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Rust resistance coatings
Posted: Tue Oct 17, 2023 12:23 pm
by torque2me
Hi all,
Got some rear brake stuff to replace and a front sub-frame.
Factory just gave a quick coat of black paint. Was this epoxy?
What do you think will be best for rear backplates? Epoxy, powder coating or even enamel coating. Would paint like Rustoleum be best?
Do you know if powder coating will adhere to epoxy paint? I know there is a system of zinc base coat (don't know if that is heat cured) with powder coating over that.
Problem with powder coatings is that once breached it acts like the early bitumen based floor pan coating of the 60's to 80's in that water ingress made matters worse but it was not obvious until latter rust stage.
All experiences/knowledge welcome.
Kev
Re: Rust resistance coatings
Posted: Wed Oct 18, 2023 6:53 pm
by valencia
I haven't restored my back plates recently but I did my wheels 5 years ago so as they are sublect to the same type of weathering I would certainly use the same method.
After a thorough cleaning and wire brushing (I've never bothered with blasting or powder coating as I didn't know of anyone local offering the service) I paint the item with an acid rust converter, one I use at the moment is Vactan, on ebay about £20 1lt. After it has thoroughly cured I paint with one or two coats of Isopon182 zinc primer and then again two coats of ordinary solvent based gloss paint. After 5 years there has been very little paint loss or chipping and of course no finish is everlasting but it seems pretty durable. Of course, much depends on operating conditions in service. Paint can be easily touched up if damaged unlike powder coating.
Each to their own and there are quite a few ways to do this so I hope this helps.
Michael
Re: Rust resistance coatings
Posted: Sat Oct 21, 2023 2:43 pm
by torque2me
valencia wrote: ↑Wed Oct 18, 2023 6:53 pm
IAfter it has thoroughly cured I paint with one or two coats of Isopon182 zinc primer and then again two coats of ordinary solvent based gloss paint. After 5 years there has been very little paint loss or chipping and of course no finish is everlasting but it seems pretty durable. Of course, much depends on operating conditions in service. Paint can be easily touched up if damaged unlike powder coating.
Each to their own and there are quite a few ways to do this so I hope this helps.
Michael
Yeah, always found zinc to be the preferred base coat (followed by Red Oxide, filler primer, primer and top coat).
The cracking/chipping of powder coating is my main concern as I feel it acts like bitumen of old in that it hides moisture/rust.
Thanks for the input.
Kev
Re: Rust resistance coatings
Posted: Mon Oct 23, 2023 6:23 pm
by Roscoe
valencia wrote: ↑Wed Oct 18, 2023 6:53 pm
I haven't restored my back plates recently but I did my wheels 5 years ago so as they are sublect to the same type of weathering I would certainly use the same method.
After a thorough cleaning and wire brushing (I've never bothered with blasting or powder coating as I didn't know of anyone local offering the service) I paint the item with an acid rust converter, one I use at the moment is Vactan, on ebay about £20 1lt. After it has thoroughly cured I paint with one or two coats of Isopon182 zinc primer and then again two coats of ordinary solvent based gloss paint. After 5 years there has been very little paint loss or chipping and of course no finish is everlasting but it seems pretty durable. Of course, much depends on operating conditions in service. Paint can be easily touched up if damaged unlike powder coating.
Each to their own and there are quite a few ways to do this so I hope this helps.
Michael
Yes I’ve used vactan as there was surface rust above the diff and underneath the rear valance on my PI mk 2 and by the rear springs it is excellent stuff I believe they use it on ships.