how that comes out of the spray gun.

[SawyerTed]

For a rust converter I've been using Ospho, which is mainly phosphoric acid.  

Most converters are phosphoric acid.  I've forgotten that I've used Ospho with good results as well.

[nativewolf]

Look into "Por 15" for painting rusty metal. I don't know what they make the stuff out of but from a wear standpoint it makes Rust-Oleum look like kids finger paint, it is absolutely amazing.

I second this.  I bought an old flatbed Hino from a fence company in Long Island.  Bed was 24' and badly welded beat to crap.  Spent a week grinding most rust off, found I had done more than needed, let it sit two weeks, painted, then came over it with same sort of paint they use in off road racing.  Por was amazing.  Just amazing.  I think you need to keep it out of sunlight if I remember.  Anyway, you might have to paint over it.  We've had logs just dumped on the bed, forks scraping, etc etc. 3 years later and 95 % of finish still on, takes a helluva thing to scrap it to metal.  

[Skipper11A]

For a rust converter I've been using Ospho, which is mainly phosphoric acid.  

Most converters are phosphoric acid.  I've forgotten that I've used Ospho with good results as well.

It sounds like there's a lot of difference between rust converters because the only converters I have used have Tannic acid and leave an acrylic polymer primer coating ready for paint after 24 hours.  I wouldn't use them if they didn't leave an acrylic primer behind.  We're talking light rust here, and no salt.

[btulloh]

I have used have Tannic acid and leave an acrylic polymer primer coating ready for paint after 24 hour

Sounds interesting.  Need to check into that.

[moodnacreek]

Used Ospro years ago and really liked it but have not been able to find it. I will have to try harder.  Also they used to say that green was the longest lasting color.

[btulloh]

Doing a little research.

A Low Cost Tannic Acid Rust Converter Formulation | Rust | Phosphoric Acid

Rust converters

Seems that phosphoric acid is a major component and tannic acid is necessary for the formation of a primer-like layer.  I'm wondering if Ospho has any tannic acid.  I'm guessing it doesn't. It would be nice to have a better understanding and comparison of some these products.  

Nativewolf, that's a good testimonial for the Por15 paint.  Was their rust remover used prior to painting?

POR-15 Rust Remover - Rust Dissolving Solution - Works in as little as 20 minutes and will not affect plastic, PVC, Viton, or most paints.

POR-15 Top Coat - Paint directly on prepped bare metal surfaces

POR-15® High Build Primer

It would be right pricey to use the Por15 primer + top coat, but it is in line with any other good paint.

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I think we may have over-answered the OP's question here.  Hope we haven't scared him off.  Maybe he's busy trying to source that plaid paint. 

[barbender]

We seemed to focus on the rust converter part of his question a little more😂

[Don_Papenburg]

Well btulloh , that plaid paint gets screwed up if you spray it on . It can only be done with a brush.  You have to brush in only one direction . No back and forth like with solid colors.

[Southside logger]

Plaid???  Somebody's not of Celtic descent.   I learned not to call it plaid any more when dating my wife.