Painting on a Mixed Surface (Bare Metal and Old Paint)

[JonnyAlpha]

I know i'll probably get shot down in flames but I'll ask these questions anyway.
In another thread I am about to order some Lechler Epoxy Primer (2Ltrs).
On the underside and in the boot I have used Jotun Jotamastic 87 all onto bare rust free metal.

I am about to paint the inside of the Mini starting with the floor, i'll probably not do the whole inside just yet as I am still working on the front end and window surrounds, so painting the floor will be to stop it rusting. Part of the floor has already been dusted with U-POL Etch Primer to stop it rusting but i'll remove this with thinners before applying the Epoxy.

The top coat will be Almond Green Cellulose with Old English White Engine Enamel on the Roof (Bought for my Subframe and Wheels and have enough left over for the roof.

Questions:
1. When I do the rest of the inside and the outside for that matter, is it ok to flat down the existing paint as much as possible but not remove it al, i.e. take of the top coat to expose the factory primer and probably some bare metal and then apply the Epoxy all over? Or should I Epoxy only onto the exposed bare metal and then use a cellulose primer over that and any existing flatted paint?

2. I have seen in another thread about wiping down bare metal with Citric Acid? I have used this before for Rust Removal but why is it used on bare clean metal before Panel Wipe?

Sorry if I have upset the painters amongst you :-)

 

[steveo3002]

yeah you can sand up the original paint and go over that as long as you trust whats on there , original factory paint is probably decent enough but if its had several paint jobs before you might want to take it off to be sure its right

 

[JonnyAlpha]

Thanks Steveo, just ordered the Lechler.
One other question after applying the Epoxy do I need another primer on top such as a Celly Primer or straight to Colour Coat?

 

[steveo3002]

for say inside a shell /boot lid etc you can just epoxy then on with the top coat

outside panels that need to be nice and straight you would use some high build primer and block sand it until its smooth and straight

 

[JonnyAlpha]

for say inside a shell /boot lid etc you can just epoxy then on with the top coat

outside panels that need to be nice and straight you would use some high build primer and block sand it until its smooth and straight

Many thanks :-)

 

[the snooper]

the other question regarding use of acid, if you did use it you would need to know that the acid has been neutralised before applying paint otherwise the acid could go on working under the paint and cause the paint to peel, personally id stay away from it, just prep the surface panel wipe and on with your choice of primer

 

[richie00boy]

My comment regarding citric on another thread was because the poster seemed to be trying to remove rust. If your metal is clean and hasn't been exposed for a long time there is no need to citric it.