wire wheel vs rust converter or media blasting

[digitalbilly]

HI guys seeking to remove rust before painting cast iron parts I'm going to ceramic coat for high-temperature application 1000+ deg talking about engine headers and turbo manifolds.

what is the preferred method for rust removal?

I've tried the wire wheel but it doesn't get into the little pours I'm leaning towards media blasting or soaking them in a rust converter.

I don't have much experience with rust converters but it claims to convert rust to a paintable primer.

 

[DavidR8]

I'd go media blasting.

 

[YotaBota]

I just went the rust "converter", LocTite, route with my truck frame and most of the frame had rust bleeding thru again a couple of days later. It took a couple of more coats to get the thing sort of under control but I'm still not happy with it. I put 5 coats on one of the cross members, then a Tremclad top coat and the rust is still bleeding thru on that piece. Yes I followed the directions to the letter but still had bleed thru. I don't know if I'd trust any of the "converters" to work for what you're doing. I would talk to a local shop that does ceramic coatings and see what they do. Are you planning to DIY the ceramic coating?
Some people do well with the liquid rust removers and others do the electrolysis method. Media blasting should work well with cast but I'll let those with experience chime in on that one.

 

[DavidR8]

I have zero experience with ceramic coating, only have had powdercoating done.
Won't they get blasted as part of the coating process?

 

[Susquatch]

HI guys seeking to remove rust before painting cast iron parts I'm going to ceramic coat for high-temperature application 1000+ deg talking about engine headers and turbo manifolds.

what is the preferred method for rust removal?

I've tried the wire wheel but it doesn't get into the little pours I'm leaning towards media blasting or soaking them in a rust converter.

I don't have much experience with rust converters but it claims to convert rust to a paintable primer.

I'm sorry. I prolly should be able to help, but can't do so without stepping outside of my comfort zone too much. At the factory, engines don't get rusty before they are painted. They are painted as part of the manufacturing process, and I've no experience with a ceramic coating either.

For the aftermarket, all I've ever seen is high temp paints applied directly to any rust.

Back in my racing days, nobody painted cast iron exhaust manifolds either - just tubular headers - at least not that I remember.

Just swagging it, I'd put my vote with blasting them as suggested by others.

But I have to ask, what in the world are you doing that requires a ceramic paint job on exhaust manifolds?

Yes, I understand the heat advantages of ceramic, but I'm of the view that it's overkill for cast iron manifolds and might become a significant problem with time. A good (emphasis on good) manifold will last several million miles without it.

If it's appearance you are after, regular high heat paint will do wonders.

 

[digitalbilly]

This is great info thanks. Yeah I’m doing a diy ceramic coating.

 

[Susquatch]

This is great info thanks. Yeah I’m doing a diy ceramic coating.

Ya, but why?

 

[digitalbilly]

Ya, but why?

For overkill. Be doing the turbo housing and down pipe too.

 

[Susquatch]

For overkill. Be doing the turbo housing and down pipe too.

So this is why I wondered why.

I don't personally think that ceramic will be overkill. I think it will be under kill. I don't think do-it-yourself ceramic will actually perform better than high temp paint on an exhaust manifold. Ceramic paints don't really bond that well to metals using available DIY processes.

Perhaps the most popular brand is cerakote. But for every guy that loves it, there are 6 that don't. It scratches way too easily. Ceramic is much better if applied in a factory oxygen free environment and applied using ionized processes.

In my opinion, a regular high temp paint will look better, last longer, and is very forgiving in a DIY environment.

I don't think you will ever see ceramic coatings applied in the open air to high quality commercial products other than in short duration (temporary) applications.

I'm also sure that you can find people who swear by cerakote - especially on firearms. I'm not one of them.

 

[digitalbilly]

There’s also VHT fireproof paint and primer

 

[YotaBota]

Doesn't the VHT need to be baked? How is that going to go over in mom's kitchen? lol

 

[Susquatch]

Doesn't the VHT need to be baked? How is that going to go over in mom's kitchen? lol

Nice thing about painting an exhaust header is that it comes with an integral paint oven. The temperature control is foot operated....... LOL!

 

[Susquatch]

There’s also VHT fireproof paint and primer

Ya, but that's not necessarily ceramic.

VHT just means Very High Temp it doesn't necessarily dictate what's in it. Some brands do have ceramic flakes in them. But like cerakote, it's not very durable and it's not at all like factory applied ceramic in a controlled environment.

 

[Six O Two]

I've had pretty poor luck with the paint-on rust converters (Rust Check brand from Canadian Tire), same experience as YotaBota - rust bleeding through shortly after painting. But I've had great success with the soaking rust remover (evaporust - currently gallon buckets on sale at PA for $80). But even if your parts aren't too awkward or big to handle a somewhat cost-efficient soak, you'll probably still have to sand or blast as surface prep prior to your ceramic coat. So you can probably just skip the soak and go straight to media blasting...

 

[Former Member]

Rust converter only work if its skin deep surface rust.

If it has any depth then the reaction occurs at the surface but the rust underneath still remains and bleeds thru.

Those that understand bluing, browning and parkerizing should see the connection.

 

[Chip Maker]

+1 for media blasting!

 

[historicalarms]

I'm gonna stand up for the VHT brand of hi-temp paint. I used that stuff to paint my full sized cannon when it was finished. I never baked it, just wire brushed the mill scale off the pipe & applied the paint, that was 8 or so yrs ago and that cannon has spent every day since out in the weather unprotected and just this year I noticed the first hint of sun radiant heat oxidation but no rust anywhere at all other than the muzzle where the heat would be "blow torch intense" for a second or so at each firing.

 

[YotaBota]

Rust converter only work if its skin deep surface rust.

Then the advertising of most of these products is very misleading, bordering on false. There is never any mention of the degree of rust that is considered to much or to deep. They say to remove the heavy scale leaving some rust and apply the product.
Next time I'll pay the money fro the blasters and be done with it.

 

[digitalbilly]

I'm gonna stand up for the VHT brand of hi-temp paint. I used that stuff to paint my full sized cannon when it was finished. I never baked it, just wire brushed the mill scale off the pipe & applied the paint, that was 8 or so yrs ago and that cannon has spent every day since out in the weather unprotected and just this year I noticed the first hint of sun radiant heat oxidation but no rust anywhere at all other than the muzzle where the heat would be "blow torch intense" for a second or so at each firing.

Are you referring to VHT rust converter? Which VHT exactly?

 

[Susquatch]

They say to remove the heavy scale leaving some rust and apply the product.
Next time I'll pay the money fro the blasters and be done with it.

I never do more than wire brush or scrape away the scale and spray it on thick enough to soak in. Seems to work fine for me on rusty old farm equipment. Of course, I'm not looking for show room quality. If I was, the wife would be doing the painting not me.