painting rusty tin

[RollTideRam]

My father has a shop around 22 years old. The tin on top has some surface rust and he is wanting to paint in. Does anyone have a suggestion on what type of paint to use. I thought I would ask before he starts experimenting. Thanks, JC

 

[firefighter9208]

JC,

Check with Tractor supply in Cullman. They have a line of paint for barns and roofs. Tractor Supply Company - BPS® HEAVY-DUTY ALUMINUM PAINT

My grandfather has a 100x100 barn that we painted the roof when I was 16. That was 19 years ago and the paint is still good. We did use a specific paint for barn roofs and it has held up well.

 

[heymack]

Preparation is the key. You either need to remove the existing rust by scraping, sanding, abrading, etc., prime, then paint. This is probably the most economical method, but takes the most time. You can also apply some sort of chemical to "treat" the rust which will leave a phosphate coating so that you can then prime and paint. Additionally you can cover with a paint like substance called por 15 or similar then proceed to paint. Por 15 is expensive so it might not be cost effective.

 

[mjarrels]

Bet my tin is more rusty than your tin! I need to paint farm building roofs about every ten years... Barn is over due... I will have to pay someone to paint that roof... ain't no way I working at that height. I don't mind painting the machine shed, garage, smokehouse and a couple other roofs.

mark

 

[kmdigital]

It's far too much work to remove all the rust! Just remove the LOOSE rust by sweeping it with a broom, and then coat it with something that is designed for this purpose. This is assumig that you want a typical aluminum coated roof.

If you want an actual painted roof use a red metal primer on the rusty areas, which is what the steel frames, columns and rafters on a steel building are painted with, and why it's called "red iron". This primer has a very high solids content, and must be well shaken and kept stirred during use to keep the solids in suspension. Then paint it with a good grade of exterior enamel paint made for use on metal, preferably oil based as it will hold up much better in this type of application.

 

[DieselPower]

I used Texotropic fibered aluminum roof coating the last time I did the barn. You would have to give Curt a call for current pricing.

 

[RalphVa]

Use a rust converter to inert the rust to iron sulfide after brushing off any loose rust with a broom or mild steel brush. Rustoleum makes one called Rust Reformer (avail. at Lowes/Home Depot). NAPA's is called Rust Extender. On the Farm Report program on TV, some outfit advertises something called Rust Converter. It's probably the same stuff. Apply it, let sit for a while (usually over night), prime and paint. It's the ONLY thing to use on rust. Rust will eventually come through any kind of paint if it isn't inerted with this material first.

Ralph

 

[Glenn9643]

There's a product called "Ospho" for treating rust. I've used it and it works. A few years ago I found a generic at the local Ace Hardware that was the same chemical, and much cheaper.
If it was my roof I would spray it with this and then paint with an aluminum paint, but I would think you should do something to stop/slow the rust during the process.

 

[RollTideRam]

Thanks for the replies. We will start checking in to some of these ideas. JC