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Painting mild steel without primer
nick205 - 31/5/20 at 06:56 PM

I've built myself a rocket stove using mild steel. It gets hot as you burn wood in it. I'd like to paint it with high temperature paint to help prevent rust, but will it paint without primer first or if I need primer can you suggest a high temp primer?

Thanks
Nick

[Edited on 31/5/20 by nick205]

r1_pete - 31/5/20 at 08:01 PM

VHT do a high temp primer, withstands just short of 1100 C.

nick205 - 1/6/20 at 06:46 AM

quote:
Originally posted by r1_pete
VHT do a high temp primer, withstands just short of 1100 C.



Thanks, will take a look.

Bluemoon - 1/6/20 at 07:26 AM

used VHT high temp paint on mild steal exhaust. Works ok, prep well and mist coat for primer..

nick205 - 1/6/20 at 08:26 AM

quote:
Originally posted by Bluemoon
used VHT high temp paint on mild steal exhaust. Works ok, prep well and mist coat for primer..



Thanks again, useful to know.

In the past (for non heat applications) I've used red oxide aerosol or brush-on primer. It's always done me very well and it's cheap to but and use as well. I just can't see that working for higher heat applications, hence my question. I'm going to investigate the VHT primers and give it a dust coat with as suggested.

Having to be back in the office will have its benefits, but it'll also seem a bit constricting in some ways!

Bluemoon - 1/6/20 at 08:30 AM

quote:
Originally posted by nick205
quote:
Originally posted by Bluemoon
used VHT high temp paint on mild steal exhaust. Works ok, prep well and mist coat for primer..



Thanks again, useful to know.

In the past (for non heat applications) I've used red oxide aerosol or brush-on primer. It's always done me very well and it's cheap to but and use as well. I just can't see that working for higher heat applications, hence my question. I'm going to investigate the VHT primers and give it a dust coat with as suggested.

Having to be back in the office will have its benefits, but it'll also seem a bit constricting in some ways!


Was not clear. The VHT heat resistance paint I have used didn't need a primer, they recommended mist coat (of the topcoat).

Dan

nick205 - 1/6/20 at 09:38 AM

quote:
Originally posted by Bluemoon
quote:
Originally posted by nick205
quote:
Originally posted by Bluemoon
used VHT high temp paint on mild steal exhaust. Works ok, prep well and mist coat for primer..



Thanks again, useful to know.

In the past (for non heat applications) I've used red oxide aerosol or brush-on primer. It's always done me very well and it's cheap to but and use as well. I just can't see that working for higher heat applications, hence my question. I'm going to investigate the VHT primers and give it a dust coat with as suggested.

Having to be back in the office will have its benefits, but it'll also seem a bit constricting in some ways!


Was not clear. The VHT heat resistance paint I have used didn't need a primer, they recommended mist coat (of the topcoat).

Dan



OK - thanks for clarifying. That's the type of info/experience I was looking for.

David Jenkins - 1/6/20 at 09:59 AM

Same experience with VHT paint - clean the bare steel as well as you can, a few light coats, then heat the thing up. In my case, it was my exhaust system so I ran the engine until the exhaust was hot.

The paint doesn't stick very well until the metal has got hot - I think it bonds during the heating phase. I don't know if a blowtorch would do the job...

nick205 - 1/6/20 at 11:18 AM

Thanks again.

I guess I'll give it a few light coats then burn some wood in it to get it good and hot.

nick205 - 1/6/20 at 01:18 PM

Bought some high temp "primerless" satin aerosol to paint the rocket stove with. Will concentrate on getting the steel as clean as I can before painting and following manufacturers instructions for best curing etc.

Photos to follow when it's painted!