Any special prep required after sandblasting?

[EastBerkshireCustoms]

Epoxy primer ; any brands in mind?

Are these only available for spray guns or also in rattle cans?

IMO, you are not going to get a 'true' epoxy primer in a rattle can. The good stuff is two part and catalyzed. There are several good epoxy primers on the market. I happen to use PPG Shop Line JP 375. It is an excellent primer, but expect to pay a 'premium' over primers like the Rustoleum found at the box stores.

 

[Tractor Seabee]

I was wondering if any special prep/work are required after sand blasting and before priming?

In the past priming/painting after blasting has led to rust within a year!

Am I missing a step?

Any advice from pro painters would be appreciated!

Thanks

Don't have tim to read all the posts, but: most paint systems require a metal prep coating on bare blasted steel. You need to get the prep and first primer coat on as blasted steel rusts real fast. There are some zinc rich one part epoxy primers (many brands) that I have found to be the best. Makes a good base for any other coating system. Note I said "coating system" not paint. I used to specify painting contracts.

Ron

 

[Gary Fowler]

That is the reason I suggested that the OP go to a paint supplier like Sherwin Wiliams, Pittsburg , etc. Get a paint system with primer, intermediate and top coat that are all compatible and assure that the top coat wont weather to an unsuitable finish. Not all paints/primers/topcoats are compatibale and not all paints are good for top coats. The top coat has to be UV resistant also if it is going to stay looking good most especially in epoxies as they will chalk bad with UV exposure and look really crappy in a few years. The best painter in the world cant take a crappy system and make it look good and last. Even Coating Engineers sometimes mess up and spec the wrong system. A knowledgeable paint supplier will know what his paint will do and which ones will work together. Best part is, this info is free.

 

[Tractor Seabee]

Amen Gary, well said. Never use epoxy it it is exposed to sunlight, or subject to abrasion. It chalks in sunlight and soon looks crappy. It is brittle and chips easy, thats why I never use on shop floors. All depends on application as to what you use. Urethane systems work real well for outdoor surfaces as the hold their sheen forever. Powder coat is ideal for tractors and implements but expensive. Consider automotive systems for implements and tractors.

Ron

 

[ericher69]

I guess I should have specified my intended use/applications

I was thinking of getting a fishing boat trailer blasted and then prime and paint.
Looks like it was powder coated from factory as coating is coming off/flaking in large chunks with rust under it. Not bad for 24 yrs of fresh water use!

Also tractor parts/implements

Thanks to all that replied

 

[Big Hammer]

Rust is the ENEMY! Where I live plastic rusts. All coatings fail. This includes powdercoat, hot dipped galv, 2 part epoxies, you name it. To get the best results with your project, I must emphasize how critical the prep before primer or any other coatings. The metal needs to be free of even microscopic rust. it is like cancer; it needs to be completly eliminated. Previous poster said "no big deal" in regards to the light rust which forms on bare steel. WRONG! The project will be doomed from the start. Good luck with all your projects. BTW I live in the Pacific NW; Oregon coast. Lots of rain combined with salt corrosion is the norm here.

 

[MasseyWV]

Perhaps I missed it, but of all the advice given, I'm surprised that noone has mentioned self-etching primer. In my opinion, aside from blasting or other similar preparation methods, good primer is one of the most important steps in preparing bare steel for paint.

talking car paint: Self-etching Primer

 

[strum456]

Not all paints/primers/topcoats are compatibale and not all paints are good for top coats. A knowledgeable paint supplier will know what his paint will do and which ones will work together. Best part is, this info is free.

There are some paint suppliers out there that have real-world experience working with the products they sell, but many do not. You really have to take what a lot of these guys say with a grain of salt. One of their favorite lines is the "compatibility" horse crap. Yes, there are plenty of paint systems that do not work together, but the general motivation for "keeping one paint system" is for a paint jobber to sell more product. The best painters I know are not brand snobs. They try different products and use them together to get the best possible results.

Never use epoxy it it is exposed to sunlight, or subject to abrasion. It chalks in sunlight and soon looks crappy. It is brittle and chips easy, thats why I never use on shop floors.
Ron

All epoxies are not created equal. If this is the experience you have been having, you should consider trying something else.

Most epoxy does not have UV inhibitors, and it will chalk if not top-coated. However, epoxy does not loose any of its corrosion protection if it chalks. The stuff I use is the only epoxy that I am aware of that HAS UV inhibitors. It takes a long long time to chalk, but still should be top coated if looks are a top priority.

SPI epoxy is the most abrasion resistant, chip resistant and flexible coating that I have ever tried. It closely rivals any quality powder coat that I have seen and out performs many (like epoxy, all powder coats are not created equally). Mix some up and leave a little in your paint cup sometime. Take the puck out days, weeks, or months later and you will see how flexible and strong it is. :thumbsup: